Merge pull request #866 from cpunion/cgo

Full cgo support

_demo/cgobasic/cgobasic.go

@@ -0,0 +1,55 @@
+package main
+
+/*
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+*/
+import "C"
+import (
+	"fmt"
+	"unsafe"
+)
+
+func main() {
+	// C.CString example
+	cstr := C.CString("Hello, World!")
+	C.puts(cstr)
+
+	// C.CBytes example
+	bytes := []byte{65, 66, 67, 68} // ABCD
+	cbytes := C.CBytes(bytes)
+
+	// C.GoString example
+	gostr := C.GoString(cstr)
+	println("Converted back to Go string: ", gostr)
+
+	// C.GoStringN example (with length limit)
+	gostringN := C.GoStringN(cstr, 5) // only take first 5 characters
+	println("Length-limited string: ", gostringN)
+
+	// C.GoBytes example
+	gobytes := C.GoBytes(cbytes, 4) // 4 is the length
+	println("Converted back to Go byte slice: ", gobytes)
+
+	// C math library examples
+	x := 2.0
+	// Calculate square root
+	sqrtResult := C.sqrt(C.double(x))
+	fmt.Printf("sqrt(%v) = %v\n", x, float64(sqrtResult))
+
+	// Calculate sine
+	sinResult := C.sin(C.double(x))
+	fmt.Printf("sin(%v) = %v\n", x, float64(sinResult))
+
+	// Calculate cosine
+	cosResult := C.cos(C.double(x))
+	fmt.Printf("cos(%v) = %v\n", x, float64(cosResult))
+
+	// Calculate natural logarithm
+	logResult := C.log(C.double(x))
+	fmt.Printf("log(%v) = %v\n", x, float64(logResult))
+
+	C.free(unsafe.Pointer(cstr))
+	C.free(cbytes)
+}

_demo/cgocfiles/cgocfiles.go

@@ -0,0 +1,15 @@
+package main
+
+/*
+#include "in.h"
+*/
+import "C"
+import "fmt"
+
+func main() {
+	r := C.test_structs(&C.s4{a: 1}, &C.s8{a: 1, b: 2}, &C.s12{a: 1, b: 2, c: 3}, &C.s16{a: 1, b: 2, c: 3, d: 4}, &C.s20{a: 1, b: 2, c: 3, d: 4, e: 5})
+	fmt.Println(r)
+	if r != 35 {
+		panic("test_structs failed")
+	}
+}

_demo/cgocfiles/in.c

@@ -0,0 +1,12 @@
+#include <stdio.h>
+#include "in.h"
+
+int test_structs(s4* s4, s8* s8, s12* s12, s16* s16, s20* s20) {
+  printf("s4.a: %d\n", s4->a);
+  printf("s8.a: %d, s8.b: %d\n", s8->a, s8->b);
+  printf("s12.a: %d, s12.b: %d, s12.c: %d\n", s12->a, s12->b, s12->c);
+  printf("s16.a: %d, s16.b: %d, s16.c: %d, s16.d: %d\n", s16->a, s16->b, s16->c, s16->d);
+  printf("s20.a: %d, s20.b: %d, s20.c: %d, s20.d: %d, s20.e: %d\n", s20->a, s20->b, s20->c, s20->d, s20->e);
+
+  return s4->a + s8->a + s8->b + s12->a + s12->b + s12->c + s16->a + s16->b + s16->c + s16->d + s20->a + s20->b + s20->c + s20->d + s20->e;
+}

_demo/cgocfiles/in.h

@@ -0,0 +1,33 @@
+#pragma once
+
+typedef struct {
+	int a;
+} s4;
+
+typedef struct {
+  int a;
+  int b;
+} s8;
+
+typedef struct {
+  int a;
+  int b;
+  int c;
+} s12;
+
+typedef struct {
+  int a;
+  int b;
+  int c;
+  int d;
+} s16;
+
+typedef struct {
+  int a;
+  int b;
+  int c;
+  int d;
+  int e;
+} s20;
+
+extern int test_structs(s4* s4, s8* s8, s12* s12, s16* s16, s20* s20);

_demo/cgofull/bar.go

@@ -0,0 +1,16 @@
+package main
+
+/*
+#cgo CFLAGS: -DBAR
+#include <stdio.h>
+#include "foo.h"
+static void foo(Foo* f) {
+	printf("foo in bar: %d\n", f->a);
+}
+*/
+import "C"
+
+func Bar(f *C.Foo) {
+	C.print_foo(f)
+	C.foo(f)
+}

