rust/src/rustllvm/PassWrapper.cpp
Alex Crichton 667d114f47 Disable all unwinding on -Z no-landing-pads LTO
When performing LTO, the rust compiler has an opportunity to completely strip
all landing pads in all dependent libraries. I've modified the LTO pass to
recognize the -Z no-landing-pads option when also running an LTO pass to flag
everything in LLVM as nothrow. I've verified that this prevents any and all
invoke instructions from being emitted.

I believe that this is one of our best options for moving forward with
accomodating use-cases where unwinding doesn't really make sense. This will
allow libraries to be built with landing pads by default but allow usage of them
in contexts where landing pads aren't necessary.

cc #10780
2013-12-11 09:18:20 -08:00

243 lines
8.2 KiB
C++

// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#include <stdio.h>
#include "rustllvm.h"
#include "llvm/Support/CBindingWrapping.h"
#include "llvm/Target/TargetLibraryInfo.h"
#include "llvm/Transforms/IPO/PassManagerBuilder.h"
#include "llvm-c/Transforms/PassManagerBuilder.h"
using namespace llvm;
extern cl::opt<bool> EnableARMEHABI;
typedef struct LLVMOpaquePass *LLVMPassRef;
typedef struct LLVMOpaqueTargetMachine *LLVMTargetMachineRef;
DEFINE_STDCXX_CONVERSION_FUNCTIONS(Pass, LLVMPassRef)
DEFINE_STDCXX_CONVERSION_FUNCTIONS(TargetMachine, LLVMTargetMachineRef)
DEFINE_STDCXX_CONVERSION_FUNCTIONS(PassManagerBuilder, LLVMPassManagerBuilderRef)
extern "C" void
LLVMInitializePasses() {
PassRegistry &Registry = *PassRegistry::getPassRegistry();
initializeCore(Registry);
initializeCodeGen(Registry);
initializeScalarOpts(Registry);
initializeVectorization(Registry);
initializeIPO(Registry);
initializeAnalysis(Registry);
initializeIPA(Registry);
initializeTransformUtils(Registry);
initializeInstCombine(Registry);
initializeInstrumentation(Registry);
initializeTarget(Registry);
}
extern "C" bool
LLVMRustAddPass(LLVMPassManagerRef PM, const char *PassName) {
PassManagerBase *pm = unwrap(PM);
StringRef SR(PassName);
PassRegistry *PR = PassRegistry::getPassRegistry();
const PassInfo *PI = PR->getPassInfo(SR);
if (PI) {
pm->add(PI->createPass());
return true;
}
return false;
}
extern "C" LLVMTargetMachineRef
LLVMRustCreateTargetMachine(const char *triple,
const char *cpu,
const char *feature,
CodeModel::Model CM,
Reloc::Model RM,
CodeGenOpt::Level OptLevel,
bool EnableSegmentedStacks,
bool UseSoftFloat) {
std::string Error;
Triple Trip(Triple::normalize(triple));
const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Trip.getTriple(),
Error);
if (TheTarget == NULL) {
LLVMRustError = Error.c_str();
return NULL;
}
TargetOptions Options;
Options.NoFramePointerElim = true;
Options.EnableSegmentedStacks = EnableSegmentedStacks;
Options.FloatABIType =
(Trip.getEnvironment() == Triple::GNUEABIHF) ? FloatABI::Hard :
FloatABI::Default;
Options.UseSoftFloat = UseSoftFloat;
if (UseSoftFloat) {
Options.FloatABIType = FloatABI::Soft;
}
TargetMachine *TM = TheTarget->createTargetMachine(Trip.getTriple(),
cpu,
feature,
Options,
RM,
CM,
OptLevel);
return wrap(TM);
}
extern "C" void
LLVMRustDisposeTargetMachine(LLVMTargetMachineRef TM) {
delete unwrap(TM);
}
// Unfortunately, LLVM doesn't expose a C API to add the corresponding analysis
// passes for a target to a pass manager. We export that functionality through
// this function.
extern "C" void
LLVMRustAddAnalysisPasses(LLVMTargetMachineRef TM,
LLVMPassManagerRef PMR,
LLVMModuleRef M) {
PassManagerBase *PM = unwrap(PMR);
PM->add(new DataLayout(unwrap(M)));
unwrap(TM)->addAnalysisPasses(*PM);
}
// Unfortunately, the LLVM C API doesn't provide a way to set the `LibraryInfo`
