feat(parser): macro expansion, conditionals and include splicing with -I

Assisted-by: GLM 5.3 Flash
2026-09-20 14:25:47 +02:00
parent 0629f5e2df
commit ad82aac663
14 changed files with 1446 additions and 26 deletions
@@ -0,0 +1,109 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: BSD-3-Clause
+
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+// writeTree writes a directory of files and returns its root.
+func writeTree(t *testing.T, files map[string]string) string {
+	t.Helper()
+	dir := t.TempDir()
+	for name, content := range files {
+		path := filepath.Join(dir, name)
+		if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+			t.Fatal(err)
+		}
+		if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return dir
+}
+
+// TestAsmMacroAndIncludeEndToEnd drives `gasm asm` over a source with an
+// in-file parameterised macro and an include resolved through -I, and checks
+// the assembled bytes came from the expansion (the loop body counts six
+// increments, two per expanded iteration).
+func TestAsmMacroAndIncludeEndToEnd(t *testing.T) {
+	if testing.Short() {
+		t.Skip("runs the assembler end to end")
+	}
+	dir := writeTree(t, map[string]string{
+		"inc/consts.h": "#define NITER 3\n",
+		"main_amd64.s": "#include \"textflag.h\"\n" +
+			"#include \"consts.h\"\n" +
+			"#define STEP(r) ADDQ $1, r; ADDQ $1, r\n" +
+			"TEXT ·f(SB), NOSPLIT, $0-8\n" +
+			"\tXORQ AX, AX\n" +
+			"\tMOVQ $NITER, CX\n" +
+			"loop:\n" +
+			"\tSTEP(AX)\n" +
+			"\tDECQ CX\n" +
+			"\tJNZ loop\n" +
+			"\tMOVQ AX, ret+0(FP)\n" +
+			"\tRET\n",
+	})
+	stdout, stderr, code := capture(func() int {
+		return cmdAsm([]string{"-I", filepath.Join(dir, "inc"), "-GOARCH", "amd64", filepath.Join(dir, "main_amd64.s")})
+	})
+	if code != 0 {
+		t.Fatalf("gasm asm exited %d: %s%s", code, stdout, stderr)
+	}
+	// The macro expanded to two ADDQ $1 encodings in the static body; the
+	// iteration count lives in the runtime loop.
+	if n := strings.Count(stdout, "83 c0 01"); n != 2 {
+		t.Errorf("found %d ADDQ $1 encodings in the image, want 2:\n%s", n, stdout)
+	}
+}
+
+// TestAsmIncludeResolutionOrder pins the -I search order end to end: the
+// including file's directory wins over the -I directories.
+func TestAsmIncludeResolutionOrder(t *testing.T) {
+	if testing.Short() {
+		t.Skip("runs the assembler end to end")
+	}
+	dir := writeTree(t, map[string]string{
+		"src/main_amd64.s": "#include \"textflag.h\"\n" +
+			"#include \"vals.h\"\n" +
+			"TEXT ·f(SB), NOSPLIT, $0\n" +
+			"\tMOVQ $VAL, AX\n" +
+			"\tRET\n",
+		"src/vals.h":   "#define VAL 1\n",
+		"late/vals.h":  "#define VAL 2\n",
+		"early/vals.h": "#define VAL 3\n",
+	})
+	stdout, stderr, code := capture(func() int {
+		return cmdAsm([]string{"-I", filepath.Join(dir, "early"), "-I", filepath.Join(dir, "late"),
+			"-GOARCH", "amd64", filepath.Join(dir, "src", "main_amd64.s")})
+	})
+	if code != 0 {
+		t.Fatalf("gasm asm exited %d: %s%s", code, stdout, stderr)
+	}
+	// VAL came from src/vals.h, not from either -I directory: the image
+	// loads the immediate 1.
+	if !strings.Contains(stdout, "b8 01 00 00 00") {
+		t.Errorf("expected the source-directory VAL (immediate 1) in:\n%s", stdout)
+	}
+}
+
+// TestAsmMissingIncludeIsAnError pins the diagnostic for an include that
+// resolves nowhere on the assembly path.
+func TestAsmMissingIncludeIsAnError(t *testing.T) {
+	if testing.Short() {
+		t.Skip("runs the assembler end to end")
+	}
+	path := writeTemp(t, "main_amd64.s", "#include \"textflag.h\"\n#include \"nothere.h\"\nTEXT ·f(SB), NOSPLIT, $0\n\tRET\n")
+	_, stderr, code := capture(func() int { return cmdAsm([]string{"-GOARCH", "amd64", path}) })
+	if code == 0 {
+		t.Fatal("gasm asm accepted a file whose include resolves nowhere")
+	}
+	if !strings.Contains(stderr, `#include "nothere.h"`) {
+		t.Errorf("stderr does not name the failing include: %s", stderr)
+	}
+}