[IDE] Misc enhancements to signature help

Author: a7medev

lib/IDE/ArgumentCompletion.cpp

@@ -113,28 +113,44 @@ static bool hasParentCallLikeExpr(Expr *E, ConstraintSystem &CS) {
 /// if it turns out to be a double apply.
 static std::optional<std::pair<ValueDecl *, AnyFunctionType *>>
 tryResolveDoubleAppliedFunction(CallExpr *OuterCall, const Solution &S) {
+  if (!OuterCall)
+    return std::nullopt;
+
   auto *InnerCall = dyn_cast<CallExpr>(OuterCall->getSemanticFn());
   if (!InnerCall)
     return std::nullopt;
 
   auto &CS = S.getConstraintSystem();
   auto *InnerCallLocator = CS.getConstraintLocator(InnerCall);
-  auto *InnerCalleeLocator = S.getCalleeLocator(InnerCallLocator);
+  auto Overload = S.getCalleeOverloadChoiceIfAvailable(InnerCallLocator);
+  if (!Overload)
+    return std::nullopt;
 
-  if (auto Overload = S.getOverloadChoiceIfAvailable(InnerCalleeLocator);
-      Overload->choice.isDecl()) {
-    auto FuncRefInfo = Overload->choice.getFunctionRefInfo();
-    if (!FuncRefInfo.isDoubleApply())
-      return std::nullopt;
+  if (!Overload->choice.isDecl())
+    return std::nullopt;
 
-    auto CalleeTy = Overload->adjustedOpenedType->getAs<AnyFunctionType>();
-    auto ResultTy = S.simplifyTypeForCodeCompletion(CalleeTy->getResult());
+  auto FuncRefInfo = Overload->choice.getFunctionRefInfo();
+  if (!FuncRefInfo.isDoubleApply())
+    return std::nullopt;
 
-    if (auto *FuncTy = ResultTy->getAs<AnyFunctionType>())
-      return std::make_pair(Overload->choice.getDecl(), FuncTy);
-  }
+  auto CalleeTy = Overload->adjustedOpenedType->getAs<AnyFunctionType>();
+  auto ResultTy = S.simplifyTypeForCodeCompletion(CalleeTy->getResult());
 
-  return std::nullopt;
+  auto *FuncTy = ResultTy->getAs<AnyFunctionType>();
+  if (!FuncTy)
+    return std::nullopt;
+
+  auto *VD = Overload->choice.getDecl();
+  auto BaseTy = Overload->choice.getBaseType();
+  bool IsOuterCallImplicitlyCurried =
+      VD->isInstanceMember() && !doesMemberRefApplyCurriedSelf(BaseTy, VD);
+
+  // The function declaration is only relevant if the function is an implicitly
+  // curried instance method.
+  if (IsOuterCallImplicitlyCurried)
+    return std::make_pair(Overload->choice.getDecl(), FuncTy);
+
+  return std::make_pair(nullptr, FuncTy);
 }
 
 void ArgumentTypeCheckCompletionCallback::sawSolutionImpl(const Solution &S) {
@@ -486,12 +502,11 @@ void ArgumentTypeCheckCompletionCallback::getSignatures(
 
   for (auto &Result : Results) {
     // Only show signature if the function isn't overridden.
-    if (!ShadowedDecls.contains(Result.FuncD)) {
-      if (!Result.FuncTy)
-        continue;
-      Signatures.push_back({Result.IsSubscript, Result.IsImplicitlyCurried,
-                            Result.IsSecondApply, Result.FuncD, Result.FuncTy,
-                            Result.ExpectedType, Result.ParamIdx});
-    }
+    if (!Result.FuncTy || ShadowedDecls.contains(Result.FuncD))
+      continue;
+
+    Signatures.push_back({Result.IsSubscript, Result.IsImplicitlyCurried,
+                          Result.IsSecondApply, Result.FuncD, Result.FuncTy,
+                          Result.ExpectedType, Result.ParamIdx});
   }
 }

lib/IDE/SignatureHelp.cpp

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2019 Apple Inc. and the Swift project authors
+// Copyright (c) 2025 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -11,12 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "swift/IDE/SignatureHelp.h"
-#include "ExprContextAnalysis.h"
-#include "swift/AST/GenericEnvironment.h"
-#include "swift/AST/NameLookup.h"
 #include "swift/IDE/ArgumentCompletion.h"
-#include "swift/IDE/TypeCheckCompletionCallback.h"
-#include "swift/Parse/IDEInspectionCallbacks.h"
 #include "swift/Sema/IDETypeChecking.h"
 
 using namespace swift;

test/SourceKit/SignatureHelp/signature_help_currying.swift

@@ -205,7 +205,7 @@ func testCurryMemberFull() {
       key.active_parameter: 0
     },
     {
-      key.name: "(first: Double?, second: Float, third: Int) -> Double",
+      key.name: "(first: Double!, second: Float, third: Int) -> Double",
       key.parameters: [
         {
           key.nameoffset: 1,
@@ -251,7 +251,7 @@ func testCurryMemberFull() {
       key.active_parameter: 0
     },
     {
-      key.name: "(x: Int, y: Int, with: (Int, Int) throws -> Int) throws -> Int?",
+      key.name: "(x: Int, y: Int, with: (Int, Int) throws -> Int) throws -> Int!",
       key.parameters: [
         {
           key.nameoffset: 1,

tools/SourceKit/include/SourceKit/Core/LangSupport.h

@@ -1012,17 +1012,17 @@ class ConformingMethodListConsumer {
   virtual void cancelled() = 0;
 };
 
