there i fixed it

Increase robustness of the delegating constructor cycle detection
mechanism. No more infinite loops on invalid or logic errors leading to
false results. Ensure that this is maintained correctly accross
serialization.

llvm-svn: 130887

clang/include/clang/Serialization/ASTBitCodes.h

@@ -362,7 +362,10 @@ namespace clang {
       FP_PRAGMA_OPTIONS = 42,
 
       /// \brief Record code for enabled OpenCL extensions.
-      OPENCL_EXTENSIONS = 43
+      OPENCL_EXTENSIONS = 43,
+
+      /// \brief The list of delegating constructor declarations.
+      DELEGATING_CTORS = 44
     };
 
     /// \brief Record types used within a source manager block.

clang/include/clang/Serialization/ASTReader.h

@@ -54,6 +54,7 @@ class Decl;
 class DeclContext;
 class NestedNameSpecifier;
 class CXXBaseSpecifier;
+class CXXConstructorDecl;
 class CXXCtorInitializer;
 class GotoStmt;
 class MacroDefinition;
@@ -564,6 +565,10 @@ private:
   /// generating warnings.
   llvm::SmallVector<uint64_t, 16> UnusedFileScopedDecls;
 
+  /// \brief A list of all the delegating constructors we've seen, to diagnose
+  /// cycles.
+  llvm::SmallVector<uint64_t, 4> DelegatingCtorDecls;
+
   /// \brief A snapshot of Sema's weak undeclared identifier tracking, for
   /// generating warnings.
   llvm::SmallVector<uint64_t, 64> WeakUndeclaredIdentifiers;

clang/lib/Sema/SemaDeclCXX.cpp

@@ -7945,52 +7945,85 @@ void Sema::SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation) {
   }
 }
 
+static
+void DelegatingCycleHelper(CXXConstructorDecl* Ctor,
+                           llvm::SmallSet<CXXConstructorDecl*, 4> &Valid,
+                           llvm::SmallSet<CXXConstructorDecl*, 4> &Invalid,
+                           llvm::SmallSet<CXXConstructorDecl*, 4> &Current,
+                           Sema &S) {
+  llvm::SmallSet<CXXConstructorDecl*, 4>::iterator CI = Current.begin(),
+                                                   CE = Current.end();
+  if (Ctor->isInvalidDecl())
+    return;
+
+  const FunctionDecl *FNTarget = 0;
+  CXXConstructorDecl *Target;
+  
+  // We ignore the result here since if we don't have a body, Target will be
+  // null below.
+  (void)Ctor->getTargetConstructor()->hasBody(FNTarget);
+  Target
+= const_cast<CXXConstructorDecl*>(cast_or_null<CXXConstructorDecl>(FNTarget));
+
+  CXXConstructorDecl *Canonical = Ctor->getCanonicalDecl(),
+                     // Avoid dereferencing a null pointer here.
+                     *TCanonical = Target ? Target->getCanonicalDecl() : 0;
+
+  if (!Current.insert(Canonical))
+    return;
+
+  // We know that beyond here, we aren't chaining into a cycle.
+  if (!Target || !Target->isDelegatingConstructor() ||
+      Target->isInvalidDecl() || Valid.count(TCanonical)) {
+    for (CI = Current.begin(), CE = Current.end(); CI != CE; ++CI)
+      Valid.insert(*CI);
+    Current.clear();
+  // We've hit a cycle.
+  } else if (TCanonical == Canonical || Invalid.count(TCanonical) ||
+             Current.count(TCanonical)) {
+    // If we haven't diagnosed this cycle yet, do so now.
+    if (!Invalid.count(TCanonical)) {
+      S.Diag((*Ctor->init_begin())->getSourceLocation(),
+             diag::err_delegating_ctor_cycle)
+        << Ctor;
+
+      // Don't add a note for a function delegating directo to itself.
+      if (TCanonical != Canonical)
+        S.Diag(Target->getLocation(), diag::note_it_delegates_to);
+
+      CXXConstructorDecl *C = Target;
+      while (C->getCanonicalDecl() != Canonical) {
+        (void)C->getTargetConstructor()->hasBody(FNTarget);
+        assert(FNTarget && "Ctor cycle through bodiless function");
+
+        C
+       = const_cast<CXXConstructorDecl*>(cast<CXXConstructorDecl>(FNTarget));
+        S.Diag(C->getLocation(), diag::note_which_delegates_to);
+      }
+    }
+
+    for (CI = Current.begin(), CE = Current.end(); CI != CE; ++CI)
+      Invalid.insert(*CI);
+    Current.clear();
+  } else {
+    DelegatingCycleHelper(Target, Valid, Invalid, Current, S);
+  }
+}
+   
+
 void Sema::CheckDelegatingCtorCycles() {
   llvm::SmallSet<CXXConstructorDecl*, 4> Valid, Invalid, Current;
 
