[clangd] Show lambda signature for lambda autocompletions
The original bug report can be found
[here](https://github.com/clangd/clangd/issues/85)
Given the following code:
```c++
void function() {
auto Lambda = [](int a, double &b) {return 1.f;};
La^
}
```
Triggering the completion at `^` would show `(lambda)` before this patch
and would show signature `(int a, double &b) const`, build a snippet etc
with this patch.
Reviewers: sammccall
Reviewed by: sammccall
Differential revision: https://reviews.llvm.org/D70445
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index 81eed43..e75aca4 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -3315,6 +3315,18 @@
return Result.TakeString();
}
+// FIXME: Right now this works well with lambdas. Add support for other functor
+// types like std::function.
+static const NamedDecl *extractFunctorCallOperator(const NamedDecl *ND) {
+ const auto *VD = dyn_cast<VarDecl>(ND);
+ if (!VD)
+ return nullptr;
+ const auto *RecordDecl = VD->getType()->getAsCXXRecordDecl();
+ if (!RecordDecl || !RecordDecl->isLambda())
+ return nullptr;
+ return RecordDecl->getLambdaCallOperator();
+}
+
CodeCompletionString *CodeCompletionResult::createCodeCompletionStringForDecl(
Preprocessor &PP, ASTContext &Ctx, CodeCompletionBuilder &Result,
bool IncludeBriefComments, const CodeCompletionContext &CCContext,
@@ -3339,9 +3351,8 @@
for (const auto *I : ND->specific_attrs<AnnotateAttr>())
Result.AddAnnotation(Result.getAllocator().CopyString(I->getAnnotation()));
- AddResultTypeChunk(Ctx, Policy, ND, CCContext.getBaseType(), Result);
-
- if (const auto *Function = dyn_cast<FunctionDecl>(ND)) {
+ auto AddFunctionTypeAndResult = [&](const FunctionDecl *Function) {
+ AddResultTypeChunk(Ctx, Policy, Function, CCContext.getBaseType(), Result);
AddQualifierToCompletionString(Result, Qualifier, QualifierIsInformative,
Ctx, Policy);
AddTypedNameChunk(Ctx, Policy, ND, Result);
@@ -3349,9 +3360,21 @@
AddFunctionParameterChunks(PP, Policy, Function, Result);
Result.AddChunk(CodeCompletionString::CK_RightParen);
AddFunctionTypeQualsToCompletionString(Result, Function);
+ };
+
+ if (const auto *Function = dyn_cast<FunctionDecl>(ND)) {
+ AddFunctionTypeAndResult(Function);
return Result.TakeString();
}
+ if (const auto *CallOperator =
+ dyn_cast_or_null<FunctionDecl>(extractFunctorCallOperator(ND))) {
+ AddFunctionTypeAndResult(CallOperator);
+ return Result.TakeString();
+ }
+
+ AddResultTypeChunk(Ctx, Policy, ND, CCContext.getBaseType(), Result);
+
if (const FunctionTemplateDecl *FunTmpl =
dyn_cast<FunctionTemplateDecl>(ND)) {
AddQualifierToCompletionString(Result, Qualifier, QualifierIsInformative,
@@ -3417,6 +3440,7 @@
Result.AddChunk(CodeCompletionString::CK_RightAngle);
return Result.TakeString();
}
+
if (const auto *Method = dyn_cast<ObjCMethodDecl>(ND)) {
Selector Sel = Method->getSelector();
if (Sel.isUnarySelector()) {