88 lines
2.4 KiB
Go
88 lines
2.4 KiB
Go
// 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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"sourcedock.dev/petrbalvin/gasm-devkit/ast"
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"sourcedock.dev/petrbalvin/gasm-devkit/token"
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)
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// amd64WordNames are the canonical 64-bit register spellings of go tool asm:
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// the assembler has no RAX/EAX/RBX forms, and a file using them assembles
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// under gasm but fails under the toolchain it must ship with. The rule code
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// (CodeNonportableRegister) is declared in lint.go.
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var amd64WordNames = map[string]string{
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"AX": "AX", "BX": "BX", "CX": "CX", "DX": "DX",
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"SI": "SI", "DI": "DI", "BP": "BP", "SP": "SP",
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}
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// nonportableRegister maps a gasm-only register alias to the canonical go
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// tool asm spelling. R or E followed by a canonical word name is the only
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// alias family; R8–R15 are already canonical.
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func nonportableRegister(name string) (string, bool) {
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up := strings.ToUpper(name)
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if len(up) != 3 {
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return "", false
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}
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var rest string
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switch up[0] {
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case 'R', 'E':
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rest = up[1:]
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default:
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return "", false
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}
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if canon, ok := amd64WordNames[rest]; ok && canon != up {
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return canon, true
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}
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return "", false
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}
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// scanNonportableRegisters returns one diagnostic per distinct non-portable
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// register spelling in t. gasm neither requires nor registers these names
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// (they parse as bare symbols), and go tool asm rejects them outright, so a
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// kernel containing one only links through the gasm goobj path, never
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// through a normal go build.
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func scanNonportableRegisters(t *ast.Text) []Diagnostic {
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seen := map[string]bool{}
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var out []Diagnostic
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report := func(name string, pos token.Position) {
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canon, ok := nonportableRegister(name)
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if !ok {
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return
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}
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key := strings.ToUpper(name)
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if seen[key] {
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return
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}
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seen[key] = true
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out = append(out, Diagnostic{
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Pos: pos,
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Severity: Warning,
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Code: CodeNonportableRegister,
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Message: fmt.Sprintf("register %q is a gasm extension; go tool asm spells it %s", name, canon),
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})
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}
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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.Addr.Sym != nil && op.Addr.Sym.Pseudo == "" {
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report(op.Addr.Sym.Name, op.Pos)
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}
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if op.Addr.Base != "" {
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report(op.Addr.Base, op.Pos)
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}
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if op.Addr.Index != "" {
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report(op.Addr.Index, op.Pos)
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}
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}
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}
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return out
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}
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