[SymbolGraph][CursorInfo] Add option to SourceKit's CursorInfo request to include the SymbolGraph JSON

include/swift/SymbolGraphGen/SymbolGraphGen.h

@@ -14,14 +14,26 @@
 #define SWIFT_SYMBOLGRAPHGEN_SYMBOLGRAPHGEN_H
 
 #include "swift/AST/Module.h"
+#include "swift/AST/Type.h"
 #include "SymbolGraphOptions.h"
 
 namespace swift {
+class ValueDecl;
+
 namespace symbolgraphgen {
 
 /// Emit a Symbol Graph JSON file for a module.
 int emitSymbolGraphForModule(ModuleDecl *M, const SymbolGraphOptions &Options);
 
+/// Print a Symbol Graph containing a single node for the given decl.
+///
+/// \returns \c EXIT_SUCCESS if the kind of the provided node is supported and
+/// its Symbo lGraph was printed, or \c EXIT_FAILURE otherwise.
+int printSymbolGraphForDecl(const ValueDecl *D, Type BaseTy,
+                             bool InSynthesizedExtensions,
+                             const SymbolGraphOptions &Options,
+                             llvm::raw_ostream &OS);
+
 } // end namespace symbolgraphgen
 } // end namespace swift
 

lib/AST/ASTPrinter.cpp

@@ -750,8 +750,14 @@ class PrintAST : public ASTVisitor<PrintAST> {
       else if (auto *ED = dyn_cast<ExtensionDecl>(Current))
         subMap = CurrentType->getContextSubstitutionMap(M, ED);
       else {
+        Decl *subTarget = Current;
+        if (isa<ParamDecl>(Current)) {
+          auto *DC = Current->getDeclContext();
+          if (auto *FD = dyn_cast<AbstractFunctionDecl>(DC))
+            subTarget = FD;
+        }
         subMap = CurrentType->getMemberSubstitutionMap(
-          M, cast<ValueDecl>(Current));
+          M, cast<ValueDecl>(subTarget));
       }
 
       T = T.subst(subMap, SubstFlags::DesugarMemberTypes);

lib/SymbolGraphGen/DeclarationFragmentPrinter.cpp

@@ -140,9 +140,11 @@ void DeclarationFragmentPrinter::printTypeRef(Type T, const TypeDecl *RefTo,
   USR.clear();
 
   auto ShouldLink = Name.str() != "Self";
-  if (const auto *TD = T->getAnyNominal()) {
-    if (SG->isImplicitlyPrivate(TD)) {
-      ShouldLink = false;
+  if (T) {
+    if (const auto *TD = T->getAnyNominal()) {
+      if (SG->isImplicitlyPrivate(TD)) {
+        ShouldLink = false;
+      }
     }
   }
 

lib/SymbolGraphGen/Edge.cpp

@@ -47,7 +47,7 @@ void Edge::serialize(llvm::json::OStream &OS) const {
           ConformanceExtension->getGenericRequirements(),
           ConformanceExtension->getExtendedNominal()
               ->getDeclContext()->getSelfNominalTypeDecl(),
-                                FilteredRequirements);
+          FilteredRequirements);
       if (!FilteredRequirements.empty()) {
         OS.attributeArray("swiftConstraints", [&](){
           for (const auto &Req :

lib/SymbolGraphGen/JSON.cpp

@@ -13,7 +13,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "swift/AST/Decl.h"
+#include "swift/AST/GenericParamList.h"
 #include "swift/AST/Module.h"
+#include "swift/AST/Type.h"
 #include "JSON.h"
 
 void swift::symbolgraphgen::serialize(const llvm::VersionTuple &VT,
@@ -115,10 +117,75 @@ void swift::symbolgraphgen::serialize(const swift::GenericTypeParamType *Param,
   });
 }
 
