feat(lint): eleven new rules over directives, data and addressing
Assisted-by: GLM 5.3
This commit is contained in:
+12
-5
@@ -131,8 +131,11 @@ Rules: `unknown-instruction`, `operand-count`, `undefined-label`,
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`abi-argsize`, `unreachable-code`, `register-clobber`,
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`abi-argsize`, `unreachable-code`, `register-clobber`,
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`funcdata-pcdata`, `unused-label`, `invalid-textflag`,
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`funcdata-pcdata`, `unused-label`, `invalid-textflag`,
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`stack-imbalance`, `register-width-mismatch`, `abi0-register-args`,
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`stack-imbalance`, `register-width-mismatch`, `abi0-register-args`,
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`nonportable-register-name`, `unencodable-instruction` and
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`nonportable-register-name`, `unencodable-instruction`,
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`reserved-register-write`.
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`reserved-register-write`, `missing-argsize`, `noframe-frame-size`,
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`unnamed-fp-reference`, `hardware-sp-addressing`, `vex-sse-mixing`,
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`unnamed-result`, `data-width`, `data-value-overflow`,
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`data-string-width`, `data-without-globl` and `data-exceeds-globl`.
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```sh
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```sh
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gasm lint kernel_amd64.s
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gasm lint kernel_amd64.s
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@@ -455,14 +458,18 @@ Provides: completion, hover, document symbols, push and pull diagnostics,
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semantic tokens, go-to-definition, find references, rename, document
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semantic tokens, go-to-definition, find references, rename, document
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formatting, inlay hints, code actions, signature help, document highlights,
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formatting, inlay hints, code actions, signature help, document highlights,
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workspace symbol search, #include document links, and folding ranges for
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workspace symbol search, #include document links, and folding ranges for
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function bodies. Definition, references and rename work across every open
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function bodies. Completion offers the architecture's registers and
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instructions, the TEXT/DATA/GLOBL directives, the annotation and padding
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pseudo-ops (PCALIGN, FUNCDATA, PCDATA, the BYTE family) and the textflag
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constants; hover documents mnemonics, registers, pseudo-registers and the
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directives. Definition, references and rename work across every open
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document and the wider workspace on disk: the server indexes the `.s` files
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document and the wider workspace on disk: the server indexes the `.s` files
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under the workspace root that the editor has never opened, an open buffer
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under the workspace root that the editor has never opened, an open buffer
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always shadows its disk copy, and watched-file events together with a
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always shadows its disk copy, and watched-file events together with a
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per-query freshness check keep the index current. The quick fixes add the
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per-query freshness check keep the index current. The quick fixes add the
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missing `#include "textflag.h"`, set the TEXT argument area to the size the
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missing `#include "textflag.h"`, set the TEXT argument area to the size the
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`// func` signature implies, add a missing `RET`, and remove an unused
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`// func` signature implies, declare that area when it is omitted entirely,
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label.
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add a missing `RET`, and remove an unused label.
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## version
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## version
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+66
-4
@@ -1,4 +1,4 @@
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.TH GASM-LINT 1 "2026-09-19" "gasm" "User Commands"
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.TH GASM-LINT 1 "2026-10-01" "gasm" "User Commands"
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.SH NAME
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.SH NAME
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gasm-lint \- run the static checks over assembly files
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gasm-lint \- run the static checks over assembly files
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.SH SYNOPSIS
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.SH SYNOPSIS
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@@ -27,7 +27,11 @@ A jump target names no label in the function.
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Two labels in one function share a name.
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Two labels in one function share a name.
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.TP
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.TP
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.B missing-ret
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.B missing-ret
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The function can fall off its end without a terminator.
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The function has no RET, or has one but can still fall off its end: the
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last instruction is neither RET nor an unconditional branch, so execution
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continues into the next TEXT. Trailing labels, GC annotations and
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padding are skipped, and traps (INT on amd64, BRK on arm64) count as
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terminators.
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.TP
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.TP
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.B missing-textflag-include
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.B missing-textflag-include
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TEXT flags are used without including textflag.h.
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TEXT flags are used without including textflag.h.
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@@ -56,8 +60,9 @@ FUNCDATA and PCDATA indices are malformed.
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A label no jump reaches.
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A label no jump reaches.
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.TP
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.TP
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.B invalid-textflag
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.B invalid-textflag
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An unknown TEXT or GLOBL flag, reported one flag at a time; numeric flags
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An unknown TEXT or GLOBL flag, or a known one misplaced (NOSPLIT on
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are accepted as textflag.h constants.
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GLOBL, RODATA on TEXT), reported one flag at a time; numeric flags are
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accepted as textflag.h constants.
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.TP
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.TP
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.B stack-imbalance
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.B stack-imbalance
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The function does not restore the stack pointer on every path.
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The function does not restore the stack pointer on every path.
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@@ -85,6 +90,63 @@ yet (amd64).
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.TP
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.TP
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.B reserved-register-write
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.B reserved-register-write
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A write to the register the runtime reserves (arm64 R18).
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A write to the register the runtime reserves (arm64 R18).
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.TP
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.B missing-argsize
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A TEXT without NOSPLIT omits the argument area its
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.B //\ function
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signature implies; the object then records ArgsSizeUnknown and go vet
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skips the size check.
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.TP
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.B noframe-frame-size
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The NOFRAME flag against a positive frame size; NOFRAME is the
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zero-frame spelling, and the negative frames of the arm64 BSD syscall
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stubs are exempt.
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.TP
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.B unnamed-fp-reference
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A numeric offset against FP, written
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.IR 0(FP) ;
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the assembler requires
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.IR name+offset(FP) .
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.TP
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.B hardware-sp-addressing
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A negative numeric offset against
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.IR (SP) ,
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which addresses the hardware stack pointer rather than the named
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virtual frame; the runtime's deliberate hardware-SP references all
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carry positive offsets.
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.TP
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.B vex-sse-mixing
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VEX-encoded instructions and legacy SSE on X registers in one function;
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each switch between the encodings pays a transition penalty
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(informational).
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.TP
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.B unnamed-result
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A result slot addressed with the generic
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.I ret
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spelling although the
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.B //\ function
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signature names the result (a hint).
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.TP
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.B data-width
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A DATA width its value cannot take: 1, 2, 4 or 8 for an integer, 4 or 8
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for a float, and the suffix itself is never optional; a string accepts
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any width.
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.TP
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.B data-value-overflow
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An integer initialiser wider than its DATA field; both assemblers
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truncate it silently to the low bytes.
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.TP
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.B data-string-width
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A string initialiser longer than its DATA field; both assemblers reject
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it.
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.TP
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.B data-without-globl
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A DATA initialiser whose symbol has no GLOBL declaration in the file;
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gasm asm requires the pairing, go tool asm sizes the symbol implicitly.
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.TP
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.B data-exceeds-globl
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A DATA initialiser writing past the GLOBL-declared size; go tool asm
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grows the symbol silently, gasm asm rejects the file.
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.SH OPTIONS
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.SH OPTIONS
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.TP
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.TP
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.B \-disable \fIcodes\fR
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.B \-disable \fIcodes\fR
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+52
@@ -67,6 +67,58 @@ func abiParamNames(doc string) ([]string, bool) {
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return names, true
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return names, true
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}
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}
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// resultSlot is one named result of a // func signature and the byte range
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// its ABI0 stack slot occupies, relative to FP.
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type resultSlot struct {
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name string
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off int64
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size int64
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}
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// abiResultSlots lays out the named result slots of the `// func …`
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// signature in a doc comment: parameters first, then the result area on a
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// word (8-byte) boundary, matching the ABI0 stack layout signatureSize
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// computes. A nameless result field contributes no slot; it is the field
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// the generic ret spelling documents. It returns ok=false when there is no
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// parseable signature or a type size cannot be determined.
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func abiResultSlots(doc string) ([]resultSlot, bool) {
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sig := signatureLine(doc)
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if sig == "" {
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return nil, false
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}
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fn, ok := parseSignature(sig)
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if !ok || fn == nil {
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return nil, false
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}
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paramsSize, _, pok := fieldsSizeAlign(fn.Type.Params)
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if !pok {
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return nil, false
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}
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results := fn.Type.Results
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if results == nil || len(results.List) == 0 {
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return nil, false
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}
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off := int64(alignUp(paramsSize, 8))
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var slots []resultSlot
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for _, field := range results.List {
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es, ea, fieldOK := typeSizeAlign(field.Type)
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if !fieldOK {
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return nil, false
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}
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n := len(field.Names)
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if n == 0 {
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off = int64(alignUp(int(off), ea)) + int64(es)
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continue
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}
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for _, nm := range field.Names {
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off = int64(alignUp(int(off), ea))
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slots = append(slots, resultSlot{name: nm.Name, off: off, size: int64(es)})
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off += int64(es)
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}
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}
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return slots, true
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}
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// parseSignature parses a `func …` line into a Go FuncDecl.