-struct SignatureHelpResult {
+struct SignatureHelpResponse {
   struct Parameter {
-    unsigned LabelBegin;
-    unsigned LabelLength;
+    unsigned Offset;
+    unsigned Length;
     StringRef DocComment;
 
     Parameter() {}
   };
 
   struct Signature {
-    StringRef Label;
+    StringRef Text;
     StringRef Doc;
     std::optional<unsigned> ActiveParam;
     ArrayRef<Parameter> Params;
@@ -1038,7 +1038,7 @@ class SignatureHelpConsumer {
 public:
   virtual ~SignatureHelpConsumer() {}
 
-  virtual void handleResult(const SignatureHelpResult &Result) = 0;
+  virtual void handleResult(const SignatureHelpResponse &Result) = 0;
   virtual void setReusingASTContext(bool flag) = 0;
   virtual void failed(StringRef ErrDescription) = 0;
   virtual void cancelled() = 0;

tools/SourceKit/lib/SwiftLang/SwiftSignatureHelp.cpp

@@ -28,14 +28,16 @@ using namespace ide;
 
 using ChunkKind = CodeCompletionString::Chunk::ChunkKind;
 
+namespace {
 struct SignatureInfo {
-  StringRef Label;
+  StringRef Text;
   StringRef DocComment;
   std::optional<unsigned> ActiveParam;
-  SmallVector<SourceKit::SignatureHelpResult::Parameter, 1> Params;
+  SmallVector<SourceKit::SignatureHelpResponse::Parameter, 1> Params;
 
   SignatureInfo() {}
 };
+} // namespace
 
 /// \returns Array of parameters of \p VD accounting for implicitly curried
 /// instance methods.
@@ -59,26 +61,18 @@ getParameterArray(const ValueDecl *VD, bool IsImplicitlyCurried,
   return {};
 }
 
-static CodeCompletionString *createSignatureLabel(
+static CodeCompletionString *createSignatureString(
     llvm::BumpPtrAllocator &Allocator, ValueDecl *FD, AnyFunctionType *AFT,
     const DeclContext *DC, GenericSignature GenericSig, bool IsSubscript,
     bool IsMember, bool IsImplicitlyCurried, bool IsSecondApply) {
-  if (IsSecondApply) {
-    // Don't use the function decl when creating the signature label
-    // if this is the second apply of a double-applied function to
-    // avoid showing incorrect information like IUOs, rethrows, or
-    // reasync which can't be used in second apply.
-    FD = nullptr;
-  }
-
   CodeCompletionStringBuilder StringBuilder(
       Allocator, /*AnnotateResults=*/false,
       /*UnderscoreEmptyArgumentLabel=*/!IsSubscript,
       /*FullParameterFlags=*/true);
 
   DeclBaseName BaseName;
 
-  if (FD) {
+  if (!IsSecondApply && FD) {
     BaseName = FD->getBaseName();
   } else if (IsSubscript) {
     BaseName = DeclBaseName::createSubscript();
@@ -98,11 +92,15 @@ static CodeCompletionString *createSignatureLabel(
   StringBuilder.addRightParen();
 
   if (!IsImplicitlyCurried) {
+    // For a second apply, we don't pass the declaration to avoid adding
+    // incorrect rethrows and reasync which are only usable in a single apply.
     StringBuilder.addEffectsSpecifiers(
-        AFT, dyn_cast_or_null<AbstractFunctionDecl>(FD));
+        AFT,
+        /*AFD=*/IsSecondApply ? nullptr
+                              : dyn_cast_or_null<AbstractFunctionDecl>(FD));
   }
 
-  if (!IsImplicitlyCurried && FD && FD->isImplicitlyUnwrappedOptional())
+  if (FD && FD->isImplicitlyUnwrappedOptional())
     StringBuilder.addTypeAnnotationForImplicitlyUnwrappedOptional(
         AFT->getResult(), DC, GenericSig);
   else
@@ -129,21 +127,21 @@ static void getSignatureInfo(const DeclContext *DC, const Signature &Sig,
   if (FD) {
     IsConstructor = isa<ConstructorDecl>(FD);
 
-    if (auto *FDC = dyn_cast<DeclContext>(FD))
-      genericSig = FDC->getGenericSignatureOfContext();
+    if (auto *GC = FD->getAsGenericContext())
+      genericSig = GC->getGenericSignature();
   }
 
