/**************************************************************************
*
* Copyright 2009-2011 VMware, Inc.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
* IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
**************************************************************************/
#include <stddef.h>
#include <llvm-c/Core.h>
#include <llvm/Target/TargetMachine.h>
#include <llvm/Target/TargetInstrInfo.h>
#include <llvm/Support/raw_ostream.h>
#include <llvm/Support/Format.h>
#if HAVE_LLVM >= 0x0306
#include <llvm/Target/TargetSubtargetInfo.h>
#else
#include <llvm/Support/MemoryObject.h>
#endif
#include <llvm/Support/TargetRegistry.h>
#include <llvm/MC/MCSubtargetInfo.h>
#include <llvm/Support/Host.h>
#include <llvm/IR/Module.h>
#include <llvm/MC/MCDisassembler.h>
#include <llvm/MC/MCAsmInfo.h>
#include <llvm/MC/MCInst.h>
#include <llvm/MC/MCInstPrinter.h>
#include <llvm/MC/MCRegisterInfo.h>
#if HAVE_LLVM >= 0x0305
#define OwningPtr std::unique_ptr
#else
#include <llvm/ADT/OwningPtr.h>
#endif
#if HAVE_LLVM >= 0x0305
#include <llvm/MC/MCContext.h>
#endif
#include "util/u_math.h"
#include "util/u_debug.h"
#include "lp_bld_debug.h"
#ifdef __linux__
#include <sys/stat.h>
#include <fcntl.h>
#endif
/**
* Check alignment.
*
* It is important that this check is not implemented as a macro or inlined
* function, as the compiler assumptions in respect to alignment of global
* and stack variables would often make the check a no op, defeating the
* whole purpose of the exercise.
*/
extern "C" boolean
lp_check_alignment(const void *ptr, unsigned alignment)
{
assert(util_is_power_of_two(alignment));
return ((uintptr_t)ptr & (alignment - 1)) == 0;
}
class raw_debug_ostream :
public llvm::raw_ostream
{
private:
uint64_t pos;
public:
raw_debug_ostream() : pos(0) { }
void write_impl(const char *Ptr, size_t Size);
uint64_t current_pos() const { return pos; }
size_t preferred_buffer_size() const { return 512; }
};
void
raw_debug_ostream::write_impl(const char *Ptr, size_t Size)
{
if (Size > 0) {
char *lastPtr = (char *)&Ptr[Size];
char last = *lastPtr;
*lastPtr = 0;
_debug_printf("%*s", Size, Ptr);
*lastPtr = last;
pos += Size;
}
}
extern "C" const char *
lp_get_module_id(LLVMModuleRef module)
{
return llvm::unwrap(module)->getModuleIdentifier().c_str();
}
/**
* Same as LLVMDumpValue, but through our debugging channels.
*/
extern "C" void
lp_debug_dump_value(LLVMValueRef value)
{
#if (defined(PIPE_OS_WINDOWS) && !defined(PIPE_CC_MSVC)) || defined(PIPE_OS_EMBDDED)
raw_debug_ostream os;
llvm::unwrap(value)->print(os);
os.flush();
#else
LLVMDumpValue(value);
#endif
}
#if HAVE_LLVM < 0x0306
/*
* MemoryObject wrapper around a buffer of memory, to be used by MC
* disassembler.
*/
class BufferMemoryObject:
public llvm::MemoryObject
{
private:
const uint8_t *Bytes;
uint64_t Length;
public:
BufferMemoryObject(const uint8_t *bytes, uint64_t length) :
Bytes(bytes), Length(length)
{
}
uint64_t getBase() const
{
return 0;
}
uint64_t getExtent() const
{
return Length;
}
int readByte(uint64_t addr, uint8_t *byte) const
{
if (addr > getExtent())
return -1;
*byte = Bytes[addr];
return 0;
}
};
#endif /* HAVE_LLVM < 0x0306 */
/*
* Disassemble a function, using the LLVM MC disassembler.