+void
+swift::symbolgraphgen::filterGenericParams(
+    TypeArrayView<GenericTypeParamType> GenericParams,
+    SmallVectorImpl<const GenericTypeParamType*> &FilteredParams,
+    SubstitutionMap SubMap) {
+
+  for (auto Param : GenericParams) {
+    if (const auto *GPD = Param->getDecl()) {
+
+      // Ignore the implicit Self param
+      if (GPD->isImplicit()) {
+        if (!isa<ExtensionDecl>(GPD->getDeclContext()))
+          continue;
+
+        // Extension decls (and their children) refer to implicit copies of the
+        // explicit params of the nominal they extend. Don't filter those out.
+        auto *ED = cast<ExtensionDecl>(GPD->getDeclContext());
+        if (auto *NTD = ED->getExtendedNominal()) {
+          if (auto *GPL = NTD->getGenericParams()) {
+            auto ImplicitAndSameName = [&](GenericTypeParamDecl *NominalGPD) {
+              return NominalGPD->isImplicit() &&
+                  GPD->getName() == NominalGPD->getName();
+            };
+            if (llvm::any_of(GPL->getParams(), ImplicitAndSameName))
+              continue;
+          }
+        }
+      }
+
+      // Ignore parameters that have been substituted.
+      if (!SubMap.empty()) {
+        Type SubTy = Type(Param).subst(SubMap);
+        if (!SubTy->hasError() && SubTy.getPointer() != Param) {
+          if (!SubTy->is<ArchetypeType>()) {
+            continue;
+          }
+          auto AT = SubTy->castTo<ArchetypeType>();
+          if (!AT->getInterfaceType()->isEqual(Param)) {
+            continue;
+          }
+        }
+      }
+
+      FilteredParams.push_back(Param);
+    }
+  }
+}
+
+static bool containsParams(swift::Type Ty, llvm::ArrayRef<const swift::GenericTypeParamType*> Others) {
+  return Ty.findIf([&](swift::Type T) -> bool {
+    if (auto AT = T->getAs<swift::ArchetypeType>()) {
+      T = AT->getInterfaceType();
+    }
+
+    for (auto *Param: Others) {
+      if (T->isEqual(const_cast<swift::GenericTypeParamType*>(Param)))
+        return true;
+    }
+    return false;
+  });
+}
+
 void swift::symbolgraphgen::filterGenericRequirements(
     ArrayRef<Requirement> Requirements,
     const NominalTypeDecl *Self,
-    SmallVectorImpl<Requirement> &FilteredRequirements) {
+    SmallVectorImpl<Requirement> &FilteredRequirements,
+    SubstitutionMap SubMap,
+    ArrayRef<const GenericTypeParamType *> FilteredParams) {
+
   for (const auto &Req : Requirements) {
     if (Req.getKind() == RequirementKind::Layout) {
       continue;
@@ -130,10 +197,29 @@ void swift::symbolgraphgen::filterGenericRequirements(
     if (Req.getSecondType()->getAnyNominal() == Self) {
       continue;
     }
-    FilteredRequirements.push_back(Req);
+
+    // Ignore requirements that don't involve the filtered set of generic
+    // parameters after substitution.
+    if (!SubMap.empty()) {
+      Type SubFirst = Req.getFirstType().subst(SubMap);
+      if (SubFirst->hasError())
+        SubFirst = Req.getFirstType();
+      Type SubSecond = Req.getSecondType().subst(SubMap);
+      if (SubSecond->hasError())
+        SubSecond = Req.getSecondType();
+
+      if (!containsParams(SubFirst, FilteredParams) &&
+          !containsParams(SubSecond, FilteredParams))
+        continue;
+
+      // Use the same requirement kind with the substituted types.
+      FilteredRequirements.emplace_back(Req.getKind(), SubFirst, SubSecond);
+    } else {
+      // Use the original requirement.
+      FilteredRequirements.push_back(Req);
+    }
   }
 }
-
 void
 swift::symbolgraphgen::filterGenericRequirements(const ExtensionDecl *Extension,
     SmallVectorImpl<Requirement> &FilteredRequirements) {

