cgo: support macros

_demo/cgomacro/cgomacro.go

@@ -0,0 +1,31 @@
+package main
+
+/*
+#cgo pkg-config: python3-embed
+#include <stdio.h>
+#include <Python.h>
+
+void test_stdout() {
+	printf("stdout ptr: %p\n", stdout);
+	fputs("outputs to stdout\n", stdout);
+}
+*/
+import "C"
+import (
+	"unsafe"
+
+	"github.com/goplus/llgo/c"
+)
+
+func main() {
+	C.test_stdout()
+	C.fputs((*C.char)(unsafe.Pointer(c.Str("hello\n"))), C.stdout)
+	C.Py_Initialize()
+	defer C.Py_Finalize()
+	C.PyObject_Print(C.Py_True, C.stdout, 0)
+	C.fputs((*C.char)(unsafe.Pointer(c.Str("\n"))), C.stdout)
+	C.PyObject_Print(C.Py_False, C.stdout, 0)
+	C.fputs((*C.char)(unsafe.Pointer(c.Str("\n"))), C.stdout)
+	C.PyObject_Print(C.Py_None, C.stdout, 0)
+	C.fputs((*C.char)(unsafe.Pointer(c.Str("\n"))), C.stdout)
+}

cl/compile.go

@@ -189,8 +189,17 @@ var (
 	argvTy = types.NewPointer(types.NewPointer(types.Typ[types.Int8]))
 )
 
-func isCgoCfunc(f *ssa.Function) bool {
-	return strings.HasPrefix(f.Name(), "_Cfunc_")
+func isCgoCfuncOrCmacro(f *ssa.Function) bool {
+	name := f.Name()
+	return isCgoCfunc(name) || isCgoCmacro(name)
+}
+
+func isCgoCfunc(name string) bool {
+	return strings.HasPrefix(name, "_Cfunc_")
+}
+
+func isCgoCmacro(name string) bool {
+	return strings.HasPrefix(name, "_Cmacro_")
 }
 