_demo/cgofull/cgofull.go

@@ -0,0 +1,95 @@
+package main
+
+/*
+#cgo windows,!amd64 CFLAGS: -D_WIN32
+#cgo !windows CFLAGS: -D_POSIX
+#cgo windows,amd64 CFLAGS: -D_WIN64
+#cgo linux,amd64 CFLAGS: -D_LINUX64
+#cgo !windows,amd64 CFLAGS: -D_UNIX64
+#include <stdio.h>
+#include "foo.h"
+typedef struct {
+	int a;
+} s4;
+
+typedef struct {
+  int a;
+  int b;
+} s8;
+
+typedef struct {
+  int a;
+  int b;
+  int c;
+} s12;
+
+typedef struct {
+  int a;
+  int b;
+  int c;
+  int d;
+} s16;
+
+typedef struct {
+  int a;
+  int b;
+  int c;
+  int d;
+  int e;
+} s20;
+
+static int test_structs(s4* s4, s8* s8, s12* s12, s16* s16, s20* s20) {
+  printf("s4.a: %d\n", s4->a);
+  printf("s8.a: %d, s8.b: %d\n", s8->a, s8->b);
+  printf("s12.a: %d, s12.b: %d, s12.c: %d\n", s12->a, s12->b, s12->c);
+  printf("s16.a: %d, s16.b: %d, s16.c: %d, s16.d: %d\n", s16->a, s16->b, s16->c, s16->d);
+  printf("s20.a: %d, s20.b: %d, s20.c: %d, s20.d: %d, s20.e: %d\n", s20->a, s20->b, s20->c, s20->d, s20->e);
+
+  return s4->a + s8->a + s8->b + s12->a + s12->b + s12->c + s16->a + s16->b + s16->c + s16->d + s20->a + s20->b + s20->c + s20->d + s20->e;
+}
+
+static void test_macros() {
+#ifdef FOO
+	printf("FOO is defined\n");
+#endif
+#ifdef BAR
+	printf("BAR is defined\n");
+#endif
+#ifdef _WIN32
+	printf("WIN32 is defined\n");
+#endif
+#ifdef _POSIX
+	printf("POSIX is defined\n");
+#endif
+#ifdef _WIN64
+	printf("WIN64 is defined\n");
+#endif
+#ifdef _LINUX64
+	printf("LINUX64 is defined\n");
+#endif
+#ifdef _UNIX64
+	printf("UNIX64 is defined\n");
+#endif
+}
+*/
+import "C"
+import "fmt"
+
+func main() {
+	runPy()
+	f := &C.Foo{a: 1}
+	Foo(f)
+	Bar(f)
+	C.test_macros()
+	r := C.test_structs(&C.s4{a: 1}, &C.s8{a: 1, b: 2}, &C.s12{a: 1, b: 2, c: 3}, &C.s16{a: 1, b: 2, c: 3, d: 4}, &C.s20{a: 1, b: 2, c: 3, d: 4, e: 5})
+	fmt.Println(r)
+	if r != 35 {
+		panic("test_structs failed")
+	}
+}
+
+func runPy() {
+	Initialize()
+	defer Finalize()
+	Run("print('Hello, Python!')")
+}

_demo/cgofull/foo.c

@@ -0,0 +1,6 @@
+#include <stdio.h>
+#include "foo.h"
+
+void print_foo(Foo* f) {
+	printf("print_foo: %d\n", f->a);
+}

_demo/cgofull/foo.go

@@ -0,0 +1,16 @@
+package main
+
+/*
+#cgo CFLAGS: -DFOO
+#include <stdio.h>
+#include "foo.h"
+static void foo(Foo* f) {
+	printf("foo in bar: %d\n", f->a);
+}
+*/
+import "C"
+
+func Foo(f *C.Foo) {
+	C.print_foo(f)
+	C.foo(f)
+}

_demo/cgofull/foo.h

@@ -0,0 +1,7 @@
+#pragma once
+
+typedef struct {
+	int a;
+} Foo;
+
+extern void print_foo(Foo* f);

_demo/cgofull/py.go

@@ -0,0 +1,24 @@
+package main
+
+/*
+#cgo pkg-config: python3-embed
+#include <Python.h>
+*/
+import "C"
+import "fmt"
+
+func Initialize() {
+	C.Py_Initialize()
+}
+
+func Finalize() {
+	C.Py_Finalize()
+}
+
+func Run(code string) error {
+	if C.PyRun_SimpleString(C.CString(code)) != 0 {
+		C.PyErr_Print()
+		return fmt.Errorf("failed to run code")
+	}
+	return nil
+}

_demo/cgopython/cgopython.go

@@ -0,0 +1,13 @@
+package main
+
+/*
+#cgo pkg-config: python3-embed
+#include <Python.h>
+*/
+import "C"
+
+func main() {
+	C.Py_Initialize()
+	defer C.Py_Finalize()
+	C.PyRun_SimpleString(C.CString("print('Hello, Python!')"))
+}

cl/_testrt/strlen/out.ll

@@ -1,6 +1,7 @@
 ; ModuleID = 'main'
 source_filename = "main"
 
+@"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

cl/_testrt/struct/out.ll

@@ -3,6 +3,7 @@ source_filename = "main"
 
 %main.Foo = type { i32, i1 }
 
+@"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

cl/_testrt/typalias/out.ll

@@ -1,6 +1,7 @@
 ; ModuleID = 'main'
 source_filename = "main"
 
+@"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

cl/compile.go

@@ -114,6 +114,11 @@ type context struct {
 	state   pkgState
 	inCFunc bool
 	skipall bool
+
+	cgoCalled bool
+	cgoArgs   []llssa.Expr
+	cgoRet    llssa.Expr
+	cgoFuncs  map[string][]string
 }
 
 type pkgState byte
@@ -163,7 +168,7 @@ func (p *context) compileMethods(pkg llssa.Package, typ types.Type) {
 func (p *context) compileGlobal(pkg llssa.Package, gbl *ssa.Global) {
 	typ := globalType(gbl)
 	name, vtype, define := p.varName(gbl.Pkg.Pkg, gbl)
-	if vtype == pyVar || ignoreName(name) || checkCgo(gbl.Name()) {
+	if vtype == pyVar || ignoreName(name) {
 		return
 	}
 	if debugInstr {
@@ -189,6 +194,10 @@ var (
 	argvTy = types.NewPointer(types.NewPointer(types.Typ[types.Int8]))
 )
 
