Don't segfault in EmitCXXGlobalInitFunc when main file is a membuf

Summary: When the main file is created from a membuffer, there is no file entry that can be retrieved. This uses "__GLOBAL_I_a" in that case which is what was always used before r208128.

Reviewers: majnemer, thakis

Reviewed By: thakis

Subscribers: yaron.keren, rsmith, cfe-commits

Differential Revision: http://reviews.llvm.org/D5043

llvm-svn: 216495
diff --git a/clang/unittests/CMakeLists.txt b/clang/unittests/CMakeLists.txt
index 936b8b2..d0e2860e 100644
--- a/clang/unittests/CMakeLists.txt
+++ b/clang/unittests/CMakeLists.txt
@@ -20,6 +20,7 @@
 add_subdirectory(Tooling)
 add_subdirectory(Format)
 add_subdirectory(Sema)
+add_subdirectory(CodeGen)
 # FIXME: Why are the libclang unit tests disabled on Windows?
 if(NOT WIN32) 
   add_subdirectory(libclang)
diff --git a/clang/unittests/CodeGen/BufferSourceTest.cpp b/clang/unittests/CodeGen/BufferSourceTest.cpp
new file mode 100644
index 0000000..f9d0991
--- /dev/null
+++ b/clang/unittests/CodeGen/BufferSourceTest.cpp
@@ -0,0 +1,78 @@
+//===- unittests/CodeGen/BufferSourceTest.cpp - MemoryBuffer source tests -===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/CodeGen/ModuleBuilder.h"
+#include "clang/Sema/Sema.h"
+#include "clang/Parse/ParseAST.h"
+#include "clang/Basic/TargetInfo.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/IR/LLVMContext.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace clang;
+
+namespace {
+
+// Emitting constructors for global objects involves looking
+// at the source file name. This makes sure that we don't crash
+// if the source file is a memory buffer.
+const char TestProgram[] =
+    "class EmitCXXGlobalInitFunc    "
+    "{                              "
+    "public:                        "
+    "   EmitCXXGlobalInitFunc() {}  "
+    "};                             "
+    "EmitCXXGlobalInitFunc test;    ";
+
+TEST(BufferSourceTest, EmitCXXGlobalInitFunc) {
+    CompilerInstance compiler;
+
+    compiler.createDiagnostics();
+    compiler.getLangOpts().CPlusPlus = 1;
+    compiler.getLangOpts().CPlusPlus11 = 1;
+
+    compiler.getTargetOpts().Triple = llvm::Triple::normalize(
+        llvm::sys::getProcessTriple());
+    compiler.setTarget(clang::TargetInfo::CreateTargetInfo(
+      compiler.getDiagnostics(),
+      std::make_shared<clang::TargetOptions>(
+        compiler.getTargetOpts())));
+
+    compiler.createFileManager();
+    compiler.createSourceManager(compiler.getFileManager());
+    compiler.createPreprocessor(clang::TU_Prefix);
+
+    compiler.createASTContext();
+
+    compiler.setASTConsumer(std::unique_ptr<ASTConsumer>(
+        CreateLLVMCodeGen(
+            compiler.getDiagnostics(),
+            "EmitCXXGlobalInitFuncTest",
+            compiler.getCodeGenOpts(),
+            compiler.getTargetOpts(),
+            llvm::getGlobalContext())));
+
+    compiler.createSema(clang::TU_Prefix,NULL);
+
+    clang::SourceManager &sm = compiler.getSourceManager();
+    sm.setMainFileID(sm.createFileID(
+        llvm::MemoryBuffer::getMemBuffer(TestProgram), clang::SrcMgr::C_User));
+
+    clang::ParseAST(compiler.getSema(), false, false);
+}
+
+}
diff --git a/clang/unittests/CodeGen/CMakeLists.txt b/clang/unittests/CodeGen/CMakeLists.txt
new file mode 100644
index 0000000..19d3d11
--- /dev/null
+++ b/clang/unittests/CodeGen/CMakeLists.txt
@@ -0,0 +1,17 @@
+set(LLVM_LINK_COMPONENTS
+  Support
+  )
+
+add_clang_unittest(CodeGenTests
+  BufferSourceTest.cpp
+  )
+
+target_link_libraries(CodeGenTests
+  clangAST
+  clangBasic
+  clangFrontend
+  clangParse
+  clangSema
+  clangTooling
+  clangCodeGen
+  )
diff --git a/clang/unittests/CodeGen/Makefile b/clang/unittests/CodeGen/Makefile
new file mode 100644
index 0000000..cf7afc2
--- /dev/null
+++ b/clang/unittests/CodeGen/Makefile
@@ -0,0 +1,20 @@
+##===- unittests/CodeGen/Makefile --------------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+CLANG_LEVEL = ../..
+TESTNAME = CodeGen
+include $(CLANG_LEVEL)/../../Makefile.config
+LINK_COMPONENTS := $(TARGETS_TO_BUILD) asmparser bitreader support mc option
+USEDLIBS = clangTooling.a clangFrontend.a clangSerialization.a clangDriver.a \
+           clangRewrite.a clangRewriteFrontend.a \
+           clangParse.a clangSema.a clangAnalysis.a \
+           clangEdit.a clangAST.a clangASTMatchers.a clangLex.a clangBasic.a \
+           clangCodeGen.a
+
+include $(CLANG_LEVEL)/unittests/Makefile
diff --git a/clang/unittests/Makefile b/clang/unittests/Makefile
index 95b1639..c2c33b4 100644
--- a/clang/unittests/Makefile
+++ b/clang/unittests/Makefile
@@ -14,7 +14,8 @@
 
 IS_UNITTEST_LEVEL := 1
 CLANG_LEVEL := ..
-PARALLEL_DIRS = Basic Lex Driver libclang Format ASTMatchers AST Tooling Sema
+PARALLEL_DIRS = CodeGen Basic Lex Driver libclang Format ASTMatchers AST Tooling \
+	        Sema
 
 include $(CLANG_LEVEL)/../..//Makefile.config