 func (p *context) compileFuncDecl(pkg llssa.Package, f *ssa.Function) (llssa.Function, llssa.PyObjRef, int) {
@@ -246,10 +255,11 @@ func (p *context) compileFuncDecl(pkg llssa.Package, f *ssa.Function) (llssa.Fun
 			fn.Inline(llssa.NoInline)
 		}
 	}
+	isCgo := isCgoCfuncOrCmacro(f)
 	if nblk := len(f.Blocks); nblk > 0 {
 		p.cgoCalled = false
 		p.cgoArgs = nil
-		if isCgoCfunc(f) {
+		if isCgo {
 			fn.MakeBlocks(1)
 		} else {
 			fn.MakeBlocks(nblk) // to set fn.HasBody() = true
@@ -278,7 +288,7 @@ func (p *context) compileFuncDecl(pkg llssa.Package, f *ssa.Function) (llssa.Fun
 			}
 			p.bvals = make(map[ssa.Value]llssa.Expr)
 			off := make([]int, len(f.Blocks))
-			if isCgoCfunc(f) {
+			if isCgo {
 				p.cgoArgs = make([]llssa.Expr, len(f.Params))
 				for i, param := range f.Params {
 					p.cgoArgs[i] = p.compileValue(b, param)
@@ -295,7 +305,7 @@ func (p *context) compileFuncDecl(pkg llssa.Package, f *ssa.Function) (llssa.Fun
 				doMainInit := (i == 0 && name == "main")
 				doModInit := (i == 1 && isInit)
 				p.compileBlock(b, block, off[i], doMainInit, doModInit)
-				if isCgoCfunc(f) {
+				if isCgo {
 					// just process first block for performance
 					break
 				}
@@ -409,36 +419,46 @@ func (p *context) compileBlock(b llssa.Builder, block *ssa.BasicBlock, n int, do
 	if funcs, ok := p.cgoFuncs[fname]; ok {
 		cgoFuncs = funcs
 	}
+	fnName := block.Parent().Name()
 	cgoReturned := false
+	isCgoCfunc := isCgoCfunc(fnName)
+	isCgoCmacro := isCgoCmacro(fnName)
 	for i, instr := range instrs {
 		if i == 1 && doModInit && p.state == pkgInPatch { // in patch package but no pkgFNoOldInit
 			initFnNameOld := initFnNameOfHasPatch(p.fn.Name())
 			fnOld := pkg.NewFunc(initFnNameOld, llssa.NoArgsNoRet, llssa.InC)
 			b.Call(fnOld.Expr)
 		}
-		if isCgoCfunc(block.Parent()) {
+		if isCgoCfunc || isCgoCmacro {
 			switch instr := instr.(type) {
 			case *ssa.Alloc:
 				// return value allocation
 				p.compileInstr(b, instr)
 			case *ssa.UnOp:
 				// load cgo function pointer
-				if instr.Op == token.MUL && strings.HasPrefix(instr.X.Name(), "_cgo_") {
-					cgoFuncs = append(cgoFuncs, instr.X.Name())
+				varName := instr.X.Name()
+				if instr.Op == token.MUL && strings.HasPrefix(varName, "_cgo_") {
+					cgoFuncs = append(cgoFuncs, varName)
 					p.cgoFuncs[fname] = cgoFuncs
 					p.compileInstr(b, instr)
 				}
 			case *ssa.Call:
-				// call c function
-				p.compileInstr(b, instr)
-				p.cgoCalled = true
+				if isCgoCmacro {
+					p.cgoRet = p.compileValue(b, instr.Call.Args[0])
+					p.cgoCalled = true
+				} else {
+					// call c function
+					p.compileInstr(b, instr)
+					p.cgoCalled = true
+				}
 			case *ssa.Return:
 				// return cgo function result
-				if len(instr.Results) > 0 {
-					b.Return(p.cgoRet)
-				} else {
-					b.Return(llssa.Nil)
+				if isCgoCmacro {
+					ty := p.type_(instr.Results[0].Type(), llssa.InGo)
+					p.cgoRet.Type = p.prog.Pointer(ty)
+					p.cgoRet = b.Load(p.cgoRet)
 				}
+				b.Return(p.cgoRet)
 				cgoReturned = true
 			}
 		} else {
@@ -446,18 +466,14 @@ func (p *context) compileBlock(b llssa.Builder, block *ssa.BasicBlock, n int, do
 		}
 	}
 	// is cgo cfunc but not return yet, some funcs has multiple blocks
-	if isCgoCfunc(block.Parent()) && !cgoReturned {
+	if (isCgoCfunc || isCgoCmacro) && !cgoReturned {
 		if !p.cgoCalled {
 			panic("cgo cfunc not called")
 		}
 		for _, block := range block.Parent().Blocks {
 			for _, instr := range block.Instrs {
-				if instr, ok := instr.(*ssa.Return); ok {
-					if len(instr.Results) > 0 {
-						b.Return(p.cgoRet)
-					} else {
-						b.Return(llssa.Nil)
-					}
+				if _, ok := instr.(*ssa.Return); ok {
+					b.Return(p.cgoRet)
 					goto end
 				}
 			}

cl/import.go

@@ -421,7 +421,6 @@ const (
 	llgoCgoCMalloc      = llgoCgoBase + 0x5
 	llgoCgoCheckPointer = llgoCgoBase + 0x6
 	llgoCgoCgocall      = llgoCgoBase + 0x7
-	llgoCgoUse          = llgoCgoBase + 0x8
 
 	llgoAtomicOpLast = llgoAtomicOpBase + int(llssa.OpUMin)
 )
@@ -438,7 +437,7 @@ func (p *context) funcName(fn *ssa.Function, ignore bool) (*types.Package, strin
 		if checkCgo(fname) {
 			return nil, fname, llgoInstr
 		}
-		if isCgoCfunc(fn) {
+		if isCgoCfuncOrCmacro(fn) {
 			if _, ok := llgoInstrs[fname]; ok {
 				return nil, fname, llgoInstr
 			}
@@ -450,7 +449,7 @@ func (p *context) funcName(fn *ssa.Function, ignore bool) (*types.Package, strin
 		}
 		p.ensureLoaded(pkg)
 		orgName = funcName(pkg, fn, false)
-		if ignore && ignoreName(orgName) || checkCgo(fn.Name()) {
+		if ignore && ignoreName(orgName) {
 			return nil, orgName, ignoredFunc
 		}
 	}

cl/instr.go

@@ -130,11 +130,6 @@ func (p *context) cgoCgocall(b llssa.Builder, args []ssa.Value) (ret llssa.Expr)
 	return p.cgoRet
 }
 
