Fix a bugs with using some Mach-O command line flags like "-arch armv7m".

The Mach-O command line flag like "-arch armv7m" does not match the
arch name part of its llvm Triple which is "thumbv7m-apple-darwin”.

I think the best way to fix this is to have
llvm::object::MachOObjectFile::getArchTriple() optionally return the
name of the Mach-O arch flag that would be used with -arch that
matches the CPUType and CPUSubType.  Then change
llvm::object::MachOUniversalBinary::ObjectForArch::getArchTypeName()
to use that and change it to getArchFlagName() as the type name is
really part of the Triple and the -arch flag name is a Mach-O thing
for a specific Triple with a specific Mcpu value.

rdar://29663637

llvm-svn: 290001

2 files changed, 5 insertions, 0 deletions

diff --git a/llvm/test/tools/llvm-objdump/ARM/Inputs/fat-armv7m.o b/llvm/test/tools/llvm-objdump/ARM/Inputs/fat-armv7m.o
new file mode 100644
index 00000000000..2b478e36c45
--- /dev/null
+++ b/llvm/test/tools/llvm-objdump/ARM/Inputs/fat-armv7m.o
diff --git a/llvm/test/tools/llvm-objdump/ARM/macho-arch-armv7m-flag.test b/llvm/test/tools/llvm-objdump/ARM/macho-arch-armv7m-flag.test
new file mode 100644
index 00000000000..6a19e306666
--- /dev/null
+++ b/llvm/test/tools/llvm-objdump/ARM/macho-arch-armv7m-flag.test
@@ -0,0 +1,5 @@
+@ RUN: llvm-objdump -macho -d -arch armv7m %p/Inputs/fat-armv7m.o | FileCheck %s
+@ CHECK: fat-armv7m.o:
+@ CHECK: (__TEXT,__text) section
+@ CHECK: foo:
+@ CHECK: 00 bf nop