feat: gasm-devkit 0.1.0 — GAsm lexer, parser, linter, formatter, LSP and amd64 assembler

Assisted-by: Qwen 3.8 Max Preview
2026-07-06 09:49:50 +02:00
commit d5a4a6de45
53 changed files with 13166 additions and 0 deletions
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+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+package lint
+
+import "testing"
+
+// TestRegisterClobber detects writes to callee-saved registers that are not
+// saved and restored.
+func TestRegisterClobber(t *testing.T) {
+	// BX (callee-saved on amd64) is written but never saved → clobbered.
+	clob := lintSrc(t, "#include \"textflag.h\"\n"+
+		"TEXT ·f(SB), NOSPLIT, $0\n"+
+		"\tMOVQ CX, BX\n"+
+		"\tRET\n")
+	if codes(clob)[CodeRegisterClobber] != 1 {
+		t.Fatalf("unsaved callee-saved write should be flagged: %+v", clob)
+	}
+
+	// Saved and restored → preserved.
+	saved := lintSrc(t, "#include \"textflag.h\"\n"+
+		"TEXT ·f(SB), NOSPLIT, $8\n"+
+		"\tPUSHQ BX\n"+
+		"\tMOVQ CX, BX\n"+
+		"\tPOPQ BX\n"+
+		"\tRET\n")
+	if codes(saved)[CodeRegisterClobber] != 0 {
+		t.Fatalf("saved/restored register must not be flagged: %+v", saved)
+	}
+
+	// A caller-saved register (CX) is fine to write.
+	caller := lintSrc(t, "#include \"textflag.h\"\n"+
+		"TEXT ·f(SB), NOSPLIT, $0\n"+
+		"\tMOVQ $1, CX\n"+
+		"\tRET\n")
+	if codes(caller)[CodeRegisterClobber] != 0 {
+		t.Fatalf("caller-saved register must not be flagged: %+v", caller)
+	}
+}
+
+// TestFuncdata validates the FUNCDATA/PCDATA structural checks.
+func TestFuncdata(t *testing.T) {
+	// Well formed: no findings.
+	good := lintSrc(t, "#include \"textflag.h\"\n"+
+		"TEXT ·f(SB), NOSPLIT, $0\n"+
+		"\tFUNCDATA $0, gclocals·abc(SB)\n"+
+		"\tPCDATA $1, $0\n"+
+		"\tRET\n")
+	if codes(good)[CodeFuncdata] != 0 {
+		t.Fatalf("well-formed FUNCDATA/PCDATA must not be flagged: %+v", good)
+	}
+
+	// FUNCDATA with one operand.
+	bad1 := lintSrc(t, "#include \"textflag.h\"\n"+
+		"TEXT ·f(SB), NOSPLIT, $0\n"+
+		"\tFUNCDATA $0\n"+
+		"\tRET\n")
+	if codes(bad1)[CodeFuncdata] == 0 {
+		t.Fatal("FUNCDATA with one operand should be flagged")
+	}
+
+	// PCDATA with a non-immediate value.
+	bad2 := lintSrc(t, "#include \"textflag.h\"\n"+
+		"TEXT ·f(SB), NOSPLIT, $0\n"+
+		"\tPCDATA $0, AX\n"+
+		"\tRET\n")
+	if codes(bad2)[CodeFuncdata] == 0 {
+		t.Fatal("PCDATA with a register value should be flagged")
+	}
+
+	// FUNCDATA index out of range.
+	bad3 := lintSrc(t, "#include \"textflag.h\"\n"+
+		"TEXT ·f(SB), NOSPLIT, $0\n"+
+		"\tFUNCDATA $99, gclocals·abc(SB)\n"+
+		"\tRET\n")
+	if codes(bad3)[CodeFuncdata] == 0 {
+		t.Fatal("out-of-range FUNCDATA index should be flagged")
+	}
+}