feat: cpp init (cloudwego#172)

* feat: cpp init

* feat: cpp testdata

* feat: cxx cpp -> ci

Author: zyl1314

.github/workflows/regression.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     #if: "!contains(github.event.pull_request.title, '[NO-REGRESSION-TEST]')"
     env:
-      LANGS: "go rust python typescript"
+      LANGS: "go rust python typescript cxx cpp"
       # ignore package version for Go e.g. 'a.b/c@506fb8ece467f3a71c29322169bef9b0bc92d554'
       DIFFJSON_IGNORE: >
         ['id']

go.sum

@@ -27,6 +27,7 @@ import (
 
 	sitter "github.com/smacker/go-tree-sitter"
 
+	"github.com/cloudwego/abcoder/lang/cpp"
 	"github.com/cloudwego/abcoder/lang/cxx"
 	"github.com/cloudwego/abcoder/lang/java"
 	javaipc "github.com/cloudwego/abcoder/lang/java/ipc"
@@ -113,6 +114,8 @@ func switchSpec(l uniast.Language, repo string) LanguageSpec {
 		return python.NewPythonSpec()
 	case uniast.Java:
 		return java.NewJavaSpec(repo)
+	case uniast.Cpp:
+		return cpp.NewCppSpec()
 	default:
 		panic(fmt.Sprintf("unsupported language %s", l))
 	}
@@ -1698,9 +1701,11 @@ func (c *Collector) getSymbolByLocation(ctx context.Context, loc Location, depth
 	// 	return sym, nil
 	// }
 
-	// 1. already loaded
-	if sym := c.findMatchingSymbolIn(loc, slices.Collect(maps.Values(c.syms))); sym != nil {
-		return sym, nil
+	if !(from.Type == "typeParameter" && c.Language == uniast.Cpp) {
+		// 1. already loaded
+		if sym := c.findMatchingSymbolIn(loc, slices.Collect(maps.Values(c.syms))); sym != nil {
+			return sym, nil
+		}
 	}
 
 	if c.LoadExternalSymbol && !c.internal(loc) && (c.NeedStdSymbol || !c.spec.IsStdToken(from)) {
@@ -1929,11 +1934,11 @@ func (c *Collector) processSymbol(ctx context.Context, sym *DocumentSymbol, dept
 
 	// function info: type params, inputs, outputs, receiver (if !needImpl)
 	if sym.Kind == SKFunction || sym.Kind == SKMethod {
-		var rsym *dependency
+		var rd *dependency
 		rec, tps, ips, ops := c.spec.FunctionSymbol(*sym)
-
-		if !hasImpl && rec >= 0 {
+		if (!hasImpl || c.Language == uniast.Cpp) && rec >= 0 {
 			rsym, err := c.getSymbolByTokenWithLimit(ctx, sym.Tokens[rec], depth)
+			rd = &dependency{sym.Tokens[rec].Location, rsym}
 			if err != nil || rsym == nil {
 				log.Error("get receiver symbol for token %v failed: %v\n", rec, err)
 			}
@@ -1942,6 +1947,18 @@ func (c *Collector) processSymbol(ctx context.Context, sym *DocumentSymbol, dept
 		ipsyms, is := c.getDepsWithLimit(ctx, sym, ips, depth-1)
 		opsyms, os := c.getDepsWithLimit(ctx, sym, ops, depth-1)
 
+		// filter tsym is type parameter
+		if c.Language == uniast.Cpp {
+			tsFiltered := make([]dependency, 0, len(ts))
+			for _, d := range ts {
+				if d.Symbol == nil || d.Symbol.Kind == SKTypeParameter {
+					continue
+				}
+				tsFiltered = append(tsFiltered, d)
+			}
+			ts = tsFiltered
+		}
+
 		//get last token of params for get signature
 		lastToken := rec
 		for _, t := range tps {
@@ -1960,18 +1977,28 @@ func (c *Collector) processSymbol(ctx context.Context, sym *DocumentSymbol, dept
 			}
 		}
 