-// func _Cgo_use(v any)
-func (p *context) cgoUse(b llssa.Builder, args []ssa.Value) {
-	// don't need to do anything
-}
-
 // -----------------------------------------------------------------------------
 
 // func index(arr *T, idx int) T
@@ -324,7 +319,6 @@ var llgoInstrs = map[string]int{
 	"_Cfunc__CMalloc":      llgoCgoCMalloc,
 	"_cgoCheckPointer":     llgoCgoCheckPointer,
 	"_cgo_runtime_cgocall": llgoCgoCgocall,
-	"_Cgo_use":             llgoCgoUse,
 }
 
 // funcOf returns a function by name and set ftype = goFunc, cFunc, etc.
@@ -468,8 +462,6 @@ func (p *context) call(b llssa.Builder, act llssa.DoAction, call *ssa.CallCommon
 			p.cgoCheckPointer(b, args)
 		case llgoCgoCgocall:
 			p.cgoCgocall(b, args)
-		case llgoCgoUse:
-			p.cgoUse(b, args)
 		case llgoAdvance:
 			ret = p.advance(b, args)
 		case llgoIndex:

internal/build/cgo.go

@@ -88,18 +88,18 @@ func buildCgo(ctx *context, pkg *aPackage, files []*ast.File, externs map[string
 			cgoLdflags = append(cgoLdflags, linkFile)
 		}, verbose)
 	}
-	re := regexp.MustCompile(`^(_cgo_[^_]+_Cfunc_)(.*)$`)
-	cgoFuncs := make(map[string]string)
+	re := regexp.MustCompile(`^(_cgo_[^_]+_(Cfunc|Cmacro)_)(.*)$`)
+	cgoSymbols := make(map[string]string)
 	mallocFix := false
-	for _, funcs := range externs {
-		for _, funcName := range funcs {
-			if m := re.FindStringSubmatch(funcName); len(m) > 0 {
-				cgoFuncs[funcName] = m[2]
+	for _, symbols := range externs {
+		for _, symbolName := range symbols {
+			if m := re.FindStringSubmatch(symbolName); len(m) > 0 {
+				cgoSymbols[symbolName] = m[3]
+				pkgPrefix := m[1]
 				// fix missing _cgo_9113e32b6599_Cfunc__Cmalloc
-				if !mallocFix {
-					pkgPrefix := m[1]
+				if !mallocFix && m[2] == "Cfunc" {
 					mallocName := pkgPrefix + "_Cmalloc"
-					cgoFuncs[mallocName] = "_Cmalloc"
+					cgoSymbols[mallocName] = "_Cmalloc"
 					mallocFix = true
 				}
 			}
@@ -113,7 +113,10 @@ func buildCgo(ctx *context, pkg *aPackage, files []*ast.File, externs map[string
 		tmpName := tmpFile.Name()
 		defer os.Remove(tmpName)
 		code := cgoHeader + "\n\n" + preamble.src
-		externDecls := genExternDeclsByClang(code, cflags, cgoFuncs)
+		externDecls, err := genExternDeclsByClang(code, cflags, cgoSymbols)
+		if err != nil {
+			return nil, err
+		}
 		if err = os.WriteFile(tmpName, []byte(code+"\n\n"+externDecls), 0644); err != nil {
 			return nil, err
 		}
@@ -134,42 +137,90 @@ type clangASTNode struct {
 	Inner []clangASTNode `json:"inner,omitempty"`
 }
 
