[x32] Introduce -mx32 flag enforcing x32 mode for other triplets

[pavel.v.chupin]

Summary

-mx32 flag setup target environment to GNUX32 and can be used for
other 32/64-bit triplets (i386-unknown-linux, x86_64-unknown-linux) to
turn on x32 mode. Compatible with GCC -mx32 flag.

[atanasyan]

LGTM with a small nit

lib/Driver/Driver.cpp

1925

AFAIK the -mx32 is applicable to X86/x86_64 targets only. Let's ignore it for other targets. As to me I would prefer to show an error if -m16 or -mx32 provided for any targets except X86/x86_64. But that is another story.

[pavel.v.chupin]

Thanks for quick response. I'll fix it before commit.

[zinovy.nis]

Closed by commit rL212817 (authored by @zinovy.nis).

include/clang/Driver/Options.td

 def EB : Flag<["-"], "EB">, Alias<mbig_endian>;
 def m16 : Flag<["-"], "m16">, Group<m_Group>, Flags<[DriverOption, CoreOption]>;
 def m32 : Flag<["-"], "m32">, Group<m_Group>, Flags<[DriverOption, CoreOption]>;
 def mqdsp6_compat : Flag<["-"], "mqdsp6-compat">, Group<m_Group>, Flags<[DriverOption,CC1Option]>,
   HelpText<"Enable hexagon-qdsp6 backward compatibility">;
 def m3dnowa : Flag<["-"], "m3dnowa">, Group<m_x86_Features_Group>;
 def m3dnow : Flag<["-"], "m3dnow">, Group<m_x86_Features_Group>;
 def m64 : Flag<["-"], "m64">, Group<m_Group>, Flags<[DriverOption, CoreOption]>;
+def mx32 : Flag<["-"], "mx32">, Group<m_Group>, Flags<[DriverOption, CoreOption]>;
 def mabi_EQ : Joined<["-"], "mabi=">, Group<m_Group>;
 def march_EQ : Joined<["-"], "march=">, Group<m_Group>;
 def masm_EQ : Joined<["-"], "masm=">, Group<m_Group>, Flags<[DriverOption]>;
 def mcmodel_EQ : Joined<["-"], "mcmodel=">, Group<m_Group>;
 def mconstant_cfstrings : Flag<["-"], "mconstant-cfstrings">, Group<clang_ignored_m_Group>;
 def mcpu_EQ : Joined<["-"], "mcpu=">, Group<m_Group>;
 def mdynamic_no_pic : Joined<["-"], "mdynamic-no-pic">, Group<m_Group>;
 def mfix_and_continue : Flag<["-"], "mfix-and-continue">, Group<clang_ignored_m_Group>;

lib/Driver/Driver.cpp

static llvm::Triple computeTargetTriple(StringRef DefaultTargetTriple,
   }
 
   // Skip further flag support on OSes which don't support '-m32' or '-m64'.
   if (Target.getArchName() == "tce" ||
       Target.getOS() == llvm::Triple::AuroraUX ||
       Target.getOS() == llvm::Triple::Minix)
     return Target;
 
-  // Handle pseudo-target flags '-m64', '-m32' and '-m16'.
-  if (Arg *A = Args.getLastArg(options::OPT_m64, options::OPT_m32,
-                               options::OPT_m16)) {
+  // Handle pseudo-target flags '-m64', '-mx32', '-m32' and '-m16'.
+  if (Arg *A = Args.getLastArg(options::OPT_m64, options::OPT_mx32,
+                               options::OPT_m32, options::OPT_m16)) {
     llvm::Triple::ArchType AT = llvm::Triple::UnknownArch;
 
     if (A->getOption().matches(options::OPT_m64))
       AT = Target.get64BitArchVariant().getArch();
-    else if (A->getOption().matches(options::OPT_m32))
+    else if (A->getOption().matches(options::OPT_mx32)) {
+      AT = Target.get64BitArchVariant().getArch();
+      Target.setEnvironment(llvm::Triple::GNUX32);
+    } else if (A->getOption().matches(options::OPT_m32))
       AT = Target.get32BitArchVariant().getArch();
     else if (A->getOption().matches(options::OPT_m16) &&
              Target.get32BitArchVariant().getArch() == llvm::Triple::x86) {
       AT = llvm::Triple::x86;
       Target.setEnvironment(llvm::Triple::CODE16);
     }
 