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// parseSignature parses a `func …` line into a Go FuncDecl.
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func parseSignature(sig string) (*ast.FuncDecl, bool) {
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func parseSignature(sig string) (*ast.FuncDecl, bool) {
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fset := token.NewFileSet()
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fset := token.NewFileSet()
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@@ -0,0 +1,63 @@
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// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
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// SPDX-License-Identifier: BSD-3-Clause
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package lint
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import (
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"fmt"
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"strings"
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|
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"sourcedock.dev/petrbalvin/gasm-sdk/ast"
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|
)
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// scanAddressing flags the two pseudo-register spellings the language
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|
// reference (docs/asm/OPERANDS.md) calls its sharpest edge: a numeric offset
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|
// against FP names no symbol, and a negative numeric offset against SP
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// addresses the hardware stack pointer rather than the virtual frame.
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|
func scanAddressing(t *ast.Text, cfg Config) []Diagnostic {
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|
var out []Diagnostic
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|
for _, s := range t.Body {
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|
in, ok := s.(*ast.Instr)
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|
if !ok {
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|
continue
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|
}
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|
for _, op := range in.Operands {
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|
if op.Kind != ast.OpAddr {
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|
continue
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|
}
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|
// FP is a pseudo-register, never a base register of a memory
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|
// operand; a Base of FP only arises from the numeric form
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|
// 0(FP), which the parser routes through memory parsing. The
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|
// toolchain rejects it with "cannot reference FP without a
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|
// symbol" and gasm with "unknown base register FP".
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|
if strings.EqualFold(op.Addr.Base, "FP") && !cfg.Disable[CodeUnnamedFPRef] {
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|
out = append(out, Diagnostic{
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|
Pos: op.Pos,
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|
Severity: Error,
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|
Code: CodeUnnamedFPRef,
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|
Message: "FP is referenced without a symbol; the assembler requires name+offset(FP)",
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|
})
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|
continue
|
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|
}
|
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|
// A numeric offset against (SP) addresses the hardware stack
|
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|
// pointer. Positive offsets are the deliberate runtime idiom
|
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|
// for reading caller frames, but a negative offset is exactly
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|
// the local-frame spelling with the name missing: x-8(SP) and
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|
// -8(SP) are one character apart and mean different registers.
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|
// Only the negative form is flagged, which keeps the rule
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|
// silent across GOROOT's 140-odd deliberate hardware-SP
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|
// references (all positive) while catching the mistyped local.
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|
if strings.EqualFold(op.Addr.Base, "SP") && op.Addr.Sym == nil &&
|
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|
op.Addr.HasOff && op.Addr.Offset < 0 && !cfg.Disable[CodeHardwareSP] {
|
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|
out = append(out, Diagnostic{
|
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|
Pos: op.Pos,
|
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|
Severity: Warning,
|
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|
Code: CodeHardwareSP,
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|
Message: fmt.Sprintf("%d(SP) addresses the hardware stack pointer, not the virtual frame; "+
|
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|
"a frame local is spelled x%d(SP)", op.Addr.Offset, op.Addr.Offset),
|
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|
})
|
||||||
|
}
|
||||||
|
}
|
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|
}
|
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|
return out
|
||||||
|
}
|
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@@ -0,0 +1,117 @@
|
|||||||
|
// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
|
||||||
|
// SPDX-License-Identifier: BSD-3-Clause
|
||||||
|
|
||||||
|
package lint
|
||||||
|
|
||||||
|
import (
|
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|
"testing"
|
||||||
|
|
||||||
|
"sourcedock.dev/petrbalvin/gasm-sdk/arch"
|
||||||
|
"sourcedock.dev/petrbalvin/gasm-sdk/parser"
|
||||||
|
)
|
||||||
|
|
||||||
|
// TestUnnamedFPReference pins the toolchain contract "cannot reference FP
|
||||||
|
// without a symbol": a numeric offset against FP parses as a memory operand
|
||||||
|
// with FP in the base, and both assemblers reject it at assembly time.
|
||||||
|
func TestUnnamedFPReference(t *testing.T) {
|
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|
diags := lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
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|
TEXT ·f(SB), NOSPLIT, $0-8
|
||||||
|
MOVQ 0(FP), AX
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeUnnamedFPRef] != 1 {
|
||||||
|
t.Fatalf("want one unnamed-fp-reference, got %+v", diags)
|
||||||
|
}
|
||||||
|
for _, d := range diags {
|
||||||
|
if d.Code == CodeUnnamedFPRef && d.Severity != Error {
|
||||||
|
t.Fatalf("unnamed FP reference must be error severity: %+v", d)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
// The named spelling is the language's requirement.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0-8
|
||||||
|
MOVQ x+0(FP), AX
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeUnnamedFPRef] != 0 {
|
||||||
|
t.Fatalf("named FP reference must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// -disable silences the rule.
|
||||||
|
f, _ := parser.Parse("t_amd64.s", "#include \"textflag.h\"\nTEXT ·f(SB), NOSPLIT, $0-8\n\tMOVQ 0(FP), AX\n\tRET\n")
|
||||||
|
diags = File(f, Config{Arch: arch.AMD64, Disable: map[string]bool{CodeUnnamedFPRef: true}})
|
||||||
|
if codes(diags)[CodeUnnamedFPRef] != 0 {
|
||||||
|
t.Fatalf("disabled rule must stay silent: %+v", diags)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
// TestHardwareSPAddressing pins the one-character edge between the virtual
|
||||||
|
// frame and the real stack pointer: a negative unnamed offset against (SP)
|
||||||
|
// is the local-frame spelling with the name missing, while the runtime's
|
||||||
|
// deliberate hardware-SP references all carry positive offsets.
|
||||||
|
func TestHardwareSPAddressing(t *testing.T) {
|
||||||
|
diags := lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $16
|
||||||
|
MOVQ $1, -8(SP)
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeHardwareSP] != 1 {
|
||||||
|
t.Fatalf("want one hardware-sp-addressing, got %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// The named local in the virtual frame, the intended spelling.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $16
|
||||||
|
MOVQ $1, x-8(SP)
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeHardwareSP] != 0 {
|
||||||
|
t.Fatalf("named SP local must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// Positive hardware-SP offsets are the runtime's caller-frame idiom.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0
|
||||||
|
MOVQ 8(SP), AX
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeHardwareSP] != 0 {
|
||||||
|
t.Fatalf("positive hardware-SP offset must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// The bare register is not a memory reference.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0
|
||||||
|
MOVQ SP, AX
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeHardwareSP] != 0 {
|
||||||
|
t.Fatalf("bare SP register must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// The rule is architecture-neutral: riscv64 numeric (SP) parses the
|
||||||
|
// same way (the parser documents 0(SP) as a RISC-V shape).
|
||||||
|
diags = lintSrcArch(t, "f_riscv64.s", `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $16
|
||||||
|
MOV $1, -8(SP)
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeHardwareSP] != 1 {
|
||||||
|
t.Fatalf("want one hardware-sp-addressing on riscv64, got %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// -disable silences the rule.
|
||||||
|
f, _ := parser.Parse("t_amd64.s", "#include \"textflag.h\"\nTEXT ·f(SB), NOSPLIT, $16\n\tMOVQ $1, -8(SP)\n\tRET\n")
|
||||||
|
diags = File(f, Config{Arch: arch.AMD64, Disable: map[string]bool{CodeHardwareSP: true}})
|
||||||
|
if codes(diags)[CodeHardwareSP] != 0 {
|
||||||
|
t.Fatalf("disabled rule must stay silent: %+v", diags)
|
||||||
|
}
|
||||||
|
}
|
||||||
+172
@@ -0,0 +1,172 @@
|
|||||||
|
// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
|
||||||
|
// SPDX-License-Identifier: BSD-3-Clause
|
||||||
|
|
||||||
|
package lint
|
||||||
|
|
||||||
|
import (
|
||||||
|
"fmt"
|
||||||
|
"strconv"
|
||||||
|
|
||||||
|
"sourcedock.dev/petrbalvin/gasm-sdk/ast"
|
||||||
|
)
|
||||||
|
|
||||||
|
// checkDataDecls validates the DATA and GLOBL structure of a file: the
|
||||||
|
// initialiser widths the language allows, values that actually fit them, and
|
||||||
|
// the GLOBL declaration that sizes each initialised symbol. Every check is
|
||||||
|
// calibrated against both assemblers: what go tool asm and gasm asm each
|
||||||
|
// reject or silently accept decides the severity, and the differences are
|
||||||
|
// spelled out in the message.
|
||||||
|
func checkDataDecls(f *ast.File, cfg Config) []Diagnostic {
|
||||||
|
// The GLOBL registry: every declared symbol keyed by package, name and
|
||||||
|
// static marker. Both assemblers pair DATA to GLOBL by name regardless
|
||||||
|
// of order, so the registry is built before any DATA is checked.