+func isCgoCfunc(f *ssa.Function) bool {
+	return strings.HasPrefix(f.Name(), "_Cfunc_")
+}
+
 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 {
@@ -242,9 +251,14 @@ func (p *context) compileFuncDecl(pkg llssa.Package, f *ssa.Function) (llssa.Fun
 			fn.Inline(llssa.NoInline)
 		}
 	}
-
 	if nblk := len(f.Blocks); nblk > 0 {
+		p.cgoCalled = false
+		p.cgoArgs = nil
+		if isCgoCfunc(f) {
+			fn.MakeBlocks(1)
+		} else {
 			fn.MakeBlocks(nblk) // to set fn.HasBody() = true
+		}
 		if f.Recover != nil { // set recover block
 			fn.SetRecover(fn.Block(f.Recover.Index))
 		}
@@ -269,9 +283,16 @@ 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) {
+				p.cgoArgs = make([]llssa.Expr, len(f.Params))
+				for i, param := range f.Params {
+					p.cgoArgs[i] = p.compileValue(b, param)
+				}
+			} else {
 				for i, block := range f.Blocks {
 					off[i] = p.compilePhis(b, block)
 				}
+			}
 			p.blkInfos = blocks.Infos(f.Blocks)
 			i := 0
 			for {
@@ -279,6 +300,10 @@ 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) {
+					// just process first block for performance
+					break
+				}
 				if i = p.blkInfos[i].Next; i < 0 {
 					break
 				}
@@ -381,14 +406,69 @@ func (p *context) compileBlock(b llssa.Builder, block *ssa.BasicBlock, n int, do
 		callRuntimeInit(b, pkg)
 		b.Call(pkg.FuncOf("main.init").Expr)
 	}
+	fname := p.goProg.Fset.Position(block.Parent().Pos()).Filename
+	if p.cgoFuncs == nil {
+		p.cgoFuncs = make(map[string][]string)
+	}
+	var cgoFuncs []string
+	if funcs, ok := p.cgoFuncs[fname]; ok {
+		cgoFuncs = funcs
+	}
+	cgoReturned := false
 	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()) {
+			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())
+					p.cgoFuncs[fname] = cgoFuncs
 					p.compileInstr(b, instr)
 				}
+			case *ssa.Call:
+				// 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)
+				}
+				cgoReturned = true
+			}
+		} else {
+			p.compileInstr(b, instr)
+		}
+	}
+	// is cgo cfunc but not return yet, some funcs has multiple blocks
+	if isCgoCfunc(block.Parent()) && !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)
+					}
+					goto end
+				}
+			}
+		}
+	}
+end:
 	if pyModInit {
 		jump := block.Instrs[n+last].(*ssa.Jump)
 		jumpTo := p.jumpTo(jump)
@@ -892,11 +972,12 @@ type Patches = map[string]Patch
 
 // NewPackage compiles a Go package to LLVM IR package.
 func NewPackage(prog llssa.Program, pkg *ssa.Package, files []*ast.File) (ret llssa.Package, err error) {
-	return NewPackageEx(prog, nil, pkg, files)
+	ret, _, err = NewPackageEx(prog, nil, pkg, files)
+	return
 }
 
 // NewPackageEx compiles a Go package to LLVM IR package.
-func NewPackageEx(prog llssa.Program, patches Patches, pkg *ssa.Package, files []*ast.File) (ret llssa.Package, err error) {
+func NewPackageEx(prog llssa.Program, patches Patches, pkg *ssa.Package, files []*ast.File) (ret llssa.Package, externs map[string][]string, err error) {
 	pkgProg := pkg.Prog
 	pkgTypes := pkg.Pkg
 	oldTypes := pkgTypes
@@ -960,6 +1041,7 @@ func NewPackageEx(prog llssa.Program, patches Patches, pkg *ssa.Package, files [
 		ctx.initAfter = nil
 		fn()
 	}
+	externs = ctx.cgoFuncs
 	return
 }
 

cl/import.go

@@ -412,6 +412,17 @@ const (
 	llgoAtomicUMax = llgoAtomicOpBase + llssa.OpUMax
 	llgoAtomicUMin = llgoAtomicOpBase + llssa.OpUMin
 
+	llgoCgoBase         = llgoInstrBase + 0x30
+	llgoCgoCString      = llgoCgoBase + 0x0
+	llgoCgoCBytes       = llgoCgoBase + 0x1
+	llgoCgoGoString     = llgoCgoBase + 0x2
+	llgoCgoGoStringN    = llgoCgoBase + 0x3
+	llgoCgoGoBytes      = llgoCgoBase + 0x4
+	llgoCgoCMalloc      = llgoCgoBase + 0x5
+	llgoCgoCheckPointer = llgoCgoBase + 0x6
+	llgoCgoCgocall      = llgoCgoBase + 0x7
+	llgoCgoUse          = llgoCgoBase + 0x8
+
 	llgoAtomicOpLast = llgoAtomicOpBase + int(llssa.OpUMin)
 )
 
@@ -423,6 +434,15 @@ func (p *context) funcName(fn *ssa.Function, ignore bool) (*types.Package, strin
 		p.ensureLoaded(pkg)
 		orgName = funcName(pkg, origin, true)
 	} else {
+		fname := fn.Name()
+		if checkCgo(fname) {
+			return nil, fname, llgoInstr
+		}
+		if isCgoCfunc(fn) {
+			if _, ok := llgoInstrs[fname]; ok {
+				return nil, fname, llgoInstr
+			}
+		}
 		if fnPkg := fn.Pkg; fnPkg != nil {
 			pkg = fnPkg.Pkg
 		} else {

cl/instr.go

@@ -66,6 +66,77 @@ func cstr(b llssa.Builder, args []ssa.Value) (ret llssa.Expr) {
 	panic("cstr(<string-literal>): invalid arguments")
 }
 
