Author: majnemer
Date: Sat Feb 20 03:23:47 2016
New Revision: 261425
URL: http://llvm.org/viewvc/llvm-project?rev=261425&view=rev
Log:
[MSVC Compat] Implement -EHc semantics
The -EHc flag implicitly adds a nothrow attribute to any extern "C"
function when exceptions are enabled.
Modified:
cfe/trunk/include/clang/Basic/LangOptions.def
cfe/trunk/include/clang/Driver/CC1Options.td
cfe/trunk/lib/Driver/Tools.cpp
cfe/trunk/lib/Frontend/CompilerInvocation.cpp
cfe/trunk/lib/Sema/SemaDecl.cpp
Modified: cfe/trunk/include/clang/Basic/LangOptions.def
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/LangOptions.def?rev=261425&r1=261424&r2=261425&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/LangOptions.def (original)
+++ cfe/trunk/include/clang/Basic/LangOptions.def Sat Feb 20 03:23:47 2016
@@ -110,6 +110,7 @@ LANGOPT(Exceptions , 1, 0, "excep
LANGOPT(ObjCExceptions , 1, 0, "Objective-C exceptions")
LANGOPT(CXXExceptions , 1, 0, "C++ exceptions")
LANGOPT(SjLjExceptions , 1, 0, "setjmp-longjump exception handling")
+LANGOPT(ExternCNoUnwind , 1, 0, "Assume extern C functions don't unwind")
LANGOPT(TraditionalCPP , 1, 0, "traditional CPP emulation")
LANGOPT(RTTI , 1, 1, "run-time type information")
LANGOPT(RTTIData , 1, 1, "emit run-time type information data")
Modified: cfe/trunk/include/clang/Driver/CC1Options.td
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/CC1Options.td?rev=261425&r1=261424&r2=261425&view=diff
==============================================================================
--- cfe/trunk/include/clang/Driver/CC1Options.td (original)
+++ cfe/trunk/include/clang/Driver/CC1Options.td Sat Feb 20 03:23:47 2016
@@ -511,6 +511,8 @@ def main_file_name : Separate<["-"], "ma
def fblocks_runtime_optional : Flag<["-"], "fblocks-runtime-optional">,
HelpText<"Weakly link in the blocks runtime">;
+def fexternc_nounwind : Flag<["-"], "fexternc-nounwind">,
+ HelpText<"Assume all functions with C linkage do not unwind">;
def fsjlj_exceptions : Flag<["-"], "fsjlj-exceptions">,
HelpText<"Use SjLj style exceptions">;
def split_dwarf_file : Separate<["-"], "split-dwarf-file">,
Modified: cfe/trunk/lib/Driver/Tools.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=261425&r1=261424&r2=261425&view=diff
==============================================================================
--- cfe/trunk/lib/Driver/Tools.cpp (original)
+++ cfe/trunk/lib/Driver/Tools.cpp Sat Feb 20 03:23:47 2016
@@ -5786,8 +5786,7 @@ struct EHFlags {
/// - s: Cleanup after "synchronous" exceptions, aka C++ exceptions.
/// - a: Cleanup after "asynchronous" exceptions, aka structured exceptions.
/// The 'a' modifier is unimplemented and fundamentally hard in LLVM IR.
-/// - c: Assume that extern "C" functions are implicitly noexcept. This
-/// modifier is an optimization, so we ignore it for now.
+/// - c: Assume that extern "C" functions are implicitly nounwind.
/// The default is /EHs-c-, meaning cleanups are disabled.
static EHFlags parseClangCLEHFlags(const Driver &D, const ArgList &Args) {
EHFlags EH;
@@ -5897,10 +5896,11 @@ void Clang::AddClangCLArgs(const ArgList
const Driver &D = getToolChain().getDriver();
EHFlags EH = parseClangCLEHFlags(D, Args);
- // FIXME: Do something with NoExceptC.
if (EH.Synch || EH.Asynch) {
CmdArgs.push_back("-fcxx-exceptions");
CmdArgs.push_back("-fexceptions");
+ if (EH.NoUnwindC)
+ CmdArgs.push_back("-fexternc-nounwind");
}
// /EP should expand to -E -P.
Modified: cfe/trunk/lib/Frontend/CompilerInvocation.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/CompilerInvocation.cpp?rev=261425&r1=261424&r2=261425&view=diff
==============================================================================
--- cfe/trunk/lib/Frontend/CompilerInvocation.cpp (original)
+++ cfe/trunk/lib/Frontend/CompilerInvocation.cpp Sat Feb 20 03:23:47 2016
@@ -1688,6 +1688,7 @@ static void ParseLangArgs(LangOptions &O
Opts.ObjCExceptions = Args.hasArg(OPT_fobjc_exceptions);
Opts.CXXExceptions = Args.hasArg(OPT_fcxx_exceptions);
Opts.SjLjExceptions = Args.hasArg(OPT_fsjlj_exceptions);
+ Opts.ExternCNoUnwind = Args.hasArg(OPT_fexternc_nounwind);
Opts.TraditionalCPP = Args.hasArg(OPT_traditional_cpp);
Opts.RTTI = Opts.CPlusPlus && !Args.hasArg(OPT_fno_rtti);
Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=261425&r1=261424&r2=261425&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Sat Feb 20 03:23:47 2016
@@ -11582,6 +11582,13 @@ void Sema::AddKnownFunctionAttributes(Fu
}
}
+ // If C++ exceptions are enabled but we are told extern "C" functions cannot
+ // throw, add an implicit nothrow attribute to any extern "C" function we
come
+ // across.
+ if (getLangOpts().CXXExceptions && getLangOpts().ExternCNoUnwind &&
+ FD->isExternC() && !FD->hasAttr<NoThrowAttr>())
+ FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation()));
+
IdentifierInfo *Name = FD->getIdentifier();
if (!Name)
return;
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