-  auto *SignatureLabel =
-      createSignatureLabel(Allocator, FD, AFT, DC, genericSig, Sig.IsSubscript,
-                           /*IsMember=*/bool(Sig.BaseType),
-                           Sig.IsImplicitlyCurried, Sig.IsSecondApply);
+  auto *SignatureString =
+      createSignatureString(Allocator, FD, AFT, DC, genericSig, Sig.IsSubscript,
+                            /*IsMember=*/bool(Sig.BaseType),
+                            Sig.IsImplicitlyCurried, Sig.IsSecondApply);
 
   llvm::SmallString<512> SS;
   llvm::raw_svector_ostream OS(SS);
 
   bool SkipResult = AFT->getResult()->isVoid() || IsConstructor;
 
-  auto Chunks = SignatureLabel->getChunks();
+  auto Chunks = SignatureString->getChunks();
   auto C = Chunks.begin();
   while (C != Chunks.end()) {
     if (C->is(ChunkKind::TypeAnnotation) && SkipResult) {
@@ -159,7 +157,7 @@ static void getSignatureInfo(const DeclContext *DC, const Signature &Sig,
       ++C;
 
       auto &P = Info.Params.emplace_back();
-      P.LabelBegin = SS.size();
+      P.Offset = SS.size();
 
       do {
         if (!C->is(ChunkKind::CallArgumentClosureType) && C->hasText())
@@ -168,7 +166,8 @@ static void getSignatureInfo(const DeclContext *DC, const Signature &Sig,
         ++C;
       } while (C != Chunks.end() && !C->endsPreviousNestedGroup(NestingLevel));
 
-      P.LabelLength = SS.size() - P.LabelBegin;
+      P.Length = SS.size() - P.Offset;
+      continue;
     }
 
     if (C->hasText())
@@ -177,7 +176,7 @@ static void getSignatureInfo(const DeclContext *DC, const Signature &Sig,
     ++C;
   }
 
-  Info.Label = copyAndClearString(Allocator, SS);
+  Info.Text = copyAndClearString(Allocator, SS);
   Info.ActiveParam = Sig.ParamIdx;
 
   // Documentation.
@@ -211,12 +210,12 @@ static void deliverResults(SourceKit::SignatureHelpConsumer &SKConsumer,
       getSignatureInfo(Result->Result->DC, Sig, Info, Allocator);
     }
 
-    SourceKit::SignatureHelpResult SKResult;
-    SmallVector<SourceKit::SignatureHelpResult::Signature, 8> SKSignatures;
+    SourceKit::SignatureHelpResponse SKResult;
+    SmallVector<SourceKit::SignatureHelpResponse::Signature, 8> SKSignatures;
 
     for (auto &Info : Infos) {
       SKSignatures.push_back(
-          {Info.Label, Info.DocComment, Info.ActiveParam, Info.Params});
+          {Info.Text, Info.DocComment, Info.ActiveParam, Info.Params});
     }
 
     SKResult.Signatures = SKSignatures;

tools/SourceKit/tools/sourcekitd/lib/Service/Requests.cpp

@@ -1488,8 +1488,10 @@ handleRequestSignatureHelp(const RequestDict &Req,
     if (!PrimaryFilePath)
       return;
 
-    assert(getInputBufferNameForRequest(Req, Rec).empty() &&
-           "Input buffer name is different from primary file");
+    StringRef InputBufferName = getInputBufferNameForRequest(Req, Rec);
+    if (!InputBufferName.empty())
+      return Rec(createErrorRequestInvalid(
+          "'key.primary_file' and 'key.sourcefile' can't be different"));
 
     SmallVector<const char *, 8> Args;
     if (getCompilerArgumentsForRequestOrEmitError(Req, Args, Rec))
@@ -3643,15 +3645,15 @@ signatureHelp(StringRef PrimaryFilePath, int64_t Offset,
   public:
     Consumer(ResponseBuilder Builder) : SKResult(Builder.getDictionary()) {}
 
-    void handleResult(const SignatureHelpResult &Result) override {
+    void handleResult(const SignatureHelpResponse &Result) override {
       SKResult.set(KeyActiveSignature, Result.ActiveSignature);
 
       auto Signatures = SKResult.setArray(KeySignatures);
 
       for (auto Signature : Result.Signatures) {
         auto SignatureElem = Signatures.appendDictionary();
 
-        SignatureElem.set(KeyName, Signature.Label);
+        SignatureElem.set(KeyName, Signature.Text);
 
         if (auto ActiveParam = Signature.ActiveParam)
           SignatureElem.set(KeyActiveParameter, ActiveParam.value());
@@ -3664,8 +3666,8 @@ signatureHelp(StringRef PrimaryFilePath, int64_t Offset,
         for (auto Param : Signature.Params) {
           auto ParamElem = Params.appendDictionary();
 
-          ParamElem.set(KeyNameOffset, Param.LabelBegin);
-          ParamElem.set(KeyNameLength, Param.LabelLength);
+          ParamElem.set(KeyNameOffset, Param.Offset);
+          ParamElem.set(KeyNameLength, Param.Length);
 
           if (!Param.DocComment.empty())
             ParamElem.set(KeyDocComment, Param.DocComment);