+// -----------------------------------------------------------------------------
+
+// func _Cfunc_CString(s string) *int8
+func (p *context) cgoCString(b llssa.Builder, args []ssa.Value) (ret llssa.Expr) {
+	if len(args) == 1 {
+		return b.CString(p.compileValue(b, args[0]))
+	}
+	panic("cgoCString(string): invalid arguments")
+}
+
+// func _Cfunc_CBytes(bytes []byte) *int8
+func (p *context) cgoCBytes(b llssa.Builder, args []ssa.Value) (ret llssa.Expr) {
+	if len(args) == 1 {
+		return b.CBytes(p.compileValue(b, args[0]))
+	}
+	panic("cgoCBytes([]byte): invalid arguments")
+}
+
+// func _Cfunc_GoString(s *int8) string
+func (p *context) cgoGoString(b llssa.Builder, args []ssa.Value) (ret llssa.Expr) {
+	if len(args) == 1 {
+		return b.GoString(p.compileValue(b, args[0]))
+	}
+	panic("cgoGoString(<cstr>): invalid arguments")
+}
+
+// func _Cfunc_GoStringN(s *int8, n int) string
+func (p *context) cgoGoStringN(b llssa.Builder, args []ssa.Value) (ret llssa.Expr) {
+	if len(args) == 2 {
+		return b.GoStringN(p.compileValue(b, args[0]), p.compileValue(b, args[1]))
+	}
+	panic("cgoGoStringN(<cstr>, n int): invalid arguments")
+}
+
+// func _Cfunc_GoBytes(s *int8, n int) []byte
+func (p *context) cgoGoBytes(b llssa.Builder, args []ssa.Value) (ret llssa.Expr) {
+	if len(args) == 2 {
+		return b.GoBytes(p.compileValue(b, args[0]), p.compileValue(b, args[1]))
+	}
+	panic("cgoGoBytes(<cstr>, n int): invalid arguments")
+}
+
+// func _Cfunc__CMalloc(n int) unsafe.Pointer
+func (p *context) cgoCMalloc(b llssa.Builder, args []ssa.Value) (ret llssa.Expr) {
+	if len(args) == 1 {
+		return b.CMalloc(p.compileValue(b, args[0]))
+	}
+	panic("cgoCMalloc(n int): invalid arguments")
+}
+
+// func _cgoCheckPointer(ptr any, arg any)
+func (p *context) cgoCheckPointer(b llssa.Builder, args []ssa.Value) {
+	// don't need to do anything
+}
+
+// func _cgo_runtime_cgocall(fn unsafe.Pointer, arg unsafe.Pointer) int
+func (p *context) cgoCgocall(b llssa.Builder, args []ssa.Value) (ret llssa.Expr) {
+	pfn := p.compileValue(b, args[0])
+	pfn.Type = p.prog.Pointer(p.fn.Type)
+	fn := b.Load(pfn)
+	p.cgoRet = b.Call(fn, p.cgoArgs...)
+	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
 func (p *context) index(b llssa.Builder, args []ssa.Value) (ret llssa.Expr) {
 	return b.Load(p.advance(b, args))
@@ -244,6 +315,16 @@ var llgoInstrs = map[string]int{
 	"atomicMin":  int(llgoAtomicMin),
 	"atomicUMax": int(llgoAtomicUMax),
 	"atomicUMin": int(llgoAtomicUMin),
+
+	"_Cfunc_CString":       llgoCgoCString,
+	"_Cfunc_CBytes":        llgoCgoCBytes,
+	"_Cfunc_GoString":      llgoCgoGoString,
+	"_Cfunc_GoStringN":     llgoCgoGoStringN,
+	"_Cfunc_GoBytes":       llgoCgoGoBytes,
+	"_Cfunc__CMalloc":      llgoCgoCMalloc,
+	"_cgoCheckPointer":     llgoCgoCheckPointer,
+	"_cgo_runtime_cgocall": llgoCgoCgocall,
+	"_Cgo_use":             llgoCgoUse,
 }
 
 // funcOf returns a function by name and set ftype = goFunc, cFunc, etc.
@@ -371,6 +452,24 @@ func (p *context) call(b llssa.Builder, act llssa.DoAction, call *ssa.CallCommon
 			ret = pystr(b, args)
 		case llgoCstr:
 			ret = cstr(b, args)
+		case llgoCgoCString:
+			ret = p.cgoCString(b, args)
+		case llgoCgoCBytes:
+			ret = p.cgoCBytes(b, args)
+		case llgoCgoGoString:
+			ret = p.cgoGoString(b, args)
+		case llgoCgoGoStringN:
+			ret = p.cgoGoStringN(b, args)
+		case llgoCgoGoBytes:
+			ret = p.cgoGoBytes(b, args)
+		case llgoCgoCMalloc:
+			ret = p.cgoCMalloc(b, args)
+		case llgoCgoCheckPointer:
+			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:
@@ -407,7 +506,7 @@ func (p *context) call(b llssa.Builder, act llssa.DoAction, call *ssa.CallCommon
 			if ftype >= llgoAtomicOpBase && ftype <= llgoAtomicOpLast {
 				ret = p.atomic(b, llssa.AtomicOp(ftype-llgoAtomicOpBase), args)
 			} else {
-				log.Panicln("unknown ftype:", ftype)
+				log.Panicf("unknown ftype: %d for %s", ftype, cv.Name())
 			}
 		}
 	default:

internal/build/build.go

@@ -201,7 +201,7 @@ func Do(args []string, conf *Config) {
 	env := llvm.New("")
 	os.Setenv("PATH", env.BinDir()+":"+os.Getenv("PATH")) // TODO(xsw): check windows
 
-	ctx := &context{env, progSSA, prog, dedup, patches, make(map[string]none), initial, mode, 0}
+	ctx := &context{env, cfg, progSSA, prog, dedup, patches, make(map[string]none), initial, mode, 0}
 	pkgs := buildAllPkgs(ctx, initial, verbose)
 
