src/gallium/auxiliary/gallivm/lp_bld_debug.cpp

   1 /**************************************************************************
   2  *
   3  * Copyright 2009-2011 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #include <stddef.h>
  29
  30 #include <llvm-c/Core.h>
  31 #include <llvm/Target/TargetMachine.h>
  32 #include <llvm/Target/TargetInstrInfo.h>
  33 #include <llvm/Support/raw_ostream.h>
  34 #include <llvm/Support/Format.h>
  35
  36 #if HAVE_LLVM >= 0x0306
  37 #include <llvm/Target/TargetSubtargetInfo.h>
  38 #else
  39 #include <llvm/Support/MemoryObject.h>
  40 #endif
  41
  42 #include <llvm/Support/TargetRegistry.h>
  43 #include <llvm/MC/MCSubtargetInfo.h>
  44
  45 #include <llvm/Support/Host.h>
  46
  47 #include <llvm/IR/Module.h>
  48
  49 #include <llvm/MC/MCDisassembler.h>
  50 #include <llvm/MC/MCAsmInfo.h>
  51 #include <llvm/MC/MCInst.h>
  52 #include <llvm/MC/MCInstPrinter.h>
  53 #include <llvm/MC/MCRegisterInfo.h>
  54
  55 #if HAVE_LLVM >= 0x0305
  56 #define OwningPtr std::unique_ptr
  57 #else
  58 #include <llvm/ADT/OwningPtr.h>
  59 #endif
  60
  61 #if HAVE_LLVM >= 0x0305
  62 #include <llvm/MC/MCContext.h>
  63 #endif
  64
  65 #include "util/u_math.h"
  66 #include "util/u_debug.h"
  67
  68 #include "lp_bld_debug.h"
  69
  70 #ifdef __linux__
  71 #include <sys/stat.h>
  72 #include <fcntl.h>
  73 #endif
  74
  75
  76
  77 /**
  78  * Check alignment.
  79  *
  80  * It is important that this check is not implemented as a macro or inlined
  81  * function, as the compiler assumptions in respect to alignment of global
  82  * and stack variables would often make the check a no op, defeating the
  83  * whole purpose of the exercise.
  84  */
  85 extern "C" boolean
  86 lp_check_alignment(const void *ptr, unsigned alignment)
  87 {
  88    assert(util_is_power_of_two(alignment));
  89    return ((uintptr_t)ptr & (alignment - 1)) == 0;
  90 }
  91
  92
  93 class raw_debug_ostream :
  94    public llvm::raw_ostream
  95 {
  96 private:
  97    uint64_t pos;
  98
  99 public:
 100    raw_debug_ostream() : pos(0) { }
 101
 102    void write_impl(const char *Ptr, size_t Size);
 103
 104    uint64_t current_pos() const { return pos; }
 105    size_t preferred_buffer_size() const { return 512; }
 106 };
 107
 108
 109 void
 110 raw_debug_ostream::write_impl(const char *Ptr, size_t Size)
 111 {
 112    if (Size > 0) {
 113       char *lastPtr = (char *)&Ptr[Size];
 114       char last = *lastPtr;
 115       *lastPtr = 0;
 116       _debug_printf("%*s", Size, Ptr);
 117       *lastPtr = last;
 118       pos += Size;
 119    }
 120 }
 121
 122
 123 extern "C" const char *
 124 lp_get_module_id(LLVMModuleRef module)
 125 {
 126    return llvm::unwrap(module)->getModuleIdentifier().c_str();
 127 }
 128
 129
 130 /**
 131  * Same as LLVMDumpValue, but through our debugging channels.
 132  */
 133 extern "C" void
 134 lp_debug_dump_value(LLVMValueRef value)
 135 {
 136 #if (defined(PIPE_OS_WINDOWS) && !defined(PIPE_CC_MSVC)) || defined(PIPE_OS_EMBDDED)
 137    raw_debug_ostream os;
 138    llvm::unwrap(value)->print(os);
 139    os.flush();
 140 #else
 141    LLVMDumpValue(value);
 142 #endif
 143 }
 144
 145
 146 #if HAVE_LLVM < 0x0306
 147
 148 /*
 149  * MemoryObject wrapper around a buffer of memory, to be used by MC
 150  * disassembler.
 151  */
 152 class BufferMemoryObject:
 153    public llvm::MemoryObject
 154 {
 155 private:
 156    const uint8_t *Bytes;
 157    uint64_t Length;
 158 public:
 159    BufferMemoryObject(const uint8_t *bytes, uint64_t length) :
 160       Bytes(bytes), Length(length)
 161    {
 162    }
 163
 164    uint64_t getBase() const
 165    {
 166       return 0;
 167    }
 168
 169    uint64_t getExtent() const
 170    {
 171       return Length;
 172    }
 173
 174    int readByte(uint64_t addr, uint8_t *byte) const
 175    {
 176       if (addr > getExtent())
 177          return -1;
 178       *byte = Bytes[addr];
 179       return 0;
 180    }
 181 };
 182
 183 #endif /* HAVE_LLVM < 0x0306 */
 184
 185
 186 /*
 187  * Disassemble a function, using the LLVM MC disassembler.
