From f18d0d8b39e891460d50f8a8b85029885b264986 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Thu, 12 Aug 2010 23:31:19 +0000
Subject: [PATCH] Teach CompilerInstance to create and hold on to the Sema
 object used for parsing, so that it can persist beyond the lifetime of the
 parsing call.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@110978 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/clang/Frontend/CompilerInstance.h | 24 +++++++++++++++++++++++
 lib/Frontend/CompilerInstance.cpp         | 12 ++++++++++++
 lib/Frontend/FrontendAction.cpp           | 18 +++++++++++------
 3 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/include/clang/Frontend/CompilerInstance.h b/include/clang/Frontend/CompilerInstance.h
index 4a4d5ae1d4..bd1791dae8 100644
--- a/include/clang/Frontend/CompilerInstance.h
+++ b/include/clang/Frontend/CompilerInstance.h
@@ -36,6 +36,7 @@ class FileManager;
 class FrontendAction;
 class PCHReader;
 class Preprocessor;
+class Sema;
 class SourceManager;
 class TargetInfo;
 
@@ -91,6 +92,9 @@ class CompilerInstance {
   /// The code completion consumer.
   llvm::OwningPtr<CodeCompleteConsumer> CompletionConsumer;
 
+  /// \brief The semantic analysis object.
+  llvm::OwningPtr<Sema> TheSema;
+  
   /// The frontend timer
   llvm::OwningPtr<llvm::Timer> FrontendTimer;
 
@@ -369,6 +373,10 @@ public:
   /// takes ownership of \arg Value.
   void setASTContext(ASTContext *Value);
 
+  /// \brief Replace the current Sema; the compiler instance takes ownership
+  /// of S.
+  void setSema(Sema *S);
+  
   /// }
   /// @name ASTConsumer
   /// {
@@ -388,6 +396,18 @@ public:
   /// takes ownership of \arg Value.
   void setASTConsumer(ASTConsumer *Value);
 
+  /// }
+  /// @name Semantic analysis
+  /// {
+  bool hasSema() const { return TheSema != 0; }
+  
+  Sema &getSema() const { 
+    assert(TheSema && "Compiler instance has no Sema object!");
+    return *TheSema;
+  }
+  
+  Sema *takeSema() { return TheSema.take(); }
+  
   /// }
   /// @name Code Completion
   /// {
@@ -526,6 +546,10 @@ public:
                                bool UseDebugPrinter, bool ShowMacros,
                                bool ShowCodePatterns, llvm::raw_ostream &OS);
 
+  /// \brief Create the Sema object to be used for parsing.
+  void createSema(bool CompleteTranslationUnit,
+                  CodeCompleteConsumer *CompletionConsumer);
+  
   /// Create the frontend timer and replace any existing one with it.
   void createFrontendTimer();
 
diff --git a/lib/Frontend/CompilerInstance.cpp b/lib/Frontend/CompilerInstance.cpp
index 76773e40d3..e2bb0f20db 100644
--- a/lib/Frontend/CompilerInstance.cpp
+++ b/lib/Frontend/CompilerInstance.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Frontend/CompilerInstance.h"
+#include "clang/Sema/Sema.h"
 #include "clang/AST/ASTConsumer.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/Basic/Diagnostic.h"
@@ -41,6 +42,7 @@ CompilerInstance::CompilerInstance()
 }
 
 CompilerInstance::~CompilerInstance() {
+  TheSema.reset();
 }
 
 void CompilerInstance::setLLVMContext(llvm::LLVMContext *Value) {
@@ -79,6 +81,10 @@ void CompilerInstance::setASTContext(ASTContext *Value) {
   Context.reset(Value);
 }
 
+void CompilerInstance::setSema(Sema *S) {
+  TheSema.reset(S);
+}
+
 void CompilerInstance::setASTConsumer(ASTConsumer *Value) {
   Consumer.reset(Value);
 }
@@ -362,6 +368,12 @@ CompilerInstance::createCodeCompletionConsumer(Preprocessor &PP,
     return new CIndexCodeCompleteConsumer(ShowMacros, ShowCodePatterns, OS);
 }
 
+void CompilerInstance::createSema(bool CompleteTranslationUnit,
+                                  CodeCompleteConsumer *CompletionConsumer) {
+  TheSema.reset(new Sema(getPreprocessor(), getASTContext(), getASTConsumer(),
+                         CompleteTranslationUnit, CompletionConsumer));
+}
+
 // Output Files
 
 void CompilerInstance::addOutputFile(llvm::StringRef Path,
diff --git a/lib/Frontend/FrontendAction.cpp b/lib/Frontend/FrontendAction.cpp
index 90b87864b8..40b4e7fa24 100644
--- a/lib/Frontend/FrontendAction.cpp
+++ b/lib/Frontend/FrontendAction.cpp
@@ -196,12 +196,16 @@ void FrontendAction::EndSourceFile() {
   // FIXME: There is more per-file stuff we could just drop here?
   if (CI.getFrontendOpts().DisableFree) {
     CI.takeASTConsumer();
-    if (!isCurrentFileAST())
+    if (!isCurrentFileAST()) {
+      CI.takeSema();
       CI.takeASTContext();
+    }
   } else {
-    CI.setASTConsumer(0);
-    if (!isCurrentFileAST())
+    if (!isCurrentFileAST()) {
+      CI.setSema(0);
       CI.setASTContext(0);
+    }
+    CI.setASTConsumer(0);
   }
 
   // Inform the preprocessor we are done.
@@ -225,6 +229,7 @@ void FrontendAction::EndSourceFile() {
   CI.getDiagnosticClient().EndSourceFile();
 
   if (isCurrentFileAST()) {
+    CI.takeSema();
     CI.takeASTContext();
     CI.takePreprocessor();
     CI.takeSourceManager();
@@ -253,9 +258,10 @@ void ASTFrontendAction::ExecuteAction() {
   if (CI.hasCodeCompletionConsumer())
     CompletionConsumer = &CI.getCodeCompletionConsumer();
 
-  ParseAST(CI.getPreprocessor(), &CI.getASTConsumer(), CI.getASTContext(),
-           CI.getFrontendOpts().ShowStats,
-           usesCompleteTranslationUnit(), CompletionConsumer);
+  if (!CI.hasSema())
+    CI.createSema(usesCompleteTranslationUnit(), CompletionConsumer);
+
+  ParseAST(CI.getSema(), CI.getFrontendOpts().ShowStats);
 }
 
 ASTConsumer *
-- 
2.40.0