[Thumb] Emit Thumb code when the triple arch is "thumb"

[olista01]

Summary

Clang currently accepts "thumb" and "thumbeb" as architectures in the triple, but emits ARM code unless -mthumb is also used.

[rengolin]

Hi Oliver,

I think this is the wrong place to fix it. I've tried that, and I realised that the problem is that the arch in triple gets forgotten by getting the default CPU, then getting the default arch for that CPU, resetting the arch to arm. If you can stop that nonsense, your problem will be fixed.

cheers,
--renato

lib/Driver/ToolChain.cpp

case llvm::Triple::thumbeb: {
     // Thumb2 is the default for V7 on Darwin.
     //
     // FIXME: Thumb should just be another -target-feaure, not in the triple.
     StringRef Suffix = Triple.isOSBinFormatMachO()
       ? tools::arm::getLLVMArchSuffixForARM(tools::arm::getARMCPUForMArch(Args, Triple))
       : tools::arm::getLLVMArchSuffixForARM(tools::arm::getARMTargetCPU(Args, Triple));
     bool ThumbDefault = Suffix.startswith("v6m") || Suffix.startswith("v7m") ||
       Suffix.startswith("v7em") ||
-      (Suffix.startswith("v7") && getTriple().isOSBinFormatMachO());
+      (Suffix.startswith("v7") && getTriple().isOSBinFormatMachO()) ||
+      getTriple().getArch() == llvm::Triple::thumb ||
+      getTriple().getArch() == llvm::Triple::thumbeb;
     // FIXME: this is invalid for WindowsCE
     if (getTriple().isOSWindows())
       ThumbDefault = true;
     std::string ArchName;
     if (IsBigEndian)
       ArchName = "armeb";
     else
       ArchName = "arm";

test/Driver/arm-cortex-cpus.c

 // CHECK-V7EM-DARWIN: "-cc1"{{.*}} "-triple" "thumbv7em-{{.*}} "-target-cpu" "cortex-m4"
 
 // RUN: %clang -target armv7a-linux-gnueabi -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7A %s
 // RUN: %clang -target arm-linux-gnueabi -march=armv7-a -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7A %s
 // CHECK-V7A: "-cc1"{{.*}} "-triple" "armv7-{{.*}} "-target-cpu" "cortex-a8"
 
 // RUN: %clang -target armv7a-linux-gnueabi -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7A-THUMB %s
 // RUN: %clang -target arm-linux-gnueabi -march=armv7-a -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7A-THUMB %s
+// RUN: %clang -target thumbv7a-linux-gnueabi -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7A-THUMB %s
 // CHECK-V7A-THUMB: "-cc1"{{.*}} "-triple" "thumbv7-{{.*}} "-target-cpu" "cortex-a8"
 
 // RUN: %clang -target armv7r-linux-gnueabi -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7R %s
 // RUN: %clang -target arm-linux-gnueabi -march=armv7-r -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7R %s
 // CHECK-V7R: "-cc1"{{.*}} "-triple" "armv7r-{{.*}} "-target-cpu" "cortex-r4"
 
 // RUN: %clang -target armv7r-linux-gnueabi -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7R-THUMB %s
 // RUN: %clang -target arm-linux-gnueabi -march=armv7-r -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7R-THUMB %s

test/Driver/netbsd.c

 // ARM-HF: as{{.*}}" "-mcpu=arm926ej-s" "-o"
 // ARM-HF: ld{{.*}}" "--eh-frame-hdr" "-dynamic-linker" "/libexec/ld.elf_so"
 // ARM-HF: "-m" "armelf_nbsd_eabihf"
 // ARM-HF: "-o" "a.out" "{{.*}}/usr/lib{{/|\\\\}}crt0.o"
 // ARM-HF: "{{.*}}/usr/lib{{/|\\\\}}eabihf{{/|\\\\}}crti.o"
 // ARM-HF: "{{.*}}/usr/lib{{/|\\\\}}crtbegin.o" "{{.*}}.o" "-lc"
 // ARM-HF: "{{.*}}/usr/lib{{/|\\\\}}crtend.o" "{{.*}}/usr/lib{{/|\\\\}}crtn.o"
 
-// THUMB: clang{{.*}}" "-cc1" "-triple" "armv5e--netbsd-eabi"
+// THUMB: clang{{.*}}" "-cc1" "-triple" "thumbv5e--netbsd-eabi"
 // THUMB: as{{.*}}" "-mcpu=arm926ej-s" "-o"
 // THUMB: ld{{.*}}" "--eh-frame-hdr" "-dynamic-linker" "/libexec/ld.elf_so"
 // THUMB: "-m" "armelf_nbsd_eabi"
 // THUMB: "-o" "a.out" "{{.*}}/usr/lib{{/|\\\\}}crt0.o"
 // THUMB: "{{.*}}/usr/lib{{/|\\\\}}eabi{{/|\\\\}}crti.o"
 // THUMB: "{{.*}}/usr/lib{{/|\\\\}}crtbegin.o" "{{.*}}.o" "-lc"
 // THUMB: "{{.*}}/usr/lib{{/|\\\\}}crtend.o" "{{.*}}/usr/lib{{/|\\\\}}crtn.o"
 
-// THUMBEB: clang{{.*}}" "-cc1" "-triple" "armebv5e--netbsd-eabi"
+// THUMBEB: clang{{.*}}" "-cc1" "-triple" "thumbebv5e--netbsd-eabi"
 // THUMBEB: as{{.*}}" "-mcpu=arm926ej-s" "-o"
 // THUMBEB: ld{{.*}}" "--eh-frame-hdr" "-dynamic-linker" "/libexec/ld.elf_so"
 // THUMBEB: "-m" "armelfb_nbsd_eabi"
 // THUMBEB: "-o" "a.out" "{{.*}}/usr/lib{{/|\\\\}}crt0.o"
 // THUMBEB: "{{.*}}/usr/lib{{/|\\\\}}eabi{{/|\\\\}}crti.o"
 // THUMBEB: "{{.*}}/usr/lib{{/|\\\\}}crtbegin.o" "{{.*}}.o" "-lc"
 // THUMBEB: "{{.*}}/usr/lib{{/|\\\\}}crtend.o" "{{.*}}/usr/lib{{/|\\\\}}crtn.o"