[clang-tools-extra] [clangd] Add inlay hints for default function arguments and implicit lambda captures (PR #95712)
Tor Shepherd via cfe-commits
cfe-commits at lists.llvm.org
Sun Jun 16 09:45:45 PDT 2024
https://github.com/torshepherd created https://github.com/llvm/llvm-project/pull/95712
Title. This PR adds support for showing implicit lambda captures:
and defaulted function arguments:
as inlay hints.
If the list of captures (or default args) is too long (based on TypeNameLimit), shows "..." instead:
Note: I wrote this before https://github.com/llvm/llvm-project/pull/85497 landed. With this we should probably also follow up with go-to-definition on the lambda captures at least; I could see that being helpful
>From 741921857955983e1bce2ba828ec369568948688 Mon Sep 17 00:00:00 2001
From: Tor Shepherd <tor.aksel.shepherd at gmail.com>
Date: Sun, 16 Jun 2024 10:54:43 -0400
Subject: [PATCH] Add default arguments and lambda captures only
---
clang-tools-extra/clangd/Config.h | 2 +
clang-tools-extra/clangd/ConfigCompile.cpp | 19 ++--
clang-tools-extra/clangd/ConfigFragment.h | 5 ++
clang-tools-extra/clangd/ConfigYAML.cpp | 9 +-
clang-tools-extra/clangd/InlayHints.cpp | 87 ++++++++++++++++++-
clang-tools-extra/clangd/Protocol.cpp | 8 +-
clang-tools-extra/clangd/Protocol.h | 33 +++++--
.../clangd/unittests/InlayHintTests.cpp | 66 +++++++++++++-
8 files changed, 206 insertions(+), 23 deletions(-)
diff --git a/clang-tools-extra/clangd/Config.h b/clang-tools-extra/clangd/Config.h
index 41143b9ebc8d2..5100214244454 100644
--- a/clang-tools-extra/clangd/Config.h
+++ b/clang-tools-extra/clangd/Config.h
@@ -148,6 +148,8 @@ struct Config {
bool DeducedTypes = true;
bool Designators = true;
bool BlockEnd = false;
+ bool LambdaCaptures = false;
+ bool DefaultArguments = false;
// Limit the length of type names in inlay hints. (0 means no limit)
uint32_t TypeNameLimit = 32;
} InlayHints;
diff --git a/clang-tools-extra/clangd/ConfigCompile.cpp b/clang-tools-extra/clangd/ConfigCompile.cpp
index f32f674443ffe..dcdb71ea01bb2 100644
--- a/clang-tools-extra/clangd/ConfigCompile.cpp
+++ b/clang-tools-extra/clangd/ConfigCompile.cpp
@@ -43,7 +43,6 @@
#include "llvm/Support/Regex.h"
#include "llvm/Support/SMLoc.h"
#include "llvm/Support/SourceMgr.h"
-#include <algorithm>
#include <memory>
#include <optional>
#include <string>
@@ -504,10 +503,10 @@ struct FragmentCompiler {
auto Fast = isFastTidyCheck(Str);
if (!Fast.has_value()) {
diag(Warning,
- llvm::formatv(
- "Latency of clang-tidy check '{0}' is not known. "
- "It will only run if ClangTidy.FastCheckFilter is Loose or None",
- Str)
+ llvm::formatv("Latency of clang-tidy check '{0}' is not known. "
+ "It will only run if ClangTidy.FastCheckFilter is "
+ "Loose or None",
+ Str)
.str(),
Arg.Range);
} else if (!*Fast) {
@@ -654,6 +653,16 @@ struct FragmentCompiler {
Out.Apply.push_back([Value(**F.BlockEnd)](const Params &, Config &C) {
C.InlayHints.BlockEnd = Value;
});
+ if (F.LambdaCaptures)
+ Out.Apply.push_back(
+ [Value(**F.LambdaCaptures)](const Params &, Config &C) {
+ C.InlayHints.LambdaCaptures = Value;
+ });
+ if (F.DefaultArguments)
+ Out.Apply.push_back(
+ [Value(**F.DefaultArguments)](const Params &, Config &C) {
+ C.InlayHints.DefaultArguments = Value;
+ });
if (F.TypeNameLimit)
Out.Apply.push_back(
[Value(**F.TypeNameLimit)](const Params &, Config &C) {
diff --git a/clang-tools-extra/clangd/ConfigFragment.h b/clang-tools-extra/clangd/ConfigFragment.h
index f3e51a9b6dbc4..ad30b43f34874 100644
--- a/clang-tools-extra/clangd/ConfigFragment.h
+++ b/clang-tools-extra/clangd/ConfigFragment.h
@@ -331,6 +331,11 @@ struct Fragment {
std::optional<Located<bool>> Designators;
/// Show defined symbol names at the end of a definition block.
