Nick Lewycky
parent
a2cf0ed2c7
commit
fb643e4d9f
|
|
@ -27,6 +27,10 @@ include $(LEVEL)/Makefile.config
|
|||
|
||||
ifeq ($(ENABLE_PIC),1)
|
||||
PARALLEL_DIRS += lto
|
||||
|
||||
ifdef BINUTILS_INCDIR
|
||||
PARALLEL_DIRS += gold
|
||||
endif
|
||||
endif
|
||||
|
||||
include $(LEVEL)/Makefile.common
|
||||
|
|
|
|||
|
|
@ -0,0 +1,29 @@
|
|||
#===- tools/gold/Makefile ----------------------------------*- Makefile -*-===##
|
||||
#
|
||||
# The LLVM Compiler Infrastructure
|
||||
#
|
||||
# This file is distributed under the University of Illinois Open Source
|
||||
# License. See LICENSE.TXT for details.
|
||||
#
|
||||
##===----------------------------------------------------------------------===##
|
||||
|
||||
LEVEL = ../..
|
||||
LIBRARYNAME = LLVMgold
|
||||
|
||||
# Include this here so we can get the configuration of the targets
|
||||
# that have been configured for construction. We have to do this
|
||||
# early so we can set up LINK_COMPONENTS before including Makefile.rules
|
||||
include $(LEVEL)/Makefile.config
|
||||
|
||||
LINK_LIBS_IN_SHARED=1
|
||||
SHARED_LIBRARY = 1
|
||||
BUILD_ARCHIVE = 0
|
||||
DONT_BUILD_RELINKED = 1
|
||||
|
||||
LINK_COMPONENTS :=
|
||||
|
||||
include $(LEVEL)/Makefile.common
|
||||
|
||||
# Because off_t is used in the public API, the largefile parts are required for
|
||||
# ABI compatibility.
|
||||
CXXFLAGS+=-I$(BINUTILS_INCDIR) -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -lLTO
|
||||
|
|
@ -0,0 +1,17 @@
|
|||
This directory contains a plugin that is designed to work with binutils
|
||||
gold linker. At present time, this is not the default linker in
|
||||
binutils, and the default build of gold does not support plugins.
|
||||
|
||||
Obtaining binutils:
|
||||
|
||||
cvs -z 9 -d :pserver:anoncvs@sourceware.org:/cvs/src login
|
||||
{enter "anoncvs" as the password}
|
||||
cvs -z 9 -d :pserver:anoncvs@sourceware.org:/cvs/src co binutils
|
||||
|
||||
This will create a src/ directory. Make a build/ directory and from
|
||||
there configure binutils with "../src/configure --enable-gold --enable-plugins".
|
||||
Then build binutils with "make all-gold".
|
||||
|
||||
To build the LLVMgold plugin, configure LLVM with the option
|
||||
--with-binutils-include=/path/to/binutils/src/include/ . To use the
|
||||
plugin, run "ld-new --plugin /path/to/libLLVMgold.so".
|
||||
|
|
@ -0,0 +1,327 @@
|
|||
//===-- gold-plugin.cpp - Plugin to gold for Link Time Optimization ------===//
|
||||
//
|
||||
// The LLVM Compiler Infrastructure
|
||||
//
|
||||
// This file is distributed under the University of Illinois Open Source
|
||||
// License. See LICENSE.TXT for details.
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
//
|
||||
// This is a gold plugin for LLVM. It provides an LLVM implementation of the
|
||||
// interface described in http://gcc.gnu.org/wiki/whopr/driver .
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#include "plugin-api.h"
|
||||
|
||||
#include "llvm-c/lto.h"
|
||||
|
||||
#include "llvm/Support/raw_ostream.h"
|
||||
#include "llvm/System/Path.h"
|
||||
|
||||
#include <cstdlib>
|
||||
#include <cstring>
|
||||
#include <list>
|
||||
#include <vector>
|
||||
|
||||
using namespace llvm;
|
||||
|
||||
namespace {
|
||||
ld_plugin_status discard_message(int level, const char *format, ...) {
|
||||
// Die loudly. Recent versions of Gold pass ld_plugin_message as the first
|
||||
// callback in the transfer vector. This should never be called.
