From: David Majnemer <david.majnemer@gmail.com>
Date: Tue, 9 Dec 2014 00:12:30 +0000 (+0000)
Subject: Revert "Driver: Objective-C should respect -fno-exceptions"
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0a2e4f2c129edc8a3f0590493fd88e5751de60c4;p=clang

Revert "Driver: Objective-C should respect -fno-exceptions"

This reverts commit r223455.  It's been succesfully argued that
-fexceptions (at the driver level) is a misnomer and has little to do
with -fobjc-exceptions.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@223723 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 9924bb8896..151d87b50d 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -1894,6 +1894,23 @@ static void getTargetFeatures(const Driver &D, const llvm::Triple &Triple,
   }
 }
 
+static bool
+shouldUseExceptionTablesForObjCExceptions(const ObjCRuntime &runtime,
+                                          const llvm::Triple &Triple) {
+  // We use the zero-cost exception tables for Objective-C if the non-fragile
+  // ABI is enabled or when compiling for x86_64 and ARM on Snow Leopard and
+  // later.
+  if (runtime.isNonFragile())
+    return true;
+
+  if (!Triple.isMacOSX())
+    return false;
+
+  return (!Triple.isMacOSXVersionLT(10,5) &&
+          (Triple.getArch() == llvm::Triple::x86_64 ||
+           Triple.getArch() == llvm::Triple::arm));
+}
+
 // exceptionSettings() exists to share the logic between -cc1 and linker
 // invocations.
 static bool exceptionSettings(const ArgList &Args, const llvm::Triple &Triple) {
@@ -1930,21 +1947,15 @@ static void addExceptionArgs(const ArgList &Args, types::ID InputType,
   // Gather the exception settings from the command line arguments.
   bool EH = exceptionSettings(Args, Triple);
 
-  if (types::isObjC(InputType)) {
-    bool ObjCExceptionsEnabled = true;
-    if (Arg *A = Args.getLastArg(options::OPT_fobjc_exceptions,
-                                 options::OPT_fno_objc_exceptions,
-                                 options::OPT_fexceptions,
-                                 options::OPT_fno_exceptions))
-      ObjCExceptionsEnabled =
-          A->getOption().matches(options::OPT_fobjc_exceptions) ||
-          A->getOption().matches(options::OPT_fexceptions);
-
-    if (ObjCExceptionsEnabled) {
-      CmdArgs.push_back("-fobjc-exceptions");
+  // Obj-C exceptions are enabled by default, regardless of -fexceptions. This
+  // is not necessarily sensible, but follows GCC.
+  if (types::isObjC(InputType) &&
+      Args.hasFlag(options::OPT_fobjc_exceptions,
+                   options::OPT_fno_objc_exceptions,
+                   true)) {
+    CmdArgs.push_back("-fobjc-exceptions");
 
-      EH = true;
-    }
+    EH |= shouldUseExceptionTablesForObjCExceptions(objcRuntime, Triple);
   }
 
   if (types::isCXX(InputType)) {
diff --git a/test/Driver/exceptions.m b/test/Driver/exceptions.m
new file mode 100644
index 0000000000..9b747bb84d
--- /dev/null
+++ b/test/Driver/exceptions.m
@@ -0,0 +1,19 @@
+// RUN: %clang -target x86_64-apple-darwin9 \
+// RUN:   -fsyntax-only -fno-exceptions %s
+
+void f1() {
+  @throw @"A";
+}
+
+void f0() {
+  @try {
+    f1();
+  } @catch (id x) {
+    ;
+  }
+}
+
+int main() {
+  f0();
+  return 0;
+}
diff --git a/test/Driver/exceptions.mm b/test/Driver/exceptions.mm
deleted file mode 100644
index 1d918cf39b..0000000000
--- a/test/Driver/exceptions.mm
+++ /dev/null
@@ -1,6 +0,0 @@
-// RUN: %clang -target x86_64-apple-darwin11 -fno-exceptions %s -o - -### 2>&1 | \
-// RUN:   FileCheck %s
-
-CHECK-NOT: "-fobjc-exceptions"
-CHECK-NOT: "-fcxx-exceptions"
-CHECK-NOT: "-fexceptions"
diff --git a/test/Driver/rewrite-legacy-objc.m b/test/Driver/rewrite-legacy-objc.m
index ceb654f946..b0b78d0081 100644
--- a/test/Driver/rewrite-legacy-objc.m
+++ b/test/Driver/rewrite-legacy-objc.m
@@ -9,5 +9,5 @@
 // RUN:   FileCheck -check-prefix=TEST1 %s
 // RUN: %clang -no-canonical-prefixes -target i386-apple-macosx10.6.0 -rewrite-legacy-objc %s -o - -### 2>&1 | \
 // RUN:   FileCheck -check-prefix=TEST2 %s
-// TEST1: "-fmessage-length" "0" "-stack-protector" "1" "-mstackrealign" "-fblocks" "-fobjc-runtime=macosx-fragile" "-fobjc-subscripting-legacy-runtime" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fmax-type-align=16" "-fdiagnostics-show-option"
-// TEST2: "-fmessage-length" "0" "-stack-protector" "1" "-mstackrealign" "-fblocks" "-fobjc-runtime=macosx-fragile" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fmax-type-align=16" "-fdiagnostics-show-option"
+// TEST1: "-fmessage-length" "0" "-stack-protector" "1" "-mstackrealign" "-fblocks" "-fobjc-runtime=macosx-fragile" "-fobjc-subscripting-legacy-runtime" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fmax-type-align=16" "-fdiagnostics-show-option"
+// TEST2: "-fmessage-length" "0" "-stack-protector" "1" "-mstackrealign" "-fblocks" "-fobjc-runtime=macosx-fragile" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fmax-type-align=16" "-fdiagnostics-show-option"