From 7f73489c3f35814192c85c3919d5847a66c8e071 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Mon, 20 Dec 2010 22:45:09 +0000
Subject: [PATCH] Fix PR8639 by making the "argument unused during compilation"
 less agressive. Now we don't warn if an argument is not used because it is
 shadowed by a subsequent argument.

llvm-svn: 122281
---
 clang/lib/Driver/ArgList.cpp | 35 ++++++++++++++++-------------------
 clang/lib/Driver/Tools.cpp   |  3 ---
 2 files changed, 16 insertions(+), 22 deletions(-)

diff --git a/clang/lib/Driver/ArgList.cpp b/clang/lib/Driver/ArgList.cpp
index e26318863db7..f52c25ac101b 100644
--- a/clang/lib/Driver/ArgList.cpp
+++ b/clang/lib/Driver/ArgList.cpp
@@ -55,62 +55,59 @@ Arg *ArgList::getLastArgNoClaim(OptSpecifier Id) const {
 }
 
 Arg *ArgList::getLastArg(OptSpecifier Id) const {
-  Arg *A = getLastArgNoClaim(Id);
-  if (A)
-    A->claim();
-  return A;
+  Arg *Res = 0;
+  for (const_iterator it = begin(), ie = end(); it != ie; ++it) {
+    if ((*it)->getOption().matches(Id)) {
+      Res = *it;
+      Res->claim();
+    }
+  }
+
+  return Res;
 }
 
 Arg *ArgList::getLastArg(OptSpecifier Id0, OptSpecifier Id1) const {
   Arg *Res = 0;
-  for (const_reverse_iterator it = rbegin(), ie = rend(); it != ie; ++it) {
+  for (const_iterator it = begin(), ie = end(); it != ie; ++it) {
     if ((*it)->getOption().matches(Id0) ||
         (*it)->getOption().matches(Id1)) {
       Res = *it;
-      break;
+      Res->claim();
+
     }
   }
 
-  if (Res)
-    Res->claim();
-
   return Res;
 }
 
 Arg *ArgList::getLastArg(OptSpecifier Id0, OptSpecifier Id1,
                          OptSpecifier Id2) const {
   Arg *Res = 0;
-  for (const_reverse_iterator it = rbegin(), ie = rend(); it != ie; ++it) {
+  for (const_iterator it = begin(), ie = end(); it != ie; ++it) {
     if ((*it)->getOption().matches(Id0) ||
         (*it)->getOption().matches(Id1) ||
         (*it)->getOption().matches(Id2)) {
       Res = *it;
-      break;
+      Res->claim();
     }
   }
 
-  if (Res)
-    Res->claim();
-
   return Res;
 }
 
 Arg *ArgList::getLastArg(OptSpecifier Id0, OptSpecifier Id1,
                          OptSpecifier Id2, OptSpecifier Id3) const {
   Arg *Res = 0;
-  for (const_reverse_iterator it = rbegin(), ie = rend(); it != ie; ++it) {
+  for (const_iterator it = begin(), ie = end(); it != ie; ++it) {
     if ((*it)->getOption().matches(Id0) ||
         (*it)->getOption().matches(Id1) ||
         (*it)->getOption().matches(Id2) ||
         (*it)->getOption().matches(Id3)) {
       Res = *it;
-      break;
+      Res->claim();
     }
   }
 
-  if (Res)
-    Res->claim();
-
   return Res;
 }
 
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 4e23ed6dda43..9df276d9c24a 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1147,9 +1147,6 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
       A->render(Args, CmdArgs);
   }
 
-  // Silence warning for "clang -O2 -O0 -c foo.c -o foo.o"
-  Args.ClaimAllArgs(options::OPT_O_Group);
-
   Args.AddAllArgs(CmdArgs, options::OPT_W_Group);
   Args.AddLastArg(CmdArgs, options::OPT_pedantic);
   Args.AddLastArg(CmdArgs, options::OPT_pedantic_errors);