From 88cdc6927e157ea872b4f8bbc9cb990824e1a559 Mon Sep 17 00:00:00 2001
From: Reid Kleckner <rnk@google.com>
Date: Fri, 18 Oct 2019 21:01:41 +0000
Subject: [PATCH] [X86] Fix register parsing in .seh_* in Intel syntax

Previously, the parser checked for a '%' prefix to indicate a register.
In Intel syntax mode, LLVM does not print a '%' prefix on registers, so
LLVM could not parse its own assembly output. Instead, require that
register numbers be integer literals, or at least start with an integer
literal, which is consistent with .cfi_* directive register parsing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375287 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/AsmParser/X86AsmParser.cpp |  7 ++--
 test/MC/AsmParser/directive_seh.s         | 46 +++++++++++++++++++++++
 2 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/lib/Target/X86/AsmParser/X86AsmParser.cpp b/lib/Target/X86/AsmParser/X86AsmParser.cpp
index 54877adf800..25be79ec2b1 100644
--- a/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -3749,11 +3749,10 @@ bool X86AsmParser::parseSEHRegisterNumber(unsigned RegClassID,
   SMLoc startLoc = getLexer().getLoc();
   const MCRegisterInfo *MRI = getContext().getRegisterInfo();
 
-  // A percent indicates a symbolic register name. Parse it as usual and check
-  // the register class.
-  if (getLexer().is(AsmToken::Percent)) {
+  // Try parsing the argument as a register first.
+  if (getLexer().getTok().isNot(AsmToken::Integer)) {
     SMLoc endLoc;
-    if (getParser().getTargetParser().ParseRegister(RegNo, startLoc, endLoc))
+    if (ParseRegister(RegNo, startLoc, endLoc))
       return true;
 
     if (!X86MCRegisterClasses[RegClassID].contains(RegNo)) {
diff --git a/test/MC/AsmParser/directive_seh.s b/test/MC/AsmParser/directive_seh.s
index 139195dcb49..f4cd29fb5e9 100644
--- a/test/MC/AsmParser/directive_seh.s
+++ b/test/MC/AsmParser/directive_seh.s
@@ -1,5 +1,9 @@
 # RUN: llvm-mc -triple x86_64-pc-win32 %s | FileCheck %s
 
+#   Round trip via intel syntax printing and back.
+# RUN: llvm-mc -triple x86_64-pc-win32 %s -output-asm-variant=1 | \
+# RUN:     llvm-mc -triple x86_64-pc-win32 -x86-asm-syntax=intel | FileCheck %s
+
     .text
     .globl func
     .def func; .scl 2; .type 32; .endef
@@ -51,3 +55,45 @@ func:
     ret
     .seh_endproc
 # CHECK: .seh_endproc
+
+# Re-run more or less the same test, but with intel syntax. Previously LLVM
+# required percent prefixing in the .seh_* directives that take registers.
+
+    .intel_syntax noprefix
+    .text
+    .globl func_intel
+    .def func_intel; .scl 2; .type 32; .endef
+    .seh_proc func_intel
+# CHECK: .seh_proc func_intel
+func_intel:
+    sub RSP, 24
+    .seh_stackalloc 24
+# CHECK: .seh_stackalloc 24
+    mov [16+RSP], RSI
+    .seh_savereg rsi, 16
+# CHECK: .seh_savereg %rsi, 16
+    .seh_savereg 6, 16
+# CHECK: .seh_savereg %rsi, 16
+    movups [RSP], XMM8
+    .seh_savexmm XMM8, 0
+# CHECK: .seh_savexmm %xmm8, 0
+    .seh_savexmm 8, 0
+# CHECK: .seh_savexmm %xmm8, 0
+    push rbx
+    .seh_pushreg rbx
+# CHECK: .seh_pushreg %rbx
+    .seh_pushreg 3
+# CHECK: .seh_pushreg %rbx
+    mov rbx, rsp
+    .seh_setframe rbx, 0
+# CHECK: .seh_setframe %rbx, 0
+    .seh_endprologue
+# CHECK: .seh_endprologue
+    .seh_handler __C_specific_handler, @except
+# CHECK: .seh_handler __C_specific_handler, @except
+    .seh_handlerdata
+# CHECK-NOT: .section{{.*}}.xdata
+# CHECK: .seh_handlerdata
+    .long 0
+    .text
+    .seh_endproc
-- 
2.50.0