Disable C++ EH by default for clang-cl and MSVC environments
We don't need any more bug reports from users telling us that MSVC-style
C++ exceptions are broken. Developers and adventurous users can still
test the existing functionality by passing along -fexceptions to either
clang or clang-cl.
llvm-svn: 241952
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 436c900..6cc92f6 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -506,7 +506,7 @@
HelpText<"Emit all declarations, even if unused">;
def fencoding_EQ : Joined<["-"], "fencoding=">, Group<f_Group>;
def ferror_limit_EQ : Joined<["-"], "ferror-limit=">, Group<f_Group>, Flags<[CoreOption]>;
-def fexceptions : Flag<["-"], "fexceptions">, Group<f_Group>, Flags<[CC1Option]>,
+def fexceptions : Flag<["-"], "fexceptions">, Group<f_Group>, Flags<[CC1Option, CoreOption]>,
HelpText<"Enable support for exception handling">;
def fexcess_precision_EQ : Joined<["-"], "fexcess-precision=">,
Group<clang_ignored_gcc_optimization_f_Group>;
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 38c3d5c..1805333 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -2041,17 +2041,6 @@
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) {
- if (Arg *A = Args.getLastArg(options::OPT_fexceptions,
- options::OPT_fno_exceptions))
- if (A->getOption().matches(options::OPT_fexceptions))
- return true;
-
- return false;
-}
-
/// Adds exception related arguments to the driver command arguments. There's a
/// master flag, -fexceptions and also language specific flags to enable/disable
/// C++ and Objective-C exceptions. This makes it possible to for example
@@ -2075,8 +2064,9 @@
return;
}
- // Gather the exception settings from the command line arguments.
- bool EH = exceptionSettings(Args, Triple);
+ // See if the user explicitly enabled exceptions.
+ bool EH = Args.hasFlag(options::OPT_fexceptions, options::OPT_fno_exceptions,
+ false);
// Obj-C exceptions are enabled by default, regardless of -fexceptions. This
// is not necessarily sensible, but follows GCC.
@@ -2089,8 +2079,11 @@
}
if (types::isCXX(InputType)) {
- bool CXXExceptionsEnabled =
- Triple.getArch() != llvm::Triple::xcore && !Triple.isPS4CPU();
+ // Disable C++ EH by default on XCore, PS4, and MSVC.
+ // FIXME: Remove MSVC from this list once things work.
+ bool CXXExceptionsEnabled = Triple.getArch() != llvm::Triple::xcore &&
+ !Triple.isPS4CPU() &&
+ !Triple.isWindowsMSVCEnvironment();
Arg *ExceptionArg = Args.getLastArg(
options::OPT_fcxx_exceptions, options::OPT_fno_cxx_exceptions,
options::OPT_fexceptions, options::OPT_fno_exceptions);
@@ -5040,6 +5033,7 @@
/// The default is /EHs-c-, meaning cleanups are disabled.
static EHFlags parseClangCLEHFlags(const Driver &D, const ArgList &Args) {
EHFlags EH;
+
std::vector<std::string> EHArgs =
Args.getAllArgValues(options::OPT__SLASH_EH);
for (auto EHVal : EHArgs) {
@@ -5061,6 +5055,15 @@
break;
}
}
+
+ // Only enable C++ exceptions if the user opts into it by passing
+ // -fexceptions. Lots of build systems implicitly pass /EHsc when users don't
+ // actually need it.
+ // FIXME: Remove this when they work out of the box.
+ if (!Args.hasFlag(options::OPT_fexceptions, options::OPT_fno_exceptions,
+ /*default=*/false))
+ EH = EHFlags();
+
return EH;
}
@@ -9102,7 +9105,9 @@
if (Args.hasArg(options::OPT_v))
CmdArgs.push_back("-v");
- if (exceptionSettings(Args, getToolChain().getTriple()))
+ // Pass -fexceptions through to the linker if it was present.
+ if (Args.hasFlag(options::OPT_fexceptions, options::OPT_fno_exceptions,
+ false))
CmdArgs.push_back("-fexceptions");
AddLinkerInputs(getToolChain(), Inputs, Args, CmdArgs);
diff --git a/clang/test/Driver/cl-eh.cpp b/clang/test/Driver/cl-eh.cpp
index a71491e..e80d39b 100644
--- a/clang/test/Driver/cl-eh.cpp
+++ b/clang/test/Driver/cl-eh.cpp
@@ -4,9 +4,13 @@
// Note: %s must be preceded by --, otherwise it may be interpreted as a
// command-line option, e.g. on Mac where %s is commonly under /Users.
+// RUN: %clang_cl /c /EHsc -fexceptions -### -- %s 2>&1 | FileCheck -check-prefix=EHscfex %s
+// EHscfex: "-fcxx-exceptions"
+// EHscfex: "-fexceptions"
+
// RUN: %clang_cl /c /EHsc -### -- %s 2>&1 | FileCheck -check-prefix=EHsc %s
-// EHsc: "-fcxx-exceptions"
-// EHsc: "-fexceptions"
+// EHsc-NOT: "-fcxx-exceptions"
+// EHsc-NOT: "-fexceptions"
// RUN: %clang_cl /c /EHs-c- -### -- %s 2>&1 | FileCheck -check-prefix=EHs_c_ %s
// EHs_c_-NOT: "-fcxx-exceptions"
@@ -16,14 +20,14 @@
// EHs_EHc_-NOT: "-fcxx-exceptions"
// EHs_EHc_-NOT: "-fexceptions"
-// RUN: %clang_cl /c /EHs- /EHs -### -- %s 2>&1 | FileCheck -check-prefix=EHs_EHs %s
+// RUN: %clang_cl /c /EHs- /EHs -fexceptions -### -- %s 2>&1 | FileCheck -check-prefix=EHs_EHs %s
// EHs_EHs: "-fcxx-exceptions"
// EHs_EHs: "-fexceptions"
-// RUN: %clang_cl /c /EHs- /EHsa -### -- %s 2>&1 | FileCheck -check-prefix=EHs_EHa %s
+// RUN: %clang_cl /c /EHs- /EHsa -fexceptions -### -- %s 2>&1 | FileCheck -check-prefix=EHs_EHa %s
// EHs_EHa: "-fcxx-exceptions"
// EHs_EHa: "-fexceptions"
-// RUN: %clang_cl /c /EHinvalid -### -- %s 2>&1 | FileCheck -check-prefix=EHinvalid %s
+// RUN: %clang_cl /c /EHinvalid -fexceptions -### -- %s 2>&1 | FileCheck -check-prefix=EHinvalid %s
// EHinvalid: error: invalid value 'invalid' in '/EH'
// EHinvalid-NOT: error: