From c996942a00d0e034b39cb3b4968203f86ce9eb59 Mon Sep 17 00:00:00 2001
From: Reid Kleckner <rnk@google.com>
Date: Tue, 3 Oct 2017 00:14:03 +0000
Subject: [PATCH] [clang-cl] Claim ignored /O[12xd] arguments

Fixes PR34809

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@314743 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Driver/ToolChains/MSVC.cpp | 40 +++++++++++++++++-----------------
 test/Driver/cl-options.c       |  3 +++
 2 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/lib/Driver/ToolChains/MSVC.cpp b/lib/Driver/ToolChains/MSVC.cpp
index 7978a6941c..334a13f0cc 100644
--- a/lib/Driver/ToolChains/MSVC.cpp
+++ b/lib/Driver/ToolChains/MSVC.cpp
@@ -1317,24 +1317,26 @@ static void TranslateOptArg(Arg *A, llvm::opt::DerivedArgList &DAL,
     case '2':
     case 'x':
     case 'd':
-      if (&OptChar == ExpandChar) {
-        if (OptChar == 'd') {
-          DAL.AddFlagArg(A, Opts.getOption(options::OPT_O0));
-        } else {
-          if (OptChar == '1') {
-            DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "s");
-          } else if (OptChar == '2' || OptChar == 'x') {
-            DAL.AddFlagArg(A, Opts.getOption(options::OPT_fbuiltin));
-            DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "2");
-          }
-          if (SupportsForcingFramePointer &&
-              !DAL.hasArgNoClaim(options::OPT_fno_omit_frame_pointer))
-            DAL.AddFlagArg(A,
-                           Opts.getOption(options::OPT_fomit_frame_pointer));
-          if (OptChar == '1' || OptChar == '2')
-            DAL.AddFlagArg(A,
-                           Opts.getOption(options::OPT_ffunction_sections));
+      // Ignore /O[12xd] flags that aren't the last one on the command line.
+      // Only the last one gets expanded.
+      if (&OptChar != ExpandChar) {
+        A->claim();
+        break;
+      }
+      if (OptChar == 'd') {
+        DAL.AddFlagArg(A, Opts.getOption(options::OPT_O0));
+      } else {
+        if (OptChar == '1') {
+          DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "s");
+        } else if (OptChar == '2' || OptChar == 'x') {
+          DAL.AddFlagArg(A, Opts.getOption(options::OPT_fbuiltin));
+          DAL.AddJoinedArg(A, Opts.getOption(options::OPT_O), "2");
         }
+        if (SupportsForcingFramePointer &&
+            !DAL.hasArgNoClaim(options::OPT_fno_omit_frame_pointer))
+          DAL.AddFlagArg(A, Opts.getOption(options::OPT_fomit_frame_pointer));
+        if (OptChar == '1' || OptChar == '2')
+          DAL.AddFlagArg(A, Opts.getOption(options::OPT_ffunction_sections));
       }
       break;
     case 'b':
@@ -1430,9 +1432,7 @@ MSVCToolChain::TranslateArgs(const llvm::opt::DerivedArgList &Args,
 
   // First step is to search for the character we'd like to expand.
   const char *ExpandChar = nullptr;
-  for (Arg *A : Args) {
-    if (!A->getOption().matches(options::OPT__SLASH_O))
-      continue;
+  for (Arg *A : Args.filtered(options::OPT__SLASH_O)) {
     StringRef OptStr = A->getValue();
     for (size_t I = 0, E = OptStr.size(); I != E; ++I) {
       char OptChar = OptStr[I];
diff --git a/test/Driver/cl-options.c b/test/Driver/cl-options.c
index 870378a829..5d866e5f17 100644
--- a/test/Driver/cl-options.c
+++ b/test/Driver/cl-options.c
@@ -178,6 +178,9 @@
 // Oy_2: -momit-leaf-frame-pointer
 // Oy_2: -O2
 
+// RUN: %clang_cl --target=i686-pc-win32 -Werror /O2 /O2 -### -- %s 2>&1 | FileCheck -check-prefix=O2O2 %s
+// O2O2: "-O2"
+
 // RUN: %clang_cl /Zs -Werror /Oy -- %s 2>&1
 
 // RUN: %clang_cl --target=i686-pc-win32 -Werror /Oy- -### -- %s 2>&1 | FileCheck -check-prefix=Oy_ %s
-- 
2.50.1