cgo: supports c/go callback funcs

cl/_testgo/cgofull/cgofull.go

@@ -77,9 +77,26 @@ static void test_macros() {
 #define MY_VERSION "1.0.0"
 #define MY_CODE 0x12345678
 
-void test_void() {
+static void test_void() {
 	printf("test_void\n");
 }
+
+typedef int (*Cb)(int);
+
+extern int go_callback(int);
+
+extern int c_callback(int i);
+
+static void test_callback(Cb cb) {
+	printf("test_callback, cb: %p, go_callback: %p, c_callback: %p\n", cb, go_callback, c_callback);
+	printf("test_callback, *cb: %p, *go_callback: %p, *c_callback: %p\n", *(void**)cb, *(void**)(go_callback), *(void**)(c_callback));
+	printf("cb result: %d\n", cb(123));
+	printf("done\n");
+}
+
+static void run_callback() {
+	test_callback(c_callback);
+}
 */
 import "C"
 import (
@@ -90,6 +107,11 @@ import (
 	"github.com/goplus/llgo/_demo/cgofull/pymod2"
 )
 
+//export go_callback
+func go_callback(i C.int) C.int {
+	return i + 1
+}
+
 func main() {
 	runPy()
 	f := &C.Foo{a: 1}
@@ -104,6 +126,16 @@ func main() {
 	fmt.Println(C.MY_VERSION)
 	fmt.Println(int(C.MY_CODE))
 	C.test_void()
+
+	println("call run_callback")
+	C.run_callback()
+
+	// test _Cgo_ptr and _cgoCheckResult
+	println("call with go_callback")
+	C.test_callback((C.Cb)(C.go_callback))
+
+	println("call with c_callback")
+	C.test_callback((C.Cb)(C.c_callback))
 }
 
 func runPy() {
@@ -112,4 +144,6 @@ func runPy() {
 	Run("print('Hello, Python!')")
 	C.PyObject_Print((*C.PyObject)(unsafe.Pointer(pymod1.Float(1.23))), C.stderr, 0)
 	C.PyObject_Print((*C.PyObject)(unsafe.Pointer(pymod2.Long(123))), C.stdout, 0)
+	// test _Cgo_use
+	C.PyObject_Print((*C.PyObject)(unsafe.Pointer(C.PyComplex_FromDoubles(C.double(1.23), C.double(4.56)))), C.stdout, 0)
 }

cl/_testgo/cgofull/foo.c

@@ -1,6 +1,12 @@
 #include <stdio.h>
 #include "foo.h"
 
-void print_foo(Foo* f) {
+void print_foo(Foo *f)
+{
 	printf("print_foo: %d\n", f->a);
 }
+
+int c_callback(int i)
+{
+	return i + 1;
+}

cl/_testgo/out.ll

@@ -1,64 +0,0 @@
-; ModuleID = 'main'
-source_filename = "main"
-
-%"github.com/goplus/llgo/internal/runtime.String" = type { ptr, i64 }
-
-@"main.init$guard" = global i1 false, align 1
-@0 = private unnamed_addr constant [5 x i8] c"hello", align 1
-@__llgo_argc = global i32 0, align 4
-@__llgo_argv = global ptr null, align 8
-
-define i64 @main.Foo(%"github.com/goplus/llgo/internal/runtime.String" %0) {
-_llgo_0:
-  %1 = extractvalue %"github.com/goplus/llgo/internal/runtime.String" %0, 1
-  ret i64 %1
-}
-
-define void @main.Test() {
-_llgo_0:
-  br label %_llgo_3
-
-_llgo_1:                                          ; preds = %_llgo_3
-  %0 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %1 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %0, i32 0, i32 0
-  store ptr @0, ptr %1, align 8
-  %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %0, i32 0, i32 1
-  store i64 5, ptr %2, align 4
-  %3 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %0, align 8
-  %4 = call i64 @main.Foo(%"github.com/goplus/llgo/internal/runtime.String" %3)
-  %5 = add i64 %6, 1
-  br label %_llgo_3
-
-_llgo_2:                                          ; preds = %_llgo_3
-  ret void
-
-_llgo_3:                                          ; preds = %_llgo_1, %_llgo_0
-  %6 = phi i64 [ 0, %_llgo_0 ], [ %5, %_llgo_1 ]
-  %7 = icmp slt i64 %6, 1000000
-  br i1 %7, label %_llgo_1, label %_llgo_2
-}
-
-define void @main.init() {
-_llgo_0:
-  %0 = load i1, ptr @"main.init$guard", align 1
-  br i1 %0, label %_llgo_2, label %_llgo_1
-
-_llgo_1:                                          ; preds = %_llgo_0
-  store i1 true, ptr @"main.init$guard", align 1
-  br label %_llgo_2
-
-_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
-  ret void
-}
-
-define i32 @main(i32 %0, ptr %1) {
-_llgo_0:
-  store i32 %0, ptr @__llgo_argc, align 4
-  store ptr %1, ptr @__llgo_argv, align 8
-  call void @"github.com/goplus/llgo/internal/runtime.init"()
-  call void @main.init()
-  call void @main.Test()
-  ret i32 0
-}
-
-declare void @"github.com/goplus/llgo/internal/runtime.init"()

