[index] The relation between the declarations in template specializations

that 'override' declarations in the base template should be recorded

This can be used for improved "go to definition" feature in Xcode.

rdar://31604739

Differential Revision: https://reviews.llvm.org/D32020

llvm-svn: 301180

4 files changed, 175 insertions, 4 deletions

diff --git a/clang/lib/Index/IndexDecl.cpp b/clang/lib/Index/IndexDecl.cpp
index 8028f8892f0..ba65889a6f9 100644
--- a/clang/lib/Index/IndexDecl.cpp
+++ b/clang/lib/Index/IndexDecl.cpp
@@ -144,6 +144,53 @@ public:
     return true;
   }
 
+  /// Gather the declarations which the given declaration \D overrides in a
+  /// pseudo-override manner.
+  ///
+  /// Pseudo-overrides occur when a class template specialization declares
+  /// a declaration that has the same name as a similar declaration in the
+  /// non-specialized template.
+  void
+  gatherTemplatePseudoOverrides(const NamedDecl *D,
+                                SmallVectorImpl<SymbolRelation> &Relations) {
+    if (!IndexCtx.getLangOpts().CPlusPlus)
+      return;
+    const auto *CTSD =
+        dyn_cast<ClassTemplateSpecializationDecl>(D->getLexicalDeclContext());
+    if (!CTSD)
+      return;
+    llvm::PointerUnion<ClassTemplateDecl *,
+                       ClassTemplatePartialSpecializationDecl *>
+        Template = CTSD->getSpecializedTemplateOrPartial();
+    if (const auto *CTD = Template.dyn_cast<ClassTemplateDecl *>()) {
+      const CXXRecordDecl *Pattern = CTD->getTemplatedDecl();
+      bool TypeOverride = isa<TypeDecl>(D);
+      for (const NamedDecl *ND : Pattern->lookup(D->getDeclName())) {
+        if (const auto *CTD = dyn_cast<ClassTemplateDecl>(ND))
+          ND = CTD->getTemplatedDecl();
+        if (ND->isImplicit())
+          continue;
+        // Types can override other types.
+        if (!TypeOverride) {
+          if (ND->getKind() != D->getKind())
+            continue;
+        } else if (!isa<TypeDecl>(ND))
+          continue;
+        if (const auto *FD = dyn_cast<FunctionDecl>(ND)) {
+          const auto *DFD = cast<FunctionDecl>(D);
+          // Function overrides are approximated using the number of parameters.
+          if (FD->getStorageClass() != DFD->getStorageClass() ||
+              FD->getNumParams() != DFD->getNumParams())
+            continue;
+        }
+        Relations.emplace_back(
+            SymbolRoleSet(SymbolRole::RelationOverrideOf) |
+                SymbolRoleSet(SymbolRole::RelationSpecializationOf),
+            ND);
+      }
+    }
+  }
+
   bool VisitFunctionDecl(const FunctionDecl *D) {
     if (D->isDeleted())
       return true;
@@ -158,6 +205,7 @@ public:
         Relations.emplace_back((unsigned)SymbolRole::RelationOverrideOf, *I);
       }
     }
+    gatherTemplatePseudoOverrides(D, Relations);
 
     TRY_DECL(D, IndexCtx.handleDecl(D, Roles, Relations));
     handleDeclarator(D);
@@ -194,14 +242,18 @@ public:
   }
 
   bool VisitVarDecl(const VarDecl *D) {
-    TRY_DECL(D, IndexCtx.handleDecl(D));
+    SmallVector<SymbolRelation, 4> Relations;
+    gatherTemplatePseudoOverrides(D, Relations);
+    TRY_DECL(D, IndexCtx.handleDecl(D, SymbolRoleSet(), Relations));
     handleDeclarator(D);
     IndexCtx.indexBody(D->getInit(), D);
     return true;
   }
 
   bool VisitFieldDecl(const FieldDecl *D) {
-    TRY_DECL(D, IndexCtx.handleDecl(D));
+    SmallVector<SymbolRelation, 4> Relations;
+    gatherTemplatePseudoOverrides(D, Relations);
+    TRY_DECL(D, IndexCtx.handleDecl(D, SymbolRoleSet(), Relations));
     handleDeclarator(D);
     if (D->isBitField())
       IndexCtx.indexBody(D->getBitWidth(), D);
@@ -233,7 +285,9 @@ public:
 
