feat(asm): add RISC-V ELF relocatable object emission and SB relocation

support
2026-08-03 08:51:00 +02:00
parent 7721353d44
commit f41a86b660
8 changed files with 824 additions and 43 deletions
@@ -29,7 +29,7 @@ func firstTextRISCV(t *testing.T, src string) *ast.Text {
 // assembleRISCVHelper assembles one TEXT function and returns its code bytes.
 func assembleRISCVHelper(t *testing.T, fn *ast.Text) []byte {
 	t.Helper()
-	code, _, err := assembleRISCV(fn)
+	code, _, _, err := assembleRISCV(fn)
 	if err != nil {
 		t.Fatalf("assemble: %v", err)
 	}
@@ -179,11 +179,11 @@ TEXT ·frame(SB), NOSPLIT, $0-8
 }

 func TestRISCV_RVC_loadStore(t *testing.T) {
-	// Verify that loads/stores from SP (X2) are compressed.
+	// Verify that loads/stores from SP are compressed.
 	fn := firstTextRISCV(t, `#include "textflag.h"
 TEXT ·rvcstore(SB), NOSPLIT, $0
-	LD 0(X2), X10
-	SD X10, 8(X2)
+	LD 0(SP), X10
+	SD X10, 8(SP)
 	RET
 `)
 	code := assembleRISCVHelper(t, fn)
@@ -574,3 +574,176 @@ TEXT ·cfsdsp(SB), NOSPLIT, $0-8
 		t.Errorf("expected 4 bytes with C.FSDSP, got %d", len(code))
 	}
 }
+
+func TestRISCV_SB_addr(t *testing.T) {
+	// MOV $sym<>(SB), rd → AUIPC + ADDI (8 bytes for SB).
+	src := `#include "textflag.h"
+TEXT ·sbaddr(SB), NOSPLIT, $0
+	MOV $answer<>(SB), X10
+	RET
+GLOBL answer<>(SB), RODATA, $8
+DATA answer<>+0(SB)/8, $42
+`
+	f, errs := parser.Parse("t_riscv64.s", src)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFileRISCV(f)
+	if err != nil {
+		t.Fatalf("AssembleFileRISCV: %v", err)
+	}
+	// AUIPC(4) + ADDI(4) + C.JR(2) = 10
+	if img.Funcs[0].Size != 10 {
+		t.Errorf("expected 10 bytes, got %d", img.Funcs[0].Size)
+	}
+}
+
+func TestRISCV_SB_store(t *testing.T) {
+	// MOV rd, sym<>(SB) → AUIPC + SD (8 bytes for SB).
+	src := `#include "textflag.h"
+TEXT ·sbstore(SB), NOSPLIT, $0
+	MOV X10, result<>(SB)
+	RET
+GLOBL result<>(SB), NOPTR, $8
+`
+	f, errs := parser.Parse("t_riscv64.s", src)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFileRISCV(f)
+	if err != nil {
+		t.Fatalf("AssembleFileRISCV: %v", err)
+	}
+	// AUIPC X31(4) + SD X10,0(X31)(4) + C.JR(2) = 10
+	if img.Funcs[0].Size != 10 {
+		t.Errorf("expected 10 bytes, got %d", img.Funcs[0].Size)
+	}
+}
+
+func TestRISCV_ELF(t *testing.T) {
+	src := `#include "textflag.h"
+TEXT ·simple(SB), NOSPLIT, $0
+	RET
+`
+	f, errs := parser.Parse("t_riscv64.s", src)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFileRISCV(f)
+	if err != nil {
+		t.Fatalf("AssembleFileRISCV: %v", err)
+	}
+	obj, err := img.ELFRISCVObject()
+	if err != nil {
+		t.Fatalf("ELFRISCVObject: %v", err)
+	}
+	if len(obj) < 4 || obj[0] != 0x7f || obj[1] != 'E' || obj[2] != 'L' || obj[3] != 'F' {