|
||||
abort();
|
||||
}
|
||||
|
||||
ld_plugin_add_symbols add_symbols = NULL;
|
||||
ld_plugin_get_symbols get_symbols = NULL;
|
||||
ld_plugin_add_input_file add_input_file = NULL;
|
||||
ld_plugin_message message = discard_message;
|
||||
|
||||
int api_version = 0;
|
||||
int gold_version = 0;
|
||||
|
||||
struct claimed_file {
|
||||
lto_module_t M;
|
||||
void *handle;
|
||||
std::vector<ld_plugin_symbol> syms;
|
||||
};
|
||||
|
||||
lto_codegen_model output_type = LTO_CODEGEN_PIC_MODEL_STATIC;
|
||||
std::list<claimed_file> Modules;
|
||||
std::vector<sys::Path> Cleanup;
|
||||
}
|
||||
|
||||
ld_plugin_status claim_file_hook(const ld_plugin_input_file *file,
|
||||
int *claimed);
|
||||
ld_plugin_status all_symbols_read_hook(void);
|
||||
ld_plugin_status cleanup_hook(void);
|
||||
|
||||
extern "C" ld_plugin_status onload(ld_plugin_tv *tv);
|
||||
ld_plugin_status onload(ld_plugin_tv *tv) {
|
||||
// We're given a pointer to the first transfer vector. We read through them
|
||||
// until we find one where tv_tag == LDPT_NULL. The REGISTER_* tagged values
|
||||
// contain pointers to functions that we need to call to register our own
|
||||
// hooks. The others are addresses of functions we can use to call into gold
|
||||
// for services.
|
||||
|
||||
bool registeredClaimFile = false;
|
||||
bool registeredAllSymbolsRead = false;
|
||||
bool registeredCleanup = false;
|
||||
|
||||
for (; tv->tv_tag != LDPT_NULL; ++tv) {
|
||||
switch (tv->tv_tag) {
|
||||
case LDPT_API_VERSION:
|
||||
api_version = tv->tv_u.tv_val;
|
||||
break;
|
||||
case LDPT_GOLD_VERSION: // major * 100 + minor
|
||||
gold_version = tv->tv_u.tv_val;
|
||||
break;
|
||||
case LDPT_LINKER_OUTPUT:
|
||||
switch (tv->tv_u.tv_val) {
|
||||
case LDPO_REL: // .o
|
||||
case LDPO_DYN: // .so
|
||||
output_type = LTO_CODEGEN_PIC_MODEL_DYNAMIC;
|
||||
break;
|
||||
case LDPO_EXEC: // .exe
|
||||
output_type = LTO_CODEGEN_PIC_MODEL_STATIC;
|
||||
break;
|
||||
default:
|
||||
(*message)(LDPL_ERROR, "Unknown output file type %d",
|
||||
tv->tv_u.tv_val);
|
||||
return LDPS_ERR;
|
||||
}
|
||||
// TODO: add an option to disable PIC.
|
||||
//output_type = LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC;
|
||||
break;
|
||||
case LDPT_OPTION:
|
||||
(*message)(LDPL_WARNING, "Ignoring flag %s", tv->tv_u.tv_string);
|
||||
break;
|
||||
case LDPT_REGISTER_CLAIM_FILE_HOOK: {
|
||||
ld_plugin_register_claim_file callback;
|
||||
callback = tv->tv_u.tv_register_claim_file;
|
||||
|
||||
if ((*callback)(claim_file_hook) != LDPS_OK)
|
||||
return LDPS_ERR;
|
||||
|
||||
registeredClaimFile = true;
|
||||
} break;
|
||||
case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK: {
|
||||
ld_plugin_register_all_symbols_read callback;
|
||||
callback = tv->tv_u.tv_register_all_symbols_read;
|
||||
|
||||
if ((*callback)(all_symbols_read_hook) != LDPS_OK)
|
||||
return LDPS_ERR;
|
||||
|
||||
registeredAllSymbolsRead = true;
|
||||
} break;
|
||||
case LDPT_REGISTER_CLEANUP_HOOK: {
|
||||
ld_plugin_register_cleanup callback;
|
||||
callback = tv->tv_u.tv_register_cleanup;
|
||||
|
||||
if ((*callback)(cleanup_hook) != LDPS_OK)
|
||||
return LDPS_ERR;
|
||||
|
||||
registeredCleanup = true;
|
||||
} break;
|
||||
case LDPT_ADD_SYMBOLS:
|
||||
add_symbols = tv->tv_u.tv_add_symbols;
|
||||
break;
|
||||
case LDPT_GET_SYMBOLS:
|
||||
get_symbols = tv->tv_u.tv_get_symbols;
|
||||
break;
|
||||
case LDPT_ADD_INPUT_FILE:
|
||||
add_input_file = tv->tv_u.tv_add_input_file;
|
||||
break;
|
||||
case LDPT_MESSAGE:
|
||||
message = tv->tv_u.tv_message;
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (!registeredClaimFile || !registeredAllSymbolsRead || !registeredCleanup ||
|
||||
!add_symbols || !get_symbols || !add_input_file) {
|
||||
(*message)(LDPL_ERROR, "Not all hooks registered for LLVMgold.");
|
||||
return LDPS_ERR;
|
||||
}
|
||||
|
||||
return LDPS_OK;
|
||||
}
|
||||
|
||||
/// claim_file_hook - called by gold to see whether this file is one that
|
||||
/// our plugin can handle. We'll try to open it and register all the symbols
|
||||
/// with add_symbol if possible.