-		c.updateFunctionInfo(sym, tsyms, ipsyms, opsyms, ts, is, os, rsym, lastToken)
+		c.updateFunctionInfo(sym, tsyms, ipsyms, opsyms, ts, is, os, rd, lastToken)
 	}
 
 	// variable info: type
 	if sym.Kind == SKVariable || sym.Kind == SKConstant {
 		i := c.spec.DeclareTokenOfSymbol(*sym)
+		// in cpp, it should search form behind to front to find the first entity token
 		// find first entity token
-		for i = i + 1; i < len(sym.Tokens); i++ {
-			if c.spec.IsEntityToken(sym.Tokens[i]) {
-				break
+		if c.Language == uniast.Cpp {
+			for i = i - 1; i >= 0; i-- {
+				if c.spec.IsEntityToken(sym.Tokens[i]) {
+					break
+				}
+			}
+		} else {
+			for i = i + 1; i < len(sym.Tokens); i++ {
+				if c.spec.IsEntityToken(sym.Tokens[i]) {
+					break
+				}
 			}
 		}
+
 		if i < 0 || i >= len(sym.Tokens) {
 			log.Error("get type token of variable symbol %s failed\n", sym)
 			return

lang/collect/collect.go

@@ -23,6 +23,7 @@ import (
 	"strings"
 
