ARM: fix mismatch between Clang and backend on exception type.

"-arch armv7k" is only normally used with a watchos target, but Clang doesn't
stop you from giving a "-miphoneos-version-min" option too, converting the
triple to "thumbv7k-apple-ios". In this case the backend will decide to use
SjLj exceptions, so Clang needs to agree so it can create the correct
predefines.

Fortunately, there's a handy function to make the decision for us now.

llvm-svn: 253355

2 files changed, 11 insertions, 7 deletions

diff --git a/clang/lib/Driver/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index d1ce3f4f1f1..ed223219f65 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -1053,12 +1053,8 @@ bool Darwin::UseSjLjExceptions(const ArgList &Args) const {
       getTriple().getArch() != llvm::Triple::thumb)
     return false;
 
-  // We can't check directly for watchOS here. ComputeLLVMTriple only
-  // fills in the ArchName correctly.
-  llvm::Triple Triple(ComputeLLVMTriple(Args));
-  return !(Triple.getArchName() == "armv7k" ||
-           Triple.getArchName() == "thumbv7k");
-
+  // Only watchOS uses the new DWARF/Compact unwinding method.
+  return !isTargetWatchOS();
 }
 
 bool MachO::isPICDefault() const { return true; }
diff --git a/clang/test/Driver/arch-armv7k.c b/clang/test/Driver/arch-armv7k.c
index 190d8999ab6..f5c33cfd9f5 100644
--- a/clang/test/Driver/arch-armv7k.c
+++ b/clang/test/Driver/arch-armv7k.c
@@ -1,5 +1,13 @@
-// Tests that make sure armv7k is mapped to the correct CPU
+// Tests that make sure armv7k is mapped to the correct CPU and ABI choices
 
 // RUN: %clang -target x86_64-apple-macosx10.9 -arch armv7k -c %s -### 2>&1 | FileCheck %s
 // CHECK: "-cc1"{{.*}} "-target-cpu" "cortex-a7"
 // CHECK-NOT: "-fsjlj-exceptions"
+
+// "thumbv7k-apple-ios" is a bit of a weird triple, but since the backend is
+// going to choose to use sjlj-based exceptions for it, the front-end needs to
+// match.
+
+// RUN: %clang -target x86_64-apple-macosx10.9 -arch armv7k -miphoneos-version-min=9.0 -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SJLJ
+// CHECK-SJLJ: "-cc1"{{.*}} "-target-cpu" "cortex-a7"
+// CHECK-SJLJ: "-fsjlj-exceptions"