Support the Nodebug emission kind for DICompileUnits.

Sample-based profiling and optimization remarks currently remove
DICompileUnits from llvm.dbg.cu to suppress the emission of debug info
from them. This is somewhat of a hack and only borderline legal IR.

This patch uses the recently introduced NoDebug emission kind in
DICompileUnit to achieve the same result without breaking the Verifier.
A nice side-effect of this change is that it is now possible to combine
NoDebug and regular compile units under LTO.

http://reviews.llvm.org/D18808
<rdar://problem/25427165>

llvm-svn: 265861

1 files changed, 3 insertions, 10 deletions

diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp
index fa4b860a58a..aa9ffcf9f3c 100644
--- a/llvm/lib/IR/DIBuilder.cpp
+++ b/llvm/lib/IR/DIBuilder.cpp
@@ -137,7 +137,7 @@ static DIScope *getNonCompileUnitScope(DIScope *N) {
 DICompileUnit *DIBuilder::createCompileUnit(
     unsigned Lang, StringRef Filename, StringRef Directory, StringRef Producer,
     bool isOptimized, StringRef Flags, unsigned RunTimeVer, StringRef SplitName,
-    DICompileUnit::DebugEmissionKind Kind, uint64_t DWOId, bool EmitDebugInfo) {
+    DICompileUnit::DebugEmissionKind Kind, uint64_t DWOId) {
 
   assert(((Lang <= dwarf::DW_LANG_Fortran08 && Lang >= dwarf::DW_LANG_C89) ||
           (Lang <= dwarf::DW_LANG_hi_user && Lang >= dwarf::DW_LANG_lo_user)) &&
@@ -152,15 +152,8 @@ DICompileUnit *DIBuilder::createCompileUnit(
       nullptr, nullptr, nullptr, nullptr, nullptr, DWOId);
 
   // Create a named metadata so that it is easier to find cu in a module.
-  // Note that we only generate this when the caller wants to actually
-  // emit debug information. When we are only interested in tracking
-  // source line locations throughout the backend, we prevent codegen from
-  // emitting debug info in the final output by not generating llvm.dbg.cu.
-  if (EmitDebugInfo) {
-    NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.cu");
-    NMD->addOperand(CUNode);
-  }
-
+  NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.cu");
+  NMD->addOperand(CUNode);
   trackIfUnresolved(CUNode);
   return CUNode;
 }