 	"github.com/cloudwego/abcoder/lang/log"
+	"github.com/cloudwego/abcoder/lang/lsp"
 	. "github.com/cloudwego/abcoder/lang/lsp"
 	"github.com/cloudwego/abcoder/lang/uniast"
 	"github.com/cloudwego/abcoder/lang/utils"
@@ -252,6 +253,21 @@ func (c *Collector) exportSymbol(repo *uniast.Repository, symbol *DocumentSymbol
 		// NOTICE: use refName as id when symbol name is missing
 		name = refName
 	}
+
+	if c.Language == uniast.Cpp {
+		// for function override, use call signature as id
+		if symbol.Kind == SKMethod || symbol.Kind == SKFunction {
+			name = c.extractCppCallSig(symbol)
+		}
+
+		// join name with namespace
+		if ns := c.scopePrefix(symbol); ns != "" {
+			if !strings.HasPrefix(name, ns+"::") {
+				name = ns + "::" + name
+			}
+		}
+	}
+
 	tmp := uniast.NewIdentity(mod, path, name)
 	id = &tmp
 	// Save to visited ONLY WHEN no errors occur
@@ -381,6 +397,18 @@ func (c *Collector) exportSymbol(repo *uniast.Repository, symbol *DocumentSymbol
 						id.Name = iid.Name + "<" + id.Name + ">"
 					}
 				}
+
+				// cpp get method name without class name
+				if c.Language == uniast.Cpp && rid != nil {
+					rec := strings.TrimSpace(rid.Name)
+					if rec != "" {
+						searchStr := rec + "::"
+						if idx := strings.Index(name, searchStr); idx >= 0 {
+							name = name[idx+len(searchStr):]
+						}
+					}
+				}
+
 				if k == SKFunction {
 					// NOTICE: class static method name is: type::method
 					id.Name += "::" + name
@@ -523,3 +551,130 @@ func mapKind(kind SymbolKind) uniast.TypeKind {
 		panic(fmt.Sprintf("unexpected kind %v", kind))
 	}
 }
+
+func (c *Collector) scopePrefix(sym *DocumentSymbol) string {
+	parts := []string{}
+	cur := sym
+	for {
+		p := c.cli.GetParent(cur)
+		if p == nil {
+			break
+		}
+		if p.Kind == lsp.SKNamespace {
+			if p.Name != "" {
+				parts = append([]string{p.Name}, parts...)
+			}
+		}
+		cur = p
+	}
+	return strings.Join(parts, "::") // "a::b"
+}
+
+func (c *Collector) cppBaseName(n string) string {
+	n = strings.TrimSpace(n)
+	if i := strings.LastIndex(n, "::"); i >= 0 {
+		n = n[i+2:]
+	}
+	n = strings.TrimSpace(n)
+	// optional: strip template args on the function name itself: foo<T> -> foo
+	if j := strings.IndexByte(n, '<'); j >= 0 {
+		n = n[:j]
+	}
+	return strings.TrimSpace(n)
+}
+
+// extractCppCallSig returns "sym.Name(params)" where params is extracted from sym.Text.
+func (c *Collector) extractCppCallSig(sym *lsp.DocumentSymbol) (ret string) {
+	name := strings.TrimSpace(sym.Name)
+	if name == "" {
+		return ""
+	}
+	text := sym.Text
+	if text == "" {
+		return name + "()"
+	}
+
+	want := c.cppBaseName(name)
+	if want == "" {
+		want = name
+	}
+	fallback := name + "()"
+
+	isIdent := func(b byte) bool {
+		return (b >= 'a' && b <= 'z') ||
+			(b >= 'A' && b <= 'Z') ||
+			(b >= '0' && b <= '9') ||
+			b == '_'
+	}
+	isWholeIdentAt := func(s string, pos int, w string) bool {
+		if pos < 0 || pos+len(w) > len(s) || s[pos:pos+len(w)] != w {
+			return false
+		}
+		if pos > 0 && isIdent(s[pos-1]) {
+			return false
+		}
+		if pos+len(w) < len(s) && isIdent(s[pos+len(w)]) {
+			return false
+		}
+		return true
+	}
+	findMatchingParenIn := func(s string, openIdx int, end int) int {
+		if openIdx < 0 || openIdx >= len(s) || s[openIdx] != '(' {
+			return -1
+		}
+		if end > len(s) {
+			end = len(s)
+		}
+		depth := 0
+		for i := openIdx; i < end; i++ {
+			switch s[i] {
+			case '(':
+				depth++
+			case ')':
+				depth--
+				if depth == 0 {
+					return i
+				}
+			}
+		}
+		return -1
+	}
+
+	headerEnd := len(text)
+	if i := strings.IndexByte(text, '{'); i >= 0 && i < headerEnd {
+		headerEnd = i
+	}
+	if i := strings.IndexByte(text, ';'); i >= 0 && i < headerEnd {
+		headerEnd = i
+	}
+	header := text[:headerEnd]
+
+	namePos := -1
+	for i := 0; i+len(want) <= len(header); i++ {
+		if isWholeIdentAt(header, i, want) {
+			namePos = i
+			break
+		}
+	}
+	if namePos < 0 {
+		return fallback
+	}
+
+	openIdx := -1
+	for i := namePos + len(want); i < len(header); i++ {
+		if header[i] == '(' {
+			openIdx = i
+			break
+		}
+	}
+	if openIdx < 0 {
+		return fallback
+	}
+
+	closeIdx := findMatchingParenIn(header, openIdx, len(header))
+	if closeIdx < 0 {
+		return fallback
+	}
+
+	return name + header[openIdx:closeIdx+1]
+}

lang/collect/export.go

@@ -0,0 +1,46 @@
+// Copyright 2025 CloudWeGo Authors
+//
+// 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
+//
+//     https://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 cpp
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/cloudwego/abcoder/lang/uniast"
+	"github.com/cloudwego/abcoder/lang/utils"
+)
+
+const MaxWaitDuration = 5 * time.Minute
+
+func InstallLanguageServer() (string, error) {
+	return "", fmt.Errorf("please install clangd-18 manually. See https://releases.llvm.org/ (clangd is in clang-extra)")
+}
+
+func GetDefaultLSP() (lang uniast.Language, name string) {
+	return uniast.Cpp, "clangd-18 --background-index=false -j=2 --clang-tidy=false"
+}
+
+func CheckRepo(repo string) (string, time.Duration) {
+	openfile := ""
+	// TODO: check if the project compiles.
+
+	// NOTICE: wait for Rust projects based on code files
+	_, size := utils.CountFiles(repo, ".cpp", "build/")
+	wait := 2*time.Second + time.Second*time.Duration(size/1024)
+	if wait > MaxWaitDuration {
+		wait = MaxWaitDuration
+	}
+	return openfile, wait
+}