// field of a PassManagerBuilder, we expose our own method of doing so.
extern "C" void
LLVMRustAddBuilderLibraryInfo(LLVMPassManagerBuilderRef PMB, LLVMModuleRef M) {
Triple TargetTriple(unwrap(M)->getTargetTriple());
unwrap(PMB)->LibraryInfo = new TargetLibraryInfo(TargetTriple);
}
// Unfortunately, the LLVM C API doesn't provide a way to create the
// TargetLibraryInfo pass, so we use this method to do so.
extern "C" void
LLVMRustAddLibraryInfo(LLVMPassManagerRef PMB, LLVMModuleRef M) {
Triple TargetTriple(unwrap(M)->getTargetTriple());
unwrap(PMB)->add(new TargetLibraryInfo(TargetTriple));
}
// Unfortunately, the LLVM C API doesn't provide an easy way of iterating over
// all the functions in a module, so we do that manually here. You'll find
// similar code in clang's BackendUtil.cpp file.
extern "C" void
LLVMRustRunFunctionPassManager(LLVMPassManagerRef PM, LLVMModuleRef M) {
FunctionPassManager *P = unwrap<FunctionPassManager>(PM);
P->doInitialization();
for (Module::iterator I = unwrap(M)->begin(),
E = unwrap(M)->end(); I != E; ++I)
if (!I->isDeclaration())
P->run(*I);
P->doFinalization();
}
extern "C" void
LLVMRustSetLLVMOptions(int Argc, char **Argv) {
// Initializing the command-line options more than once is not allowed. So,
// check if they've already been initialized. (This could happen if we're
// being called from rustpkg, for example). If the arguments change, then
// that's just kinda unfortunate.
static bool initialized = false;
if (initialized) return;
initialized = true;
cl::ParseCommandLineOptions(Argc, Argv);
}
extern "C" bool
LLVMRustWriteOutputFile(LLVMTargetMachineRef Target,
LLVMPassManagerRef PMR,
LLVMModuleRef M,
const char *path,
TargetMachine::CodeGenFileType FileType) {
PassManager *PM = unwrap<PassManager>(PMR);
std::string ErrorInfo;
raw_fd_ostream OS(path, ErrorInfo, sys::fs::F_Binary);
if (ErrorInfo != "") {
LLVMRustError = ErrorInfo.c_str();
return false;
}
formatted_raw_ostream FOS(OS);
unwrap(Target)->addPassesToEmitFile(*PM, FOS, FileType, false);
PM->run(*unwrap(M));
return true;
}
extern "C" void
LLVMRustPrintModule(LLVMPassManagerRef PMR,
LLVMModuleRef M,
const char* path) {
PassManager *PM = unwrap<PassManager>(PMR);
std::string ErrorInfo;
raw_fd_ostream OS(path, ErrorInfo, sys::fs::F_Binary);
formatted_raw_ostream FOS(OS);
PM->add(createPrintModulePass(&FOS));
PM->run(*unwrap(M));
}
extern "C" void
LLVMRustPrintPasses() {
LLVMInitializePasses();
struct MyListener : PassRegistrationListener {
void passEnumerate(const PassInfo *info) {
if (info->getPassArgument() && *info->getPassArgument()) {
printf("%15s - %s\n", info->getPassArgument(),
info->getPassName());
}
}
} listener;
PassRegistry *PR = PassRegistry::getPassRegistry();
PR->enumerateWith(&listener);
}
extern "C" void
LLVMRustAddAlwaysInlinePass(LLVMPassManagerBuilderRef PMB, bool AddLifetimes) {
unwrap(PMB)->Inliner = createAlwaysInlinerPass(AddLifetimes);
}
extern "C" void
LLVMRustRunRestrictionPass(LLVMModuleRef M, char **symbols, size_t len) {
PassManager passes;
ArrayRef<const char*> ref(symbols, len);
passes.add(llvm::createInternalizePass(ref));
passes.run(*unwrap(M));
}
extern "C" void
LLVMRustMarkAllFunctionsNounwind(LLVMModuleRef M) {
for (Module::iterator GV = unwrap(M)->begin(),
E = unwrap(M)->end(); GV != E; ++GV) {
GV->setDoesNotThrow();
Function *F = dyn_cast<Function>(GV);
if (F == NULL)
continue;
for (Function::iterator B = F->begin(), BE = F->end(); B != BE; ++B) {
for (BasicBlock::iterator I = B->begin(), IE = B->end();
I != IE; ++I) {
if (isa<InvokeInst>(I)) {
InvokeInst *CI = cast<InvokeInst>(I);
CI->setDoesNotThrow();
}
}
}
}
}