std::optional<Located<bool>> BlockEnd;
+ /// Show names of captured variables by default capture groups in lambdas.
+ std::optional<Located<bool>> LambdaCaptures;
+ /// Show parameter names and default values of default arguments after all
+ /// of the explicit arguments.
+ std::optional<Located<bool>> DefaultArguments;
/// Limit the length of type name hints. (0 means no limit)
std::optional<Located<uint32_t>> TypeNameLimit;
};
diff --git a/clang-tools-extra/clangd/ConfigYAML.cpp b/clang-tools-extra/clangd/ConfigYAML.cpp
index 3e9b6a07d3b32..58e5f8bead101 100644
--- a/clang-tools-extra/clangd/ConfigYAML.cpp
+++ b/clang-tools-extra/clangd/ConfigYAML.cpp
@@ -14,7 +14,6 @@
#include "llvm/Support/YAMLParser.h"
#include <optional>
#include <string>
-#include <system_error>
namespace clang {
namespace clangd {
@@ -264,6 +263,14 @@ class Parser {
if (auto Value = boolValue(N, "BlockEnd"))
F.BlockEnd = *Value;
});
+ Dict.handle("LambdaCaptures", [&](Node &N) {
+ if (auto Value = boolValue(N, "LambdaCaptures"))
+ F.LambdaCaptures = *Value;
+ });
+ Dict.handle("DefaultArguments", [&](Node &N) {
+ if (auto Value = boolValue(N, "DefaultArguments"))
+ F.DefaultArguments = *Value;
+ });
Dict.handle("TypeNameLimit", [&](Node &N) {
if (auto Value = uint32Value(N, "TypeNameLimit"))
F.TypeNameLimit = *Value;
diff --git a/clang-tools-extra/clangd/InlayHints.cpp b/clang-tools-extra/clangd/InlayHints.cpp
index cd4f1931b3ce1..2631c17409eab 100644
--- a/clang-tools-extra/clangd/InlayHints.cpp
+++ b/clang-tools-extra/clangd/InlayHints.cpp
@@ -11,27 +11,37 @@
#include "Config.h"
#include "HeuristicResolver.h"
#include "ParsedAST.h"
+#include "Protocol.h"
#include "SourceCode.h"
#include "clang/AST/ASTDiagnostic.h"
#include "clang/AST/Decl.h"
+#include "clang/AST/DeclBase.h"
#include "clang/AST/DeclarationName.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
+#include "clang/AST/LambdaCapture.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/Stmt.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/AST/Type.h"
#include "clang/Basic/Builtins.h"
+#include "clang/Basic/Lambda.h"
#include "clang/Basic/OperatorKinds.h"
+#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/Casting.h"
+#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/SaveAndRestore.h"
#include "llvm/Support/ScopedPrinter.h"
#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <iterator>
#include <optional>
#include <string>
@@ -372,6 +382,34 @@ maybeDropCxxExplicitObjectParameters(ArrayRef<const ParmVarDecl *> Params) {
return Params;
}
+llvm::StringRef getLambdaCaptureName(const LambdaCapture &Capture) {
+ if (Capture.capturesVariable())
+ return Capture.getCapturedVar()->getName();
+ if (Capture.capturesThis())
+ return llvm::StringRef{"this"};
+ return llvm::StringRef{"unknown"};
+}
+
+template <typename R, typename P>
+std::string joinAndTruncate(R &&Range, size_t MaxLength,
+ P &&GetAsStringFunction) {
+ std::string Out;
+ bool IsFirst = true;
+ for (auto &&Element : Range) {
+ if (!IsFirst)
+ Out.append(", ");
+ else
+ IsFirst = false;
+ auto AsString = GetAsStringFunction(Element);
+ if (Out.size() + AsString.size() >= MaxLength) {
+ Out.append("...");
+ break;
+ }
+ Out.append(AsString);
+ }
+ return Out;
+}
+
struct Callee {
// Only one of Decl or Loc is set.
