r179092 - One more follow-up to r179082 - parse PIC/PIE arguments even on platfroms that force default PIC (like Darwin x86-64), otherwise specifying -fPIC will produce bogus unused argument warning

[Alexey Samsonov]

Author: samsonov
Date: Tue Apr  9 07:28:19 2013
New Revision: 179092

URL: http://llvm.org/viewvc/llvm-project?rev=179092&view=rev
Log:
One more follow-up to r179082 - parse PIC/PIE arguments even on platfroms that force default PIC (like Darwin x86-64), otherwise specifying -fPIC will produce bogus unused argument warning

Modified:
    cfe/trunk/lib/Driver/Tools.cpp
    cfe/trunk/test/Driver/pic.c

Modified: cfe/trunk/lib/Driver/Tools.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=179092&r1=179091&r2=179092&view=diff
==============================================================================
--- cfe/trunk/lib/Driver/Tools.cpp (original)
+++ cfe/trunk/lib/Driver/Tools.cpp Tue Apr  9 07:28:19 2013
@@ -1996,22 +1996,23 @@ void Clang::ConstructJob(Compilation &C,
   bool PIC = PIE || getToolChain().isPICDefault();
   bool IsPICLevelTwo = PIC;
 
+  // For the PIC and PIE flag options, this logic is different from the
+  // legacy logic in very old versions of GCC, as that logic was just
+  // a bug no one had ever fixed. This logic is both more rational and
+  // consistent with GCC's new logic now that the bugs are fixed. The last
+  // argument relating to either PIC or PIE wins, and no other argument is
+  // used. If the last argument is any flavor of the '-fno-...' arguments,
+  // both PIC and PIE are disabled. Any PIE option implicitly enables PIC
+  // at the same level.
+  Arg *LastPICArg =Args.getLastArg(options::OPT_fPIC, options::OPT_fno_PIC,
+                                 options::OPT_fpic, options::OPT_fno_pic,
+                                 options::OPT_fPIE, options::OPT_fno_PIE,
+                                 options::OPT_fpie, options::OPT_fno_pie);
   // Check whether the tool chain trumps the PIC-ness decision. If the PIC-ness
   // is forced, then neither PIC nor PIE flags will have no effect.
   if (!getToolChain().isPICDefaultForced()) {
-    // For the PIC and PIE flag options, this logic is different from the
-    // legacy logic in very old versions of GCC, as that logic was just
-    // a bug no one had ever fixed. This logic is both more rational and
-    // consistent with GCC's new logic now that the bugs are fixed. The last
-    // argument relating to either PIC or PIE wins, and no other argument is
-    // used. If the last argument is any flavor of the '-fno-...' arguments,
-    // both PIC and PIE are disabled. Any PIE option implicitly enables PIC
-    // at the same level.
-    if (Arg *A = Args.getLastArg(options::OPT_fPIC, options::OPT_fno_PIC,
-                                 options::OPT_fpic, options::OPT_fno_pic,
-                                 options::OPT_fPIE, options::OPT_fno_PIE,
-                                 options::OPT_fpie, options::OPT_fno_pie)) {
-      Option O = A->getOption();
+    if (LastPICArg) {
+      Option O = LastPICArg->getOption();
       if (O.matches(options::OPT_fPIC) || O.matches(options::OPT_fpic) ||
           O.matches(options::OPT_fPIE) || O.matches(options::OPT_fpie)) {
         PIE = O.matches(options::OPT_fPIE) || O.matches(options::OPT_fpie);

Modified: cfe/trunk/test/Driver/pic.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/pic.c?rev=179092&r1=179091&r2=179092&view=diff
==============================================================================
--- cfe/trunk/test/Driver/pic.c (original)
+++ cfe/trunk/test/Driver/pic.c Tue Apr  9 07:28:19 2013
@@ -36,6 +36,8 @@
 //
 // CHECK-NO-PIE-NOT: "-pie"
 //
+// CHECK-NO-UNUSED-ARG-NOT: argument unused during compilation
+//
 // RUN: %clang -c %s -target i386-unknown-unknown -### 2>&1 \
 // RUN:   | FileCheck %s --check-prefix=CHECK-NO-PIC
 // RUN: %clang -c %s -target i386-unknown-unknown -fpic -### 2>&1 \
@@ -164,6 +166,8 @@
 // RUN:   | FileCheck %s --check-prefix=CHECK-PIC2
 // RUN: %clang -c %s -target x86_64-apple-darwin -fPIE -### 2>&1 \
 // RUN:   | FileCheck %s --check-prefix=CHECK-PIC2
+// RUN: %clang -c %s -target x86_64-apple-darwin -fPIC -### 2>&1 \
+// RUN:   | FileCheck %s --check-prefix=CHECK-NO-UNUSED-ARG
 //
 // Darwin gets even more special with '-mdynamic-no-pic'. This flag is only
 // valid on Darwin, and it's behavior is very strange but needs to remain