+		t.Fatal("not a valid ELF file")
+	}
+	if len(obj) >= 20 {
+		machine := uint16(obj[18]) | uint16(obj[19])<<8
+		if machine != 243 {
+			t.Errorf("e_machine = %d, want 243 (EM_RISCV)", machine)
+		}
+	}
+}
+
+func TestRISCV_ELF_withData(t *testing.T) {
+	src := `#include "textflag.h"
+TEXT ·get(SB), NOSPLIT, $0
+	RET
+GLOBL val<>(SB), RODATA, $4
+DATA val<>+0(SB)/4, $7
+`
+	f, errs := parser.Parse("t_riscv64.s", src)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFileRISCV(f)
+	if err != nil {
+		t.Fatalf("AssembleFileRISCV: %v", err)
+	}
+	if len(img.DataSyms) != 1 {
+		t.Fatalf("expected 1 data symbol, got %d", len(img.DataSyms))
+	}
+	if img.DataSyms[0].Name != "val" {
+		t.Errorf("data symbol name = %q, want val", img.DataSyms[0].Name)
+	}
+	if img.DataSyms[0].Size != 4 {
+		t.Errorf("data symbol size = %d, want 4", img.DataSyms[0].Size)
+	}
+	obj, err := img.ELFRISCVObject()
+	if err != nil {
+		t.Fatalf("ELFRISCVObject: %v", err)
+	}
+	_ = obj
+}
+
+func TestRISCV_SB_load(t *testing.T) {
+	// MOV sym<>(SB), rd → AUIPC + LD (8 bytes for SB).
+	src := `#include "textflag.h"
+TEXT ·sbload(SB), NOSPLIT, $0
+	MOV answer<>(SB), X10
+	RET
+GLOBL answer<>(SB), RODATA, $8
+DATA answer<>+0(SB)/8, $42
+`
+	f, errs := parser.Parse("t_riscv64.s", src)
+	if len(errs) > 0 {
+		t.Fatalf("parse: %v", errs)
+	}
+	img, err := AssembleFileRISCV(f)
+	if err != nil {
+		t.Fatalf("AssembleFileRISCV: %v", err)
+	}
+	// AUIPC(4) + LD(4) + C.JR(2) = 10
+	if img.Funcs[0].Size != 10 {
+		t.Errorf("expected 10 bytes, got %d", img.Funcs[0].Size)
+	}
+}
+
+func TestRISCV_system_instrs(t *testing.T) {
+	// Test FENCE, ECALL, EBREAK encoding.
+	fn := firstTextRISCV(t, `#include "textflag.h"
+TEXT ·sys(SB), NOSPLIT, $0
+	FENCE
+	ECALL
+	EBREAK
+	RET
+`)
+	code := assembleRISCVHelper(t, fn)
+	// 3 system instructions × 4 bytes + C.JR(2) = 14
+	if len(code) != 14 {
+		t.Errorf("expected 14 bytes, got %d (% x)", len(code), code)
+	}
+}
+
+func TestRISCV_MOV_sym_FP_error(t *testing.T) {
+	// MOV $sym(FP), rd should return an error (unsupported).
+	fn := firstTextRISCV(t, `#include "textflag.h"
+TEXT ·badfp(SB), NOSPLIT, $0
+	MOV $arg(FP), X10
+	RET
+`)
+	_, _, _, err := assembleRISCV(fn)
+	if err == nil {
+		t.Error("expected error for MOV $arg(FP), got nil")
+	}
+}
+
+func TestRISCV_CALL(t *testing.T) {
+	// CALL target → AUIPC + JALR (8 bytes).
+	fn := firstTextRISCV(t, `#include "textflag.h"
+TEXT ·calltest(SB), NOSPLIT, $0
+	CALL sub
+done:
+	RET
+sub:
+	RET
+`)
+	code := assembleRISCVHelper(t, fn)
+	// CALL(8) + C.JR(2) + C.JR(2) = 12
+	if len(code) != 12 {
+		t.Errorf("expected 12 bytes with CALL, got %d", len(code))
+	}
+}