lib/SymbolGraphGen/JSON.h

@@ -19,6 +19,7 @@
 #include "llvm/Support/JSON.h"
 #include "llvm/Support/VersionTuple.h"
 #include "swift/AST/GenericSignature.h"
+#include "swift/AST/SubstitutionMap.h"
 #include "swift/AST/Type.h"
 
 namespace swift {
@@ -41,16 +42,20 @@ void serialize(const llvm::VersionTuple &VT, llvm::json::OStream &OS);
 void serialize(const llvm::Triple &T, llvm::json::OStream &OS);
 void serialize(const ExtensionDecl *Extension, llvm::json::OStream &OS);
 void serialize(const Requirement &Req, llvm::json::OStream &OS);
-void serialize(const swift::GenericTypeParamType *Param,
-               llvm::json::OStream &OS);
+void serialize(const swift::GenericTypeParamType *Param, llvm::json::OStream &OS);
 
+void filterGenericParams(
+    TypeArrayView<GenericTypeParamType> GenericParams,
+    SmallVectorImpl<const GenericTypeParamType*> &FilteredParams,
+    SubstitutionMap SubMap = {});
 
 /// Filter generic requirements on an extension that aren't relevant
 /// for documentation.
-void
-filterGenericRequirements(ArrayRef<Requirement> Requirements,
-                          const NominalTypeDecl *Self,
-                          SmallVectorImpl<Requirement> &FilteredRequirements);
+void filterGenericRequirements(
+    ArrayRef<Requirement> Requirements, const NominalTypeDecl *Self,
+    SmallVectorImpl<Requirement> &FilteredRequirements,
+    SubstitutionMap SubMap = {},
+    ArrayRef<const GenericTypeParamType *> FilteredParams = {});
 
 /// Filter generic requirements on an extension that aren't relevant
 /// for documentation.

lib/SymbolGraphGen/Symbol.cpp

@@ -26,10 +26,15 @@ using namespace swift;
 using namespace symbolgraphgen;
 
 Symbol::Symbol(SymbolGraph *Graph, const ValueDecl *VD,
-               const NominalTypeDecl *SynthesizedBaseTypeDecl)
+               const NominalTypeDecl *SynthesizedBaseTypeDecl,
+               Type BaseType)
 : Graph(Graph),
   VD(VD),
-  SynthesizedBaseTypeDecl(SynthesizedBaseTypeDecl) {}
+  BaseType(BaseType),
+  SynthesizedBaseTypeDecl(SynthesizedBaseTypeDecl) {
+    if (!BaseType && SynthesizedBaseTypeDecl)
+      BaseType = SynthesizedBaseTypeDecl->getDeclaredInterfaceType();
+  }
 
 void Symbol::serializeKind(StringRef Identifier, StringRef DisplayName,
                            llvm::json::OStream &OS) const {
@@ -40,6 +45,9 @@ void Symbol::serializeKind(StringRef Identifier, StringRef DisplayName,
 }
 
 void Symbol::serializeKind(llvm::json::OStream &OS) const {
+  // supportsKind and serializeKind must agree.
+  assert(Symbol::supportsKind(VD->getKind()) && "unsupported decl kind");
+
   AttributeRAII A("kind", OS);
   switch (VD->getKind()) {
   case swift::DeclKind::Class:
@@ -244,7 +252,8 @@ void Symbol::serializeFunctionSignature(llvm::json::OStream &OS) const {
                 }
                 Graph->serializeDeclarationFragments("declarationFragments",
                                                      Symbol(Graph, Param,
-                                                            nullptr), OS);
+                                                            getSynthesizedBaseTypeDecl(),
+                                                            getBaseType()), OS);
               }); // end parameter object
             }
           }); // end parameters:
@@ -253,35 +262,62 @@ void Symbol::serializeFunctionSignature(llvm::json::OStream &OS) const {
 
       // Returns
       if (const auto ReturnType = FD->getResultInterfaceType()) {
-        Graph->serializeDeclarationFragments("returns", ReturnType, OS);
+        Graph->serializeDeclarationFragments("returns", ReturnType, BaseType,
+                                             OS);
       }
     });
   }
 }
 