 	var llFiles []string
@@ -249,6 +249,7 @@ const (
 
 type context struct {
 	env     *llvm.Env
+	conf    *packages.Config
 	progSSA *ssa.Program
 	prog    llssa.Program
 	dedup   packages.Deduper
@@ -286,8 +287,14 @@ func buildAllPkgs(ctx *context, initial []*packages.Package, verbose bool) (pkgs
 			pkg.ExportFile = ""
 		case cl.PkgLinkIR, cl.PkgLinkExtern, cl.PkgPyModule:
 			if len(pkg.GoFiles) > 0 {
-				buildPkg(ctx, aPkg, verbose)
+				cgoParts, err := buildPkg(ctx, aPkg, verbose)
-				pkg.ExportFile = " " + concatPkgLinkFiles(ctx, pkg, verbose) + " " + pkg.ExportFile
+				if err != nil {
+					panic(err)
+				}
+				linkParts := concatPkgLinkFiles(ctx, pkg, verbose)
+				allParts := append(linkParts, cgoParts...)
+				allParts = append(allParts, pkg.ExportFile)
+				pkg.ExportFile = " " + strings.Join(allParts, " ")
 			} else {
 				// panic("todo")
 				// TODO(xsw): support packages out of llgo
@@ -337,7 +344,12 @@ func buildAllPkgs(ctx *context, initial []*packages.Package, verbose bool) (pkgs
 				}
 			}
 		default:
-			buildPkg(ctx, aPkg, verbose)
+			cgoParts, err := buildPkg(ctx, aPkg, verbose)
+			if err != nil {
+				panic(err)
+			}
+			allParts := append(cgoParts, pkg.ExportFile)
+			pkg.ExportFile = " " + strings.Join(allParts, " ")
 			setNeedRuntimeOrPyInit(pkg, prog.NeedRuntime, prog.NeedPyInit)
 		}
 	}
@@ -483,7 +495,7 @@ func linkMainPkg(ctx *context, pkg *packages.Package, pkgs []*aPackage, llFiles
 	return
 }
 
-func buildPkg(ctx *context, aPkg *aPackage, verbose bool) {
+func buildPkg(ctx *context, aPkg *aPackage, verbose bool) (cgoParts []string, err error) {
 	pkg := aPkg.Package
 	pkgPath := pkg.PkgPath
 	if debugBuild || verbose {
@@ -503,12 +515,13 @@ func buildPkg(ctx *context, aPkg *aPackage, verbose bool) {
 		cl.SetDebug(cl.DbgFlagAll)
 	}
 
-	ret, err := cl.NewPackageEx(ctx.prog, ctx.patches, aPkg.SSA, syntax)
+	ret, externs, err := cl.NewPackageEx(ctx.prog, ctx.patches, aPkg.SSA, syntax)
 	if showDetail {
 		llssa.SetDebug(0)
 		cl.SetDebug(0)
 	}
 	check(err)
+	cgoParts, err = buildCgo(ctx, aPkg, aPkg.Package.Syntax, externs, verbose)
 	if needLLFile(ctx.mode) {
 		pkg.ExportFile += ".ll"
 		os.WriteFile(pkg.ExportFile, []byte(ret.String()), 0644)
@@ -517,6 +530,7 @@ func buildPkg(ctx *context, aPkg *aPackage, verbose bool) {
 		}
 	}
 	aPkg.LPkg = ret
+	return
 }
 
 const (
@@ -690,25 +704,11 @@ func isSingleLinkFile(ret string) bool {
 	return len(ret) > 0 && ret[0] != ' '
 }
 
-func concatPkgLinkFiles(ctx *context, pkg *packages.Package, verbose bool) string {
+func concatPkgLinkFiles(ctx *context, pkg *packages.Package, verbose bool) (parts []string) {
-	var b strings.Builder
-	var ret string
-	var n int
 	llgoPkgLinkFiles(ctx, pkg, func(linkFile string) {
-		if n == 0 {
+		parts = append(parts, linkFile)
-			ret = linkFile
-		} else {
-			b.WriteByte(' ')
-			b.WriteString(linkFile)
-		}
-		n++
 	}, verbose)
-	if n > 1 {
+	return
-		b.WriteByte(' ')
-		b.WriteString(ret)
-		return b.String()
-	}
-	return ret
 }
 
 // const LLGoFiles = "file1; file2; ..."

