Write a C package in Go

.github/codecov.yml

@@ -2,6 +2,7 @@ coverage:
   ignore:
     - "chore"
     - "cmd"
+    - "cl/cltest"
     - "internal/build"
     - "internal/llgen"
     - "internal/mockable"

.gitignore

@@ -15,6 +15,7 @@ stories*.bin
 .DS_Store
 err.log
 numpy.txt
+result.txt
 
 _go/
 _runtime/

cl/_testdata/cpkg/in.go

@@ -0,0 +1,13 @@
+package C
+
+func Xadd(a, b int) int {
+	return add(a, b)
+}
+
+func Double(x float64) float64 {
+	return 2 * x
+}
+
+func add(a, b int) int {
+	return a + b
+}

cl/_testdata/cpkg/out.ll

@@ -0,0 +1,35 @@
+; ModuleID = 'github.com/goplus/llgo/cl/_testdata/cpkg'
+source_filename = "github.com/goplus/llgo/cl/_testdata/cpkg"
+
+@"github.com/goplus/llgo/cl/_testdata/cpkg.init$guard" = global i1 false, align 1
+
+define double @Double(double %0) {
+_llgo_0:
+  %1 = fmul double 2.000000e+00, %0
+  ret double %1
+}
+
+define i64 @add(i64 %0, i64 %1) {
+_llgo_0:
+  %2 = call i64 @"github.com/goplus/llgo/cl/_testdata/cpkg.add"(i64 %0, i64 %1)
+  ret i64 %2
+}
+
+define i64 @"github.com/goplus/llgo/cl/_testdata/cpkg.add"(i64 %0, i64 %1) {
+_llgo_0:
+  %2 = add i64 %0, %1
+  ret i64 %2
+}
+
+define void @"github.com/goplus/llgo/cl/_testdata/cpkg.init"() {
+_llgo_0:
+  %0 = load i1, ptr @"github.com/goplus/llgo/cl/_testdata/cpkg.init$guard", align 1
+  br i1 %0, label %_llgo_2, label %_llgo_1
+
+_llgo_1:                                          ; preds = %_llgo_0
+  store i1 true, ptr @"github.com/goplus/llgo/cl/_testdata/cpkg.init$guard", align 1
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
+  ret void
+}

cl/cltest/cltest.go

@@ -18,6 +18,7 @@ package cltest
 
 import (
 	"archive/zip"
+	"bytes"
 	"go/ast"
 	"go/parser"
 	"go/token"
@@ -35,6 +36,7 @@ import (
 	"github.com/goplus/llgo/cl"
 	"github.com/goplus/llgo/internal/llgen"
 	"github.com/goplus/llgo/ssa/ssatest"
+	"github.com/qiniu/x/test"
 	"golang.org/x/tools/go/ssa"
 	"golang.org/x/tools/go/ssa/ssautil"
 
@@ -112,14 +114,13 @@ func testFrom(t *testing.T, pkgDir, sel string) {
 		return
 	}
 	log.Println("Parsing", pkgDir)
+	v := llgen.GenFrom(pkgDir)
 	out := pkgDir + "/out.ll"
-	b, err := os.ReadFile(out)
-	if err != nil {
-		t.Fatal("ReadFile failed:", err)
-	}
-	expected := string(b)
-	if v := llgen.GenFrom(pkgDir); v != expected && expected != ";" { // expected == ";" means skipping out.ll
-		t.Fatalf("\n==> got:\n%s\n==> expected:\n%s\n", v, expected)
+	b, _ := os.ReadFile(out)
+	if !bytes.Equal(b, []byte{';'}) { // expected == ";" means skipping out.ll
+		if test.Diff(t, pkgDir+"/result.txt", []byte(v), b) {
+			t.Fatal("llgen.GenFrom: unexpect result")
+		}
 	}
 }
 

