cl: _testdata/importpkg

cl/import.go

@@ -0,0 +1,140 @@
+/*
+ * 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 cl
+
+import (
+	"bytes"
+	"go/ast"
+	"go/token"
+	"go/types"
+	"os"
+	"strings"
+
+	llssa "github.com/goplus/llgo/ssa"
+	"golang.org/x/tools/go/ssa"
+)
+
+type contentLines = [][]byte
+type contentMap = map[string]contentLines
+
+func contentOf(m contentMap, file string) (lines contentLines, err error) {
+	if v, ok := m[file]; ok {
+		return v, nil
+	}
+	b, err := os.ReadFile(file)
+	if err == nil {
+		lines = bytes.Split(b, []byte{'\n'})
+		m[file] = lines
+	}
+	return
+}
+
+func (p *context) importPkg(pkg *types.Package) {
+	scope := pkg.Scope()
+	if scope.Lookup("LLGoPackage") == nil {
+		return
+	}
+	fset := p.fset
+	names := scope.Names()
+	contents := make(contentMap)
+	pkgPath := pkg.Path()
+	for _, name := range names {
+		if token.IsExported(name) {
+			obj := scope.Lookup(name)
+			if obj, ok := obj.(*types.Func); ok {
+				if pos := obj.Pos(); pos != token.NoPos {
+					f := fset.File(pos)
+					if fp := f.PositionFor(pos, false); fp.Line > 2 {
+						lines, err := contentOf(contents, fp.Filename)
+						if err != nil {
+							panic(err)
+						}
+						if i := fp.Line - 2; i < len(lines) {
+							line := string(lines[i])
+							p.initLinkname(pkgPath, line)
+						}
+					}
+				}
+			}
+		}
+	}
+}
+
+func (p *context) initFiles(pkgPath string, files []*ast.File) {
+	for _, file := range files {
+		for _, decl := range file.Decls {
+			if decl, ok := decl.(*ast.FuncDecl); ok {
+				if decl.Recv == nil {
+					if doc := decl.Doc; doc != nil {
+						if n := len(doc.List); n > 0 {
+							line := doc.List[n-1].Text
+							p.initLinkname(pkgPath, line)
+						}
+					}
+				}
+			}
+		}
+	}
+}
+
+func (p *context) initLinkname(pkgPath, line string) {
+	const (
+		linkname = "//go:linkname "
+	)
+	if strings.HasPrefix(line, linkname) {
+		text := strings.TrimSpace(line[len(linkname):])
+		if idx := strings.IndexByte(text, ' '); idx > 0 {
+			name := pkgPath + "." + text[:idx]
+			link := strings.TrimLeft(text[idx+1:], " ")
+			p.link[name] = link
+		}
+	}
+}
+
+func fullName(pkg *types.Package, name string) string {
+	return pkg.Path() + "." + name
+}
+
+func funcName(pkg *types.Package, fn *ssa.Function) string {
+	ret := fullName(pkg, fn.Name())
+	if ret == "main.main" {
+		ret = "main"
+	}
+	return ret
+}
+
+func (p *context) funcName(pkg *types.Package, fn *ssa.Function) string {
+	name := funcName(pkg, fn)
+	if v, ok := p.link[name]; ok {
+		return v
+	}
+	return name
+}
+
+func (p *context) funcOf(fn *ssa.Function) llssa.Function {
+	pkgTypes := fn.Pkg.Pkg
+	if _, ok := p.loaded[pkgTypes]; !ok {
+		p.loaded[pkgTypes] = none{}
+		p.importPkg(pkgTypes)
+	}
+	pkg := p.pkg
+	name := p.funcName(pkgTypes, fn)
+	if ret := pkg.FuncOf(name); ret != nil {
+		return ret
+	}
+	return pkg.NewFunc(name, fn.Signature)
+}