DebugInfo: make DW_TAG_atomic_type valid

DW_TAG_atomic_type was already included in Dwarf.defs and emitted correctly,
however Verifier didn't recognize it as valid.
Thus we introduce the following changes:

  * Make DW_TAG_atomic_type valid tag for IR and DWARF (enabled only with -gdwarf-5)
  * Add it to related docs
  * Add DebugInfo tests

Differential Revision: https://reviews.llvm.org/D26144

llvm-svn: 285624

3 files changed, 8 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
index a1fd0dc8869..5cc8b4e4555 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -1091,6 +1091,7 @@ TypeIndex CodeViewDebug::lowerType(const DIType *Ty, const DIType *ClassTy) {
     return lowerTypeMemberPointer(cast<DIDerivedType>(Ty));
   case dwarf::DW_TAG_const_type:
   case dwarf::DW_TAG_volatile_type:
+  // TODO: add support for DW_TAG_atomic_type here
     return lowerTypeModifier(cast<DIDerivedType>(Ty));
   case dwarf::DW_TAG_subroutine_type:
     if (ClassTy) {
@@ -1399,7 +1400,7 @@ TypeIndex CodeViewDebug::lowerTypeModifier(const DIDerivedType *Ty) {
   bool IsModifier = true;
   const DIType *BaseTy = Ty;
   while (IsModifier && BaseTy) {
-    // FIXME: Need to add DWARF tag for __unaligned.
+    // FIXME: Need to add DWARF tags for __unaligned and _Atomic
     switch (BaseTy->getTag()) {
     case dwarf::DW_TAG_const_type:
       Mods |= ModifierOptions::Const;
diff --git a/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp b/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp
index 357d67fa2e5..d30f106a939 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp
@@ -98,7 +98,7 @@ uint64_t DebugHandlerBase::getBaseTypeSize(const DITypeRef TyRef) {
 
   if (Tag != dwarf::DW_TAG_member && Tag != dwarf::DW_TAG_typedef &&
       Tag != dwarf::DW_TAG_const_type && Tag != dwarf::DW_TAG_volatile_type &&
-      Tag != dwarf::DW_TAG_restrict_type)
+      Tag != dwarf::DW_TAG_restrict_type && Tag != dwarf::DW_TAG_atomic_type)
     return DDTy->getSizeInBits();
 
   DIType *BaseType = DDTy->getBaseType().resolve();
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index d653f8da477..2dcb616a67f 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -546,7 +546,7 @@ static bool isUnsignedDIType(DwarfDebug *DD, const DIType *Ty) {
       return true;
     assert(T == dwarf::DW_TAG_typedef || T == dwarf::DW_TAG_const_type ||
            T == dwarf::DW_TAG_volatile_type ||
-           T == dwarf::DW_TAG_restrict_type);
+           T == dwarf::DW_TAG_restrict_type || T == dwarf::DW_TAG_atomic_type);
     DITypeRef Deriv = DTy->getBaseType();
     assert(Deriv && "Expected valid base type");
     return isUnsignedDIType(DD, DD->resolve(Deriv));
@@ -707,6 +707,10 @@ DIE *DwarfUnit::getOrCreateTypeDIE(const MDNode *TyNode) {
   if (Ty->getTag() == dwarf::DW_TAG_restrict_type && DD->getDwarfVersion() <= 2)
     return getOrCreateTypeDIE(resolve(cast<DIDerivedType>(Ty)->getBaseType()));
 
+  // DW_TAG_atomic_type is not supported in DWARF < 5
+  if (Ty->getTag() == dwarf::DW_TAG_atomic_type && DD->getDwarfVersion() < 5)
+    return getOrCreateTypeDIE(resolve(cast<DIDerivedType>(Ty)->getBaseType()));
+
   // Construct the context before querying for the existence of the DIE in case
   // such construction creates the DIE.
   auto *Context = resolve(Ty->getScope());