|
||||
ld_plugin_status claim_file_hook(const ld_plugin_input_file *file,
|
||||
int *claimed) {
|
||||
// If set, this means gold found IR in an ELF section. LLVM doesn't wrap its
|
||||
// IR in ELF, so we know it's not us.
|
||||
if (file->offset)
|
||||
return LDPS_OK;
|
||||
|
||||
if (!lto_module_is_object_file(file->name))
|
||||
return LDPS_OK;
|
||||
|
||||
*claimed = 1;
|
||||
Modules.resize(Modules.size() + 1);
|
||||
claimed_file &cf = Modules.back();
|
||||
|
||||
cf.M = lto_module_create(file->name);
|
||||
if (!cf.M) {
|
||||
(*message)(LDPL_ERROR, "Failed to create LLVM module: %s",
|
||||
lto_get_error_message());
|
||||
return LDPS_ERR;
|
||||
}
|
||||
cf.handle = file->handle;
|
||||
unsigned sym_count = lto_module_get_num_symbols(cf.M);
|
||||
cf.syms.reserve(sym_count);
|
||||
|
||||
for (unsigned i = 0; i != sym_count; ++i) {
|
||||
lto_symbol_attributes attrs = lto_module_get_symbol_attribute(cf.M, i);
|
||||
if ((attrs & LTO_SYMBOL_SCOPE_MASK) == LTO_SYMBOL_SCOPE_INTERNAL)
|
||||
continue;
|
||||
|
||||
cf.syms.push_back(ld_plugin_symbol());
|
||||
ld_plugin_symbol &sym = cf.syms.back();
|
||||
sym.name = const_cast<char *>(lto_module_get_symbol_name(cf.M, i));
|
||||
sym.version = NULL;
|
||||
|
||||
int scope = attrs & LTO_SYMBOL_SCOPE_MASK;
|
||||
switch (scope) {
|
||||
case LTO_SYMBOL_SCOPE_HIDDEN:
|
||||
sym.visibility = LDPV_HIDDEN;
|
||||
break;
|
||||
case LTO_SYMBOL_SCOPE_PROTECTED:
|
||||
sym.visibility = LDPV_PROTECTED;
|
||||
break;
|
||||
case 0: // extern
|
||||
case LTO_SYMBOL_SCOPE_DEFAULT:
|
||||
sym.visibility = LDPV_DEFAULT;
|
||||
break;
|
||||
default:
|
||||
(*message)(LDPL_ERROR, "Unknown scope attribute: %d", scope);
|
||||
return LDPS_ERR;
|
||||
}
|
||||
|
||||
int definition = attrs & LTO_SYMBOL_DEFINITION_MASK;
|
||||
switch (definition) {
|
||||
case LTO_SYMBOL_DEFINITION_REGULAR:
|
||||
sym.def = LDPK_DEF;
|
||||
break;
|
||||
case LTO_SYMBOL_DEFINITION_UNDEFINED:
|
||||
sym.def = LDPK_UNDEF;
|
||||
break;
|
||||
case LTO_SYMBOL_DEFINITION_TENTATIVE:
|
||||
sym.def = LDPK_COMMON;
|
||||
break;
|
||||
case LTO_SYMBOL_DEFINITION_WEAK:
|
||||
sym.def = LDPK_WEAKDEF;
|
||||
break;
|
||||
default:
|
||||
(*message)(LDPL_ERROR, "Unknown definition attribute: %d", definition);
|
||||
return LDPS_ERR;
|
||||
}
|
||||
|
||||
// LLVM never emits COMDAT.
|
||||
sym.size = 0;
|
||||
sym.comdat_key = NULL;
|
||||
|
||||
sym.resolution = LDPR_UNKNOWN;
|
||||
}
|
||||
|
||||
cf.syms.reserve(cf.syms.size());
|
||||
|
||||
if (!cf.syms.empty()) {
|
||||
if ((*add_symbols)(cf.handle, cf.syms.size(), &cf.syms[0]) != LDPS_OK) {
|
||||
(*message)(LDPL_ERROR, "Unable to add symbols!");
|
||||
return LDPS_ERR;
|
||||
}
|
||||
}
|
||||
|
||||
return LDPS_OK;
|
||||
}
|
||||
|
||||
/// all_symbols_read_hook - gold informs us that all symbols have been read.