internal/build/cgo.go

@@ -0,0 +1,312 @@
+/*
+ * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package build
+
+import (
+	"encoding/json"
+	"fmt"
+	"go/ast"
+	"go/token"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"github.com/goplus/llgo/internal/buildtags"
+)
+
+type cgoDecl struct {
+	tag     string
+	cflags  string
+	ldflags string
+}
+
+type cgoPreamble struct {
+	goFile string
+	src    string
+}
+
+const (
+	cgoHeader = `
+#include <stdlib.h>
+static void* _Cmalloc(size_t size) {
+	return malloc(size);
+}
+`
+)
+
+func buildCgo(ctx *context, pkg *aPackage, files []*ast.File, externs map[string][]string, verbose bool) (cgoParts []string, err error) {
+	cfiles, preambles, cdecls, err := parseCgo_(pkg, files)
+	if err != nil {
+		return
+	}
+	tagUsed := make(map[string]bool)
+	for _, cdecl := range cdecls {
+		if cdecl.tag != "" {
+			tagUsed[cdecl.tag] = false
+		}
+	}
+	buildtags.CheckTags(ctx.conf.BuildFlags, tagUsed)
+	cflags := []string{}
+	ldflags := []string{}
+	for _, cdecl := range cdecls {
+		if cdecl.tag == "" || tagUsed[cdecl.tag] {
+			if cdecl.cflags != "" {
+				cflags = append(cflags, cdecl.cflags)
+			}
+			if cdecl.ldflags != "" {
+				ldflags = append(ldflags, cdecl.ldflags)
+			}
+		}
+	}
+	incDirs := make(map[string]none)
+	for _, preamble := range preambles {
+		dir, _ := filepath.Split(preamble.goFile)
+		if _, ok := incDirs[dir]; !ok {
+			incDirs[dir] = none{}
+			cflags = append(cflags, "-I"+dir)
+		}
+	}
+	for _, cfile := range cfiles {
+		clFile(ctx, cflags, cfile, pkg.ExportFile, func(linkFile string) {
+			cgoParts = append(cgoParts, linkFile)
+		}, verbose)
+	}
+	re := regexp.MustCompile(`^(_cgo_[^_]+_Cfunc_)(.*)$`)
+	cgoFuncs := 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]
+				// fix missing _cgo_9113e32b6599_Cfunc__Cmalloc
+				if !mallocFix {
+					pkgPrefix := m[1]
+					mallocName := pkgPrefix + "_Cmalloc"
+					cgoFuncs[mallocName] = "_Cmalloc"
+					mallocFix = true
+				}
+			}
+		}
+	}
+	for _, preamble := range preambles {
+		tmpFile, err := os.CreateTemp("", "-cgo-*.c")
+		if err != nil {
+			return nil, fmt.Errorf("failed to create temp file: %v", err)
+		}
+		tmpName := tmpFile.Name()
+		defer os.Remove(tmpName)
+		code := cgoHeader + "\n\n" + preamble.src
+		externDecls := genExternDeclsByClang(code, cflags, cgoFuncs)
+		if err = os.WriteFile(tmpName, []byte(code+"\n\n"+externDecls), 0644); err != nil {
+			return nil, err
+		}
+		clFile(ctx, cflags, tmpName, pkg.ExportFile, func(linkFile string) {
+			cgoParts = append(cgoParts, linkFile)
+		}, verbose)
+	}
+	cgoParts = append(cgoParts, ldflags...)
+	return
+}
+
+// clangASTNode represents a node in clang's AST
+type clangASTNode struct {
+	Kind  string         `json:"kind"`
+	Name  string         `json:"name,omitempty"`
+	Inner []clangASTNode `json:"inner,omitempty"`
+}
+
+func genExternDeclsByClang(src string, cflags []string, cgoFuncs map[string]string) string {
+	tmpSrc, err := os.CreateTemp("", "cgo-src-*.c")
+	if err != nil {
+		return ""
+	}
+	defer os.Remove(tmpSrc.Name())
+	if err := os.WriteFile(tmpSrc.Name(), []byte(src), 0644); err != nil {
+		return ""
+	}
+	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 ""
+	}
+	var astRoot clangASTNode
+	if err := json.Unmarshal(output, &astRoot); err != nil {
+		return ""
+	}
+
+	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 _, funcName := range toRemove {
+		delete(cgoFuncs, funcName)
+	}
+	return b.String()
+}
+
+func extractFuncNames(node *clangASTNode, funcNames map[string]bool) {
+	for _, inner := range node.Inner {
+		if inner.Kind == "FunctionDecl" && inner.Name != "" {
+			funcNames[inner.Name] = true
+		}
+	}
+}
+
+func parseCgo_(pkg *aPackage, files []*ast.File) (cfiles []string, preambles []cgoPreamble, cdecls []cgoDecl, err error) {
+	dirs := make(map[string]none)
+	for _, file := range files {
+		pos := pkg.Fset.Position(file.Name.NamePos)
+		dir, _ := filepath.Split(pos.Filename)
+		dirs[dir] = none{}
+	}
+	for dir := range dirs {
+		files, err := filepath.Glob(filepath.Join(dir, "*.c"))
+		if err != nil {
+			continue
+		}
+		cfiles = append(cfiles, files...)
+	}
+
+	for _, file := range files {
+		for _, decl := range file.Decls {
+			switch decl := decl.(type) {
+			case *ast.GenDecl:
+				if decl.Tok == token.IMPORT {
+					if doc := decl.Doc; doc != nil && len(decl.Specs) == 1 {
+						spec := decl.Specs[0].(*ast.ImportSpec)
+						if spec.Path.Value == "\"unsafe\"" {
+							pos := pkg.Fset.Position(doc.Pos())
+							preamble, flags, err := parseCgoPreamble(pos, doc.Text())
+							if err != nil {
+								panic(err)
+							}
+							preambles = append(preambles, preamble)
+							cdecls = append(cdecls, flags...)
+						}
+					}
+				}
+			}
+		}
+	}
+	return
+}
+
+func parseCgoPreamble(pos token.Position, text string) (preamble cgoPreamble, decls []cgoDecl, err error) {
+	b := strings.Builder{}
+	fline := pos.Line
+	fname := pos.Filename
+	b.WriteString(fmt.Sprintf("#line %d %q\n", fline, fname))
+
+	for _, line := range strings.Split(text, "\n") {
+		fline++
+		line = strings.TrimSpace(line)
+		if strings.HasPrefix(line, "#cgo ") {
+			var cgoDecls []cgoDecl
+			cgoDecls, err = parseCgoDecl(line)
+			if err != nil {
+				return
+			}
+			decls = append(decls, cgoDecls...)
+			b.WriteString(fmt.Sprintf("#line %d %q\n", fline, fname))
+		} else {
+			b.WriteString(line)
+			b.WriteString("\n")
+		}
+	}
+	preamble = cgoPreamble{
+		goFile: pos.Filename,
+		src:    b.String(),
+	}
+	return
+}
+
+// Parse cgo directive like:
+// #cgo pkg-config: python3
+// #cgo windows CFLAGS: -IC:/Python312/include
+// #cgo windows LDFLAGS: -LC:/Python312/libs -lpython312
+// #cgo CFLAGS: -I/usr/include/python3.12
+// #cgo LDFLAGS: -L/usr/lib/python3.12/config-3.12-x86_64-linux-gnu -lpython3.12
+func parseCgoDecl(line string) (cgoDecls []cgoDecl, err error) {
+	idx := strings.Index(line, ":")
+	if idx == -1 {
+		err = fmt.Errorf("invalid cgo format: %v", line)
+		return
+	}
+
+	decl := strings.TrimSpace(line[:idx])
+	arg := strings.TrimSpace(line[idx+1:])
+
+	// Split on first space to remove #cgo
+	parts := strings.SplitN(decl, " ", 2)
+	if len(parts) < 2 {
+		err = fmt.Errorf("invalid cgo directive: %v", line)
+		return
+	}
+
+	// Process remaining part
+	remaining := strings.TrimSpace(parts[1])
+	var tag, flag string
+
+	// Split on last space to get flag
+	if lastSpace := strings.LastIndex(remaining, " "); lastSpace != -1 {
+		tag = strings.TrimSpace(remaining[:lastSpace])
+		flag = strings.TrimSpace(remaining[lastSpace+1:])
+	} else {
+		flag = remaining
+	}
+
+	switch flag {
+	case "pkg-config":
+		ldflags, e := exec.Command("pkg-config", "--libs", arg).Output()
+		if e != nil {
+			err = fmt.Errorf("pkg-config: %v", e)
+			return
+		}
+		cflags, e := exec.Command("pkg-config", "--cflags", arg).Output()
+		if e != nil {
+			err = fmt.Errorf("pkg-config: %v", e)
+			return
+		}
+		cgoDecls = append(cgoDecls, cgoDecl{
+			tag:     tag,
+			cflags:  strings.TrimSpace(string(cflags)),
+			ldflags: strings.TrimSpace(string(ldflags)),
+		})
+	case "CFLAGS":
+		cgoDecls = append(cgoDecls, cgoDecl{
+			tag:    tag,
+			cflags: arg,
+		})
+	case "LDFLAGS":
+		cgoDecls = append(cgoDecls, cgoDecl{
+			tag:     tag,
+			ldflags: arg,
+		})
+	}
+	return
+}

