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author | Ilya Biryukov <ibiryukov@google.com> | 2019-05-23 07:45:35 +0000 |
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committer | Ilya Biryukov <ibiryukov@google.com> | 2019-05-23 07:45:35 +0000 |
commit | 37d9edc0c5cfeae8b2e7dac173129ae6ab2c9429 (patch) | |
tree | 14147b39533c059be0fe84589c76ebffe05cc621 /lib | |
parent | dd1ae44165e7d8263f3758fc00d654fd3edc1673 (diff) | |
download | clang-37d9edc0c5cfeae8b2e7dac173129ae6ab2c9429.tar.gz |
[CodeComplete] Complete a lambda when preferred type is a function
Summary: Uses a heuristic to detect std::function and friends.
Reviewers: kadircet
Reviewed By: kadircet
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D62238
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@361461 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Sema/SemaCodeComplete.cpp | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/lib/Sema/SemaCodeComplete.cpp b/lib/Sema/SemaCodeComplete.cpp index 0f33442e4a..e6093141ab 100644 --- a/lib/Sema/SemaCodeComplete.cpp +++ b/lib/Sema/SemaCodeComplete.cpp @@ -4108,6 +4108,69 @@ static void AddEnumerators(ResultBuilder &Results, ASTContext &Context, Results.ExitScope(); } +/// Try to find a corresponding FunctionProtoType for function-like types (e.g. +/// function pointers, std::function, etc). +static const FunctionProtoType *TryDeconstructFunctionLike(QualType T) { + assert(!T.isNull()); + // Try to extract first template argument from std::function<> and similar. + // Note we only handle the sugared types, they closely match what users wrote. + // We explicitly choose to not handle ClassTemplateSpecializationDecl. + if (auto *Specialization = T->getAs<TemplateSpecializationType>()) { + if (Specialization->getNumArgs() != 1) + return nullptr; + const TemplateArgument &Argument = Specialization->getArg(0); + if (Argument.getKind() != TemplateArgument::Type) + return nullptr; + return Argument.getAsType()->getAs<FunctionProtoType>(); + } + // Handle other cases. + if (T->isPointerType()) + T = T->getPointeeType(); + return T->getAs<FunctionProtoType>(); +} + +/// Adds a pattern completion for a lambda expression with the specified +/// parameter types and placeholders for parameter names. +static void AddLambdaCompletion(ResultBuilder &Results, + llvm::ArrayRef<QualType> Parameters, + const LangOptions &LangOpts) { + CodeCompletionBuilder Completion(Results.getAllocator(), + Results.getCodeCompletionTUInfo()); + // [](<parameters>) {} + Completion.AddChunk(CodeCompletionString::CK_LeftBracket); + Completion.AddPlaceholderChunk("="); + Completion.AddChunk(CodeCompletionString::CK_RightBracket); + if (!Parameters.empty()) { + Completion.AddChunk(CodeCompletionString::CK_LeftParen); + bool First = true; + for (auto Parameter : Parameters) { + if (!First) + Completion.AddChunk(CodeCompletionString::ChunkKind::CK_Comma); + else + First = false; + + constexpr llvm::StringLiteral NamePlaceholder = "!#!NAME_GOES_HERE!#!"; + std::string Type = NamePlaceholder; + Parameter.getAsStringInternal(Type, PrintingPolicy(LangOpts)); + llvm::StringRef Prefix, Suffix; + std::tie(Prefix, Suffix) = llvm::StringRef(Type).split(NamePlaceholder); + Prefix = Prefix.rtrim(); + Suffix = Suffix.ltrim(); + + Completion.AddTextChunk(Completion.getAllocator().CopyString(Prefix)); + Completion.AddChunk(CodeCompletionString::CK_HorizontalSpace); + Completion.AddPlaceholderChunk("parameter"); + Completion.AddTextChunk(Completion.getAllocator().CopyString(Suffix)); + }; + Completion.AddChunk(CodeCompletionString::CK_RightParen); + } + Completion.AddChunk(CodeCompletionString::CK_LeftBrace); + Completion.AddPlaceholderChunk("body"); + Completion.AddChunk(CodeCompletionString::CK_RightBrace); + + Results.AddResult(Completion.TakeString()); +} + /// Perform code-completion in an expression context when we know what /// type we're looking for. void Sema::CodeCompleteExpression(Scope *S, @@ -4169,6 +4232,14 @@ void Sema::CodeCompleteExpression(Scope *S, if (CodeCompleter->includeMacros()) AddMacroResults(PP, Results, CodeCompleter->loadExternal(), false, PreferredTypeIsPointer); + + // Complete a lambda expression when preferred type is a function. + if (!Data.PreferredType.isNull() && getLangOpts().CPlusPlus11) { + if (const FunctionProtoType *F = + TryDeconstructFunctionLike(Data.PreferredType)) + AddLambdaCompletion(Results, F->getParamTypes(), getLangOpts()); + } + HandleCodeCompleteResults(this, CodeCompleter, Results.getCompletionContext(), Results.data(), Results.size()); } |