cl/_testrt/strlen/out.ll

@@ -1,12 +1,23 @@
 ; ModuleID = 'main'
 source_filename = "main"
 
+%"github.com/goplus/llgo/internal/runtime.eface" = type { ptr, ptr }
+
 @"github.com/goplus/llgo/internal/runtime.cgoAlwaysFalse" = external global i1, align 1
 @main.format = global [10 x i8] zeroinitializer, align 1
 @"main.init$guard" = global i1 false, align 1
 @__llgo_argc = global i32 0, align 4
 @__llgo_argv = global ptr null, align 8
 
+define ptr @main._Cgo_ptr(ptr %0) {
+_llgo_0:
+  ret ptr %0
+}
+
+declare void @runtime.cgoUse(%"github.com/goplus/llgo/internal/runtime.eface")
+
+declare void @runtime.cgoCheckResult(%"github.com/goplus/llgo/internal/runtime.eface")
+
 define void @main.init() {
 _llgo_0:
   %0 = load i1, ptr @"main.init$guard", align 1

cl/_testrt/struct/out.ll

@@ -2,6 +2,7 @@
 source_filename = "main"
 
 %main.Foo = type { i32, i1 }
+%"github.com/goplus/llgo/internal/runtime.eface" = type { ptr, ptr }
 
 @"github.com/goplus/llgo/internal/runtime.cgoAlwaysFalse" = external global i1, align 1
 @main.format = global [10 x i8] zeroinitializer, align 1
@@ -35,6 +36,15 @@ _llgo_0:
   ret void
 }
 
+define ptr @main._Cgo_ptr(ptr %0) {
+_llgo_0:
+  ret ptr %0
+}
+
+declare void @runtime.cgoUse(%"github.com/goplus/llgo/internal/runtime.eface")
+
+declare void @runtime.cgoCheckResult(%"github.com/goplus/llgo/internal/runtime.eface")
+
 define void @main.init() {
 _llgo_0:
   %0 = load i1, ptr @"main.init$guard", align 1

cl/_testrt/typalias/out.ll

@@ -1,6 +1,8 @@
 ; ModuleID = 'main'
 source_filename = "main"
 
+%"github.com/goplus/llgo/internal/runtime.eface" = type { ptr, ptr }
+
 @"github.com/goplus/llgo/internal/runtime.cgoAlwaysFalse" = external global i1, align 1
 @main.format = global [10 x i8] zeroinitializer, align 1
 @"main.init$guard" = global i1 false, align 1
@@ -23,6 +25,15 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
   ret void
 }
 
+define ptr @main._Cgo_ptr(ptr %0) {
+_llgo_0:
+  ret ptr %0
+}
+
+declare void @runtime.cgoUse(%"github.com/goplus/llgo/internal/runtime.eface")
+
+declare void @runtime.cgoCheckResult(%"github.com/goplus/llgo/internal/runtime.eface")
+
 define void @main.init() {
 _llgo_0:
   %0 = load i1, ptr @"main.init$guard", align 1

cl/compile.go

@@ -189,7 +189,7 @@ var (
 	argvTy = types.NewPointer(types.NewPointer(types.Typ[types.Int8]))
 )
 
-func isCgoCfuncOrCmacro(f *ssa.Function) bool {
+func isCgoExternSymbol(f *ssa.Function) bool {
 	name := f.Name()
 	return isCgoCfunc(name) || isCgoCmacro(name)
 }
@@ -202,6 +202,10 @@ func isCgoCmacro(name string) bool {
 	return strings.HasPrefix(name, "_Cmacro_")
 }
 