 188  *
 189  * See also:
 190  * - http://blog.llvm.org/2010/01/x86-disassembler.html
 191  * - http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html
 192  */
 193 static size_t
 194 disassemble(const void* func, llvm::raw_ostream & Out)
 195 {
 196    using namespace llvm;
 197
 198    const uint8_t *bytes = (const uint8_t *)func;
 199
 200    /*
 201     * Limit disassembly to this extent
 202     */
 203    const uint64_t extent = 96 * 1024;
 204
 205    uint64_t max_pc = 0;
 206
 207    /*
 208     * Initialize all used objects.
 209     */
 210
 211    std::string Triple = sys::getDefaultTargetTriple();
 212
 213    std::string Error;
 214    const Target *T = TargetRegistry::lookupTarget(Triple, Error);
 215
 216 #if HAVE_LLVM >= 0x0304
 217    OwningPtr<const MCAsmInfo> AsmInfo(T->createMCAsmInfo(*T->createMCRegInfo(Triple), Triple));
 218 #else
 219    OwningPtr<const MCAsmInfo> AsmInfo(T->createMCAsmInfo(Triple));
 220 #endif
 221
 222    if (!AsmInfo) {
 223       Out << "error: no assembly info for target " << Triple << "\n";
 224       Out.flush();
 225       return 0;
 226    }
 227
 228    unsigned int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
 229
 230    OwningPtr<const MCRegisterInfo> MRI(T->createMCRegInfo(Triple));
 231    if (!MRI) {
 232       Out << "error: no register info for target " << Triple.c_str() << "\n";
 233       Out.flush();
 234       return 0;
 235    }
 236
 237    OwningPtr<const MCInstrInfo> MII(T->createMCInstrInfo());
 238    if (!MII) {
 239       Out << "error: no instruction info for target " << Triple.c_str() << "\n";
 240       Out.flush();
 241       return 0;
 242    }
 243
 244 #if HAVE_LLVM >= 0x0305
 245    OwningPtr<const MCSubtargetInfo> STI(T->createMCSubtargetInfo(Triple, sys::getHostCPUName(), ""));
 246    OwningPtr<MCContext> MCCtx(new MCContext(AsmInfo.get(), MRI.get(), 0));
 247    OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler(*STI, *MCCtx));
 248 #else
 249    OwningPtr<const MCSubtargetInfo> STI(T->createMCSubtargetInfo(Triple, sys::getHostCPUName(), ""));
 250    OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler(*STI));
 251 #endif
 252    if (!DisAsm) {
 253       Out << "error: no disassembler for target " << Triple << "\n";
 254       Out.flush();
 255       return 0;
 256    }
 257
 258
 259 #if HAVE_LLVM >= 0x0307
 260    OwningPtr<MCInstPrinter> Printer(
 261          T->createMCInstPrinter(llvm::Triple(Triple), AsmPrinterVariant, *AsmInfo, *MII, *MRI));
 262 #else
 263    OwningPtr<MCInstPrinter> Printer(
 264          T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, *MII, *MRI, *STI));
 265 #endif
 266    if (!Printer) {
 267       Out << "error: no instruction printer for target " << Triple.c_str() << "\n";
 268       Out.flush();
 269       return 0;
 270    }
 271
 272    TargetOptions options;
 273 #if defined(DEBUG) && HAVE_LLVM < 0x0307
 274    options.JITEmitDebugInfo = true;
 275 #endif
 276 #if defined(PIPE_ARCH_X86)
 277    options.StackAlignmentOverride = 4;
 278 #endif
 279 #if defined(DEBUG) || defined(PROFILE)
 280 #if HAVE_LLVM < 0x0307
 281    options.NoFramePointerElim = true;
 282 #endif
 283 #endif
 284    OwningPtr<TargetMachine> TM(T->createTargetMachine(Triple, sys::getHostCPUName(), "", options));
 285
 286    /*
 287     * Wrap the data in a MemoryObject
 288     */
 289 #if HAVE_LLVM >= 0x0306
 290    ArrayRef<uint8_t> memoryObject((const uint8_t *)bytes, extent);
 291 #else
 292    BufferMemoryObject memoryObject((const uint8_t *)bytes, extent);
 293 #endif
 294
 295    uint64_t pc;
 296    pc = 0;
 297    while (true) {
 298       MCInst Inst;
 299       uint64_t Size;
 300
 301       /*
 302        * Print address.  We use addresses relative to the start of the function,
 303        * so that between runs.
 304        */
 305
 306       Out << llvm::format("%6lu:\t", (unsigned long)pc);
 307
 308       if (!DisAsm->getInstruction(Inst, Size, memoryObject,
 309                                  pc,
 310                                   nulls(), nulls())) {
 311          Out << "invalid";
 312          pc += 1;
 313       }
 314
 315       /*
 316        * Output the bytes in hexidecimal format.