|
||||||
|
type globlDecl struct {
|
||||||
|
size int64
|
||||||
|
hasSize bool
|
||||||
|
}
|
||||||
|
globls := map[string]globlDecl{}
|
||||||
|
for _, d := range f.Decls {
|
||||||
|
g, ok := d.(*ast.Globl)
|
||||||
|
if !ok || g.Name == nil || g.Name.Pseudo != "SB" {
|
||||||
|
continue
|
||||||
|
}
|
||||||
|
gd := globlDecl{}
|
||||||
|
if g.Size != nil && g.Size.Imm.HasVal {
|
||||||
|
gd.size, gd.hasSize = g.Size.Imm.Val, true
|
||||||
|
}
|
||||||
|
globls[dataSymKey(g.Name)] = gd
|
||||||
|
}
|
||||||
|
|
||||||
|
var out []Diagnostic
|
||||||
|
for _, d := range f.Decls {
|
||||||
|
dd, ok := d.(*ast.Data)
|
||||||
|
if !ok || dd.Name == nil || dd.Name.Pseudo != "SB" {
|
||||||
|
continue
|
||||||
|
}
|
||||||
|
name := dd.Name.Name
|
||||||
|
if dd.Name.Static {
|
||||||
|
name += "<>"
|
||||||
|
}
|
||||||
|
w := int64(dd.Width)
|
||||||
|
|
||||||
|
// Width. An integer initialiser allows exactly 1, 2, 4 or 8, a
|
||||||
|
// float needs its full 4 or 8 IEEE-754 bytes, and a string allows
|
||||||
|
// any width (its bytes are zero-padded to the field, which GOROOT's
|
||||||
|
// own messages rely on, /84 and all). The suffix itself is never
|
||||||
|
// optional. Both assemblers reject the rest (go tool asm: "bad int
|
||||||
|
// size for DATA argument", "bad float size", "expect /size").
|
||||||
|
isFloat := dd.Value != nil && dd.Value.Imm.Float != "" && !dd.Value.Imm.HasVal
|
||||||
|
isStr := dd.Value != nil && dd.Value.Imm.Str != "" && !dd.Value.Imm.HasVal
|
||||||
|
if !cfg.Disable[CodeDataWidth] {
|
||||||
|
var msg string
|
||||||
|
switch {
|
||||||
|
case w == 0:
|
||||||
|
msg = "DATA requires a /width suffix"
|
||||||
|
case isFloat && w != 4 && w != 8:
|
||||||
|
msg = fmt.Sprintf("DATA width %d cannot hold a floating-point value, want 4 or 8", w)
|
||||||
|
case !isFloat && !isStr && w != 1 && w != 2 && w != 4 && w != 8:
|
||||||
|
msg = fmt.Sprintf("DATA width must be 1, 2, 4 or 8 for an integer value, got %d", w)
|
||||||
|
}
|
||||||
|
if msg != "" {
|
||||||
|
out = append(out, Diagnostic{
|
||||||
|
Pos: dd.Keyword.Pos,
|
||||||
|
End: dd.Keyword.End,
|
||||||
|
Severity: Error,
|
||||||
|
Code: CodeDataWidth,
|
||||||
|
Message: msg,
|
||||||
|
})
|
||||||
|
continue
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
// Value fit. An integer wider than the field is silently truncated
|
||||||
|
// by both assemblers, and a string longer than the field is rejected
|
||||||
|
// by both (go tool asm: "bad string size"; a shorter one is
|
||||||
|
// zero-padded, which is the documented layout, not a defect).
|
||||||
|
if v := dd.Value; v != nil {
|
||||||
|
if v.Imm.Str != "" && !v.Imm.HasVal && !cfg.Disable[CodeDataStringWidth] {
|
||||||
|
if text, err := strconv.Unquote(v.Imm.Str); err == nil && int64(len(text)) > w {
|
||||||
|
out = append(out, Diagnostic{
|
||||||
|
Pos: dd.Keyword.Pos,
|
||||||
|
End: dd.Keyword.End,
|
||||||
|
Severity: Error,
|
||||||
|
Code: CodeDataStringWidth,
|
||||||
|
Message: fmt.Sprintf("string of %d bytes does not fit DATA width %d", len(text), w),
|
||||||
|
})
|
||||||
|
}
|
||||||
|
}
|
||||||
|
if v.Imm.HasVal && !cfg.Disable[CodeDataValueOverflow] {
|
||||||
|
val := v.Imm.Val
|
||||||
|
if v.Imm.Neg {
|
||||||
|
val = -val
|
||||||
|
}
|
||||||
|
if lo, hi := dataValueRange(w); val < lo || val > hi {
|
||||||
|
out = append(out, Diagnostic{
|
||||||
|
Pos: dd.Keyword.Pos,
|
||||||
|
End: dd.Keyword.End,
|
||||||
|
Severity: Warning,
|
||||||
|
Code: CodeDataValueOverflow,
|
||||||
|
Message: fmt.Sprintf("DATA value %d does not fit width %d and is silently truncated: "+
|
||||||
|
"both assemblers keep only the low %d bytes", val, w, w),
|
||||||
|
})
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
// The GLOBL pairing: gasm requires a matching GLOBL and bounds every
|
||||||
|
// initialiser by its size, while go tool asm sizes an unpaired symbol
|
||||||
|
// implicitly and grows a too-small one silently, so the declared size
|
||||||
|
// stops matching the data.
|
||||||
|
g, declared := globls[dataSymKey(dd.Name)]
|
||||||
|
if !declared {
|
||||||
|
if !cfg.Disable[CodeDataNoGlobl] {
|
||||||
|
out = append(out, Diagnostic{
|
||||||
|
Pos: dd.Keyword.Pos,
|
||||||
|
End: dd.Keyword.End,
|
||||||
|
Severity: Warning,
|
||||||
|
Code: CodeDataNoGlobl,
|
||||||
|
Message: fmt.Sprintf("DATA initialiser for %q has no GLOBL declaration in this file; "+
|
||||||
|
"gasm asm requires one, go tool asm sizes the symbol implicitly", name),
|
||||||
|
})
|
||||||
|
}
|
||||||
|
continue
|
||||||
|
}
|
||||||
|
if g.hasSize && !cfg.Disable[CodeDataExceedsGlobl] {
|
||||||
|
if end := dd.Name.Offset + w; dd.Name.Offset < 0 || end > g.size {
|
||||||
|
out = append(out, Diagnostic{
|
||||||
|
Pos: dd.Keyword.Pos,
|
||||||
|
End: dd.Keyword.End,
|
||||||
|
Severity: Warning,
|
||||||
|
Code: CodeDataExceedsGlobl,
|
||||||
|
Message: fmt.Sprintf("DATA %s+%d/%d exceeds the GLOBL size %d; "+
|
||||||
|
"go tool asm grows the symbol silently, gasm asm rejects the file",
|
||||||
|
name, dd.Name.Offset, w, g.size),
|
||||||
|
})
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
return out
|
||||||
|
}
|
||||||
|
|
||||||
|
// dataSymKey identifies a data symbol within a file: package prefix, base
|
||||||
|
// name and the file-local <> marker, the same identity both assemblers pair
|
||||||
|
// DATA and GLOBL by.
|
||||||
|
func dataSymKey(sym *ast.Symbol) string {
|
||||||
|
key := sym.Pkg + "\x00" + sym.Name
|
||||||
|
if sym.Static {
|
||||||
|
key += "\x00static"
|
||||||
|
}
|
||||||
|
return key
|
||||||
|
}
|
||||||
|
|
||||||
|
// dataValueRange returns the closed range of integers an initialiser of
|
||||||
|
// width w bytes round-trips: the low half of the unsigned range is read back
|
||||||
|
// as negative, so -2^(8w-1) through 2^(8w)-1 all survive the truncation. At
|
||||||
|
// width 8 every int64 is in range, and the unsigned bound is not
|
||||||
|
// representable, so the signed extremes stand in.
|
||||||
|
func dataValueRange(w int64) (lo, hi int64) {
|
||||||
|
if w == 8 {
|
||||||
|
return -1 << 63, 1<<63 - 1
|
||||||
|
}
|
||||||
|
return -(1 << (8*w - 1)), (1 << (8 * w)) - 1
|
||||||
|
}
|
||||||
@@ -0,0 +1,204 @@
|
|||||||
|
// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
|
||||||
|
// SPDX-License-Identifier: BSD-3-Clause
|
||||||
|
|
||||||
|
package lint
|
||||||
|
|
||||||
|
import (
|
||||||
|
"testing"
|
||||||
|
|
||||||
|
"sourcedock.dev/petrbalvin/gasm-sdk/arch"
|
||||||
|
"sourcedock.dev/petrbalvin/gasm-sdk/parser"
|
||||||
|
)
|
||||||
|
|
||||||
|
func TestDataWidth(t *testing.T) {
|
||||||
|
// Both assemblers reject the integer widths beyond 1, 2, 4 and 8 (go
|
||||||
|
// tool asm: "bad int size for DATA argument: 3").
|
||||||
|
diags := lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA ·tab+0(SB)/3, $0x010203
|
||||||
|
GLOBL ·tab(SB), RODATA, $8
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataWidth] != 1 {
|
||||||
|
t.Fatalf("want one data-width, got %+v", diags)
|
||||||
|
}
|
||||||
|
for _, d := range diags {
|
||||||
|
if d.Code == CodeDataWidth && d.Severity != Error {
|
||||||
|
t.Fatalf("bad width must be error severity: %+v", d)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
// The missing suffix is not a default ("expect /size").
