rust/compiler/rustc_llvm/llvm-wrapper/SymbolWrapper.cpp
2023-11-22 09:10:53 -08:00

98 lines
3.4 KiB
C++

// Derived from code in LLVM, which is:
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// Derived from:
// * https://github.com/llvm/llvm-project/blob/8ef3e895ad8ab1724e2b87cabad1dacdc7a397a3/llvm/include/llvm/Object/ArchiveWriter.h
// * https://github.com/llvm/llvm-project/blob/8ef3e895ad8ab1724e2b87cabad1dacdc7a397a3/llvm/lib/Object/ArchiveWriter.cpp
#include "SuppressLLVMWarnings.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/Object/ObjectFile.h"
using namespace llvm;
using namespace llvm::sys;
using namespace llvm::object;
static bool isArchiveSymbol(const object::BasicSymbolRef &S) {
Expected<uint32_t> SymFlagsOrErr = S.getFlags();
if (!SymFlagsOrErr)
// FIXME: Actually report errors helpfully.
report_fatal_error(SymFlagsOrErr.takeError());
if (*SymFlagsOrErr & object::SymbolRef::SF_FormatSpecific)
return false;
if (!(*SymFlagsOrErr & object::SymbolRef::SF_Global))
return false;
if (*SymFlagsOrErr & object::SymbolRef::SF_Undefined)
return false;
return true;
}
typedef void *(*LLVMRustGetSymbolsCallback)(void *, const char *);
typedef void *(*LLVMRustGetSymbolsErrorCallback)(const char *);
// Note: This is implemented in C++ instead of using the C api from Rust as IRObjectFile doesn't
// implement getSymbolName, only printSymbolName, which is inaccessible from the C api.
extern "C" void *LLVMRustGetSymbols(
char *BufPtr, size_t BufLen, void *State, LLVMRustGetSymbolsCallback Callback,
LLVMRustGetSymbolsErrorCallback ErrorCallback) {
std::unique_ptr<MemoryBuffer> Buf =
MemoryBuffer::getMemBuffer(StringRef(BufPtr, BufLen), StringRef("LLVMRustGetSymbolsObject"),
false);
SmallString<0> SymNameBuf;
raw_svector_ostream SymName(SymNameBuf);
// In the scenario when LLVMContext is populated SymbolicFile will contain a
// reference to it, thus SymbolicFile should be destroyed first.
LLVMContext Context;
std::unique_ptr<object::SymbolicFile> Obj;
const file_magic Type = identify_magic(Buf->getBuffer());
if (!object::SymbolicFile::isSymbolicFile(Type, &Context)) {
return 0;
}
if (Type == file_magic::bitcode) {
auto ObjOrErr = object::SymbolicFile::createSymbolicFile(
Buf->getMemBufferRef(), file_magic::bitcode, &Context);
if (!ObjOrErr) {
Error E = ObjOrErr.takeError();
SmallString<0> ErrorBuf;
raw_svector_ostream Error(ErrorBuf);
Error << E << '\0';
return ErrorCallback(Error.str().data());
}
Obj = std::move(*ObjOrErr);
} else {
auto ObjOrErr = object::SymbolicFile::createSymbolicFile(Buf->getMemBufferRef());
if (!ObjOrErr) {
Error E = ObjOrErr.takeError();
SmallString<0> ErrorBuf;
raw_svector_ostream Error(ErrorBuf);
Error << E << '\0';
return ErrorCallback(Error.str().data());
}
Obj = std::move(*ObjOrErr);
}
for (const object::BasicSymbolRef &S : Obj->symbols()) {
if (!isArchiveSymbol(S))
continue;
if (Error E = S.printName(SymName)) {
SmallString<0> ErrorBuf;
raw_svector_ostream Error(ErrorBuf);
Error << E << '\0';
return ErrorCallback(Error.str().data());
}
SymName << '\0';
if (void *E = Callback(State, SymNameBuf.str().data())) {
return E;
}
SymNameBuf.clear();
}
return 0;
}