 317        */
 318
 319       if (0) {
 320          unsigned i;
 321          for (i = 0; i < Size; ++i) {
 322             Out << llvm::format("%02x ", ((const uint8_t*)bytes)[pc + i]);
 323          }
 324          for (; i < 16; ++i) {
 325             Out << "   ";
 326          }
 327       }
 328
 329       /*
 330        * Print the instruction.
 331        */
 332 #if HAVE_LLVM >= 0x0307
 333       Printer->printInst(&Inst, Out, "", *STI);
 334 #else
 335       Printer->printInst(&Inst, Out, "");
 336 #endif
 337
 338       /*
 339        * Advance.
 340        */
 341
 342       pc += Size;
 343
 344       const MCInstrDesc &TID = MII->get(Inst.getOpcode());
 345
 346       /*
 347        * Keep track of forward jumps to a nearby address.
 348        */
 349
 350       if (TID.isBranch()) {
 351          for (unsigned i = 0; i < Inst.getNumOperands(); ++i) {
 352             const MCOperand &operand = Inst.getOperand(i);
 353             if (operand.isImm()) {
 354                uint64_t jump;
 355
 356                /*
 357                 * FIXME: Handle both relative and absolute addresses correctly.
 358                 * EDInstInfo actually has this info, but operandTypes and
 359                 * operandFlags enums are not exposed in the public interface.
 360                 */
 361
 362                if (1) {
 363                   /*
 364                    * PC relative addr.
 365                    */
 366
 367                   jump = pc + operand.getImm();
 368                } else {
 369                   /*
 370                    * Absolute addr.
 371                    */
 372
 373                   jump = (uint64_t)operand.getImm();
 374                }
 375
 376                /*
 377                 * Output the address relative to the function start, given
 378                 * that MC will print the addresses relative the current pc.
 379                 */
 380                Out << "\t\t; " << jump;
 381
 382                /*
 383                 * Ignore far jumps given it could be actually a tail return to
 384                 * a random address.
 385                 */
 386
 387                if (jump > max_pc &&
 388                    jump < extent) {
 389                   max_pc = jump;
 390                }
 391             }
 392          }
 393       }
 394
 395       Out << "\n";
 396
 397       /*
 398        * Stop disassembling on return statements, if there is no record of a
 399        * jump to a successive address.
 400        */
 401
 402       if (TID.isReturn()) {
 403          if (pc > max_pc) {
 404             break;
 405          }
 406       }
 407
 408       if (pc >= extent) {
 409          Out << "disassembly larger than " << extent << "bytes, aborting\n";
 410          break;
 411       }
 412    }
 413
 414    Out << "\n";
 415    Out.flush();
 416
 417    /*
 418     * Print GDB command, useful to verify output.
 419     */
 420    if (0) {
 421       _debug_printf("disassemble %p %p\n", bytes, bytes + pc);
 422    }
 423
 424    return pc;
 425 }
 426
 427
 428 extern "C" void
 429 lp_disassemble(LLVMValueRef func, const void *code) {
 430    raw_debug_ostream Out;
 431    Out << LLVMGetValueName(func) << ":\n";
 432    disassemble(code, Out);
 433 }
 434
 435
 436 /*
 437  * Linux perf profiler integration.
 438  *
 439  * See also:
 440  * - http://penberg.blogspot.co.uk/2009/06/jato-has-profiler.html
 441  * - https://github.com/penberg/jato/commit/73ad86847329d99d51b386f5aba692580d1f8fdc
 442  * - http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=80d496be89ed7dede5abee5c057634e80a31c82d
 443  */
 444 extern "C" void
 445 lp_profile(LLVMValueRef func, const void *code)
 446 {
 447 #if defined(__linux__) && (defined(DEBUG) || defined(PROFILE))
 448    static boolean first_time = TRUE;
 449    static FILE *perf_map_file = NULL;
 450    static int perf_asm_fd = -1;
 451    if (first_time) {
 452       /*
 453        * We rely on the disassembler for determining a function's size, but
 454        * the disassembly is a leaky and slow operation, so avoid running
 455        * this except when running inside linux perf, which can be inferred
 456        * by the PERF_BUILDID_DIR environment variable.
 457        */
 458       if (getenv("PERF_BUILDID_DIR")) {
 459          pid_t pid = getpid();
 460          char filename[256];
 461          util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map", (unsigned long long)pid);
 462          perf_map_file = fopen(filename, "wt");
 463          util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map.asm", (unsigned long long)pid);
 464          mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
 465          perf_asm_fd = open(filename, O_WRONLY | O_CREAT, mode);
 466       }
 467       first_time = FALSE;
 468    }
 469    if (perf_map_file) {
 470       const char *symbol = LLVMGetValueName(func);
 471       unsigned long addr = (uintptr_t)code;
 472       llvm::raw_fd_ostream Out(perf_asm_fd, false);
 473       Out << symbol << ":\n";
 474       unsigned long size = disassemble(code, Out);
 475       fprintf(perf_map_file, "%lx %lx %s\n", addr, size, symbol);
 476       fflush(perf_map_file);
 477    }
 478 #else
 479    (void)func;
 480    (void)code;
 481 #endif
 482 }
 483
 484