internal/buildtags/buildtags.go

@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package buildtags
+
+import (
+	"fmt"
+	"go/build"
+	"io"
+	"io/fs"
+	"strings"
+)
+
+// checkTags checks which build tags are valid by creating virtual test files
+// and using build.Context.MatchFile to verify them
+func CheckTags(buildFlags []string, testTags map[string]bool) {
+	buildCtx := build.Default
+	buildCtx.BuildTags = parseBuildTags(buildFlags)
+
+	// Create virtual filesystem
+	vfs := &virtualFS{
+		files: make(map[string]virtualFile),
+	}
+
+	// Generate virtual files for each test tag
+	i := 0
+	fileToTag := make(map[string]string) // Map to track which file corresponds to which tag
+	for tag := range testTags {
+		fileName := fmt.Sprintf("a%02d.go", i)
+		content := fmt.Sprintf("// +build %s\n\npackage check\n", tag)
+		vfs.files[fileName] = virtualFile{
+			name:    fileName,
+			content: content,
+			dir:     ".",
+		}
+		fileToTag[fileName] = tag
+		i++
+	}
+
+	// Override OpenFile to return our virtual file contents
+	buildCtx.OpenFile = func(name string) (io.ReadCloser, error) {
+		if file, ok := vfs.files[name]; ok {
+			return io.NopCloser(strings.NewReader(file.content)), nil
+		}
+		return nil, fs.ErrNotExist
+	}
+
+	// Check each file against build context
+	for fileName, tag := range fileToTag {
+		match, err := buildCtx.MatchFile(".", fileName)
+		if err == nil && match {
+			testTags[tag] = true
+		}
+	}
+}
+
+// virtualFile represents a virtual build tag check file
+type virtualFile struct {
+	name    string
+	content string
+	dir     string
+}
+
+// virtualFS implements a virtual filesystem for build tag checking
+type virtualFS struct {
+	files map[string]virtualFile
+}
+
+func parseBuildTags(buildFlags []string) []string {
+	buildTags := make([]string, 0)
+	// Extract tags from buildFlags
+	for i := 0; i < len(buildFlags); i++ {
+		flag := buildFlags[i]
+		if flag == "-tags" && i+1 < len(buildFlags) {
+			// Handle "-tags xxx" format
+			tags := strings.FieldsFunc(buildFlags[i+1], func(r rune) bool {
+				return r == ',' || r == ' '
+			})
+			buildTags = append(buildTags, tags...)
+			i++ // Skip the next item since we've processed it
+		} else if strings.HasPrefix(flag, "-tags=") {
+			// Handle "-tags=xxx" format
+			value := strings.TrimPrefix(flag, "-tags=")
+			tags := strings.FieldsFunc(value, func(r rune) bool {
+				return r == ',' || r == ' '
+			})
+			buildTags = append(buildTags, tags...)
+		}
+	}
+
+	// Remove duplicates from tags
+	seen := make(map[string]bool)
+	uniqueBuildTags := make([]string, 0, len(buildTags))
+	for _, tag := range buildTags {
+		if !seen[tag] {
+			seen[tag] = true
+			uniqueBuildTags = append(uniqueBuildTags, tag)
+		}
+	}
+	return uniqueBuildTags
+}