+func isCgoVar(name string) bool {
+	return strings.HasPrefix(name, "__cgo_")
+}
+
 func (p *context) compileFuncDecl(pkg llssa.Package, f *ssa.Function) (llssa.Function, llssa.PyObjRef, int) {
 	pkgTypes, name, ftype := p.funcName(f, true)
 	if ftype != goFunc {
@@ -255,7 +259,7 @@ func (p *context) compileFuncDecl(pkg llssa.Package, f *ssa.Function) (llssa.Fun
 			fn.Inline(llssa.NoInline)
 		}
 	}
-	isCgo := isCgoCfuncOrCmacro(f)
+	isCgo := isCgoExternSymbol(f)
 	if nblk := len(f.Blocks); nblk > 0 {
 		p.cgoCalled = false
 		p.cgoArgs = nil
@@ -918,7 +922,17 @@ func (p *context) compileValue(b llssa.Builder, v ssa.Value) llssa.Expr {
 		}
 		return pyFn.Expr
 	case *ssa.Global:
+		varName := v.Name()
 		val := p.varOf(b, v)
+		if isCgoVar(varName) {
+			fname := p.fset.Position(v.Pos()).Filename
+			funcs, ok := p.cgoFuncs[fname]
+			if !ok {
+				funcs = make([]string, 0, 1)
+			}
+			funcs = append(funcs, val.Name())
+			p.cgoFuncs[fname] = funcs
+		}
 		if debugSymbols {
 			pos := p.fset.Position(v.Pos())
 			b.DIGlobal(val, v.Name(), pos)
@@ -1053,6 +1067,26 @@ func NewPackageEx(prog llssa.Program, patches Patches, pkg *ssa.Package, files [
 		fn()
 	}
 	externs = ctx.cgoFuncs
+	// TODO(lijie): read export name
+	for _, funcs := range externs {
+		for _, funcName := range funcs {
+			if strings.Contains(funcName, ".__cgo_") {
+				goFnName := strings.Replace(funcName, ".__cgo_", ".", 1)
+				idx := strings.LastIndex(funcName, ".__cgo_")
+				cfuncName := funcName[idx+len(".__cgo_"):]
+				v := ret.VarOf(funcName)
+				if fn := ret.FuncOf(goFnName); fn != nil {
+					// TODO(lijie): naive go:export, need better way from comment
+					fn.SetName(cfuncName)
+					// Replace symbol instead of static linking
+					v.ReplaceAllUsesWith(fn.Expr)
+				} else if fn := ret.FuncOf(cfuncName); fn != nil {
+					// Replace symbol instead of static linking
+					v.ReplaceAllUsesWith(fn.Expr)
+				}
+			}
+		}
+	}
 	return
 }
 

cl/import.go

@@ -448,7 +448,7 @@ func (p *context) funcName(fn *ssa.Function, ignore bool) (*types.Package, strin
 		if checkCgo(fname) && !cgoIgnored(fname) {
 			return nil, fname, llgoInstr
 		}
-		if isCgoCfuncOrCmacro(fn) {
+		if isCgoExternSymbol(fn) {
 			if _, ok := llgoInstrs[fname]; ok {
 				return nil, fname, llgoInstr
 			}

internal/build/build.go

@@ -525,6 +525,7 @@ func buildPkg(ctx *context, aPkg *aPackage, verbose bool) (cgoLdflags []string,
 		cl.SetDebug(0)
 	}
 	check(err)
+	aPkg.LPkg = ret
 	cgoLdflags, err = buildCgo(ctx, aPkg, aPkg.Package.Syntax, externs, verbose)
 	if needLLFile(ctx.mode) {
 		pkg.ExportFile += ".ll"
@@ -533,7 +534,6 @@ func buildPkg(ctx *context, aPkg *aPackage, verbose bool) (cgoLdflags []string,
 			fmt.Fprintf(os.Stderr, "==> Export %s: %s\n", aPkg.PkgPath, pkg.ExportFile)
 		}
 	}
-	aPkg.LPkg = ret
 	return
 }
 

internal/build/cgo.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"go/ast"
 	"go/token"
+	"go/types"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -29,6 +30,7 @@ import (
 
 	"github.com/goplus/llgo/internal/buildtags"
 	"github.com/goplus/llgo/internal/safesplit"
+	llssa "github.com/goplus/llgo/ssa"
 )
 
