From b9c61f0c040411acf246663e2858b440e44cdbf3 Mon Sep 17 00:00:00 2001
From: Renato Golin <renato.golin@linaro.org>
Date: Wed, 27 Jul 2016 12:31:58 +0000
Subject: [PATCH] [ARM] Set a non-conflicting comment character for assembly in
 MSVC mode
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Currently, for ARMCOFFMCAsmInfoMicrosoft, no comment character is set, thus the
idefault, '#', is used.

The hash character doesn't work as comment character in ARM assembly, since '#'
is used for immediate values.

The comment character is set to ';', which is the comment character used by MS
armasm.exe. (The microsoft armasm.exe uses a different directive syntax than
what LLVM currently supports though, similar to ARM's armasm.)

This allows inline assembly with immediate constants to be built (and brings the
assembly output from clang -S closer to being possible to assemble).

A test is added that verifies that ';' is correctly interpreted as comments in
this mode, and verifies that assembling code that includes literal constants
with a '#' works.

Patch by Martin Storsjö.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276859 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.cpp |  1 +
 test/MC/ARM/Windows/literals-comments.s      | 13 +++++++++++++
 2 files changed, 14 insertions(+)
 create mode 100644 test/MC/ARM/Windows/literals-comments.s

diff --git a/lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.cpp b/lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.cpp
index 53cd29a6061..1e062ad45af 100644
--- a/lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.cpp
+++ b/lib/Target/ARM/MCTargetDesc/ARMMCAsmInfo.cpp
@@ -90,6 +90,7 @@ ARMCOFFMCAsmInfoMicrosoft::ARMCOFFMCAsmInfoMicrosoft() {
 
   PrivateGlobalPrefix = "$M";
   PrivateLabelPrefix = "$M";
+  CommentString = ";";
 }
 
 void ARMCOFFMCAsmInfoGNU::anchor() { }
diff --git a/test/MC/ARM/Windows/literals-comments.s b/test/MC/ARM/Windows/literals-comments.s
new file mode 100644
index 00000000000..be988742dba
--- /dev/null
+++ b/test/MC/ARM/Windows/literals-comments.s
@@ -0,0 +1,13 @@
+; RUN: llvm-mc -triple armv7-windows-msvc -filetype obj -o - %s
+
+  .syntax unified
+  .thumb
+
+  .text
+
+  .global function
+  .thumb_func
+function:
+  ; this is a comment
+  mov r0, #42 ; this # was not
+  bx lr
-- 
2.11.0