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA ·tab+0(SB), $7
|
||||||
|
GLOBL ·tab(SB), RODATA, $8
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataWidth] != 1 {
|
||||||
|
t.Fatalf("missing width must be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// A float needs its full 4 or 8 IEEE-754 bytes ("bad float size").
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA ·f+0(SB)/2, $1.5
|
||||||
|
GLOBL ·f(SB), RODATA, $8
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataWidth] != 1 {
|
||||||
|
t.Fatalf("float in a narrow width must be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// A string accepts any width: GOROOT's own messages use /84 and the
|
||||||
|
// bytes are zero-padded.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA ·s+0(SB)/3, $"hi"
|
||||||
|
GLOBL ·s(SB), RODATA, $3
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataWidth] != 0 {
|
||||||
|
t.Fatalf("string data in width 3 must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// The valid integer widths and float widths are clean.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA ·tab+0(SB)/1, $1
|
||||||
|
DATA ·tab+1(SB)/2, $2
|
||||||
|
DATA ·tab+4(SB)/4, $4
|
||||||
|
DATA ·f+0(SB)/4, $1.5
|
||||||
|
GLOBL ·tab(SB), RODATA, $8
|
||||||
|
GLOBL ·f(SB), RODATA, $4
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataWidth] != 0 {
|
||||||
|
t.Fatalf("valid widths must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func TestDataValueOverflow(t *testing.T) {
|
||||||
|
// $0x1ff into one byte: both assemblers keep 0xff silently.
|
||||||
|
diags := lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA ·tab+0(SB)/1, $0x1ff
|
||||||
|
GLOBL ·tab(SB), RODATA, $8
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataValueOverflow] != 1 {
|
||||||
|
t.Fatalf("want one data-value-overflow, got %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// The full signed and unsigned range of the width round-trips.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA ·tab+0(SB)/1, $255
|
||||||
|
DATA ·tab+1(SB)/1, $-128
|
||||||
|
DATA ·tab+2(SB)/2, $65535
|
||||||
|
GLOBL ·tab(SB), RODATA, $8
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataValueOverflow] != 0 {
|
||||||
|
t.Fatalf("in-range values must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// Width 8 holds every int64 (the regression where the range itself
|
||||||
|
// overflowed and flagged 0).
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA ·tab+0(SB)/8, $0
|
||||||
|
DATA ·tab+8(SB)/8, $16
|
||||||
|
GLOBL ·tab(SB), RODATA, $16
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataValueOverflow] != 0 {
|
||||||
|
t.Fatalf("width 8 must hold every int64: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// -disable silences the rule.
|
||||||
|
f, _ := parser.Parse("t_amd64.s", "#include \"textflag.h\"\nDATA ·tab+0(SB)/1, $0x1ff\nGLOBL ·tab(SB), RODATA, $8\n")
|
||||||
|
diags = File(f, Config{Arch: arch.AMD64, Disable: map[string]bool{CodeDataValueOverflow: true}})
|
||||||
|
if codes(diags)[CodeDataValueOverflow] != 0 {
|
||||||
|
t.Fatalf("disabled rule must stay silent: %+v", diags)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func TestDataStringWidth(t *testing.T) {
|
||||||
|
// Both assemblers reject a string longer than the field.
|
||||||
|
diags := lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA ·msg+0(SB)/2, $"hello"
|
||||||
|
GLOBL ·msg(SB), RODATA, $5
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataStringWidth] != 1 {
|
||||||
|
t.Fatalf("want one data-string-width, got %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// A shorter string is zero-padded to the width, the documented layout.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA ·msg+0(SB)/8, $"hi"
|
||||||
|
GLOBL ·msg(SB), RODATA, $8
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataStringWidth] != 0 {
|
||||||
|
t.Fatalf("padded string must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func TestDataWithoutGlobl(t *testing.T) {
|
||||||
|
// gasm asm rejects an unpaired initialiser ("no matching GLOBL"); go
|
||||||
|
// tool asm sizes the symbol implicitly.
|
||||||
|
diags := lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA ·tab+0(SB)/8, $0x0102030405060708
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataNoGlobl] != 1 {
|
||||||
|
t.Fatalf("want one data-without-globl, got %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// The pairing is order-independent: both assemblers resolve by name.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
GLOBL ·tab(SB), RODATA, $8
|
||||||
|
DATA ·tab+0(SB)/8, $0x0102030405060708
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataNoGlobl] != 0 {
|
||||||
|
t.Fatalf("GLOBL before DATA must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA ·tab+0(SB)/8, $0x0102030405060708
|
||||||
|
GLOBL ·tab(SB), RODATA, $8
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataNoGlobl] != 0 {
|
||||||
|
t.Fatalf("DATA before GLOBL must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// A static symbol pairs with its own static GLOBL.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA mask<>+0(SB)/4, $0x80020100
|
||||||
|
GLOBL mask<>(SB), RODATA, $4
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataNoGlobl] != 0 {
|
||||||
|
t.Fatalf("static pairing must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func TestDataExceedsGlobl(t *testing.T) {
|
||||||
|
// gasm asm bounds every initialiser by the declared size; go tool asm
|
||||||
|
// grows the symbol silently, so the declared size stops matching the
|
||||||
|
// data.
|
||||||
|
diags := lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
GLOBL ·tab(SB), RODATA, $4
|
||||||
|
DATA ·tab+0(SB)/8, $0x0102030405060708
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataExceedsGlobl] != 1 {
|
||||||
|
t.Fatalf("want one data-exceeds-globl, got %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// An initialiser that fits the declaration is clean, at either order.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
DATA ·tab+0(SB)/4, $1
|
||||||
|
DATA ·tab+4(SB)/4, $2
|
||||||
|
GLOBL ·tab(SB), RODATA, $8
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeDataExceedsGlobl] != 0 {
|
||||||
|
t.Fatalf("fitting initialisers must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
}
|
||||||
@@ -0,0 +1,113 @@
|
|||||||
|
// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
|
||||||
|
// SPDX-License-Identifier: BSD-3-Clause
|
||||||
|
|
||||||
|
package lint
|
||||||
|
|
||||||
|
import (
|
||||||
|
"fmt"
|
||||||
|
"strings"
|
||||||
|
|
||||||
|
"sourcedock.dev/petrbalvin/gasm-sdk/ast"
|
||||||
|
)
|
||||||
|
|
||||||
|
// checkTextDirectives holds the two directive-hygiene checks that read the
|
||||||
|
// TEXT line against the layer it lives in: the NOFRAME flag against the
|
||||||
|
// declared frame, and a missing argument area where the // func signature
|
||||||
|
// implies one.
|
||||||
|
func checkTextDirectives(t *ast.Text, cfg Config) []Diagnostic {
|
||||||
|
var out []Diagnostic
|
||||||
|
if t.Frame == nil || !t.Frame.Imm.HasVal {
|
||||||
|
return out
|
||||||
|
}
|
||||||
|
|
||||||
|
// NOFRAME is only valid with a frame size of zero (textflag.h); the
|
||||||
|
// toolchain accepts a non-zero combination silently and still allocates
|
||||||
|
// the frame, so the flag states an arrangement the directive does not
|
||||||
|
// describe. Negative frames are the ABI-wrapper spelling and are left
|
||||||
|
// alone: the arm64 BSD syscall stubs deliberately pair NOFRAME with $-8.
|
||||||
|
if !cfg.Disable[CodeNoFrameFrameSize] && hasTextFlag(t, "NOFRAME") && t.Frame.Imm.Val > 0 {
|
||||||
|
out = append(out, Diagnostic{
|
||||||
|
Pos: t.Keyword.Pos,
|
||||||
|
Severity: Warning,
|
||||||
|
Code: CodeNoFrameFrameSize,
|
||||||
|
Message: fmt.Sprintf("NOFRAME suppresses frame setup and is only valid with a zero frame size, "+
|
||||||
|
"but this TEXT declares $%d", t.Frame.Imm.Val),
|
||||||
|
})
|
||||||
|
}
|
||||||
|
|
||||||
|
// Without NOSPLIT the stack-growth preamble runs, and the argument area
|
||||||
|
// the wrapper laid out should be stated explicitly: an omitted area
|
||||||
|
// records ArgsSizeUnknown (funcdata.h) in the object and go vet then
|
||||||
|
// skips the size check against the prototype. Only functions whose
|
||||||
|
// // func signature implies a non-zero area are flagged; with no
|
||||||
|
// signature or a zero area, $frame alone is the normal spelling.