     if (AT != llvm::Triple::UnknownArch)

test/Driver/linux-ld.c

 // CHECK-X32: "-L[[SYSROOT]]/usr/lib/../libx32"
 // CHECK-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0"
 // CHECK-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0/../../../../x86_64-unknown-linux/lib"
 // CHECK-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0/../../.."
 // CHECK-X32: "-L[[SYSROOT]]/lib"
 // CHECK-X32: "-L[[SYSROOT]]/usr/lib"
 //
 // RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=x86_64-unknown-linux -mx32 \
+// RUN:     --sysroot=%S/Inputs/multilib_64bit_linux_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-64-TO-X32 %s
+// CHECK-64-TO-X32: "{{.*}}ld{{(.exe)?}}" "--sysroot=[[SYSROOT:[^"]+]]"
+// CHECK-64-TO-X32: "{{.*}}/usr/lib/gcc/x86_64-unknown-linux/4.6.0/x32{{/|\\\\}}crtbegin.o"
+// CHECK-64-TO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0/x32"
+// CHECK-64-TO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0/../../../../x86_64-unknown-linux/lib/../libx32"
+// CHECK-64-TO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0/../../../../libx32"
+// CHECK-64-TO-X32: "-L[[SYSROOT]]/lib/../libx32"
+// CHECK-64-TO-X32: "-L[[SYSROOT]]/usr/lib/../libx32"
+// CHECK-64-TO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0"
+// CHECK-64-TO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0/../../../../x86_64-unknown-linux/lib"
+// CHECK-64-TO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0/../../.."
+// CHECK-64-TO-X32: "-L[[SYSROOT]]/lib"
+// CHECK-64-TO-X32: "-L[[SYSROOT]]/usr/lib"
+//
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=i386-unknown-linux -mx32 \
+// RUN:     --sysroot=%S/Inputs/multilib_64bit_linux_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-32-TO-X32 %s
+// CHECK-32-TO-X32: "{{.*}}ld{{(.exe)?}}" "--sysroot=[[SYSROOT:[^"]+]]"
+// CHECK-32-TO-X32: "{{.*}}/usr/lib/gcc/x86_64-unknown-linux/4.6.0/x32{{/|\\\\}}crtbegin.o"
+// CHECK-32-TO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0/x32"
+// CHECK-32-TO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0/../../../../x86_64-unknown-linux/lib/../libx32"
+// CHECK-32-TO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0/../../../../libx32"
+// CHECK-32-TO-X32: "-L[[SYSROOT]]/lib/../libx32"
+// CHECK-32-TO-X32: "-L[[SYSROOT]]/usr/lib/../libx32"
+// CHECK-32-TO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0"
+// CHECK-32-TO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0/../../../../x86_64-unknown-linux/lib"
+// CHECK-32-TO-X32: "-L[[SYSROOT]]/usr/lib/gcc/x86_64-unknown-linux/4.6.0/../../.."
+// CHECK-32-TO-X32: "-L[[SYSROOT]]/lib"
+// CHECK-32-TO-X32: "-L[[SYSROOT]]/usr/lib"
+//
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
 // RUN:     --target=x86_64-unknown-linux -m32 \
 // RUN:     --gcc-toolchain=%S/Inputs/multilib_64bit_linux_tree/usr \
 // RUN:     --sysroot=%S/Inputs/multilib_32bit_linux_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-64-TO-32-SYSROOT %s
 // CHECK-64-TO-32-SYSROOT: "{{.*}}ld{{(.exe)?}}" "--sysroot=[[SYSROOT:[^"]+]]"
 // CHECK-64-TO-32-SYSROOT: "{{.*}}/usr/lib/gcc/x86_64-unknown-linux/4.6.0/32{{/|\\\\}}crtbegin.o"
 // CHECK-64-TO-32-SYSROOT: "-L{{[^"]*}}/Inputs/multilib_64bit_linux_tree/usr/lib/gcc/x86_64-unknown-linux/4.6.0/32"
 // CHECK-64-TO-32-SYSROOT: "-L[[SYSROOT]]/lib/../lib32"