   bool VisitTypedefNameDecl(const TypedefNameDecl *D) {
     if (!D->isTransparentTag()) {
-      TRY_DECL(D, IndexCtx.handleDecl(D));
+      SmallVector<SymbolRelation, 4> Relations;
+      gatherTemplatePseudoOverrides(D, Relations);
+      TRY_DECL(D, IndexCtx.handleDecl(D, SymbolRoleSet(), Relations));
       IndexCtx.indexTypeSourceInfo(D->getTypeSourceInfo(), D);
     }
     return true;
@@ -243,7 +297,9 @@ public:
     // Non-free standing tags are handled in indexTypeSourceInfo.
     if (D->isFreeStanding()) {
       if (D->isThisDeclarationADefinition()) {
-        IndexCtx.indexTagDecl(D);
+        SmallVector<SymbolRelation, 4> Relations;
+        gatherTemplatePseudoOverrides(D, Relations);
+        IndexCtx.indexTagDecl(D, Relations);
       } else {
         auto *Parent = dyn_cast<NamedDecl>(D->getDeclContext());
         return IndexCtx.handleReference(D, D->getLocation(), Parent,
diff --git a/clang/lib/Index/IndexingContext.cpp b/clang/lib/Index/IndexingContext.cpp
index 254abecd4e4..709a23657b0 100644
--- a/clang/lib/Index/IndexingContext.cpp
+++ b/clang/lib/Index/IndexingContext.cpp
@@ -28,6 +28,10 @@ bool IndexingContext::shouldIndex(const Decl *D) {
   return !isGeneratedDecl(D);
 }
 
+const LangOptions &IndexingContext::getLangOpts() const {
+  return Ctx->getLangOpts();
+}
+
 bool IndexingContext::shouldIndexFunctionLocalSymbols() const {
   return IndexOpts.IndexFunctionLocals;
 }
diff --git a/clang/lib/Index/IndexingContext.h b/clang/lib/Index/IndexingContext.h
index c70cb0a8272..566651c83a7 100644
--- a/clang/lib/Index/IndexingContext.h
+++ b/clang/lib/Index/IndexingContext.h
@@ -50,6 +50,8 @@ public:
 
   bool shouldIndex(const Decl *D);
 