|
||||||
|
if !cfg.Disable[CodeMissingArgSize] && t.Args == nil && !hasTextFlag(t, "NOSPLIT") {
|
||||||
|
if want, ok := abiExpectedArgSize(t.Doc); ok && want > 0 {
|
||||||
|
out = append(out, Diagnostic{
|
||||||
|
Pos: t.Keyword.Pos,
|
||||||
|
Severity: Warning,
|
||||||
|
Code: CodeMissingArgSize,
|
||||||
|
Message: fmt.Sprintf("TEXT omits the argument area; the // func signature implies %d bytes, "+
|
||||||
|
"so the frame should read $%d-%d (an omitted area records ArgsSizeUnknown)", want, t.Frame.Imm.Val, want),
|
||||||
|
})
|
||||||
|
}
|
||||||
|
}
|
||||||
|
return out
|
||||||
|
}
|
||||||
|
|
||||||
|
// checkResultNaming flags result slots addressed with the generic ret
|
||||||
|
// spelling although the // func signature names its results. The name is
|
||||||
|
// documentation the toolchain enforces for FP references, and go vet checks
|
||||||
|
// it against the prototype, so a signature that names a result and a body
|
||||||
|
// that writes ret+N(FP) disagree about what the bytes mean.
|
||||||
|
func checkResultNaming(t *ast.Text) []Diagnostic {
|
||||||
|
results, ok := abiResultSlots(t.Doc)
|
||||||
|
if !ok || len(results) == 0 {
|
||||||
|
return nil
|
||||||
|
}
|
||||||
|
// A parameter named ret makes the spelling a parameter reference, not
|
||||||
|
// the generic result name; the rule cannot tell them apart and stays
|
||||||
|
// silent.
|
||||||
|
params, pok := abiParamNames(t.Doc)
|
||||||
|
if pok {
|
||||||
|
for _, p := range params {
|
||||||
|
if strings.EqualFold(p, "ret") {
|
||||||
|
return nil
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
var out []Diagnostic
|
||||||
|
for _, s := range t.Body {
|
||||||
|
in, ok := s.(*ast.Instr)
|
||||||
|
if !ok {
|
||||||
|
continue
|
||||||
|
}
|
||||||
|
for _, op := range in.Operands {
|
||||||
|
sym := op.Addr.Sym
|
||||||
|
if op.Kind != ast.OpAddr || sym == nil || sym.Pseudo != "FP" {
|
||||||
|
continue
|
||||||
|
}
|
||||||
|
if !strings.EqualFold(sym.Name, "ret") || !sym.HasOff {
|
||||||
|
continue
|
||||||
|
}
|
||||||
|
for _, r := range results {
|
||||||
|
// A result the signature itself names ret coincides with
|
||||||
|
// the generic spelling; there is no better name to suggest.
|
||||||
|
if strings.EqualFold(r.name, "ret") {
|
||||||
|
break
|
||||||
|
}
|
||||||
|
if sym.Offset >= r.off && sym.Offset < r.off+r.size {
|
||||||
|
out = append(out, Diagnostic{
|
||||||
|
Pos: op.Pos,
|
||||||
|
Severity: Hint,
|
||||||
|
Code: CodeUnnamedResult,
|
||||||
|
Message: fmt.Sprintf("the // func signature names this result %q; "+
|
||||||
|
"reference it as %q+%d(FP) rather than ret+%d(FP)", r.name, r.name, r.off, sym.Offset),
|
||||||
|
})
|
||||||
|
break
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
return out
|
||||||
|
}
|
||||||
@@ -0,0 +1,324 @@
|
|||||||
|
// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
|
||||||
|
// SPDX-License-Identifier: BSD-3-Clause
|
||||||
|
|
||||||
|
package lint
|
||||||
|
|
||||||
|
import (
|
||||||
|
"testing"
|
||||||
|
|
||||||
|
"sourcedock.dev/petrbalvin/gasm-sdk/arch"
|
||||||
|
"sourcedock.dev/petrbalvin/gasm-sdk/parser"
|
||||||
|
)
|
||||||
|
|
||||||
|
func TestNoFrameFrameSize(t *testing.T) {
|
||||||
|
// NOFRAME against a positive frame: the flag states an arrangement the
|
||||||
|
// directive does not describe.
|
||||||
|
diags := lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT|NOFRAME, $8
|
||||||
|
MOVQ $1, AX
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeNoFrameFrameSize] != 1 {
|
||||||
|
t.Fatalf("want one noframe-frame-size, got %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// The valid spelling: NOFRAME with a zero frame.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT|NOFRAME, $0
|
||||||
|
MOVQ $1, AX
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeNoFrameFrameSize] != 0 {
|
||||||
|
t.Fatalf("NOFRAME with $0 must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// A negative frame with NOFRAME is the arm64 BSD syscall-stub pattern
|
||||||
|
// (GOROOT's sys_netbsd_arm64.s runtime·open), not a defect.
|
||||||
|
diags = lintSrcArch(t, "f_arm64.s", `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·open(SB),NOSPLIT|NOFRAME,$-8
|
||||||
|
MOVD name+0(FP), R0
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeNoFrameFrameSize] != 0 {
|
||||||
|
t.Fatalf("NOFRAME with a negative frame must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// A frame without the flag is the ordinary spelling.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $8
|
||||||
|
MOVQ $1, AX
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeNoFrameFrameSize] != 0 {
|
||||||
|
t.Fatalf("a frame without NOFRAME must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// -disable silences the rule.
|
||||||
|
f, _ := parser.Parse("t_amd64.s", "#include \"textflag.h\"\nTEXT ·f(SB), NOSPLIT|NOFRAME, $8\n\tRET\n")
|
||||||
|
diags = File(f, Config{Arch: arch.AMD64, Disable: map[string]bool{CodeNoFrameFrameSize: true}})
|
||||||
|
if codes(diags)[CodeNoFrameFrameSize] != 0 {
|
||||||
|
t.Fatalf("disabled rule must stay silent: %+v", diags)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func TestMissingArgSize(t *testing.T) {
|
||||||
|
// Without NOSPLIT and without an argument area, the object records
|
||||||
|
// ArgsSizeUnknown even though the signature states the size.
|
||||||
|
diags := lintSrc(t, `
|
||||||
|
// func f(a int) int
|
||||||
|
TEXT ·f(SB), $0
|
||||||
|
MOVQ a+0(FP), AX
|
||||||
|
MOVQ AX, ret+8(FP)
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeMissingArgSize] != 1 {
|
||||||
|
t.Fatalf("want one missing-argsize, got %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// The declared area matching the signature is clean.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
// func f(a int) int
|
||||||
|
TEXT ·f(SB), $0-16
|
||||||
|
MOVQ a+0(FP), AX
|
||||||
|
MOVQ AX, ret+8(FP)
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeMissingArgSize] != 0 {
|
||||||
|
t.Fatalf("a declared argument area must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// NOSPLIT functions omit the area throughout GOROOT; not flagged.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
// func f(a int) int
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0
|
||||||
|
MOVQ a+0(FP), AX
|
||||||
|
MOVQ AX, ret+8(FP)
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeMissingArgSize] != 0 {
|
||||||
|
t.Fatalf("NOSPLIT without an area must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// No signature, no opinion.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), $0
|
||||||
|
MOVQ $1, AX
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeMissingArgSize] != 0 {
|
||||||
|
t.Fatalf("signature-less function must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// A signature whose argument area is empty implies nothing to declare.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
// func f()
|
||||||
|
TEXT ·f(SB), $0
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeMissingArgSize] != 0 {
|
||||||
|
t.Fatalf("zero-size signature must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
// TestMissingRetFallthroughEnd pins the second shape of missing-ret: the
|
||||||
|
// body knows how to return, but its tail can run off the end, and the
|
||||||
|
// toolchain appends nothing, so execution continues into the next TEXT.
