Merge pull request swiftlang#19005 from nkcsgexi/request-usr-gen

IDE: refactor USR generation to request evaluator model.

Author: nkcsgexi

include/swift/AST/TypeCheckRequests.h

@@ -297,6 +297,31 @@ class RequirementRequest :
   void cacheResult(Requirement value) const;
 };
 
+/// Generate the USR for the given declaration.
+class USRGenerationRequest :
+    public SimpleRequest<USRGenerationRequest,
+                         CacheKind::Cached,
+                         std::string,
+                         const ValueDecl*>
+{
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend class SimpleRequest;
+
+  // Evaluation.
+  llvm::Expected<std::string> evaluate(Evaluator &eval, const ValueDecl* d) const;
+
+public:
+  // Cycle handling
+  void diagnoseCycle(DiagnosticEngine &diags) const;
+  void noteCycleStep(DiagnosticEngine &diags) const;
+
+  // Caching
+  bool isCached() const { return true; }
+};
+
 /// The zone number for the type checker.
 #define SWIFT_TYPE_CHECKER_REQUESTS_TYPEID_ZONE 10
 

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -21,3 +21,4 @@ SWIFT_TYPEID(OverriddenDeclsRequest)
 SWIFT_TYPEID(IsObjCRequest)
 SWIFT_TYPEID(IsDynamicRequest)
 SWIFT_TYPEID(RequirementRequest)
+SWIFT_TYPEID(USRGenerationRequest)

include/swift/Basic/CTypeIDZone.def

@@ -32,6 +32,7 @@ SWIFT_TYPEID_NAMED(double, Double)
 SWIFT_TYPEID_NAMED(bool, Bool)
 SWIFT_TYPEID_NAMED(decltype(nullptr), NullPtr)
 SWIFT_TYPEID_NAMED(void, Void)
+SWIFT_TYPEID_NAMED(std::string, String)
 
 // C++ standard library types.
 SWIFT_TYPEID_TEMPLATE1_NAMED(std::vector, Vector, typename T, T)

include/swift/Basic/SimpleDisplay.h

@@ -49,6 +49,7 @@ namespace swift {
   HAS_TRIVIAL_DISPLAY(float);
   HAS_TRIVIAL_DISPLAY(double);
   HAS_TRIVIAL_DISPLAY(bool);
+  HAS_TRIVIAL_DISPLAY(std::string);
 
 #undef HAS_TRIVIAL_DISPLAY
 

lib/AST/TypeCheckRequests.cpp

@@ -412,3 +412,19 @@ void RequirementRequest::cacheResult(Requirement value) const {
     break;
   }
 }
+
+//----------------------------------------------------------------------------//
+// USR computation.
+//----------------------------------------------------------------------------//
+
+void USRGenerationRequest::diagnoseCycle(DiagnosticEngine &diags) const {
+  const auto &storage = getStorage();
+  auto &d = std::get<0>(storage);
+  diags.diagnose(d, diag::circular_reference);
+}
+
+void USRGenerationRequest::noteCycleStep(DiagnosticEngine &diags) const {
+  const auto &storage = getStorage();
+  auto &d = std::get<0>(storage);
+  diags.diagnose(d, diag::circular_reference);
+}

lib/AST/USRGeneration.cpp

@@ -15,6 +15,7 @@
 #include "swift/AST/USRGeneration.h"
 #include "swift/AST/ASTMangler.h"
 #include "swift/AST/SwiftNameTranslation.h"
+#include "swift/AST/TypeCheckRequests.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/raw_ostream.h"
@@ -163,13 +164,14 @@ static bool shouldUseObjCUSR(const Decl *D) {
   return false;
 }
 
-bool ide::printDeclUSR(const ValueDecl *D, raw_ostream &OS) {
+llvm::Expected<std::string>
+swift::USRGenerationRequest::evaluate(Evaluator &evaluator, const ValueDecl* D) const {
   if (!D->hasName() && !isa<ParamDecl>(D) && !isa<AccessorDecl>(D))
-    return true; // Ignore.
+    return std::string(); // Ignore.
   if (D->getModuleContext()->isBuiltinModule())
-    return true; // Ignore.
+    return std::string(); // Ignore.
   if (isa<ModuleDecl>(D))
-    return true; // Ignore.
+    return std::string(); // Ignore.
 
   auto interpretAsClangNode = [](const ValueDecl *D)->ClangNode {
     ClangNode ClangN = D->getClangNode();
@@ -200,13 +202,17 @@ bool ide::printDeclUSR(const ValueDecl *D, raw_ostream &OS) {
     return ClangN;
   };
 
+  llvm::SmallString<128> Buffer;
+  llvm::raw_svector_ostream OS(Buffer);
+
   if (ClangNode ClangN = interpretAsClangNode(D)) {
-    llvm::SmallString<128> Buf;
     if (auto ClangD = ClangN.getAsDecl()) {
-      bool Ignore = clang::index::generateUSRForDecl(ClangD, Buf);
-      if (!Ignore)
-        OS << Buf.str();
-      return Ignore;
+      bool Ignore = clang::index::generateUSRForDecl(ClangD, Buffer);
+      if (!Ignore) {
+        return Buffer.str();
+      } else {
+        return std::string();
+      }
     }
 
     auto &Importer = *D->getASTContext().getClangModuleLoader();
@@ -215,30 +221,41 @@ bool ide::printDeclUSR(const ValueDecl *D, raw_ostream &OS) {
     bool Ignore = clang::index::generateUSRForMacro(
         D->getBaseName().getIdentifier().str(),
         ClangMacroInfo->getDefinitionLoc(),
-        Importer.getClangASTContext().getSourceManager(), Buf);
+        Importer.getClangASTContext().getSourceManager(), Buffer);
     if (!Ignore)
-      OS << Buf.str();
-    return Ignore;
+      return Buffer.str();
+    else
+      return std::string();
   }
 
   if (shouldUseObjCUSR(D)) {
-    return printObjCUSR(D, OS);
+    if (printObjCUSR(D, OS)) {
+      return std::string();
+    } else {
+      return OS.str();
+    }
   }
 
   if (!D->hasInterfaceType())
-    return true;
+    return std::string();
 
   // Invalid code.
   if (D->getInterfaceType().findIf([](Type t) -> bool {
         return t->is<ModuleType>();
       }))
-    return true;
+    return std::string();
 
   Mangle::ASTMangler NewMangler;
-  std::string Mangled = NewMangler.mangleDeclAsUSR(D, getUSRSpacePrefix());
-
-  OS << Mangled;
+  return NewMangler.mangleDeclAsUSR(D, getUSRSpacePrefix());
+}
 
+bool ide::printDeclUSR(const ValueDecl *D, raw_ostream &OS) {
+  auto result = evaluateOrDefault(D->getASTContext().evaluator,
+                                  USRGenerationRequest { D },
+                                  std::string());
+  if (result.empty())
+    return true;
+  OS << result;
   return false;
 }