Reimplement the structural-equality checks used to determine whether

two types in different AST contexts are equivalent. Rather than
transforming the type from one context into the other context, we
perform a deep structural comparison of the types. This change
addresses a serious problem with recursive data types like

  struct ListNode {
    int value;
    struct ListNode *Next;
  } xList;

llvm-svn: 96278

clang/include/clang/AST/ASTImporter.h

@@ -193,6 +193,9 @@ namespace clang {
     /// \brief Retrieve the file manager that AST nodes are being imported from.
     FileManager &getFromFileManager() const { return FromFileManager; }
 
+    /// \brief Retrieve the diagnostic formatter.
+    Diagnostic &getDiags() const { return Diags; }
+    
     /// \brief Report a diagnostic in the "to" context.
     DiagnosticBuilder ToDiag(SourceLocation Loc, unsigned DiagID);
     

clang/include/clang/AST/Type.h

@@ -1193,7 +1193,8 @@ protected:
   }
 public:
   bool isSpelledAsLValue() const { return SpelledAsLValue; }
-
+  bool isInnerRef() const { return InnerRef; }
+  
   QualType getPointeeTypeAsWritten() const { return PointeeType; }
   QualType getPointeeType() const {
     // FIXME: this might strip inner qualifiers; okay?
@@ -2582,6 +2583,12 @@ public:
   /// interface type, or 0 if there are none.
   unsigned getNumProtocols() const { return NumProtocols; }
 
+  /// \brief Retrieve the Ith protocol.
+  ObjCProtocolDecl *getProtocol(unsigned I) const {
+    assert(I < getNumProtocols() && "Out-of-range protocol access");
+    return qual_begin()[I];
+  }
+  
   /// qual_iterator and friends: this provides access to the (potentially empty)
   /// list of protocols qualifying this interface.
   typedef ObjCProtocolDecl*  const * qual_iterator;
@@ -2683,6 +2690,12 @@ public:
   /// interface type, or 0 if there are none.
   unsigned getNumProtocols() const { return NumProtocols; }
 
+  /// \brief Retrieve the Ith protocol.
+  ObjCProtocolDecl *getProtocol(unsigned I) const {
+    assert(I < getNumProtocols() && "Out-of-range protocol access");
+    return qual_begin()[I];
+  }
+  
   bool isSugared() const { return false; }
   QualType desugar() const { return QualType(this, 0); }
 

clang/test/ASTMerge/Inputs/struct1.c

@@ -44,10 +44,14 @@ struct S9 { int i; float f; } *x9;
 // Incomplete type
 struct S10 *x10;
 
-// FIXME: Matches, but crashes the importer
-#if 0
+// Matches
 struct ListNode {
   int value;
   struct ListNode *Next;
 } xList;
-#endif
+
+// Mismatch due to struct used internally
+struct DeepError {
+  int value;
+  struct DeeperError { int i; int f; } *Deeper;
+} xDeep;

clang/test/ASTMerge/Inputs/struct2.c

@@ -46,3 +46,9 @@ struct ListNode {
   int value;
   struct ListNode *Next;
 } xList;
+
+// Mismatch due to struct used internally
+struct DeepError {
+  int value;
+  struct DeeperError { int i; float f; } *Deeper;
+} xDeep;

clang/test/ASTMerge/struct.c

@@ -31,4 +31,9 @@
 // CHECK: struct2.c:33:33: note: bit-field 'j' with type 'unsigned int' and length 16 here
 // CHECK: struct2.c:33:43: error: external variable 'x7' declared with incompatible types in different translation units ('struct S7' vs. 'struct S7')
 // CHECK: struct1.c:36:42: note: declared here with type 'struct S7'
-// CHECK: 29 diagnostics
+// CHECK: struct1.c:56:10: warning: type 'struct DeeperError' has incompatible definitions in different translation units
+// CHECK: struct1.c:56:35: note: field 'f' has type 'int' here
+// CHECK: struct2.c:53:37: note: field 'f' has type 'float' here
+// CHECK: struct2.c:54:3: error: external variable 'xDeep' declared with incompatible types in different translation units ('struct DeepError' vs. 'struct DeepError')
+// CHECK: struct1.c:57:3: note: declared here with type 'struct DeepError'
+// CHECK: 37 diagnostics