|
||||||
|
func TestMissingRetFallthroughEnd(t *testing.T) {
|
||||||
|
diags := lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0
|
||||||
|
CMPQ AX, $0
|
||||||
|
JNE done
|
||||||
|
RET
|
||||||
|
done:
|
||||||
|
MOVQ $2, BX
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeMissingRet] != 1 {
|
||||||
|
t.Fatalf("want one missing-ret for the fall-through tail, got %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// Ending in RET is clean, trailing labels included.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0
|
||||||
|
CMPQ AX, $0
|
||||||
|
JNE done
|
||||||
|
MOVQ $1, AX
|
||||||
|
done:
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeMissingRet] != 0 {
|
||||||
|
t.Fatalf("RET last must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// Ending in an unconditional branch is a tail call, not a defect.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0
|
||||||
|
MOVQ $1, AX
|
||||||
|
JMP ·g(SB)
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeMissingRet] != 0 {
|
||||||
|
t.Fatalf("a tail call must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// A conditional branch last, with a RET earlier, still falls through.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0
|
||||||
|
JE done
|
||||||
|
RET
|
||||||
|
done:
|
||||||
|
CMPQ AX, $0
|
||||||
|
JNE done
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeMissingRet] != 1 {
|
||||||
|
t.Fatalf("conditional-branch tail must be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// GC annotations after the terminator carry no control flow.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0
|
||||||
|
RET
|
||||||
|
FUNCDATA $1, ·sm(SB)
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeMissingRet] != 0 {
|
||||||
|
t.Fatalf("FUNCDATA after RET must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// Trapping tails: the runtime's abort paths end in INT (amd64) or BRK
|
||||||
|
// (arm64); they never return, so no RET is needed.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·abort(SB), NOSPLIT, $0
|
||||||
|
INT $3
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeMissingRet] != 0 {
|
||||||
|
t.Fatalf("INT tail must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
diags = lintSrcArch(t, "f_arm64.s", `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·abort(SB), NOSPLIT, $0
|
||||||
|
BRK
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeMissingRet] != 0 {
|
||||||
|
t.Fatalf("BRK tail must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// A file that includes non-textflag headers may hide the terminator in
|
||||||
|
// a macro, so the heuristic stays silent there.
|
||||||
|
diags = lintSrcArch(t, "f_amd64.s", `
|
||||||
|
#include "go_tls.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0
|
||||||
|
MOVQ $1, AX
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeMissingRet] != 0 {
|
||||||
|
t.Fatalf("macro-using files must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func TestInvalidFlagPlacement(t *testing.T) {
|
||||||
|
// NOSPLIT is a TEXT flag; on GLOBL it does nothing.
|
||||||
|
diags := lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
GLOBL ·tab(SB), NOSPLIT, $8
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeInvalidFlag] != 1 {
|
||||||
|
t.Fatalf("want one invalid-textflag for the misplaced NOSPLIT, got %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// RODATA belongs to data declarations, not to TEXT.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), RODATA, $0
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeInvalidFlag] != 1 {
|
||||||
|
t.Fatalf("want one invalid-textflag for RODATA on TEXT, got %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// Correct placements stay silent, on both directives.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT|DUPOK, $0
|
||||||
|
RET
|
||||||
|
GLOBL ·tab(SB), RODATA|NOPTR, $8
|
||||||
|
DATA ·tab+0(SB)/8, $0
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeInvalidFlag] != 0 {
|
||||||
|
t.Fatalf("correct flag placements must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func TestUnnamedResult(t *testing.T) {
|
||||||
|
// The signature names its results, the body uses the generic spelling.
|
||||||
|
diags := lintSrc(t, `
|
||||||
|
// func kevent(kq int, ch unsafe.Pointer) (n int, err error)
|
||||||
|
TEXT ·kevent(SB), NOSPLIT, $0-40
|
||||||
|
MOVL kq+0(FP), AX
|
||||||
|
MOVQ ch+8(FP), BX
|
||||||
|
MOVL AX, ret+16(FP)
|
||||||
|
MOVL $0, err+24(FP)
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeUnnamedResult] != 1 {
|
||||||
|
t.Fatalf("want one unnamed-result hint, got %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// Referencing the result by its declared name is the clean spelling.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
// func kevent(kq int, ch unsafe.Pointer) (n int, err error)
|
||||||
|
TEXT ·kevent(SB), NOSPLIT, $0-40
|
||||||
|
MOVL kq+0(FP), AX
|
||||||
|
MOVQ ch+8(FP), BX
|
||||||
|
MOVL AX, n+16(FP)
|
||||||
|
MOVL $0, err+24(FP)
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeUnnamedResult] != 0 {
|
||||||
|
t.Fatalf("named result reference must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// An unnamed result is exactly what the ret spelling documents.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
// func f(a int) int
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0-16
|
||||||
|
MOVQ a+0(FP), AX
|
||||||
|
MOVQ AX, ret+8(FP)
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeUnnamedResult] != 0 {
|
||||||
|
t.Fatalf("unnamed result via ret must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// A result the signature itself names ret coincides with the generic
|
||||||
|
// spelling; there is nothing better to suggest.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
// func f(a int) (ret int)
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0-16
|
||||||
|
MOVQ a+0(FP), AX
|
||||||
|
MOVQ AX, ret+8(FP)
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeUnnamedResult] != 0 {
|
||||||
|
t.Fatalf("a result literally named ret must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// A parameter named ret turns the spelling into a parameter reference.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
// func f(ret int) (n int)
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0-16
|
||||||
|
MOVQ ret+0(FP), AX
|
||||||
|
MOVQ AX, n+8(FP)
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeUnnamedResult] != 0 {
|
||||||
|
t.Fatalf("a parameter named ret must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
}
|
||||||
+137
-4
@@ -10,6 +10,7 @@ package lint
|
|||||||
|
|
||||||
import (
|
import (
|
||||||
"fmt"
|
"fmt"
|
||||||
|
"slices"
|
||||||
"strconv"
|
"strconv"
|
||||||
"strings"
|
"strings"
|
||||||
"unicode/utf8"
|
"unicode/utf8"
|
||||||
@@ -84,6 +85,17 @@ const (
|
|||||||
CodeNonportableRegister = "nonportable-register-name"
|
CodeNonportableRegister = "nonportable-register-name"
|
||||||
CodeUnencodable = "unencodable-instruction"
|
CodeUnencodable = "unencodable-instruction"
|
||||||
CodeReservedRegister = "reserved-register-write"
|
CodeReservedRegister = "reserved-register-write"
|
||||||
|
CodeMissingArgSize = "missing-argsize"
|
||||||
|
CodeNoFrameFrameSize = "noframe-frame-size"
|
||||||
|
CodeUnnamedFPRef = "unnamed-fp-reference"
|
||||||
|
CodeHardwareSP = "hardware-sp-addressing"
|
||||||
|
CodeVEXSSEMixing = "vex-sse-mixing"
|
||||||
|
CodeUnnamedResult = "unnamed-result"
|
||||||
|
CodeDataWidth = "data-width"
|
||||||
|
CodeDataValueOverflow = "data-value-overflow"
|
||||||
|
CodeDataStringWidth = "data-string-width"
|
||||||
|
CodeDataNoGlobl = "data-without-globl"
|
||||||
|
CodeDataExceedsGlobl = "data-exceeds-globl"
|
||||||
)
|
)
|
||||||
|
|
||||||
// knownTextFlags are the flags recognised by runtime/textflag.h, plus the
|
// knownTextFlags are the flags recognised by runtime/textflag.h, plus the
|
||||||
@@ -95,6 +107,19 @@ var knownTextFlags = map[string]bool{
|
|||||||
"TOPFRAME": true, "ABIWRAPPER": true,
|
"TOPFRAME": true, "ABIWRAPPER": true,
|
||||||
}
|
}
|
||||||
|
|
||||||
|
// textOnlyFlags and dataOnlyFlags carry the placement half of the textflag.h
|
||||||
|
// table: the names that exist on one directive but not the other. NOPROF and
|
||||||
|
// DUPOK apply to both, and every name outside these two sets is either
|
||||||
|
// shared or already reported by the unknown-flag check.
|
||||||
|
var textOnlyFlags = map[string]bool{
|
||||||
|
"NOSPLIT": true, "WRAPPER": true, "NEEDCTXT": true, "NOFRAME": true,
|
||||||
|
"REFLECTED": true, "REFLECTMETHOD": true, "TOPFRAME": true, "ABIWRAPPER": true,
|
||||||
|
}
|
||||||
|
|
||||||
|
var dataOnlyFlags = map[string]bool{
|
||||||
|
"RODATA": true, "NOPTR": true, "TLSBSS": true,
|
||||||
|
}
|
||||||
|
|
||||||
// pseudoOps are assembler pseudo-operations that are valid instruction-position
|
// pseudoOps are assembler pseudo-operations that are valid instruction-position
|
||||||
// tokens but are not machine instructions and so absent from the arch tables.
|
// tokens but are not machine instructions and so absent from the arch tables.