*
* See also:
* - http://blog.llvm.org/2010/01/x86-disassembler.html
* - http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html
*/
static size_t
disassemble(const void* func, llvm::raw_ostream & Out)
{
using namespace llvm;
const uint8_t *bytes = (const uint8_t *)func;
/*
* Limit disassembly to this extent
*/
const uint64_t extent = 96 * 1024;
uint64_t max_pc = 0;
/*
* Initialize all used objects.
*/
std::string Triple = sys::getDefaultTargetTriple();
std::string Error;
const Target *T = TargetRegistry::lookupTarget(Triple, Error);
#if HAVE_LLVM >= 0x0304
OwningPtr<const MCAsmInfo> AsmInfo(T->createMCAsmInfo(*T->createMCRegInfo(Triple), Triple));
#else
OwningPtr<const MCAsmInfo> AsmInfo(T->createMCAsmInfo(Triple));
#endif
if (!AsmInfo) {
Out << "error: no assembly info for target " << Triple << "\n";
Out.flush();
return 0;
}
unsigned int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
OwningPtr<const MCRegisterInfo> MRI(T->createMCRegInfo(Triple));
if (!MRI) {
Out << "error: no register info for target " << Triple.c_str() << "\n";
Out.flush();
return 0;
}
OwningPtr<const MCInstrInfo> MII(T->createMCInstrInfo());
if (!MII) {
Out << "error: no instruction info for target " << Triple.c_str() << "\n";
Out.flush();
return 0;
}
#if HAVE_LLVM >= 0x0305
OwningPtr<const MCSubtargetInfo> STI(T->createMCSubtargetInfo(Triple, sys::getHostCPUName(), ""));
OwningPtr<MCContext> MCCtx(new MCContext(AsmInfo.get(), MRI.get(), 0));
OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler(*STI, *MCCtx));
#else
OwningPtr<const MCSubtargetInfo> STI(T->createMCSubtargetInfo(Triple, sys::getHostCPUName(), ""));
OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler(*STI));
#endif
if (!DisAsm) {
Out << "error: no disassembler for target " << Triple << "\n";
Out.flush();
return 0;
}
#if HAVE_LLVM >= 0x0307
OwningPtr<MCInstPrinter> Printer(
T->createMCInstPrinter(llvm::Triple(Triple), AsmPrinterVariant, *AsmInfo, *MII, *MRI));
#else
OwningPtr<MCInstPrinter> Printer(
T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, *MII, *MRI, *STI));
#endif
if (!Printer) {
Out << "error: no instruction printer for target " << Triple.c_str() << "\n";
Out.flush();
return 0;
}
TargetOptions options;
#if defined(DEBUG) && HAVE_LLVM < 0x0307
options.JITEmitDebugInfo = true;
#endif
#if defined(PIPE_ARCH_X86)
options.StackAlignmentOverride = 4;
#endif
#if defined(DEBUG) || defined(PROFILE)
options.NoFramePointerElim = true;
#endif
OwningPtr<TargetMachine> TM(T->createTargetMachine(Triple, sys::getHostCPUName(), "", options));
/*
* Wrap the data in a MemoryObject
*/
#if HAVE_LLVM >= 0x0306
ArrayRef<uint8_t> memoryObject((const uint8_t *)bytes, extent);
#else
BufferMemoryObject memoryObject((const uint8_t *)bytes, extent);
#endif
uint64_t pc;
pc = 0;
while (true) {
MCInst Inst;
uint64_t Size;
/*
* Print address. We use addresses relative to the start of the function,
* so that between runs.
*/
Out << llvm::format("%6lu:\t", (unsigned long)pc);
if (!DisAsm->getInstruction(Inst, Size, memoryObject,
pc,
nulls(), nulls())) {
Out << "invalid";
pc += 1;
}
/*
* Output the bytes in hexidecimal format.