// Loc is for calls through function pointers.
@@ -422,7 +460,8 @@ class InlayHintVisitor : public RecursiveASTVisitor<InlayHintVisitor> {
Callee.Decl = E->getConstructor();
if (!Callee.Decl)
return true;
- processCall(Callee, {E->getArgs(), E->getNumArgs()});
+ processCall(Callee, E->getParenOrBraceRange().getEnd(),
+ {E->getArgs(), E->getNumArgs()});
return true;
}
@@ -495,7 +534,7 @@ class InlayHintVisitor : public RecursiveASTVisitor<InlayHintVisitor> {
dyn_cast_or_null<CXXMethodDecl>(Callee.Decl))
if (IsFunctor || Method->hasCXXExplicitFunctionObjectParameter())
Args = Args.drop_front(1);
- processCall(Callee, Args);
+ processCall(Callee, E->getRParenLoc(), Args);
return true;
}
@@ -598,6 +637,15 @@ class InlayHintVisitor : public RecursiveASTVisitor<InlayHintVisitor> {
}
bool VisitLambdaExpr(LambdaExpr *E) {
+ if (Cfg.InlayHints.LambdaCaptures && E->getCaptureDefault() != LCD_None &&
+ !E->implicit_captures().empty()) {
+ std::string FormattedCaptureList =
+ joinAndTruncate(E->implicit_captures(), Cfg.InlayHints.TypeNameLimit,
+ [](const LambdaCapture &ImplicitCapture) {
+ return getLambdaCaptureName(ImplicitCapture);
+ });
+ addImplicitCaptureHint(E->getCaptureDefaultLoc(), FormattedCaptureList);
+ }
FunctionDecl *D = E->getCallOperator();
if (!E->hasExplicitResultType())
addReturnTypeHint(D, E->hasExplicitParameters()
@@ -709,7 +757,8 @@ class InlayHintVisitor : public RecursiveASTVisitor<InlayHintVisitor> {
private:
using NameVec = SmallVector<StringRef, 8>;
- void processCall(Callee Callee, llvm::ArrayRef<const Expr *> Args) {
+ void processCall(Callee Callee, SourceRange LParenOrBraceRange,
+ llvm::ArrayRef<const Expr *> Args) {
assert(Callee.Decl || Callee.Loc);
if (!Cfg.InlayHints.Parameters || Args.size() == 0)
@@ -721,6 +770,9 @@ class InlayHintVisitor : public RecursiveASTVisitor<InlayHintVisitor> {
if (Ctor->isCopyOrMoveConstructor())
return;
+ SmallVector<std::string> FormattedDefaultArgs;
+ bool HasNonDefaultArgs = false;
+
ArrayRef<const ParmVarDecl *> Params, ForwardedParams;
// Resolve parameter packs to their forwarded parameter
SmallVector<const ParmVarDecl *> ForwardedParamsStorage;
@@ -755,12 +807,34 @@ class InlayHintVisitor : public RecursiveASTVisitor<InlayHintVisitor> {
bool NameHint = shouldHintName(Args[I], Name);
bool ReferenceHint = shouldHintReference(Params[I], ForwardedParams[I]);
+ bool IsDefault = isa<CXXDefaultArgExpr>(Args[I]);
+ HasNonDefaultArgs |= !IsDefault;
+ if (Cfg.InlayHints.DefaultArguments && IsDefault) {
+ auto SourceText = Lexer::getSourceText(
+ CharSourceRange::getTokenRange(Params[I]->getDefaultArgRange()),
+ Callee.Decl->getASTContext().getSourceManager(),
+ Callee.Decl->getASTContext().getLangOpts());
+ FormattedDefaultArgs.emplace_back(llvm::formatv(
+ "{0} = {1}", Name,
+ SourceText.size() > Cfg.InlayHints.TypeNameLimit ? "..."