|
||||||
var pseudoOps = map[string]bool{
|
var pseudoOps = map[string]bool{
|
||||||
@@ -165,12 +190,15 @@ func File(f *ast.File, cfg Config) []Diagnostic {
|
|||||||
for _, d := range f.Decls {
|
for _, d := range f.Decls {
|
||||||
var flags []string
|
var flags []string
|
||||||
var pos token.Position
|
var pos token.Position
|
||||||
|
var directive string
|
||||||
switch dd := d.(type) {
|
switch dd := d.(type) {
|
||||||
case *ast.Text:
|
case *ast.Text:
|
||||||
flags = dd.Flags
|
flags = dd.Flags
|
||||||
pos = dd.Keyword.Pos
|
pos = dd.Keyword.Pos
|
||||||
|
directive = "TEXT"
|
||||||
case *ast.Globl:
|
case *ast.Globl:
|
||||||
flags = dd.Flags
|
flags = dd.Flags
|
||||||
|
directive = "GLOBL"
|
||||||
if dd.Name != nil {
|
if dd.Name != nil {
|
||||||
pos = dd.Name.Pos
|
pos = dd.Name.Pos
|
||||||
}
|
}
|
||||||
@@ -188,11 +216,28 @@ func File(f *ast.File, cfg Config) []Diagnostic {
|
|||||||
Code: CodeInvalidFlag,
|
Code: CodeInvalidFlag,
|
||||||
Message: fmt.Sprintf("unknown TEXT/GLOBL flag %q", fl),
|
Message: fmt.Sprintf("unknown TEXT/GLOBL flag %q", fl),
|
||||||
})
|
})
|
||||||
|
continue
|
||||||
|
}
|
||||||
|
// Placement: the textflag.h table binds half the names to
|
||||||
|
// one directive. Both assemblers accept a misplaced name
|
||||||
|
// silently, so the flag simply does nothing.
|
||||||
|
if (directive == "TEXT" && dataOnlyFlags[fl]) ||
|
||||||
|
(directive == "GLOBL" && textOnlyFlags[fl]) {
|
||||||
|
out = append(out, Diagnostic{
|
||||||
|
Pos: pos,
|
||||||
|
Severity: Warning,
|
||||||
|
Code: CodeInvalidFlag,
|
||||||
|
Message: fmt.Sprintf("flag %q does not apply to %s", fl, directive),
|
||||||
|
})
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
|
// DATA and GLOBL structure: widths, values that fit them, and the
|
||||||
|
// GLOBL declaration that sizes each initialised symbol.
|
||||||
|
out = append(out, checkDataDecls(f, cfg)...)
|
||||||
|
|
||||||
sortDiagnostics(out)
|
sortDiagnostics(out)
|
||||||
return out
|
return out
|
||||||
}
|
}
|
||||||
@@ -376,17 +421,33 @@ func lintText(t *ast.Text, tab *arch.Table, archKnown bool, cfg Config, macros m
|
|||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
// Missing RET heuristic. Functions that invoke a macro are skipped: the
|
// Missing RET. Two shapes of the same defect, a function that can run
|
||||||
// macro body (opaque to us) may supply the RET. A TEXT whose symbol is
|
// off the end of its body: one with no RET anywhere, and one that has a
|
||||||
// missing (already reported by the parser) is skipped too.
|
// RET (or a terminator) somewhere but whose last instruction is not a
|
||||||
|
// terminator, so the tail falls through into whatever follows the TEXT.
|
||||||
|
// Functions that invoke a macro are skipped: the macro body (opaque to
|
||||||
|
// us) may supply the RET. A TEXT whose symbol is missing (already
|
||||||
|
// reported by the parser) is skipped too.
|
||||||
if doLabelChecks && !cfg.Disable[CodeMissingRet] && t.Name != nil &&
|
if doLabelChecks && !cfg.Disable[CodeMissingRet] && t.Name != nil &&
|
||||||
instrCount > 0 && !hasRet && !lastTerminal && !hasMacro {
|
instrCount > 0 && !hasMacro {
|
||||||
|
if !trailingTerminal(t, cfg.Arch) {
|
||||||
|
if !hasRet && !lastTerminal {
|
||||||
out = append(out, Diagnostic{
|
out = append(out, Diagnostic{
|
||||||
Pos: t.Keyword.Pos,
|
Pos: t.Keyword.Pos,
|
||||||
Severity: Warning,
|
Severity: Warning,
|
||||||
Code: CodeMissingRet,
|
Code: CodeMissingRet,
|
||||||
Message: fmt.Sprintf("function %q has no RET", t.Name.Name),
|
Message: fmt.Sprintf("function %q has no RET", t.Name.Name),
|
||||||
})
|
})
|
||||||
|
} else {
|
||||||
|
out = append(out, Diagnostic{
|
||||||
|
Pos: t.Keyword.Pos,
|
||||||
|
Severity: Warning,
|
||||||
|
Code: CodeMissingRet,
|
||||||
|
Message: fmt.Sprintf("function %q can fall off its end: the last instruction is neither "+
|
||||||
|
"RET nor an unconditional branch, so execution continues into the next TEXT", t.Name.Name),
|
||||||
|
})
|
||||||
|
}
|
||||||
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
// Stack imbalance: track SP changes and flag if the net delta at RET
|
// Stack imbalance: track SP changes and flag if the net delta at RET
|
||||||
@@ -485,9 +546,81 @@ func lintText(t *ast.Text, tab *arch.Table, archKnown bool, cfg Config, macros m
|
|||||||
// FUNCDATA / PCDATA structural validation.
|
// FUNCDATA / PCDATA structural validation.
|
||||||
out = append(out, checkFuncdata(t, cfg)...)
|
out = append(out, checkFuncdata(t, cfg)...)
|
||||||
|
|
||||||
|
// TEXT directive hygiene: the NOFRAME flag against a non-zero frame, and
|
||||||
|
// a missing argument area where the // func signature implies one.
|
||||||
|
out = append(out, checkTextDirectives(t, cfg)...)
|
||||||
|
|
||||||
|
// Addressing edges: unnamed FP references and hardware stack pointer
|
||||||
|
// offsets, the one-character spellings OPERANDS.md calls the sharpest
|
||||||
|
// edge in the language.
|
||||||
|
out = append(out, scanAddressing(t, cfg)...)
|
||||||
|
|
||||||
|
// Encoding mixing: VEX and legacy SSE in one kernel pay a transition
|
||||||
|
// penalty on every switch (amd64 only).
|
||||||
|
if cfg.Arch == arch.AMD64 && !hasMacro && !cfg.Disable[CodeVEXSSEMixing] {
|
||||||
|
out = append(out, checkVectorEncoding(t, tab, macros)...)
|
||||||
|
}
|
||||||
|
|
||||||
|
// Result naming: the // func signature names its results, but the body
|
||||||
|
// addresses a result slot with the generic ret spelling.
|
||||||
|
if !cfg.Disable[CodeUnnamedResult] {
|
||||||
|
out = append(out, checkResultNaming(t)...)
|
||||||
|
}
|
||||||
|
|
||||||
return out
|
return out
|
||||||
}
|
}
|
||||||
|
|
||||||
|
// trailingTerminal reports whether the function's last real instruction ends
|
||||||
|
// control flow: RET, UNDEF, an arch-conditional unconditional branch, or an
|
||||||
|
// architectural trap. Trailing labels, GC annotations and code/data padding
|
||||||
|
// pseudo-ops are skipped, so a terminator followed by padding (the goexit
|
||||||
|
// traceback pattern) still counts. A body of nothing but skipped statements
|
||||||
|
// counts as terminal: there is no fall-through instruction to report.
|
||||||
|
func trailingTerminal(t *ast.Text, a arch.Arch) bool {
|
||||||
|
for _, s := range slices.Backward(t.Body) {
|
||||||
|
in, ok := s.(*ast.Instr)
|
||||||
|
if !ok {
|
||||||
|
continue // a trailing label
|
||||||
|
}
|
||||||
|
upper := strings.ToUpper(in.Mnemonic.Text)
|
||||||
|
switch upper {
|
||||||
|
case "FUNCDATA", "PCDATA", "GO_ARGS", "PCALIGN",
|
||||||
|
"BYTE", "WORD", "LONG", "QUAD", "FLOAT":
|
||||||
|
continue // annotations and padding carry no control flow
|
||||||
|
}
|
||||||
|
return upper == "RET" || upper == "UNDEF" ||
|
||||||
|
isUnconditionalJump(a, upper) || isTrap(a, upper)
|
||||||
|
}
|
||||||
|
return true
|
||||||
|
}
|
||||||
|
|
||||||
|
// isTrap reports whether the mnemonic is an architectural trap: an
|
||||||
|
// instruction whose execution cannot continue (a breakpoint or an
|
||||||
|
// unconditional fault). The runtime ends its abort paths with these.
|
||||||
|
func isTrap(a arch.Arch, upper string) bool {
|
||||||
|
switch a {
|
||||||
|
case arch.AMD64:
|
||||||
|
return upper == "INT"
|
||||||
|
case arch.ARM64:
|
||||||
|
return upper == "BRK"
|
||||||
|
case arch.RISCV:
|
||||||
|
return upper == "EBREAK"
|
||||||
|
case arch.LOONG64:
|
||||||
|
return upper == "BREAK"
|
||||||
|
}
|
||||||
|
return false
|
||||||
|
}
|
||||||
|
|
||||||
|
// hasTextFlag reports whether the TEXT carries the named flag.
