[cfe-dev] Calling Extern Function
Paul Griffiths
gafferuk at gmail.com
Wed Aug 18 07:44:25 PDT 2010
Yes, it is c++;
ave also tried it with
extern "C"
int yipee(int aVar)
{
return 5;
}
but still no luck.
heres my full listing, im stuck.
// Whistle.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include "clang/CodeGen/CodeGenAction.h"
#include "clang/Driver/Compilation.h"
#include "clang/Driver/Driver.h"
#include "clang/Driver/Tool.h"
#include "clang/Frontend/CompilerInvocation.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/Frontend/DiagnosticOptions.h"
#include "clang/Frontend/FrontendDiagnostic.h"
#include "clang/Frontend/TextDiagnosticPrinter.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Support/TypeBuilder.h"
#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/Config/config.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Config/config.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/System/Host.h"
#include "llvm/System/Path.h"
#include "llvm/Target/TargetSelect.h"
using namespace clang;
using namespace clang::driver;
extern "C"
int yipee(int val)
{
fprintf(stderr, "yipee!");
return 1;
}
llvm::sys::Path GetExecutablePath(const char *Argv0) {
// This just needs to be some symbol in the binary; C++ doesn't
// allow taking the address of ::main however.
void *MainAddr = (void*) (intptr_t) GetExecutablePath;
return llvm::sys::Path::GetMainExecutable(Argv0, MainAddr);
}
int Execute(llvm::Module *Mod, char * const *envp) {
llvm::InitializeNativeTarget();
std::string Error;
llvm::OwningPtr<llvm::ExecutionEngine> EE(
llvm::ExecutionEngine::createJIT(Mod, &Error));
if (!EE) {
llvm::errs() << "unable to make execution engine: " << Error << "\n";
return 255;
}
// code I have added
---------------------------------------------------------------------------------------------
llvm::FunctionType* ft =
llvm::FunctionType::get(llvm::Type::getInt32Ty(llvm::getGlobalContext()),
std::vector<const llvm::Type*>(1,
llvm::Type::getInt32Ty(llvm::getGlobalContext())), false);
llvm::Function* F = llvm::Function::Create(ft,
llvm::Function::ExternalLinkage, "yipee", Mod);
EE->addGlobalMapping(F, (void*)(intptr_t)yipee);
llvm::Function *YipeeFn = Mod->getFunction("yipee");
if (!YipeeFn) {
llvm::errs() << "'yipee' function not found in module.\n";
return 255;
}
// end code I have added
---------------------------------------------------------------------------------------------
llvm::Function *EntryFn = Mod->getFunction("main");
if (!EntryFn) {
llvm::errs() << "'main' function not found in module.\n";
return 255;
}
// FIXME: Support passing arguments.
std::vector<std::string> Args;
Args.push_back(Mod->getModuleIdentifier());
return EE->runFunctionAsMain(EntryFn, Args, envp);
}
int main(int argc, const char **argv, char * const *envp) {
void *MainAddr = (void*) (intptr_t) GetExecutablePath;
llvm::sys::Path Path = GetExecutablePath(argv[0]);
TextDiagnosticPrinter DiagClient(llvm::errs(), DiagnosticOptions());
Diagnostic Diags(&DiagClient);
Driver TheDriver(Path.str(), llvm::sys::getHostTriple(),
"a.out", /*IsProduction=*/false, /*CXXIsProduction=*/false,
Diags);
TheDriver.setTitle("clang interpreter");
// FIXME: This is a hack to try to force the driver to do something we can
// recognize. We need to extend the driver library to support this use model
// (basically, exactly one input, and the operation mode is hard wired).
llvm::SmallVector<const char *, 16> Args(argv, argv + argc);
Args.push_back("-fsyntax-only");
llvm::OwningPtr<Compilation> C(TheDriver.BuildCompilation(Args.size(),
Args.data()));
if (!C)
return 0;
// FIXME: This is copied from ASTUnit.cpp; simplify and eliminate.
