ARM: diagnose ARM/Thumb assembly switches on CPUs only supporting one.

Some ARM CPUs only support ARM mode (ancient v4 ones, for example) and some
only support Thumb mode (M-class ones currently). This makes sure such CPUs
default to the correct mode and makes the AsmParser diagnose an attempt to
switch modes incorrectly.

rdar://14024354

llvm-svn: 183710

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCTargetDesc.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCTargetDesc.cpp
index 164f57b2d05..14fd03fad8e 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCTargetDesc.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCTargetDesc.cpp
@@ -61,6 +61,7 @@ std::string ARM_MC::ParseARMTriple(StringRef TT, StringRef CPU) {
     unsigned SubVer = TT[Idx];
     if (SubVer >= '7' && SubVer <= '9') {
       if (Len >= Idx+2 && TT[Idx+1] == 'm') {
+        isThumb = true;
         if (NoCPU)
           // v7m: FeatureNoARM, FeatureDB, FeatureHWDiv, FeatureMClass
           ARMArchFeature = "+v7,+noarm,+db,+hwdiv,+mclass";
@@ -99,6 +100,7 @@ std::string ARM_MC::ParseARMTriple(StringRef TT, StringRef CPU) {
       if (Len >= Idx+3 && TT[Idx+1] == 't' && TT[Idx+2] == '2')
         ARMArchFeature = "+v6t2";
       else if (Len >= Idx+2 && TT[Idx+1] == 'm') {
+        isThumb = true;
         if (NoCPU)
           // v6m: FeatureNoARM, FeatureMClass
           ARMArchFeature = "+v6,+noarm,+mclass";