-func genExternDeclsByClang(src string, cflags []string, cgoFuncs map[string]string) string {
+func genExternDeclsByClang(src string, cflags []string, cgoSymbols map[string]string) (string, error) {
 	tmpSrc, err := os.CreateTemp("", "cgo-src-*.c")
 	if err != nil {
-		return ""
+		return "", err
 	}
 	defer os.Remove(tmpSrc.Name())
 	if err := os.WriteFile(tmpSrc.Name(), []byte(src), 0644); err != nil {
-		return ""
+		return "", err
 	}
-	args := append([]string{"-Xclang", "-ast-dump=json", "-fsyntax-only"}, cflags...)
-	args = append(args, tmpSrc.Name())
-	cmd := exec.Command("clang", args...)
-	output, err := cmd.Output()
-	if err != nil {
-		return ""
+	symbolNames := make(map[string]bool)
+	if err := getFuncNames(tmpSrc.Name(), cflags, symbolNames); err != nil {
+		return "", err
 	}
-	var astRoot clangASTNode
-	if err := json.Unmarshal(output, &astRoot); err != nil {
-		return ""
+	macroNames := make(map[string]bool)
+	if err := getMacroNames(tmpSrc.Name(), cflags, macroNames); err != nil {
+		return "", err
 	}
 
-	funcNames := make(map[string]bool)
-	extractFuncNames(&astRoot, funcNames)
-
 	b := strings.Builder{}
 	var toRemove []string
-	for cgoFunc, funcName := range cgoFuncs {
-		if funcNames[funcName] {
-			b.WriteString(fmt.Sprintf("void* %s = (void*)%s;\n", cgoFunc, funcName))
-			toRemove = append(toRemove, cgoFunc)
+	for cgoName, symbolName := range cgoSymbols {
+		if symbolNames[symbolName] {
+			b.WriteString(fmt.Sprintf("void* %s = (void*)%s;\n", cgoName, symbolName))
+			toRemove = append(toRemove, cgoName)
+		} else if macroNames[symbolName] {
+			/* template:
+			typeof(stdout) _cgo_1574167f3838_Cmacro_stdout;
+
+			__attribute__((constructor))
+			static void _init__cgo_1574167f3838_Cmacro_stdout() {
+				_cgo_1574167f3838_Cmacro_stdout = stdout;
+			}*/
+			b.WriteString(fmt.Sprintf(`
+typeof(%s) %s;
+
+__attribute__((constructor))
+static void _init_%s() {
+	%s = %s;
+}
+`, symbolName, cgoName, cgoName, cgoName, symbolName))
+			toRemove = append(toRemove, cgoName)
 		}
 	}
 	for _, funcName := range toRemove {
-		delete(cgoFuncs, funcName)
+		delete(cgoSymbols, funcName)
 	}
-	return b.String()
+	return b.String(), nil
+}
+
+func getMacroNames(file string, cflags []string, macroNames map[string]bool) error {
+	args := append([]string{"-dM", "-E"}, cflags...)
+	args = append(args, file)
+	cmd := exec.Command("clang", args...)
+	output, err := cmd.Output()
+	if err != nil {
+		return err
+	}
+	for _, line := range strings.Split(string(output), "\n") {
+		if strings.HasPrefix(line, "#define ") {
+			define := strings.TrimPrefix(line, "#define ")
+			parts := strings.SplitN(define, " ", 2)
+			if len(parts) > 1 {
+				macroNames[parts[0]] = true
+			}
+		}
+	}
+	return nil
+}
+
+func getFuncNames(file string, cflags []string, symbolNames map[string]bool) error {
+	args := append([]string{"-Xclang", "-ast-dump=json", "-fsyntax-only"}, cflags...)
+	args = append(args, file)
+	cmd := exec.Command("clang", args...)
+	output, err := cmd.Output()
+	if err != nil {
+		return err
+	}
+	var astRoot clangASTNode
+	if err := json.Unmarshal(output, &astRoot); err != nil {
+		return err
+	}
+
+	extractFuncNames(&astRoot, symbolNames)
+	return nil
 }
 
 func extractFuncNames(node *clangASTNode, funcNames map[string]bool) {