feat(riscv64): GOROOT instruction shapes, DATA order and offset expressions

Assisted-by: GLM 5.3 Flash
2026-09-19 19:58:43 +02:00
parent 1e77e58250
commit f37f183577
7 changed files with 310 additions and 95 deletions
@@ -440,83 +440,90 @@ type dataSym struct {
 }

 // collectData gathers the file's static symbols (GLOBL) and their initial
-// contents (DATA) into byte buffers, in declaration order.
+// contents (DATA) into byte buffers.  Two passes: the Plan 9 convention puts
+// every DATA line before its symbol's GLOBL, so the symbols are registered
+// before the initialisers are applied.
 func collectData(f *ast.File) ([]dataSym, error) {
 	index := map[string]int{}
 	var syms []dataSym
 	for _, d := range f.Decls {
-		switch dd := d.(type) {
-		case *ast.Globl:
-			if dd.Name == nil || dd.Name.Pseudo != "SB" {
-				continue
-			}
-			name := dd.Name.Name
-			if _, dup := index[name]; dup {
-				return nil, fmt.Errorf("duplicate GLOBL %q", name)
-			}
-			size := 0
-			if dd.Size != nil && dd.Size.Imm.HasVal {
-				size = int(dd.Size.Imm.Val)
-			}
-			index[name] = len(syms)
-			ds := dataSym{
-				name:   name,
-				pkg:    dd.Name.Pkg,
-				buf:    make([]byte, size),
-				size:   size,
-				static: dd.Name.Static,
-			}
-			for _, f := range dd.Flags {
-				switch f {
-				case "RODATA":
-					ds.rodata = true
-				case "DUPOK":
-					ds.dupok = true
-				default:
-					// Legacy numeric flag constants (runtime/textflag.h):
-					// DUPOK is 2, RODATA is 8; combinations arrive as one
-					// number (e.g. 10 = RODATA|DUPOK).
-					if n, err := strconv.Atoi(f); err == nil {
-						if n&2 != 0 {
-							ds.dupok = true
-						}
-						if n&8 != 0 {
-							ds.rodata = true
-						}
+		gd, ok := d.(*ast.Globl)
+		if !ok {
+			continue
+		}
+		if gd.Name == nil || gd.Name.Pseudo != "SB" {
+			continue
+		}
+		name := gd.Name.Name
+		if _, dup := index[name]; dup {
+			return nil, fmt.Errorf("duplicate GLOBL %q", name)
+		}
+		size := 0
+		if gd.Size != nil && gd.Size.Imm.HasVal {
+			size = int(gd.Size.Imm.Val)
+		}
+		index[name] = len(syms)
+		ds := dataSym{
+			name:   name,
+			pkg:    gd.Name.Pkg,
+			buf:    make([]byte, size),
+			size:   size,
+			static: gd.Name.Static,
+		}
+		for _, f := range gd.Flags {
+			switch f {
+			case "RODATA":
+				ds.rodata = true
+			case "DUPOK":
+				ds.dupok = true
+			default:
+				// Legacy numeric flag constants (runtime/textflag.h):
+				// DUPOK is 2, RODATA is 8; combinations arrive as one
+				// number (e.g. 10 = RODATA|DUPOK).
+				if n, err := strconv.Atoi(f); err == nil {
+					if n&2 != 0 {
+						ds.dupok = true
+					}
+					if n&8 != 0 {
+						ds.rodata = true
 					}
 				}
 			}
-			syms = append(syms, ds)
-
-		case *ast.Data:
-			if dd.Name == nil || dd.Name.Pseudo != "SB" {
-				continue
-			}
-			i, ok := index[dd.Name.Name]
-			if !ok {
-				return nil, fmt.Errorf("DATA %q: no matching GLOBL", dd.Name.Name)
-			}
-			if dd.Value == nil || !dd.Value.Imm.HasVal {
-				return nil, fmt.Errorf("DATA %q: value must be an integer immediate", dd.Name.Name)
-			}
-			w := dd.Width
-			switch w {
-			case 1, 2, 4, 8:
-			default:
-				return nil, fmt.Errorf("DATA %q: invalid width %d (want 1, 2, 4 or 8)", dd.Name.Name, w)
-			}
-			off := dd.Name.Offset
-			buf := syms[i].buf
-			if off < 0 || off+int64(w) > int64(len(buf)) {
-				return nil, fmt.Errorf("DATA %q+%d/%d exceeds GLOBL size %d", dd.Name.Name, off, w, len(buf))
-			}
-			v := dd.Value.Imm.Val
-			if dd.Value.Imm.Neg {
-				v = -v
-			}
-			for j := range w {
-				buf[off+int64(j)] = byte(v >> (8 * j))
-			}
+		}
+		syms = append(syms, ds)
+	}
+	for _, d := range f.Decls {
+		dd, ok := d.(*ast.Data)
+		if !ok {
+			continue
+		}
+		if dd.Name == nil || dd.Name.Pseudo != "SB" {
+			continue
+		}
+		i, ok := index[dd.Name.Name]
+		if !ok {
+			return nil, fmt.Errorf("DATA %q: no matching GLOBL", dd.Name.Name)
+		}
+		if dd.Value == nil || !dd.Value.Imm.HasVal {
+			return nil, fmt.Errorf("DATA %q: value must be an integer immediate", dd.Name.Name)
+		}
+		w := dd.Width
+		switch w {
+		case 1, 2, 4, 8:
+		default:
+			return nil, fmt.Errorf("DATA %q: invalid width %d (want 1, 2, 4 or 8)", dd.Name.Name, w)
+		}
+		off := dd.Name.Offset
+		buf := syms[i].buf
+		if off < 0 || off+int64(w) > int64(len(buf)) {
+			return nil, fmt.Errorf("DATA %q+%d/%d exceeds GLOBL size %d", dd.Name.Name, off, w, len(buf))
+		}
+		v := dd.Value.Imm.Val
+		if dd.Value.Imm.Neg {
+			v = -v
+		}
+		for j := range w {
+			buf[off+int64(j)] = byte(v >> (8 * j))
 		}
 	}
 	return syms, nil