+static SubstitutionMap getSubMapForDecl(const ValueDecl *D, Type BaseType) {
+  if (!BaseType || BaseType->isExistentialType())
+    return {};
+
+  // Map from the base type into the this declaration's innermost type context,
+  // or if we're dealing with an extention rather than a member, into its
+  // extended nominal (the extension's own requirements shouldn't be considered
+  // in the substitution).
+  swift::DeclContext *DC;
+  if (isa<swift::ExtensionDecl>(D))
+    DC = cast<swift::ExtensionDecl>(D)->getExtendedNominal();
+  else
+    DC = D->getInnermostDeclContext()->getInnermostTypeContext();
+
+  swift::ModuleDecl *M = DC->getParentModule();
+  if (isa<swift::NominalTypeDecl>(D) || isa<swift::ExtensionDecl>(D)) {
+    return BaseType->getContextSubstitutionMap(M, DC);
+  }
+
+  const swift::ValueDecl *SubTarget = D;
+  if (isa<swift::ParamDecl>(D)) {
+    auto *DC = D->getDeclContext();
+    if (auto *FD = dyn_cast<swift::AbstractFunctionDecl>(DC))
+      SubTarget = FD;
+  }
+  return BaseType->getMemberSubstitutionMap(M, SubTarget);
+}
+
 void Symbol::serializeSwiftGenericMixin(llvm::json::OStream &OS) const {
+
+  SubstitutionMap SubMap;
+  if (BaseType)
+    SubMap = getSubMapForDecl(VD, BaseType);
+
   if (const auto *GC = VD->getAsGenericContext()) {
     if (const auto Generics = GC->getGenericSignature()) {
 
       SmallVector<const GenericTypeParamType *, 4> FilteredParams;
       SmallVector<Requirement, 4> FilteredRequirements;
-      for (const auto Param : Generics->getGenericParams()) {
-        if (const auto *D = Param->getDecl()) {
-          if (D->isImplicit()) {
-            continue;
-          }
-          FilteredParams.push_back(Param);
-        }
-      }
+      filterGenericParams(Generics->getGenericParams(), FilteredParams,
+                          SubMap);
 
       const auto *Self = dyn_cast<NominalTypeDecl>(VD);
       if (!Self) {
         Self = VD->getDeclContext()->getSelfNominalTypeDecl();
       }
 
-      filterGenericRequirements(Generics->getRequirements(),
-                                Self,
-                                FilteredRequirements);
+      filterGenericRequirements(Generics->getRequirements(), Self,
+                                FilteredRequirements, SubMap, FilteredParams);
 
       if (FilteredParams.empty() && FilteredRequirements.empty()) {
         return;
@@ -503,3 +539,23 @@ void Symbol::getUSR(SmallVectorImpl<char> &USR) const {
     ide::printDeclUSR(SynthesizedBaseTypeDecl, OS);
   }
 }
+
+bool Symbol::supportsKind(DeclKind Kind) {
+  switch (Kind) {
+  case DeclKind::Class: LLVM_FALLTHROUGH;
+  case DeclKind::Struct: LLVM_FALLTHROUGH;
+  case DeclKind::Enum: LLVM_FALLTHROUGH;
+  case DeclKind::EnumElement: LLVM_FALLTHROUGH;
+  case DeclKind::Protocol: LLVM_FALLTHROUGH;
+  case DeclKind::Constructor: LLVM_FALLTHROUGH;
+  case DeclKind::Destructor: LLVM_FALLTHROUGH;
+  case DeclKind::Func: LLVM_FALLTHROUGH;
+  case DeclKind::Var: LLVM_FALLTHROUGH;
+  case DeclKind::Subscript: LLVM_FALLTHROUGH;
+  case DeclKind::TypeAlias: LLVM_FALLTHROUGH;
+  case DeclKind::AssociatedType:
+    return true;
+  default:
+    return false;
+  }
+}