*/
if (0) {
unsigned i;
for (i = 0; i < Size; ++i) {
Out << llvm::format("%02x ", ((const uint8_t*)bytes)[pc + i]);
}
for (; i < 16; ++i) {
Out << " ";
}
}
/*
* Print the instruction.
*/
#if HAVE_LLVM >= 0x0307
Printer->printInst(&Inst, Out, "", *STI);
#else
Printer->printInst(&Inst, Out, "");
#endif
/*
* Advance.
*/
pc += Size;
const MCInstrDesc &TID = MII->get(Inst.getOpcode());
/*
* Keep track of forward jumps to a nearby address.
*/
if (TID.isBranch()) {
for (unsigned i = 0; i < Inst.getNumOperands(); ++i) {
const MCOperand &operand = Inst.getOperand(i);
if (operand.isImm()) {
uint64_t jump;
/*
* FIXME: Handle both relative and absolute addresses correctly.
* EDInstInfo actually has this info, but operandTypes and
* operandFlags enums are not exposed in the public interface.
*/
if (1) {
/*
* PC relative addr.
*/
jump = pc + operand.getImm();
} else {
/*
* Absolute addr.
*/
jump = (uint64_t)operand.getImm();
}
/*
* Output the address relative to the function start, given
* that MC will print the addresses relative the current pc.
*/
Out << "\t\t; " << jump;
/*
* Ignore far jumps given it could be actually a tail return to
* a random address.
*/
if (jump > max_pc &&
jump < extent) {
max_pc = jump;
}
}
}
}
Out << "\n";
/*
* Stop disassembling on return statements, if there is no record of a
* jump to a successive address.
*/
if (TID.isReturn()) {
if (pc > max_pc) {
break;
}
}
if (pc >= extent) {
Out << "disassembly larger than " << extent << "bytes, aborting\n";
break;
}
}
Out << "\n";
Out.flush();
/*
* Print GDB command, useful to verify output.
*/
if (0) {
_debug_printf("disassemble %p %p\n", bytes, bytes + pc);
}
return pc;
}
extern "C" void
lp_disassemble(LLVMValueRef func, const void *code) {
raw_debug_ostream Out;
Out << LLVMGetValueName(func) << ":\n";
disassemble(code, Out);
}
/*
* Linux perf profiler integration.
*
* See also:
* - http://penberg.blogspot.co.uk/2009/06/jato-has-profiler.html
* - https://github.com/penberg/jato/commit/73ad86847329d99d51b386f5aba692580d1f8fdc
* - http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=80d496be89ed7dede5abee5c057634e80a31c82d
*/
extern "C" void
lp_profile(LLVMValueRef func, const void *code)
{
#if defined(__linux__) && (defined(DEBUG) || defined(PROFILE))
static boolean first_time = TRUE;
static FILE *perf_map_file = NULL;
static int perf_asm_fd = -1;
if (first_time) {
/*
* We rely on the disassembler for determining a function's size, but
* the disassembly is a leaky and slow operation, so avoid running
* this except when running inside linux perf, which can be inferred
* by the PERF_BUILDID_DIR environment variable.
*/
if (getenv("PERF_BUILDID_DIR")) {
pid_t pid = getpid();
char filename[256];
util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map", (unsigned long long)pid);
perf_map_file = fopen(filename, "wt");
util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map.asm", (unsigned long long)pid);
mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
perf_asm_fd = open(filename, O_WRONLY | O_CREAT, mode);
}
first_time = FALSE;
}
if (perf_map_file) {
const char *symbol = LLVMGetValueName(func);
unsigned long addr = (uintptr_t)code;
llvm::raw_fd_ostream Out(perf_asm_fd, false);
Out << symbol << ":\n";
unsigned long size = disassemble(code, Out);
fprintf(perf_map_file, "%lx %lx %s\n", addr, size, symbol);
fflush(perf_map_file);
}
#else
(void)func;
(void)code;
#endif
}