[DWARF5]Addition of alignment atrribute in typedef DIE.

This patch, adds support for DW_AT_alignment[DWARF5] attribute, to be emitted with typdef DIE.
When explicit alignment is specified.

Patch by Awanish Pandey <Awanish.Pandey@amd.com>

Reviewers: aprantl, dblaikie, jini.susan.george, SouraVX, alok,
deadalinx

Differential Revision: https://reviews.llvm.org/D70111

3 files changed, 16 insertions, 6 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 9d7fee1d5b3..86522a85427 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -800,6 +800,15 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, const DIDerivedType *DTy) {
   if (!Name.empty())
     addString(Buffer, dwarf::DW_AT_name, Name);
 
+  // If alignment is specified for a typedef , create and insert DW_AT_alignment
+  // attribute in DW_TAG_typedef DIE.
+  if (Tag == dwarf::DW_TAG_typedef && DD->getDwarfVersion() >= 5) {
+    uint32_t AlignInBytes = DTy->getAlignInBytes();
+    if (AlignInBytes > 0)
+      addUInt(Buffer, dwarf::DW_AT_alignment, dwarf::DW_FORM_udata,
+              AlignInBytes);
+  }
+
   // Add size if non-zero (derived types might be zero-sized.)
   if (Size && Tag != dwarf::DW_TAG_pointer_type
            && Tag != dwarf::DW_TAG_ptr_to_member_type
diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp
index 59b4a5ef8a1..3280106cf9f 100644
--- a/llvm/lib/IR/DIBuilder.cpp
+++ b/llvm/lib/IR/DIBuilder.cpp
@@ -306,9 +306,11 @@ DIDerivedType *DIBuilder::createReferenceType(
 
 DIDerivedType *DIBuilder::createTypedef(DIType *Ty, StringRef Name,
                                         DIFile *File, unsigned LineNo,
-                                        DIScope *Context) {
+                                        DIScope *Context,
+                                        Optional<unsigned> AlignInBits) {
   return DIDerivedType::get(VMContext, dwarf::DW_TAG_typedef, Name, File,
-                            LineNo, getNonCompileUnitScope(Context), Ty, 0, 0,
+                            LineNo, getNonCompileUnitScope(Context), Ty, 0,
+                            AlignInBits.hasValue() ? AlignInBits.getValue() : 0,
                             0, None, DINode::FlagZero);
 }
 
diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
index 1bbe6b85d26..62bfeb5c5d7 100644
--- a/llvm/lib/IR/DebugInfo.cpp
+++ b/llvm/lib/IR/DebugInfo.cpp
@@ -1108,11 +1108,10 @@ LLVMMetadataRef
 LLVMDIBuilderCreateTypedef(LLVMDIBuilderRef Builder, LLVMMetadataRef Type,
                            const char *Name, size_t NameLen,
                            LLVMMetadataRef File, unsigned LineNo,
-                           LLVMMetadataRef Scope) {
+                           LLVMMetadataRef Scope, uint32_t AlignInBits) {
   return wrap(unwrap(Builder)->createTypedef(
-                  unwrapDI<DIType>(Type), {Name, NameLen},
-                  unwrapDI<DIFile>(File), LineNo,
-                  unwrapDI<DIScope>(Scope)));
+      unwrapDI<DIType>(Type), {Name, NameLen}, unwrapDI<DIFile>(File), LineNo,
+      unwrapDI<DIScope>(Scope), AlignInBits));
 }
 
 LLVMMetadataRef