+ : SourceText));
+ }
+
if (NameHint || ReferenceHint) {
addInlayHint(Args[I]->getSourceRange(), HintSide::Left,
InlayHintKind::Parameter, ReferenceHint ? "&" : "",
NameHint ? Name : "", ": ");
}
}
+
+ if (!FormattedDefaultArgs.empty()) {
+ std::string Hint =
+ joinAndTruncate(FormattedDefaultArgs, Cfg.InlayHints.TypeNameLimit,
+ [](const auto &E) { return E; });
+ addInlayHint(LParenOrBraceRange, HintSide::Left,
+ InlayHintKind::DefaultArgument,
+ HasNonDefaultArgs ? ", " : "", Hint, "");
+ }
}
static bool isSetter(const FunctionDecl *Callee, const NameVec &ParamNames) {
@@ -968,6 +1042,8 @@ class InlayHintVisitor : public RecursiveASTVisitor<InlayHintVisitor> {
CHECK_KIND(Type, DeducedTypes);
CHECK_KIND(Designator, Designators);
CHECK_KIND(BlockEnd, BlockEnd);
+ CHECK_KIND(LambdaCapture, LambdaCaptures);
+ CHECK_KIND(DefaultArgument, DefaultArguments);
#undef CHECK_KIND
}
@@ -1021,6 +1097,11 @@ class InlayHintVisitor : public RecursiveASTVisitor<InlayHintVisitor> {
/*Prefix=*/"", Text, /*Suffix=*/"=");
}
+ void addImplicitCaptureHint(SourceRange R, llvm::StringRef Text) {
+ addInlayHint(R, HintSide::Right, InlayHintKind::LambdaCapture,
+ /*Prefix=*/": ", Text, /*Suffix=*/"");
+ }
+
bool shouldPrintTypeHint(llvm::StringRef TypeName) const noexcept {
return Cfg.InlayHints.TypeNameLimit == 0 ||
TypeName.size() < Cfg.InlayHints.TypeNameLimit;
diff --git a/clang-tools-extra/clangd/Protocol.cpp b/clang-tools-extra/clangd/Protocol.cpp
index c08f80442eaa0..dafc3f4eab567 100644
--- a/clang-tools-extra/clangd/Protocol.cpp
+++ b/clang-tools-extra/clangd/Protocol.cpp
@@ -209,7 +209,7 @@ bool fromJSON(const llvm::json::Value &Params, ChangeAnnotation &R,
O.map("needsConfirmation", R.needsConfirmation) &&
O.mapOptional("description", R.description);
}
-llvm::json::Value toJSON(const ChangeAnnotation & CA) {
+llvm::json::Value toJSON(const ChangeAnnotation &CA) {
llvm::json::Object Result{{"label", CA.label}};
if (CA.needsConfirmation)
Result["needsConfirmation"] = *CA.needsConfirmation;
@@ -1477,6 +1477,8 @@ llvm::json::Value toJSON(const InlayHintKind &Kind) {
return 2;
case InlayHintKind::Designator:
case InlayHintKind::BlockEnd:
+ case InlayHintKind::LambdaCapture:
+ case InlayHintKind::DefaultArgument:
// This is an extension, don't serialize.
return nullptr;
}
@@ -1517,6 +1519,10 @@ llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, InlayHintKind Kind) {
return "designator";
case InlayHintKind::BlockEnd:
return "block-end";
+ case InlayHintKind::LambdaCapture:
+ return "lambda-capture";
+ case InlayHintKind::DefaultArgument:
+ return "default-argument";
}
llvm_unreachable("Unknown clang.clangd.InlayHintKind");
};
diff --git a/clang-tools-extra/clangd/Protocol.h b/clang-tools-extra/clangd/Protocol.h
index a0f8b04bc4ffd..793eebf4d51df 100644
--- a/clang-tools-extra/clangd/Protocol.h
+++ b/clang-tools-extra/clangd/Protocol.h
@@ -281,7 +281,7 @@ struct TextDocumentEdit {
/// The text document to change.