+  const LangOptions &getLangOpts() const;
+
   bool shouldSuppressRefs() const {
     return false;
   }
diff --git a/clang/test/Index/Core/index-source.cpp b/clang/test/Index/Core/index-source.cpp
index 5d4a1be4568..76b8a150edb 100644
--- a/clang/test/Index/Core/index-source.cpp
+++ b/clang/test/Index/Core/index-source.cpp
@@ -111,3 +111,112 @@ template<>
 class PartialSpecilizationClass<int, int> { };
 // CHECK: [[@LINE-1]]:7 | class(Gen,TS)/C++ | PartialSpecilizationClass | c:@S@PartialSpecilizationClass>#I#I | <no-cgname> | Def,RelSpecialization | rel: 1
 // CHECK-NEXT: RelSpecialization | PartialSpecilizationClass | c:@ST>2#T#T@PartialSpecilizationClass
+
+template<typename T, typename S>
+class PseudoOverridesInSpecializations {
+  void function() { }
+  void function(int) { }
+
+  static void staticFunction() { }
+
+  int field;
+  static int variable;
+
+  typedef T TypeDef;
+  using TypeAlias = T;
+
+  enum anEnum { };
+
+  struct Struct { };
+  union Union { };
+
+  using TypealiasOrRecord = void;
+
+  template<typename U> struct InnerTemplate { };
+  template<typename U> struct InnerTemplate <U*> { };
+};
+
+template<>
+class PseudoOverridesInSpecializations<double, int> {
+  void function() { }
+// CHECK: [[@LINE-1]]:8 | instance-method/C++ | function | c:@S@PseudoOverridesInSpecializations>#d#I@F@function# | __ZN32PseudoOverridesInSpecializationsIdiE8functionEv | Def,RelChild,RelOver,RelSpecialization | rel: 2
+// CHECK-NEXT: RelChild
+// CHECK-NEXT: RelOver,RelSpecialization | function | c:@ST>2#T#T@PseudoOverridesInSpecializations@F@function#
+
+  void staticFunction() { }
+// CHECK: [[@LINE-1]]:8 | instance-method/C++ | staticFunction | c:@S@PseudoOverridesInSpecializations>#d#I@F@staticFunction# | __ZN32PseudoOverridesInSpecializationsIdiE14staticFunctionEv | Def,RelChild | rel: 1
+// CHECK-NOT: RelOver
+
+  int notOverridingField = 0;
+
+// CHECK-LABEL: checLabelBreak
+  int checLabelBreak = 0;
+
+  int field = 0;
+// CHECK: [[@LINE-1]]:7 | field/C++ | field | c:@S@PseudoOverridesInSpecializations>#d#I@FI@field | <no-cgname> | Def,RelChild,RelOver,RelSpecialization | rel: 2
+// CHECK-NEXT: RelChild
+// CHECK-NEXT: RelOver,RelSpecialization | field | c:@ST>2#T#T@PseudoOverridesInSpecializations@FI@field
+
+  static double variable;
+// CHECK: [[@LINE-1]]:17 | static-property/C++ | variable | c:@S@PseudoOverridesInSpecializations>#d#I@variable | __ZN32PseudoOverridesInSpecializationsIdiE8variableE | Decl,RelChild,RelOver,RelSpecialization | rel: 2
+// CHECK-NEXT: RelChild
+// CHECK-NEXT: RelOver,RelSpecialization | variable | c:@ST>2#T#T@PseudoOverridesInSpecializations@variable
+
+  typedef double TypeDef;
+// CHECK: [[@LINE-1]]:18 | type-alias/C | TypeDef | c:index-source.cpp@S@PseudoOverridesInSpecializations>#d#I@T@TypeDef | <no-cgname> | Def,RelChild,RelOver,RelSpecialization | rel: 2
+// CHECK-NEXT: RelChild
+// CHECK-NEXT: RelOver,RelSpecialization | TypeDef | c:index-source.cpp@ST>2#T#T@PseudoOverridesInSpecializations@T@TypeDef
+
+  using TypeAlias = int;
+// CHECK: [[@LINE-1]]:9 | type-alias/C++ | TypeAlias | c:@S@PseudoOverridesInSpecializations>#d#I@TypeAlias | <no-cgname> | Def,RelChild,RelOver,RelSpecialization | rel: 2
+// CHECK-NEXT: RelChild
+// CHECK-NEXT: RelOver,RelSpecialization | TypeAlias | c:@ST>2#T#T@PseudoOverridesInSpecializations@TypeAlias
+
+  enum anEnum { };
+// CHECK: [[@LINE-1]]:8 | enum/C | anEnum | c:@S@PseudoOverridesInSpecializations>#d#I@E@anEnum | <no-cgname> | Def,RelChild,RelOver,RelSpecialization | rel: 2
+// CHECK-NEXT: RelChild
+// CHECK-NEXT: RelOver,RelSpecialization | anEnum | c:@ST>2#T#T@PseudoOverridesInSpecializations@E@anEnum
+  class Struct { };
+// CHECK: [[@LINE-1]]:9 | class/C++ | Struct | c:@S@PseudoOverridesInSpecializations>#d#I@S@Struct | <no-cgname> | Def,RelChild,RelOver,RelSpecialization | rel: 2
+// CHECK-NEXT: RelChild
+// CHECK-NEXT: RelOver,RelSpecialization | Struct | c:@ST>2#T#T@PseudoOverridesInSpecializations@S@Struct
+  union Union { };
+// CHECK: [[@LINE-1]]:9 | union/C | Union | c:@S@PseudoOverridesInSpecializations>#d#I@U@Union | <no-cgname> | Def,RelChild,RelOver,RelSpecialization | rel: 2
+// CHECK-NEXT: RelChild
+// CHECK-NEXT: RelOver,RelSpecialization | Union | c:@ST>2#T#T@PseudoOverridesInSpecializations@U@Union
+
+  struct TypealiasOrRecord { };
+// CHECK: [[@LINE-1]]:10 | struct/C | TypealiasOrRecord | c:@S@PseudoOverridesInSpecializations>#d#I@S@TypealiasOrRecord | <no-cgname> | Def,RelChild,RelOver,RelSpecialization | rel: 2
+// CHECK-NEXT: RelChild
+// CHECK-NEXT: RelOver,RelSpecialization | TypealiasOrRecord | c:@ST>2#T#T@PseudoOverridesInSpecializations@TypealiasOrRecord
+
+  template<typename U> struct InnerTemplate { };
+// CHECK: [[@LINE-1]]:31 | struct(Gen)/C++ | InnerTemplate | c:@S@PseudoOverridesInSpecializations>#d#I@ST>1#T@InnerTemplate | <no-cgname> | Def,RelChild,RelOver,RelSpecialization | rel: 2
+// CHECK-NEXT: RelChild
+// CHECK-NEXT: RelOver,RelSpecialization | InnerTemplate | c:@ST>2#T#T@PseudoOverridesInSpecializations@ST>1#T@InnerTemplate
+  template<typename U> struct InnerTemplate <U*> { };
+// CHECK-NOT: RelOver
+};
+
+template<typename S>
+class PseudoOverridesInSpecializations<float, S> {
+  typedef float TypealiasOrRecord;
+// CHECK: [[@LINE-1]]:17 | type-alias/C | TypealiasOrRecord | c:index-source.cpp@SP>1#T@PseudoOverridesInSpecializations>#f#t0.0@T@TypealiasOrRecord | <no-cgname> | Def,RelChild,RelOver,RelSpecialization | rel: 2
+// CHECK-NEXT: RelChild
+// CHECK-NEXT: RelOver,RelSpecialization | TypealiasOrRecord | c:@ST>2#T#T@PseudoOverridesInSpecializations@TypealiasOrRecord
+};
+
+template<typename T, typename U>
+class ConflictingPseudoOverridesInSpecialization {
+  void foo(T x);
+  void foo(U x);
+};
+
+template<typename T>
+class ConflictingPseudoOverridesInSpecialization<int, T> {
+  void foo(T x);
+// CHECK: [[@LINE-1]]:8 | instance-method/C++ | foo | c:@SP>1#T@ConflictingPseudoOverridesInSpecialization>#I#t0.0@F@foo#S0_# | <no-cgname> | Decl,RelChild,RelOver,RelSpecialization | rel: 3
+// CHECK-NEXT: RelChild
+// CHECK-NEXT: RelOver,RelSpecialization | foo | c:@ST>2#T#T@ConflictingPseudoOverridesInSpecialization@F@foo#t0.0#
+// CHECK-NEXT: RelOver,RelSpecialization | foo | c:@ST>2#T#T@ConflictingPseudoOverridesInSpecialization@F@foo#t0.1#
+};