internal/buildtags/buildtags_test.go

@@ -0,0 +1,153 @@
+package buildtags
+
+import (
+	"reflect"
+	"runtime"
+	"testing"
+)
+
+func TestCheckTags(t *testing.T) {
+	tests := []struct {
+		name       string
+		buildFlags []string
+		testTags   map[string]bool
+		want       map[string]bool
+	}{
+		{
+			name:       "mywindows tags",
+			buildFlags: []string{"-tags", "mywindows"},
+			testTags: map[string]bool{
+				"mywindows":         false,
+				"!mywindows":        false,
+				"mywindows,myamd64": false,
+			},
+			want: map[string]bool{
+				"mywindows":         true,
+				"!mywindows":        false,
+				"mywindows,myamd64": runtime.GOARCH == "myamd64",
+			},
+		},
+		{
+			name:       "non-mywindows tags",
+			buildFlags: []string{"-tags", "mylinux"},
+			testTags: map[string]bool{
+				"mywindows":          false,
+				"!mywindows":         false,
+				"mylinux,myamd64":    false,
+				"!mywindows,myamd64": false,
+			},
+			want: map[string]bool{
+				"mywindows":          false,
+				"!mywindows":         true,
+				"mylinux,myamd64":    runtime.GOARCH == "myamd64",
+				"!mywindows,myamd64": runtime.GOARCH == "myamd64",
+			},
+		},
+		{
+			name:       "multiple tags",
+			buildFlags: []string{"-tags", "mywindows,myamd64"},
+			testTags: map[string]bool{
+				"mywindows":         false,
+				"myamd64":           false,
+				"mywindows,myamd64": false,
+				"mylinux,myamd64":   false,
+			},
+			want: map[string]bool{
+				"mywindows":         true,
+				"myamd64":           true,
+				"mywindows,myamd64": true,
+				"mylinux,myamd64":   false,
+			},
+		},
+		{
+			name:       "tags with equals format",
+			buildFlags: []string{"-tags=mywindows,myamd64"},
+			testTags: map[string]bool{
+				"mywindows":         false,
+				"myamd64":           false,
+				"mywindows,myamd64": false,
+			},
+			want: map[string]bool{
+				"mywindows":         true,
+				"myamd64":           true,
+				"mywindows,myamd64": true,
+			},
+		},
+		{
+			name:       "complex tag combinations",
+			buildFlags: []string{"-tags", "mylinux,myamd64"},
+			testTags: map[string]bool{
+				"mywindows":          false,
+				"!mywindows":         false,
+				"mylinux":            false,
+				"mylinux,myamd64":    false,
+				"!mywindows,myamd64": false,
+			},
+			want: map[string]bool{
+				"mywindows":          false,
+				"!mywindows":         true,
+				"mylinux":            true,
+				"mylinux,myamd64":    true,
+				"!mywindows,myamd64": true,
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			testTags := make(map[string]bool)
+			for k := range tt.testTags {
+				testTags[k] = false
+			}
+
+			CheckTags(tt.buildFlags, testTags)
+
+			if !reflect.DeepEqual(testTags, tt.want) {
+				t.Errorf("CheckTags() = %v, want %v", testTags, tt.want)
+			}
+		})
+	}
+}
+
+func TestParseBuildTags(t *testing.T) {
+	tests := []struct {
+		name       string
+		buildFlags []string
+		want       []string
+	}{
+		{
+			name:       "space separated tags",
+			buildFlags: []string{"-tags", "mywindows myamd64"},
+			want:       []string{"mywindows", "myamd64"},
+		},
+		{
+			name:       "equals format",
+			buildFlags: []string{"-tags=mywindows,myamd64"},
+			want:       []string{"mywindows", "myamd64"},
+		},
+		{
+			name:       "multiple -tags flags",
+			buildFlags: []string{"-tags", "mywindows", "-tags", "myamd64"},
+			want:       []string{"mywindows", "myamd64"},
+		},
+		{
+			name:       "duplicate tags",
+			buildFlags: []string{"-tags", "mywindows myamd64", "-tags=mywindows"},
+			want:       []string{"mywindows", "myamd64"},
+		},
+		{
+			name:       "empty tags",
+			buildFlags: []string{},
+			want:       []string{},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := parseBuildTags(tt.buildFlags)
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("name: %v, parseBuildTags() = %v, want %v", tt.name, got, tt.want)
+			}
+		})
+	}
+}

internal/runtime/z_cgo.go

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package runtime
+
+import (
+	"unsafe"
+
+	"github.com/goplus/llgo/c"
+)
+
+func CString(s string) *int8 {
+	p := c.Malloc(uintptr(len(s)) + 1)
+	return CStrCopy(p, *(*String)(unsafe.Pointer(&s)))
+}
+
+func CBytes(b []byte) *int8 {
+	p := c.Malloc(uintptr(len(b)))
+	c.Memcpy(p, unsafe.Pointer(&b[0]), uintptr(len(b)))
+	return (*int8)(p)
+}
+
+func GoString(p *int8) string {
+	return GoStringN(p, int(c.Strlen(p)))
+}
+
+func GoStringN(p *int8, n int) string {
+	return string((*[1 << 30]byte)(unsafe.Pointer(p))[:n:n])
+}
+
+func GoBytes(p *int8, n int) []byte {
+	return (*[1 << 30]byte)(unsafe.Pointer(p))[:n:n]
+}

ssa/expr.go

@@ -254,6 +254,41 @@ func (b Builder) CStr(v string) Expr {
 	return Expr{llvm.CreateGlobalStringPtr(b.impl, v), b.Prog.CStr()}
 }
 
+// CString returns a c-style string
+func (b Builder) CString(v Expr) Expr {
+	fn := b.Pkg.rtFunc("CString")
+	return b.Call(fn, v)
+}
+
+// CBytes returns a c-style bytes
+func (b Builder) CBytes(v Expr) Expr {
+	fn := b.Pkg.rtFunc("CBytes")
+	return b.Call(fn, v)
+}
+
+// GoString returns a Go string
+func (b Builder) GoString(v Expr) Expr {
+	fn := b.Pkg.rtFunc("GoString")
+	return b.Call(fn, v)
+}
+
+// GoStringN returns a Go string
+func (b Builder) GoStringN(v Expr, n Expr) Expr {
+	fn := b.Pkg.rtFunc("GoStringN")
+	return b.Call(fn, v, n)
+}
+
+// GoBytes returns a Go bytes
+func (b Builder) GoBytes(v Expr, n Expr) (ret Expr) {
+	fn := b.Pkg.rtFunc("GoBytes")
+	return b.Call(fn, v, n)
+}
+
+// CMalloc returns a c-style pointer
+func (b Builder) CMalloc(n Expr) Expr {
+	return b.malloc(n)
+}
+
 // Str returns a Go string constant expression.
 func (b Builder) Str(v string) Expr {
 	prog := b.Prog
@@ -982,7 +1017,7 @@ func (b Builder) Call(fn Expr, args ...Expr) (ret Expr) {
 		bi := raw.(*builtinTy)
 		return b.BuiltinCall(bi.name, args...)
 	default:
-		log.Panicf("unreachable: %d(%T)\n", kind, raw)
+		log.Panicf("unreachable: %d(%T), %v\n", kind, raw, fn.RawType())
 	}
 	ret.Type = b.Prog.retType(sig)
 	ret.impl = llvm.CreateCall(b.impl, ll, fn.impl, llvmParamsEx(data, args, sig.Params(), b))