VersionedTextDocumentIdentifier textDocument;
- /// The edits to be applied.
+ /// The edits to be applied.
/// FIXME: support the AnnotatedTextEdit variant.
std::vector<TextEdit> edits;
};
@@ -557,7 +557,7 @@ struct ClientCapabilities {
/// The client supports versioned document changes for WorkspaceEdit.
bool DocumentChanges = false;
-
+
/// The client supports change annotations on text edits,
bool ChangeAnnotation = false;
@@ -1013,12 +1013,12 @@ struct WorkspaceEdit {
/// Versioned document edits.
///
/// If a client neither supports `documentChanges` nor
- /// `workspace.workspaceEdit.resourceOperations` then only plain `TextEdit`s
- /// using the `changes` property are supported.
+ /// `workspace.workspaceEdit.resourceOperations` then only plain `TextEdit`s
+ /// using the `changes` property are supported.
std::optional<std::vector<TextDocumentEdit>> documentChanges;
-
+
/// A map of change annotations that can be referenced in
- /// AnnotatedTextEdit.
+ /// AnnotatedTextEdit.
std::map<std::string, ChangeAnnotation> changeAnnotations;
};
bool fromJSON(const llvm::json::Value &, WorkspaceEdit &, llvm::json::Path);
@@ -1274,13 +1274,13 @@ enum class InsertTextFormat {
/// Additional details for a completion item label.
struct CompletionItemLabelDetails {
/// An optional string which is rendered less prominently directly after label
- /// without any spacing. Should be used for function signatures or type
+ /// without any spacing. Should be used for function signatures or type
/// annotations.
std::string detail;
/// An optional string which is rendered less prominently after
- /// CompletionItemLabelDetails.detail. Should be used for fully qualified
- /// names or file path.
+ /// CompletionItemLabelDetails.detail. Should be used for fully qualified
+ /// names or file path.
std::string description;
};
llvm::json::Value toJSON(const CompletionItemLabelDetails &);
@@ -1681,6 +1681,21 @@ enum class InlayHintKind {
/// This is a clangd extension.
BlockEnd = 4,
+ /// An inlay hint that is for a variable captured implicitly in a lambda.
+ ///
+ /// An example of parameter hint for implicit lambda captures:
+ /// [&^] { return A; };
+ /// Adds an inlay hint ": A".
+ LambdaCapture = 5,
+
+ /// An inlay hint that is for a default argument.
+ ///
+ /// An example of a parameter hint for a default argument:
+ /// void foo(bool A = true);
+ /// foo(^);
+ /// Adds an inlay hint "A = true".