|
||||||
|
func hasTextFlag(t *ast.Text, name string) bool {
|
||||||
|
for _, f := range t.Flags {
|
||||||
|
if strings.EqualFold(f, name) {
|
||||||
|
return true
|
||||||
|
}
|
||||||
|
}
|
||||||
|
return false
|
||||||
|
}
|
||||||
|
|
||||||
// reachesRuntime reports whether a function can reach the Go runtime: it is
|
// reachesRuntime reports whether a function can reach the Go runtime: it is
|
||||||
// not NOSPLIT (so the stack-split and traceback machinery runs) or it makes a
|
// not NOSPLIT (so the stack-split and traceback machinery runs) or it makes a
|
||||||
// CALL. Goroutine-pointer registers must survive such functions; a NOSPLIT
|
// CALL. Goroutine-pointer registers must survive such functions; a NOSPLIT
|
||||||
|
|||||||
@@ -0,0 +1,70 @@
|
|||||||
|
// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
|
||||||
|
// SPDX-License-Identifier: BSD-3-Clause
|
||||||
|
|
||||||
|
package lint
|
||||||
|
|
||||||
|
import (
|
||||||
|
"strings"
|
||||||
|
|
||||||
|
"sourcedock.dev/petrbalvin/gasm-sdk/arch"
|
||||||
|
"sourcedock.dev/petrbalvin/gasm-sdk/ast"
|
||||||
|
)
|
||||||
|
|
||||||
|
// checkVectorEncoding reports a kernel that mixes VEX-encoded instructions
|
||||||
|
// with legacy SSE operating on X registers. Every switch between the two
|
||||||
|
// encodings pays a transition penalty (the upper YMM halves must be saved
|
||||||
|
// and restored by the processor), so a kernel is written in one encoding or
|
||||||
|
// the other; the runtime's memmove mixes them deliberately behind feature
|
||||||
|
// dispatch, which is why the severity is informational.
|
||||||
|
func checkVectorEncoding(t *ast.Text, tab *arch.Table, macros map[string]bool) []Diagnostic {
|
||||||
|
vex, legacy := false, false
|
||||||
|
for _, s := range t.Body {
|
||||||
|
in, ok := s.(*ast.Instr)
|
||||||
|
if !ok {
|
||||||
|
continue
|
||||||
|
}
|
||||||
|
upper := strings.ToUpper(in.Mnemonic.Text)
|
||||||
|
if isMacroInvocation(in.Mnemonic.Text, macros) {
|
||||||
|
continue
|
||||||
|
}
|
||||||
|
// VZEROUPPER and VZEROALL are the boundary management: their purpose
|
||||||
|
// is to clean the upper halves before legacy SSE code, so they count
|
||||||
|
// as neither side of the mixing.
|
||||||
|
if strings.HasPrefix(upper, "V") && upper != "VZEROUPPER" && upper != "VZEROALL" {
|
||||||
|
vex = true
|
||||||
|
continue
|
||||||
|
}
|
||||||
|
if !strings.HasPrefix(upper, "V") && hasXMMOperand(in, tab) {
|
||||||
|
legacy = true
|
||||||
|
}
|
||||||
|
}
|
||||||
|
if !vex || !legacy {
|
||||||
|
return nil
|
||||||
|
}
|
||||||
|
return []Diagnostic{{
|
||||||
|
Pos: t.Keyword.Pos,
|
||||||
|
Severity: Information,
|
||||||
|
Code: CodeVEXSSEMixing,
|
||||||
|
Message: "mixes VEX-encoded instructions with legacy SSE on X registers; each switch " +
|
||||||
|
"between the encodings pays a transition penalty, so keep one encoding per kernel",
|
||||||
|
}}
|
||||||
|
}
|
||||||
|
|
||||||
|
// hasXMMOperand reports whether an instruction addresses an X (128-bit SSE)
|
||||||
|
// register. Symbol names that collide with the spelling (a bare X86, say)
|
||||||
|
// are excluded by the register table lookup.
|
||||||
|
func hasXMMOperand(in *ast.Instr, tab *arch.Table) bool {
|
||||||
|
for _, op := range in.Operands {
|
||||||
|
if op.Kind != ast.OpAddr || op.Addr.Sym == nil {
|
||||||
|
continue
|
||||||
|
}
|
||||||
|
name := op.Addr.Sym.Name
|
||||||
|
if op.Addr.Sym.Pseudo != "" || op.Addr.Base != "" || op.Addr.Index != "" || name == "" {
|
||||||
|
continue
|
||||||
|
}
|
||||||
|
if r, ok := tab.Register(name); ok && r.Class == arch.Vector && strings.HasPrefix(strings.ToUpper(name), "X") {
|
||||||
|
return true
|
||||||
|
}
|
||||||
|
}
|
||||||
|
return false
|
||||||
|
}
|
||||||
@@ -0,0 +1,95 @@
|
|||||||
|
// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
|
||||||
|
// SPDX-License-Identifier: BSD-3-Clause
|
||||||
|
|
||||||
|
package lint
|
||||||
|
|
||||||
|
import (
|
||||||
|
"testing"
|
||||||
|
|
||||||
|
"sourcedock.dev/petrbalvin/gasm-sdk/arch"
|
||||||
|
"sourcedock.dev/petrbalvin/gasm-sdk/parser"
|
||||||
|
)
|
||||||
|
|
||||||
|
// TestVEXSSEMixing checks the encoding-mixing advisory: VEX and legacy SSE
|
||||||
|
// in one kernel pay a transition penalty on every switch, so the finding is
|
||||||
|
// informational, not a defect.
|
||||||
|
func TestVEXSSEMixing(t *testing.T) {
|
||||||
|
// GOROOT's memmove shape: VMOVDQU on Y registers beside MOVOU on X.
|
||||||
|
diags := lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·copy(SB), NOSPLIT, $0
|
||||||
|
VMOVDQU (SI), Y4
|
||||||
|
MOVOU (SI), X0
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeVEXSSEMixing] != 1 {
|
||||||
|
t.Fatalf("want one vex-sse-mixing, got %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// One encoding throughout is the recommendation.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·copy(SB), NOSPLIT, $0
|
||||||
|
VMOVDQU (SI), Y4
|
||||||
|
VPSUBD Y1, Y2, Y3
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeVEXSSEMixing] != 0 {
|
||||||
|
t.Fatalf("pure VEX kernel must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·copy(SB), NOSPLIT, $0
|
||||||
|
MOVOU (SI), X0
|
||||||
|
PADDB X1, X2
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeVEXSSEMixing] != 0 {
|
||||||
|
t.Fatalf("pure legacy kernel must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// VZEROUPPER is the boundary management, not a side of the mixing: the
|
||||||
|
// idiomatic epilogue after legacy SSE stays clean.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·copy(SB), NOSPLIT, $0
|
||||||
|
MOVOU (SI), X0
|
||||||
|
PADDB X1, X2
|
||||||
|
VZEROUPPER
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeVEXSSEMixing] != 0 {
|
||||||
|
t.Fatalf("VZEROUPPER epilogue must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// A symbol whose name collides with the register spelling (the runtime's
|
||||||
|
// internal∕cpu·X86 feature flags) is not a register.
|
||||||
|
diags = lintSrc(t, `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·probe(SB), NOSPLIT, $0
|
||||||
|
CMPB internal∕cpu·X86+const_offsetX86HasERMS(SB), $1
|
||||||
|
VMOVDQU (SI), Y4
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeVEXSSEMixing] != 0 {
|
||||||
|
t.Fatalf("a symbol named X86 must not count as legacy SSE: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// The rule is amd64-only: arm64 V registers are not SSE at all.
|
||||||
|
diags = lintSrcArch(t, "f_arm64.s", `
|
||||||
|
#include "textflag.h"
|
||||||
|
TEXT ·f(SB), NOSPLIT, $0
|
||||||
|
VLD1 (R0), [V1.B16]
|
||||||
|
RET
|
||||||
|
`)
|
||||||
|
if codes(diags)[CodeVEXSSEMixing] != 0 {
|
||||||
|
t.Fatalf("arm64 must not be flagged: %+v", diags)
|
||||||
|
}
|
||||||
|
|
||||||
|
// -disable silences the rule.
|
||||||
|
f, _ := parser.Parse("t_amd64.s", "#include \"textflag.h\"\nTEXT ·copy(SB), NOSPLIT, $0\n\tVMOVDQU (SI), Y4\n\tMOVOU (SI), X0\n\tRET\n")
|
||||||
|
diags = File(f, Config{Arch: arch.AMD64, Disable: map[string]bool{CodeVEXSSEMixing: true}})
|
||||||
|
if codes(diags)[CodeVEXSSEMixing] != 0 {
|
||||||
|
t.Fatalf("disabled rule must stay silent: %+v", diags)
|
||||||
|
}
|
||||||
|
}
|
||||||
Reference in New Issue
Block a user