commit f7226ed67d2212d72af99f600c7df882d4b1f826
author Alexey Bataev <a.bataev@hotmail.com> Tue Apr 03 17:28:55 2018 +0000
committer Alexey Bataev <a.bataev@hotmail.com> Tue Apr 03 17:28:55 2018 +0000
tree c9a21eff2ebf6b8df3acc03f0638b87faa225a1a
parent 8c63bafdd369d178456b1c57e5c4741fc7673443

[DEBUGINFO] Add option that allows to disable emission of flags in .loc directives.

Summary:
Some targets do not support extended format of .loc directive and
support only simple format: .loc <FileID> <Line> <Column>. Patch adds
MCAsmInfo flag and option that allows emit .loc directive without
additional flags.

Reviewers: echristo

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45184

llvm-svn: 329089

llvm/lib/MC/MCAsmInfo.cpp

diff --git a/llvm/lib/MC/MCAsmInfo.cpp b/llvm/lib/MC/MCAsmInfo.cpp
index f059040..30f22d2 100644
--- a/llvm/lib/MC/MCAsmInfo.cpp
+++ b/llvm/lib/MC/MCAsmInfo.cpp
@@ -17,9 +17,18 @@
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCStreamer.h"
+#include "llvm/Support/CommandLine.h"
 
 using namespace llvm;
 
+enum DefaultOnOff { Default, Enable, Disable };
+static cl::opt<DefaultOnOff> DwarfExtendedLoc(
+    "dwarf-extended-loc", cl::Hidden,
+    cl::desc("Disable emission of the extended flags in .loc directives."),
+    cl::values(clEnumVal(Default, "Default for platform"),
+               clEnumVal(Enable, "Enabled"), clEnumVal(Disable, "Disabled")),
+    cl::init(Default));
+
 MCAsmInfo::MCAsmInfo() {
   SeparatorString = ";";
   CommentString = "#";
@@ -41,6 +50,8 @@
   Data64bitsDirective = "\t.quad\t";
   GlobalDirective = "\t.globl\t";
   WeakDirective = "\t.weak\t";
+  if (DwarfExtendedLoc != Default)
+    SupportsExtendedDwarfLocDirective = DwarfExtendedLoc == Enable;
 
   // FIXME: Clang's logic should be synced with the logic used to initialize
   //        this member and the two implementations should be merged.

llvm/lib/MC/MCAsmStreamer.cpp

diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
index c1d74a0..01e1744 100644
--- a/llvm/lib/MC/MCAsmStreamer.cpp
+++ b/llvm/lib/MC/MCAsmStreamer.cpp
@@ -1171,28 +1171,30 @@
                                           unsigned Discriminator,
                                           StringRef FileName) {
   OS << "\t.loc\t" << FileNo << " " << Line << " " << Column;
-  if (Flags & DWARF2_FLAG_BASIC_BLOCK)
-    OS << " basic_block";
-  if (Flags & DWARF2_FLAG_PROLOGUE_END)
-    OS << " prologue_end";
-  if (Flags & DWARF2_FLAG_EPILOGUE_BEGIN)
-    OS << " epilogue_begin";
+  if (MAI->supportsExtendedDwarfLocDirective()) {
+    if (Flags & DWARF2_FLAG_BASIC_BLOCK)
+      OS << " basic_block";
+    if (Flags & DWARF2_FLAG_PROLOGUE_END)
+      OS << " prologue_end";
+    if (Flags & DWARF2_FLAG_EPILOGUE_BEGIN)
+      OS << " epilogue_begin";
 
-  unsigned OldFlags = getContext().getCurrentDwarfLoc().getFlags();
-  if ((Flags & DWARF2_FLAG_IS_STMT) != (OldFlags & DWARF2_FLAG_IS_STMT)) {
-    OS << " is_stmt ";
+    unsigned OldFlags = getContext().getCurrentDwarfLoc().getFlags();
+    if ((Flags & DWARF2_FLAG_IS_STMT) != (OldFlags & DWARF2_FLAG_IS_STMT)) {
+      OS << " is_stmt ";
 
-    if (Flags & DWARF2_FLAG_IS_STMT)
-      OS << "1";
-    else
-      OS << "0";
+      if (Flags & DWARF2_FLAG_IS_STMT)
+        OS << "1";
+      else
+        OS << "0";
+    }
+
+    if (Isa)
+      OS << " isa " << Isa;
+    if (Discriminator)
+      OS << " discriminator " << Discriminator;
   }
 
-  if (Isa)
-    OS << " isa " << Isa;
-  if (Discriminator)
-    OS << " discriminator " << Discriminator;
-
   if (IsVerboseAsm) {
     OS.PadToColumn(MAI->getCommentColumn());
     OS << MAI->getCommentString() << ' ' << FileName << ':'