[IR] Add DISuprogram and DIE for a func decl

A unique DISubprogram may be attached to a function declaration used for
call site debug info.

([6/13] Introduce the debug entry values.)

Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>

Differential Revision: https://reviews.llvm.org/D60713

llvm-svn: 364500

2 files changed, 10 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 24802dc2c9a..8e842f08bc0 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -706,6 +706,11 @@ DwarfDebug::getOrCreateDwarfCompileUnit(const DICompileUnit *DIUnit) {
     NewCU.setSection(Asm->getObjFileLowering().getDwarfInfoSection());
   }
 
+  // Create DIEs for function declarations used for call site debug info.
+  for (auto Scope : DIUnit->getRetainedTypes())
+    if (auto *SP = dyn_cast_or_null<DISubprogram>(Scope))
+      NewCU.getOrCreateSubprogramDIE(SP);
+
   CUMap.insert({DIUnit, &NewCU});
   CUDieMap.insert({&NewCU.getUnitDie(), &NewCU});
   return NewCU;
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index c3bc733bac1..8fc6cb70243 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -2263,8 +2263,11 @@ void Verifier::visitFunction(const Function &F) {
            MDs.empty() ? nullptr : MDs.front().second);
   } else if (F.isDeclaration()) {
     for (const auto &I : MDs) {
-      AssertDI(I.first != LLVMContext::MD_dbg,
-               "function declaration may not have a !dbg attachment", &F);
+      // This is used for call site debug information.
+      AssertDI(I.first != LLVMContext::MD_dbg ||
+                   !cast<DISubprogram>(I.second)->isDistinct(),
+               "function declaration may only have a unique !dbg attachment",
+               &F);
       Assert(I.first != LLVMContext::MD_prof,
              "function declaration may not have a !prof attachment", &F);