cl/compile.go

@@ -213,15 +213,8 @@ func isCgoVar(name string) bool {
 }
 
 func (p *context) compileFuncDecl(pkg llssa.Package, f *ssa.Function) (llssa.Function, llssa.PyObjRef, int) {
-	pkgTypes, name, ftype := p.funcName(f, true)
+	pkgTypes, name, ftype := p.funcName(f)
 	if ftype != goFunc {
-		/*
-			if ftype == pyFunc {
-				// TODO(xsw): pyMod == ""
-				fnName := pysymPrefix + p.pyMod + "." + name
-				return nil, pkg.NewPyFunc(fnName, f.Signature, call), pyFunc
-			}
-		*/
 		return nil, nil, ignoredFunc
 	}
 	sig := f.Signature
@@ -1012,7 +1005,7 @@ func NewPackageEx(prog llssa.Program, patches Patches, pkg *ssa.Package, files [
 		cgoSymbols: make([]string, 0, 128),
 	}
 	ctx.initPyModule()
-	ctx.initFiles(pkgPath, files)
+	ctx.initFiles(pkgPath, files, pkgName == "C")
 	ctx.prog.SetPatch(ctx.patchType)
 	ret.SetPatch(ctx.patchType)
 	ret.SetResolveLinkname(ctx.resolveLinkname)

cl/import.go

@@ -174,13 +174,18 @@ start:
 	syms.initLinknames(p)
 }
 
-func (p *context) initFiles(pkgPath string, files []*ast.File) {
+func (p *context) initFiles(pkgPath string, files []*ast.File, cPkg bool) {
 	for _, file := range files {
 		for _, decl := range file.Decls {
 			switch decl := decl.(type) {
 			case *ast.FuncDecl:
 				fullName, inPkgName := astFuncName(pkgPath, decl)
-				p.initLinknameByDoc(decl.Doc, fullName, inPkgName, false)
+				if !p.initLinknameByDoc(decl.Doc, fullName, inPkgName, false) && cPkg {
+					// package C (https://github.com/goplus/llgo/issues/1165)
+					if decl.Recv == nil && token.IsExported(inPkgName) {
+						p.prog.SetLinkname(fullName, strings.TrimPrefix(inPkgName, "X"))
+					}
+				}
 			case *ast.GenDecl:
 				switch decl.Tok {
 				case token.VAR:
@@ -266,51 +271,58 @@ func (p *context) collectSkip(line string, prefix int) {
 	}
 }
 
-func (p *context) initLinknameByDoc(doc *ast.CommentGroup, fullName, inPkgName string, isVar bool) {
+func (p *context) initLinknameByDoc(doc *ast.CommentGroup, fullName, inPkgName string, isVar bool) bool {
 	if doc != nil {
 		for n := len(doc.List) - 1; n >= 0; n-- {
 			line := doc.List[n].Text
-			found := p.initLinkname(line, func(name string) (_ string, _, ok bool) {
+			ret := p.initLinkname(line, func(name string) (_ string, _, ok bool) {
 				return fullName, isVar, name == inPkgName
 			})
-			if !found {
-				break
+			if ret != unknownDirective {
+				return ret == hasLinkname
 			}
 		}
 	}
+	return false
 }
 
-func (p *context) initLinkname(line string, f func(inPkgName string) (fullName string, isVar, ok bool)) bool {
+const (
+	noDirective = iota
+	hasLinkname
+	unknownDirective = -1
+)
+
+func (p *context) initLinkname(line string, f func(inPkgName string) (fullName string, isVar, ok bool)) int {
 	const (
-		linkname   = "//go:linkname "
-		llgolink   = "//llgo:link "
-		llgolink2  = "// llgo:link "
-		exportName = "//export "
-		directive  = "//go:"
+		linkname  = "//go:linkname "
+		llgolink  = "//llgo:link "
+		llgolink2 = "// llgo:link "
+		export    = "//export "
+		directive = "//go:"
 	)
 	if strings.HasPrefix(line, linkname) {
 		p.initLink(line, len(linkname), f)
-		return true
+		return hasLinkname
 	} else if strings.HasPrefix(line, llgolink2) {
 		p.initLink(line, len(llgolink2), f)
-		return true
+		return hasLinkname
 	} else if strings.HasPrefix(line, llgolink) {
 		p.initLink(line, len(llgolink), f)
-		return true
-	} else if strings.HasPrefix(line, exportName) {
-		p.initCgoExport(line, len(exportName), f)
-		return true
+		return hasLinkname
+	} else if strings.HasPrefix(line, export) {
+		p.initCgoExport(line, len(export), f)
+		return hasLinkname
 	} else if strings.HasPrefix(line, directive) {
 		// skip unknown annotation but continue to parse the next annotation
-		return true
+		return unknownDirective
 	}
-	return false
+	return noDirective
 }
 
 func (p *context) initCgoExport(line string, prefix int, f func(inPkgName string) (fullName string, isVar, ok bool)) {
 	name := strings.TrimSpace(line[prefix:])
 	if fullName, _, ok := f(name); ok {
-		p.cgoExports[fullName] = name
+		p.cgoExports[fullName] = name // TODO(xsw): why not use prog.SetLinkname?
 	}
 }
 