-  llvm::SmallSet<CXXConstructorDecl*, 4>::iterator ci = Current.begin(),
-                                                   ce = Current.end();
+  llvm::SmallSet<CXXConstructorDecl*, 4>::iterator CI = Current.begin(),
+                                                   CE = Current.end();
 
   for (llvm::SmallVector<CXXConstructorDecl*, 4>::iterator
-         i = DelegatingCtorDecls.begin(),
-         e = DelegatingCtorDecls.end();
-       i != e; ++i) {
-    const FunctionDecl *FNTarget;
-    CXXConstructorDecl *Target;
-    (*i)->getTargetConstructor()->hasBody(FNTarget);
-    Target
-      = const_cast<CXXConstructorDecl*>(cast<CXXConstructorDecl>(FNTarget));
-
-    if (!Target || !Target->isDelegatingConstructor() || Valid.count(Target)) {
-      Valid.insert(*i);
-      for (ci = Current.begin(), ce = Current.end(); ci != ce; ++ci)
-        Valid.insert(*ci);
-      Current.clear();
-    } else if (Target == *i || Invalid.count(Target) || Current.count(Target)) {
-      if (!Invalid.count(Target)) {
-        Diag((*(*i)->init_begin())->getSourceLocation(),
-             diag::err_delegating_ctor_cycle)
-          << *i;
-        if (Target != *i)
-          Diag(Target->getLocation(), diag::note_it_delegates_to);
-        CXXConstructorDecl *Current = Target;
-        while (Current != *i) {
-          Current->getTargetConstructor()->hasBody(FNTarget);
-          Current
-         = const_cast<CXXConstructorDecl*>(cast<CXXConstructorDecl>(FNTarget));
-          Diag(Current->getLocation(), diag::note_which_delegates_to);
-        }
-      }
-
-      (*i)->setInvalidDecl();
-      Invalid.insert(*i);
-      for (ci = Current.begin(), ce = Current.end(); ci != ce; ++ci) {
-        (*ci)->setInvalidDecl();
-        Invalid.insert(*i);
-      }
-      Current.clear();
-    } else {
-      Current.insert(*i);
-    }
+         I = DelegatingCtorDecls.begin(),
+         E = DelegatingCtorDecls.end();
+       I != E; ++I) {
+   DelegatingCycleHelper(*I, Valid, Invalid, Current, *this);
   }
+
+  for (CI = Invalid.begin(), CE = Invalid.end(); CI != CE; ++CI)
+    (*CI)->setInvalidDecl();
 }

clang/lib/Serialization/ASTReader.cpp

@@ -2114,15 +2114,6 @@ ASTReader::ReadASTBlock(PerFileData &F) {
       TotalVisibleDeclContexts += Record[3];
       break;
 
-    case TENTATIVE_DEFINITIONS:
-      // Optimization for the first block.
-      if (TentativeDefinitions.empty())
-        TentativeDefinitions.swap(Record);
-      else
-        TentativeDefinitions.insert(TentativeDefinitions.end(),
-                                    Record.begin(), Record.end());
-      break;
-
     case UNUSED_FILESCOPED_DECLS:
       // Optimization for the first block.
       if (UnusedFileScopedDecls.empty())
@@ -2132,6 +2123,15 @@ ASTReader::ReadASTBlock(PerFileData &F) {
                                      Record.begin(), Record.end());
       break;
 
+    case DELEGATING_CTORS:
+      // Optimization for the first block.
+      if (DelegatingCtorDecls.empty())
+        DelegatingCtorDecls.swap(Record);
+      else
+        DelegatingCtorDecls.insert(DelegatingCtorDecls.end(),
+                                   Record.begin(), Record.end());
+      break;
+
     case WEAK_UNDECLARED_IDENTIFIERS:
       // Later blocks overwrite earlier ones.
       WeakUndeclaredIdentifiers.swap(Record);
@@ -2331,6 +2331,15 @@ ASTReader::ReadASTBlock(PerFileData &F) {
       // Later tables overwrite earlier ones.
       OpenCLExtensions.swap(Record);
       break;
+
+    case TENTATIVE_DEFINITIONS:
+      // Optimization for the first block.
+      if (TentativeDefinitions.empty())
+        TentativeDefinitions.swap(Record);
+      else
+        TentativeDefinitions.insert(TentativeDefinitions.end(),
+                                    Record.begin(), Record.end());
+      break;
     }
     First = false;
   }
@@ -4100,6 +4109,13 @@ void ASTReader::InitializeSema(Sema &S) {
     SemaObj->UnusedFileScopedDecls.push_back(D);
   }
 
+  // If there were any delegating constructors, add them to Sema's list
+  for (unsigned I = 0, N = DelegatingCtorDecls.size(); I != N; ++I) {
+    CXXConstructorDecl *D
+     = cast<CXXConstructorDecl>(GetDecl(DelegatingCtorDecls[I]));
+    SemaObj->DelegatingCtorDecls.push_back(D);
+  }
+
   // If there were any locally-scoped external declarations,
   // deserialize them and add them to Sema's table of locally-scoped
   // external declarations.