// We expect to get back exactly one command job, if we didn't something
// failed. Extract that job from the compilation.
const driver::JobList &Jobs = C->getJobs();
if (Jobs.size() != 1 || !isa<driver::Command>(Jobs.begin())) {
llvm::SmallString<256> Msg;
llvm::raw_svector_ostream OS(Msg);
C->PrintJob(OS, C->getJobs(), "; ", true);
Diags.Report(diag::err_fe_expected_compiler_job) << OS.str();
return 1;
}
const driver::Command *Cmd = cast<driver::Command>(*Jobs.begin());
if (llvm::StringRef(Cmd->getCreator().getName()) != "clang") {
Diags.Report(diag::err_fe_expected_clang_command);
return 1;
}
// Initialize a compiler invocation object from the clang (-cc1) arguments.
const driver::ArgStringList &CCArgs = Cmd->getArguments();
llvm::OwningPtr<CompilerInvocation> CI(new CompilerInvocation);
CompilerInvocation::CreateFromArgs(*CI,
const_cast<const char **>(CCArgs.data()),
const_cast<const char **>(CCArgs.data()) +
CCArgs.size(),
Diags);
// Show the invocation, with -v.
if (CI->getHeaderSearchOpts().Verbose) {
llvm::errs() << "clang invocation:\n";
C->PrintJob(llvm::errs(), C->getJobs(), "\n", true);
llvm::errs() << "\n";
}
// FIXME: This is copied from cc1_main.cpp; simplify and eliminate.
// Create a compiler instance to handle the actual work.
CompilerInstance Clang;
Clang.setLLVMContext(new llvm::LLVMContext);
Clang.setInvocation(CI.take());
// Create the compilers actual diagnostics engine.
Clang.createDiagnostics(int(CCArgs.size()),const_cast<char**>(CCArgs.data()));
if (!Clang.hasDiagnostics())
return 1;
// Infer the builtin include path if unspecified.
if (Clang.getHeaderSearchOpts().UseBuiltinIncludes &&
Clang.getHeaderSearchOpts().ResourceDir.empty())
Clang.getHeaderSearchOpts().ResourceDir =
CompilerInvocation::GetResourcesPath(argv[0], MainAddr);
// Create and execute the frontend to generate an LLVM bitcode module.
llvm::OwningPtr<CodeGenAction> Act(new EmitLLVMOnlyAction());
if (!Clang.ExecuteAction(*Act))
return 1;
int Res = 255;
if (llvm::Module *Module = Act->takeModule())
{
Res = Execute(Module, envp);
}
// Shutdown.
llvm::llvm_shutdown();
return Res;
}
On 18 August 2010 14:36, <o.j.sivart at gmail.com> wrote:
> I assume you are compiling your program as c++. In this case your problem is that "yipee" will have been name mangled by the c++ compiler.
>
> On 18/08/2010, at 9:08 PM, Paul Griffiths wrote:
>
>> Can someone please tell me what I am doing wrong?
>>
>> Im trying to register an external function with the JIT, so can call
>> functions in my music application(heres an image :
>> http://img534.imageshack.us/img534/3995/87647073.jpg).
>>
>> Here my functions
>>
>> int yipee(int aVar)
>> {
>> return 5;
>> }
>>
>> int Execute(llvm::Module *Mod, char * const *envp) {
>> llvm::InitializeNativeTarget();
>>
>> std::string Error;
>> llvm::OwningPtr<llvm::ExecutionEngine> EE(
>> llvm::ExecutionEngine::createJIT(Mod, &Error));
>> if (!EE) {
>> llvm::errs() << "unable to make execution engine: " << Error << "\n";
>> return 255;
>> }
>>
>> // code I have added
>> ---------------------------------------------------------------------------------------------
>> llvm::FunctionType* ft =
>> llvm::FunctionType::get(llvm::Type::getInt32Ty(llvm::getGlobalContext()),
>> std::vector<const llvm::Type*>(0,
>> llvm::Type::getInt32Ty(llvm::getGlobalContext())), false);
>>
>> llvm::Function* f = llvm::Function::Create(ft,
>> llvm::Function::ExternalLinkage, "yipee", Mod);
>> EE->addGlobalMapping(f, yipee);
>> llvm::Function *YipeeFn = Mod->getFunction("yipee");
>> if (!YipeeFn) {
>> llvm::errs() << "'yipee' function not found in module.\n";
>> return 255;
>> }
>> // end code I have added
>> ---------------------------------------------------------------------------------------------
>>
>> llvm::Function *EntryFn = Mod->getFunction("main");
>> if (!EntryFn) {
>> llvm::errs() << "'main' function not found in module.\n";
>> return 255;
>> }
>>
>> // FIXME: Support passing arguments.
>> std::vector<std::string> Args;
>> Args.push_back(Mod->getModuleIdentifier());
>>
>> return EE->runFunctionAsMain(EntryFn, Args, envp);
>> }
>>
>>
>>
>> // here the C code to be ran with JIT
>> -------------------------------------------------------------------
>>
>> int main() {
>> int dd = yipee(1);
>> return 1;
>> }
>> _______________________________________________
>> cfe-dev mailing list
>> cfe-dev at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>
>
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