llcppsymg:translation unit util

chore/_xtool/llcppsymg/clangutils/clangutils.go

@@ -0,0 +1,72 @@
+package clangutils
+
+import (
+	"errors"
+	"unsafe"
+
+	"github.com/goplus/llgo/c"
+	"github.com/goplus/llgo/c/clang"
+)
+
+type Config struct {
+	File  string
+	Temp  bool
+	Args  []string
+	IsCpp bool
+	Index *clang.Index
+}
+
+func CreateTranslationUnit(config *Config) (*clang.Index, *clang.TranslationUnit, error) {
+	// default use the c/c++ standard of clang; c:gnu17 c++:gnu++17
+	// https://clang.llvm.org/docs/CommandGuide/clang.html
+	defaultArgs := []string{"-x", "c"}
+	if config.IsCpp {
+		defaultArgs = []string{"-x", "c++"}
+	}
+	allArgs := append(defaultArgs, config.Args...)
+
+	cArgs := make([]*c.Char, len(allArgs))
+	for i, arg := range allArgs {
+		cArgs[i] = c.AllocaCStr(arg)
+	}
+
+	var index *clang.Index
+	if config.Index != nil {
+		index = config.Index
+	} else {
+		index = clang.CreateIndex(0, 0)
+	}
+
+	var unit *clang.TranslationUnit
+
+	if config.Temp {
+		content := c.AllocaCStr(config.File)
+		tempFile := &clang.UnsavedFile{
+			Filename: c.Str("temp.h"),
+			Contents: content,
+			Length:   c.Ulong(c.Strlen(content)),
+		}
+
+		unit = index.ParseTranslationUnit(
+			tempFile.Filename,
+			unsafe.SliceData(cArgs), c.Int(len(cArgs)),
+			tempFile, 1,
+			clang.DetailedPreprocessingRecord,
+		)
+
+	} else {
+		cFile := c.AllocaCStr(config.File)
+		unit = index.ParseTranslationUnit(
+			cFile,
+			unsafe.SliceData(cArgs), c.Int(len(cArgs)),
+			nil, 0,
+			clang.DetailedPreprocessingRecord,
+		)
+	}
+
+	if unit == nil {
+		return nil, nil, errors.New("failed to parse translation unit")
+	}
+
+	return index, unit, nil
+}