clang/lib/Serialization/ASTWriter.cpp

@@ -764,6 +764,7 @@ void ASTWriter::WriteBlockInfoBlock() {
   RECORD(HEADER_SEARCH_TABLE);
   RECORD(FP_PRAGMA_OPTIONS);
   RECORD(OPENCL_EXTENSIONS);
+  RECORD(DELEGATING_CTORS);
   
   // SourceManager Block.
   BLOCK(SOURCE_MANAGER_BLOCK);
@@ -2723,6 +2724,10 @@ void ASTWriter::WriteASTCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
   for (unsigned i=0, e = SemaRef.UnusedFileScopedDecls.size(); i !=e; ++i)
     AddDeclRef(SemaRef.UnusedFileScopedDecls[i], UnusedFileScopedDecls);
 
+  RecordData DelegatingCtorDecls;
+  for (unsigned i=0, e = SemaRef.DelegatingCtorDecls.size(); i != e; ++i)
+    AddDeclRef(SemaRef.DelegatingCtorDecls[i], DelegatingCtorDecls);
+
   RecordData WeakUndeclaredIdentifiers;
   if (!SemaRef.WeakUndeclaredIdentifiers.empty()) {
     WeakUndeclaredIdentifiers.push_back(
@@ -2897,6 +2902,10 @@ void ASTWriter::WriteASTCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
   // Write the record containing CUDA-specific declaration references.
   if (!CUDASpecialDeclRefs.empty())
     Stream.EmitRecord(CUDA_SPECIAL_DECL_REFS, CUDASpecialDeclRefs);
+  
+  // Write the delegating constructors.
+  if (!DelegatingCtorDecls.empty())
+    Stream.EmitRecord(DELEGATING_CTORS, DelegatingCtorDecls);
 
   // Some simple statistics
   Record.clear();
@@ -2971,6 +2980,14 @@ void ASTWriter::WriteASTChain(Sema &SemaRef, MemorizeStatCalls *StatCalls,
       AddDeclRef(SemaRef.UnusedFileScopedDecls[i], UnusedFileScopedDecls);
   }
 
+  // Build a record containing all of the delegating constructor decls in this
+  // file.
+  RecordData DelegatingCtorDecls;
+  for (unsigned i=0, e = SemaRef.DelegatingCtorDecls.size(); i != e; ++i) {
+    if (SemaRef.DelegatingCtorDecls[i]->getPCHLevel() == 0)
+      AddDeclRef(SemaRef.DelegatingCtorDecls[i], DelegatingCtorDecls);
+  }
+
   // We write the entire table, overwriting the tables from the chain.
   RecordData WeakUndeclaredIdentifiers;
   if (!SemaRef.WeakUndeclaredIdentifiers.empty()) {
@@ -3128,6 +3145,10 @@ void ASTWriter::WriteASTChain(Sema &SemaRef, MemorizeStatCalls *StatCalls,
   // Write the record containing declaration references of Sema.
   if (!SemaDeclRefs.empty())
     Stream.EmitRecord(SEMA_DECL_REFS, SemaDeclRefs);
+  
+  // Write the delegating constructors.
+  if (!DelegatingCtorDecls.empty())
+    Stream.EmitRecord(DELEGATING_CTORS, DelegatingCtorDecls);
 
   // Write the updates to DeclContexts.
   for (llvm::SmallPtrSet<const DeclContext *, 16>::iterator

clang/test/PCH/cxx0x-delegating-ctors.cpp

@@ -1,12 +1,20 @@
 // Test this without pch.
-// RUN: %clang_cc1 -include %S/cxx0x-delegating-ctors.h -std=c++0x -fsyntax-only -verify %s
+// RUN: %clang_cc1 -include %s -std=c++0x -fsyntax-only -verify %s
 
 // Test with pch.
-// RUN: %clang_cc1 -x c++-header -std=c++0x -emit-pch -o %t %S/cxx0x-delegating-ctors.h
+// RUN: %clang_cc1 -x c++-header -std=c++0x -emit-pch -o %t %s
 // RUN: %clang_cc1 -std=c++0x -include-pch %t -fsyntax-only -verify %s 
 
-// Currently we can't deal with a note in the header
-// XFAIL: *
-
+#ifndef PASS1
+#define PASS1
+struct foo {
+  foo(int) : foo() { } // expected-note{{it delegates to}}
+  foo();
+  foo(bool) : foo('c') { } // expected-note{{it delegates to}}
+  foo(char) : foo(true) { } // expected-error{{creates a delegation cycle}} \
+                            // expected-note{{which delegates to}}
+};
+#else
 foo::foo() : foo(1) { } // expected-error{{creates a delegation cycle}} \
                         // expected-note{{which delegates to}}
+#endif

clang/test/PCH/cxx0x-delegating-ctors.h

@@ -1,6 +0,0 @@
-// Header for PCH test cxx0x-delegating-ctors.cpp
-
-struct foo {
-  foo(int) : foo() { } // expected-note{{it delegates to}}
-  foo();
-};