Debug Info: add a "Debug Info Version" module flag to output the current debug

info version number.

Will error out when modules have different version numbers.

llvm-svn: 195495

2 files changed, 13 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 4d51fb02bb4..8240f8d38c1 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -258,6 +258,11 @@ void CodeGenModule::Release() {
     // We can change from Warning to Latest if such mode is supported.
     getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version",
                               CodeGenOpts.DwarfVersion);
+  if (DebugInfo)
+    // We support a single version in the linked module: error out when
+    // modules do not have the same version.
+    getModule().addModuleFlag(llvm::Module::Error, "Debug Info Version",
+                              llvm::dwarf::DEBUG_INFO_VERSION);
 
   SimplifyPersonality();
 
diff --git a/clang/test/CodeGen/debug-info-version.c b/clang/test/CodeGen/debug-info-version.c
new file mode 100644
index 00000000000..3a74876de59
--- /dev/null
+++ b/clang/test/CodeGen/debug-info-version.c
@@ -0,0 +1,8 @@
+// RUN: %clang -g -S -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang -S -emit-llvm -o - %s | FileCheck %s --check-prefix=NO_DEBUG
+int main (void) {
+  return 0;
+}
+
+// CHECK: metadata !{i32 1, metadata !"Debug Info Version", i32 1}
+// NO_DEBUG-NOT: metadata !"Debug Info Version"