|
||||
/// At this point, we use get_symbols to see if any of our definitions have
|
||||
/// been overridden by a native object file. Then, perform optimization and
|
||||
/// codegen.
|
||||
ld_plugin_status all_symbols_read_hook(void) {
|
||||
lto_code_gen_t cg = lto_codegen_create();
|
||||
|
||||
for (std::list<claimed_file>::iterator I = Modules.begin(),
|
||||
E = Modules.end(); I != E; ++I)
|
||||
lto_codegen_add_module(cg, I->M);
|
||||
|
||||
// If we don't preserve any symbols, libLTO will assume that all symbols are
|
||||
// needed. Keep all symbols unless we're producing a final executable.
|
||||
if (output_type == LTO_CODEGEN_PIC_MODEL_STATIC) {
|
||||
bool anySymbolsPreserved = false;
|
||||
for (std::list<claimed_file>::iterator I = Modules.begin(),
|
||||
E = Modules.end(); I != E; ++I) {
|
||||
(*get_symbols)(I->handle, I->syms.size(), &I->syms[0]);
|
||||
for (unsigned i = 0, e = I->syms.size(); i != e; i++) {
|
||||
(*message)(LDPL_WARNING, "def: %d visibility: %d resolution %d",
|
||||
I->syms[i].def, I->syms[i].visibility, I->syms[i].resolution);
|
||||
if (I->syms[i].resolution == LDPR_PREVAILING_DEF) {
|
||||
lto_codegen_add_must_preserve_symbol(cg, I->syms[i].name);
|
||||
anySymbolsPreserved = true;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (!anySymbolsPreserved) {
|
||||
// This entire file is unnecessary!
|
||||
lto_codegen_dispose(cg);
|
||||
return LDPS_OK;
|
||||
}
|
||||
}
|
||||
|
||||
lto_codegen_set_pic_model(cg, output_type);
|
||||
lto_codegen_set_debug_model(cg, LTO_DEBUG_MODEL_DWARF);
|
||||
|
||||
size_t bufsize = 0;
|
||||
const char *buffer = static_cast<const char *>(lto_codegen_compile(cg,
|
||||
&bufsize));
|
||||
|
||||
std::string ErrMsg;
|
||||
|
||||
sys::Path uniqueObjPath("/tmp/llvmgold.o");
|
||||
if (uniqueObjPath.createTemporaryFileOnDisk(true, &ErrMsg)) {
|
||||
(*message)(LDPL_ERROR, "%s", ErrMsg.c_str());
|
||||
return LDPS_ERR;
|
||||
}
|
||||
raw_fd_ostream *objFile = new raw_fd_ostream(uniqueObjPath.c_str(), true,
|
||||
ErrMsg);
|
||||
if (!ErrMsg.empty()) {
|
||||
delete objFile;
|
||||
(*message)(LDPL_ERROR, "%s", ErrMsg.c_str());
|
||||
return LDPS_ERR;
|
||||
}
|
||||
|
||||
objFile->write(buffer, bufsize);
|
||||
objFile->close();
|
||||
|
||||
lto_codegen_dispose(cg);
|
||||
|
||||
if ((*add_input_file)(const_cast<char*>(uniqueObjPath.c_str())) != LDPS_OK) {
|
||||
(*message)(LDPL_ERROR, "Unable to add .o file to the link.");
|
||||
(*message)(LDPL_ERROR, "File left behind in: %s", uniqueObjPath.c_str());
|
||||
return LDPS_ERR;
|
||||
}
|
||||
|
||||
Cleanup.push_back(uniqueObjPath);
|
||||
|
||||
return LDPS_OK;
|
||||
}
|
||||
|
||||
ld_plugin_status cleanup_hook(void) {
|
||||
std::string ErrMsg;
|
||||
|
||||
for (int i = 0, e = Cleanup.size(); i != e; ++i)
|
||||
if (Cleanup[i].eraseFromDisk(false, &ErrMsg))
|
||||
(*message)(LDPL_ERROR, "Failed to delete '%s': %s", Cleanup[i].c_str(),
|
||||
ErrMsg.c_str());
|
||||
|
||||
return LDPS_OK;
|
||||
}
|
||||
Loading…
Reference in New Issue