[libclang] In ASTUnit::Parse copy the CompilerInvocation object instead of

modifying directly for the preamble.

This avoids an awful, hard to find, bug where "PreprocessorOpts.DisablePCHValidation = true"
would be persistent for subsequent reparses of the translation unit which would result
in defines, present in command-line but not in the PCH, being ignored.

Fixes rdar://9615399.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139512 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Frontend/ASTUnit.cpp

@@ -879,7 +879,10 @@ bool ASTUnit::Parse(llvm::MemoryBuffer *OverrideMainBuffer) {
   llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
     CICleanup(Clang.get());
 
-  Clang->setInvocation(&*Invocation);
+  llvm::IntrusiveRefCntPtr<CompilerInvocation>
+    CCInvocation(new CompilerInvocation(*Invocation));
+
+  Clang->setInvocation(CCInvocation.getPtr());
   OriginalSourceFile = Clang->getFrontendOpts().Inputs[0].second;
     
   // Set up diagnostics, capturing any diagnostics that would
@@ -942,13 +945,11 @@ bool ASTUnit::Parse(llvm::MemoryBuffer *OverrideMainBuffer) {
   PreprocessorOptions &PreprocessorOpts = Clang->getPreprocessorOpts();
   PreprocessorOpts.DetailedRecordIncludesNestedMacroExpansions
     = NestedMacroExpansions;
-  std::string PriorImplicitPCHInclude;
   if (OverrideMainBuffer) {
     PreprocessorOpts.addRemappedFile(OriginalSourceFile, OverrideMainBuffer);
     PreprocessorOpts.PrecompiledPreambleBytes.first = Preamble.size();
     PreprocessorOpts.PrecompiledPreambleBytes.second
                                                     = PreambleEndsAtStartOfLine;
-    PriorImplicitPCHInclude = PreprocessorOpts.ImplicitPCHInclude;
     PreprocessorOpts.ImplicitPCHInclude = PreambleFile;
     PreprocessorOpts.DisablePCHValidation = true;
     
@@ -967,9 +968,6 @@ bool ASTUnit::Parse(llvm::MemoryBuffer *OverrideMainBuffer) {
 
     // Keep track of the override buffer;
     SavedMainFileBuffer = OverrideMainBuffer;
-  } else {
-    PreprocessorOpts.PrecompiledPreambleBytes.first = 0;
-    PreprocessorOpts.PrecompiledPreambleBytes.second = false;
   }
   
   llvm::OwningPtr<TopLevelDeclTrackerAction> Act(
@@ -1003,21 +1001,11 @@ bool ASTUnit::Parse(llvm::MemoryBuffer *OverrideMainBuffer) {
   
   Act->EndSourceFile();
 
-  // Remove the overridden buffer we used for the preamble.
-  if (OverrideMainBuffer) {
-    PreprocessorOpts.eraseRemappedFile(
-                               PreprocessorOpts.remapped_file_buffer_end() - 1);
-    PreprocessorOpts.ImplicitPCHInclude = PriorImplicitPCHInclude;
-  }
-
   return false;
 
 error:
   // Remove the overridden buffer we used for the preamble.
   if (OverrideMainBuffer) {
-    PreprocessorOpts.eraseRemappedFile(
-                               PreprocessorOpts.remapped_file_buffer_end() - 1);
-    PreprocessorOpts.ImplicitPCHInclude = PriorImplicitPCHInclude;
     delete OverrideMainBuffer;
     SavedMainFileBuffer = 0;
   }

lib/Serialization/ASTReader.cpp

@@ -2595,7 +2595,11 @@ ASTReader::ASTReadResult ASTReader::ReadAST(const std::string &FileName,
   // Here comes stuff that we only do once the entire chain is loaded.
   
   // Check the predefines buffers.
-  if (!DisableValidation && Type != MK_Module && CheckPredefinesBuffers())
+  if (!DisableValidation && Type != MK_Module && Type != MK_Preamble &&
+      // FIXME: CheckPredefinesBuffers also sets the SuggestedPredefines;
+      // if DisableValidation is true, defines that were set on command-line
+      // but not in the PCH file will not be added to SuggestedPredefines.
+      CheckPredefinesBuffers())
     return IgnorePCH;
 
   // Initialization of keywords and pragmas occurs before the

test/Index/preamble-reparse-cmd-define.c

@@ -0,0 +1,9 @@
+// RUN: c-index-test -write-pch %t.h.pch %s.h
+// RUN: env CINDEXTEST_EDITING=1 CINDEXTEST_REMAP_AFTER_TRIAL=1 c-index-test -test-load-source-reparse 3 local \ 
+// RUN:           "-remap-file=%s;%s.remap" %s -include %t.h -D CMD_MACRO=1 2>&1 | FileCheck %s
+
+// CHECK-NOT: error:
+
+int foo() {
+  return x;
+}

test/Index/preamble-reparse-cmd-define.c.h

@@ -0,0 +1 @@
+extern int x;

test/Index/preamble-reparse-cmd-define.c.remap

@@ -0,0 +1,8 @@
+
+#ifndef CMD_MACRO
+#error CMD_MACRO undefined
+#endif 
+
+int foo() {
+  return x;
+}