 type cgoDecl struct {
@@ -93,12 +95,21 @@ func buildCgo(ctx *context, pkg *aPackage, files []*ast.File, externs map[string
 	mallocFix := false
 	for _, symbols := range externs {
 		for _, symbolName := range symbols {
-			if m := re.FindStringSubmatch(symbolName); len(m) > 0 {
+			lastPart := symbolName
-				cgoSymbols[symbolName] = m[3]
+			lastDot := strings.LastIndex(symbolName, ".")
-				pkgPrefix := m[1]
+			if lastDot != -1 {
+				lastPart = symbolName[lastDot+1:]
+			}
+			if strings.HasPrefix(lastPart, "__cgo_") {
+				// func ptr var: main.__cgo_func_name
+				cgoSymbols[symbolName] = lastPart
+			} else if m := re.FindStringSubmatch(symbolName); len(m) > 0 {
+				prefix := m[1] // _cgo_hash_(Cfunc|Cmacro)_
+				name := m[3]   // remaining part
+				cgoSymbols[symbolName] = name
 				// fix missing _cgo_9113e32b6599_Cfunc__Cmalloc
 				if !mallocFix && m[2] == "Cfunc" {
-					mallocName := pkgPrefix + "_Cmalloc"
+					mallocName := prefix + "_Cmalloc"
 					cgoSymbols[mallocName] = "_Cmalloc"
 					mallocFix = true
 				}
@@ -113,7 +124,7 @@ 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, err := genExternDeclsByClang(code, cflags, cgoSymbols)
+		externDecls, err := genExternDeclsByClang(pkg, code, cflags, cgoSymbols)
 		if err != nil {
 			return nil, err
 		}
@@ -137,7 +148,7 @@ type clangASTNode struct {
 	Inner []clangASTNode `json:"inner,omitempty"`
 }
 
-func genExternDeclsByClang(src string, cflags []string, cgoSymbols map[string]string) (string, error) {
+func genExternDeclsByClang(pkg *aPackage, src string, cflags []string, cgoSymbols map[string]string) (string, error) {
 	tmpSrc, err := os.CreateTemp("", "cgo-src-*.c")
 	if err != nil {
 		return "", err
@@ -158,25 +169,37 @@ func genExternDeclsByClang(src string, cflags []string, cgoSymbols map[string]st
 	b := strings.Builder{}
 	var toRemove []string
 	for cgoName, symbolName := range cgoSymbols {
-		if symbolNames[symbolName] {
+		if strings.HasPrefix(symbolName, "__cgo_") {
-			b.WriteString(fmt.Sprintf("void* %s = (void*)%s;\n", cgoName, symbolName))
+			cfuncName := symbolName[len("__cgo_"):]
+			cfn := pkg.LPkg.NewFunc(cfuncName, types.NewSignature(nil, nil, nil, false), llssa.InC)
+			cgoVar := pkg.LPkg.VarOf(cgoName)
+			cgoVar.ReplaceAllUsesWith(cfn.Expr)
 			toRemove = append(toRemove, cgoName)
-		} else if macroNames[symbolName] {
+		} else {
+			usePtr := ""
+			if symbolNames[symbolName] {
+				usePtr = "*"
+			} else if !macroNames[symbolName] {
+				continue
+			}
 			/* template:
-			typeof(stdout) _cgo_1574167f3838_Cmacro_stdout;
+			typeof(fputs)* _cgo_1574167f3838_Cfunc_fputs;
 
 			__attribute__((constructor))
-			static void _init__cgo_1574167f3838_Cmacro_stdout() {
+			static void _init__cgo_1574167f3838_Cfunc_fputs() {
-				_cgo_1574167f3838_Cmacro_stdout = stdout;
+				_cgo_1574167f3838_Cfunc_fputs = fputs;
 			}*/
 			b.WriteString(fmt.Sprintf(`
-typeof(%s) %s;
+typeof(%s)%s %s;
 
 __attribute__((constructor))
 static void _init_%s() {
 	%s = %s;
 }
-`, symbolName, cgoName, cgoName, cgoName, symbolName))
+`,
+				symbolName, usePtr, cgoName,
+				cgoName,
+				cgoName, symbolName))
 			toRemove = append(toRemove, cgoName)
 		}
 	}

ssa/decl.go

@@ -117,6 +117,10 @@ func (g Global) InitNil() {
 	g.impl.SetInitializer(llvm.ConstNull(g.impl.GlobalValueType()))
 }
 
+func (g Global) ReplaceAllUsesWith(v Expr) {
+	g.impl.ReplaceAllUsesWith(v.impl)
+}
+
 // -----------------------------------------------------------------------------
 
 // Function represents the parameters, results, and code of a function

ssa/expr.go

@@ -59,6 +59,15 @@ func (v Expr) SetOrdering(ordering AtomicOrdering) Expr {
 	return v
 }
 
+func (v Expr) SetName(alias string) Expr {
+	v.impl.SetName(alias)
+	return v
+}
+
+func (v Expr) Name() string {
+	return v.impl.Name()
+}
+
 // -----------------------------------------------------------------------------
 
 type builtinTy struct {