@@ -497,7 +509,7 @@ const (
 	llgoAtomicOpLast = llgoAtomicOpBase + int(llssa.OpUMin)
 )
 
-func (p *context) funcName(fn *ssa.Function, ignore bool) (*types.Package, string, int) {
+func (p *context) funcName(fn *ssa.Function) (*types.Package, string, int) {
 	var pkg *types.Package
 	var orgName string
 	if origin := fn.Origin(); origin != nil {

cl/instr.go

@@ -334,7 +334,7 @@ var llgoInstrs = map[string]int{
 // funcOf returns a function by name and set ftype = goFunc, cFunc, etc.
 // or returns nil and set ftype = llgoCstr, llgoAlloca, llgoUnreachable, etc.
 func (p *context) funcOf(fn *ssa.Function) (aFn llssa.Function, pyFn llssa.PyObjRef, ftype int) {
-	pkgTypes, name, ftype := p.funcName(fn, false)
+	pkgTypes, name, ftype := p.funcName(fn)
 	switch ftype {
 	case pyFunc:
 		if kind, mod := pkgKindByScope(pkgTypes.Scope()); kind == PkgPyModule {

internal/build/build.go

@@ -184,7 +184,7 @@ func Do(args []string, conf *Config) ([]Package, error) {
 	prog := llssa.NewProgram(target)
 	sizes := func(sizes types.Sizes, compiler, arch string) types.Sizes {
 		if arch == "wasm" {
-			sizes = &types.StdSizes{4, 4}
+			sizes = &types.StdSizes{WordSize: 4, MaxAlign: 4}
 		}
 		return prog.TypeSizes(sizes)
 	}
@@ -803,15 +803,15 @@ func buildPkg(ctx *context, aPkg *aPackage, verbose bool) error {
 			fmt.Fprintf(os.Stderr, "==> Export %s: %s\n", aPkg.PkgPath, pkg.ExportFile)
 		}
 		if IsCheckEnable() {
-			if err, msg := llcCheck(ctx.env, pkg.ExportFile); err != nil {
+			if msg, err := llcCheck(ctx.env, pkg.ExportFile); err != nil {
 				fmt.Fprintf(os.Stderr, "==> lcc %v: %v\n%v\n", pkg.PkgPath, pkg.ExportFile, msg)
 			}
 		}
 	}
 	return nil
 }
 
-func llcCheck(env *llvm.Env, exportFile string) (err error, msg string) {
+func llcCheck(env *llvm.Env, exportFile string) (msg string, err error) {
 	bin := filepath.Join(env.BinDir(), "llc")
 	cmd := exec.Command(bin, "-filetype=null", exportFile)
 	var buf bytes.Buffer
@@ -904,6 +904,7 @@ func createSSAPkg(prog *ssa.Program, p *packages.Package, verbose bool) *ssa.Pac
 	return pkgSSA
 }
 
+/*
 var (
 	// TODO(xsw): complete build flags
 	buildFlags = map[string]bool{
@@ -922,6 +923,7 @@ var (
 		"-ldflags":   true,  // --ldflags 'flag list': arguments to pass on each go tool link invocation
 	}
 )
+*/
 
 const llgoDebug = "LLGO_DEBUG"
 const llgoDbgSyms = "LLGO_DEBUG_SYMBOLS"

internal/build/clean.go

@@ -26,12 +26,14 @@ import (
 	"github.com/goplus/llgo/internal/packages"
 )
 
+/*
 var (
 	// TODO(xsw): complete clean flags
 	cleanFlags = map[string]bool{
 		"-v": false, // -v: print the paths of packages as they are clean
 	}
 )
+*/
 
 func Clean(patterns []string, conf *Config) {
 	if conf.Goos == "" {