+ DefaultArgument = 6,
+
/// Other ideas for hints that are not currently implemented:
///
/// * Chaining hints, showing the types of intermediate expressions
diff --git a/clang-tools-extra/clangd/unittests/InlayHintTests.cpp b/clang-tools-extra/clangd/unittests/InlayHintTests.cpp
index 5b1531eb2fa60..65ab743fb3e38 100644
--- a/clang-tools-extra/clangd/unittests/InlayHintTests.cpp
+++ b/clang-tools-extra/clangd/unittests/InlayHintTests.cpp
@@ -15,9 +15,12 @@
#include "support/Context.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/ScopedPrinter.h"
+#include "llvm/Support/raw_ostream.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
+#include <optional>
#include <string>
+#include <utility>
#include <vector>
namespace clang {
@@ -81,6 +84,8 @@ Config noHintsConfig() {
C.InlayHints.DeducedTypes = false;
C.InlayHints.Designators = false;
C.InlayHints.BlockEnd = false;
+ C.InlayHints.LambdaCaptures = false;
+ C.InlayHints.DefaultArguments = false;
return C;
}
@@ -1458,13 +1463,66 @@ TEST(TypeHints, DefaultTemplateArgs) {
struct A {};
A<float> foo();
auto $var[[var]] = foo();
- A<float> bar[1];
+ A<float> baz;
+ A<float> bar[1]{};
auto [$binding[[value]]] = bar;
)cpp",
ExpectedHint{": A<float>", "var"},
ExpectedHint{": A<float>", "binding"});
}
+TEST(LambdaCaptures, Smoke) {
+ Config Cfg;
+ Cfg.InlayHints.Parameters = false;
+ Cfg.InlayHints.DeducedTypes = false;
+ Cfg.InlayHints.Designators = false;
+ Cfg.InlayHints.BlockEnd = false;
+ Cfg.InlayHints.DefaultArguments = false;
+
+ Cfg.InlayHints.LambdaCaptures = true;
+ Cfg.InlayHints.TypeNameLimit = 10;
+ WithContextValue WithCfg(Config::Key, std::move(Cfg));
+
+ assertHints(InlayHintKind::LambdaCapture, R"cpp(
+ void foo() {
+ int A = 1;
+ int ReallyLongName = 1;
+ auto B = [$byvalue[[=]]] { return A; };
+ auto C = [$byref[[&]]] { return A; };
+ auto D = [$trunc[[=]], &A] { B(); (void)ReallyLongName; return A; };
+ }
+ )cpp",
+ ExpectedHint{": A", "byvalue", Right},
+ ExpectedHint{": A", "byref", Right},
+ ExpectedHint{": B, ...", "trunc", Right});
+}
+
+TEST(DefaultArguments, Smoke) {
+ Config Cfg;
+ Cfg.InlayHints.Parameters =
+ true; // To test interplay of parameters and default parameters
+ Cfg.InlayHints.DeducedTypes = false;
+ Cfg.InlayHints.Designators = false;
+ Cfg.InlayHints.BlockEnd = false;
+ Cfg.InlayHints.LambdaCaptures = false;
+
+ Cfg.InlayHints.DefaultArguments = true;
+ WithContextValue WithCfg(Config::Key, std::move(Cfg));
+
+ const auto *Code = R"cpp(
+ int foo(int A = 4) { return A; }
+ int bar(int A, int B = 1, bool C = foo($default1[[)]]) { return A; }
+ int A = bar($explicit[[2]]$default2[[)]];
+ )cpp";
+
+ assertHints(InlayHintKind::DefaultArgument, Code,
+ ExpectedHint{"A = 4", "default1", Left},
+ ExpectedHint{", B = 1, C = foo()", "default2", Left});
+
+ assertHints(InlayHintKind::Parameter, Code,
+ ExpectedHint{"A: ", "explicit", Left});
+}
+
TEST(TypeHints, Deduplication) {
assertTypeHints(R"cpp(
template <typename T>
@@ -1568,7 +1626,7 @@ TEST(TypeHints, SubstTemplateParameterAliases) {
)cpp";
llvm::StringRef VectorIntPtr = R"cpp(
- vector<int *> array;
+ vector<int *> $init[[array]];
auto $no_modifier[[x]] = array[3];
auto* $ptr_modifier[[ptr]] = &array[3];
auto& $ref_modifier[[ref]] = array[3];
@@ -1592,7 +1650,7 @@ TEST(TypeHints, SubstTemplateParameterAliases) {
ExpectedHint{": non_template_iterator", "end"});
llvm::StringRef VectorInt = R"cpp(
- vector<int> array;
+ vector<int> $init[[array]];
auto $no_modifier[[by_value]] = array[3];
auto* $ptr_modifier[[ptr]] = &array[3];
auto& $ref_modifier[[ref]] = array[3];
@@ -1741,7 +1799,7 @@ TEST(ParameterHints, PseudoObjectExpr) {
int printf(const char *Format, ...);
int main() {
- S s;
+ S $init[[s]];
__builtin_dump_struct(&s, printf); // Not `Format: __builtin_dump_struct()`
printf($Param[["Hello, %d"]], 42); // Normal calls are not affected.
// This builds a PseudoObjectExpr, but here it's useful for showing the
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