src/gallium/auxiliary/gallivm/lp_bld_debug.cpp

   1 /**************************************************************************
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   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 #include <llvm/Support/MemoryObject.h>
  36
  37 #include <llvm/Support/TargetRegistry.h>
  38 #include <llvm/MC/MCSubtargetInfo.h>
  39
  40 #include <llvm/Support/Host.h>
  41
  42 #include <llvm/MC/MCDisassembler.h>
  43 #include <llvm/MC/MCAsmInfo.h>
  44 #include <llvm/MC/MCInst.h>
  45 #include <llvm/MC/MCInstPrinter.h>
  46 #include <llvm/MC/MCRegisterInfo.h>
  47
  48 #if HAVE_LLVM >= 0x0303
  49 #include <llvm/ADT/OwningPtr.h>
  50 #endif
  51
  52 #if HAVE_LLVM >= 0x0305
  53 #include <llvm/MC/MCContext.h>
  54 #endif
  55
  56 #include "util/u_math.h"
  57 #include "util/u_debug.h"
  58
  59 #include "lp_bld_debug.h"
  60
  61 #ifdef __linux__
  62 #include <sys/stat.h>
  63 #include <fcntl.h>
  64 #endif
  65
  66
  67
  68 /**
  69  * Check alignment.
  70  *
  71  * It is important that this check is not implemented as a macro or inlined
  72  * function, as the compiler assumptions in respect to alignment of global
  73  * and stack variables would often make the check a no op, defeating the
  74  * whole purpose of the exercise.
  75  */
  76 extern "C" boolean
  77 lp_check_alignment(const void *ptr, unsigned alignment)
  78 {
  79    assert(util_is_power_of_two(alignment));
  80    return ((uintptr_t)ptr & (alignment - 1)) == 0;
  81 }
  82
  83
  84 class raw_debug_ostream :
  85    public llvm::raw_ostream
  86 {
  87 private:
  88    uint64_t pos;
  89
  90 public:
  91    raw_debug_ostream() : pos(0) { }
  92
  93    void write_impl(const char *Ptr, size_t Size);
  94
  95    uint64_t current_pos() const { return pos; }
  96    size_t preferred_buffer_size() const { return 512; }
  97 };
  98
  99
 100 void
 101 raw_debug_ostream::write_impl(const char *Ptr, size_t Size)
 102 {
 103    if (Size > 0) {
 104       char *lastPtr = (char *)&Ptr[Size];
 105       char last = *lastPtr;
 106       *lastPtr = 0;
 107       _debug_printf("%*s", Size, Ptr);
 108       *lastPtr = last;
 109       pos += Size;
 110    }
 111 }
 112
 113
 114 /**
 115  * Same as LLVMDumpValue, but through our debugging channels.
 116  */
 117 extern "C" void
 118 lp_debug_dump_value(LLVMValueRef value)
 119 {
 120 #if (defined(PIPE_OS_WINDOWS) && !defined(PIPE_CC_MSVC)) || defined(PIPE_OS_EMBDDED)
 121    raw_debug_ostream os;
 122    llvm::unwrap(value)->print(os);
 123    os.flush();
 124 #else
 125    LLVMDumpValue(value);
 126 #endif
 127 }
 128
 129
 130 /*
 131  * MemoryObject wrapper around a buffer of memory, to be used by MC
 132  * disassembler.
 133  */
 134 class BufferMemoryObject:
 135    public llvm::MemoryObject
 136 {
 137 private:
 138    const uint8_t *Bytes;
 139    uint64_t Length;
 140 public:
 141    BufferMemoryObject(const uint8_t *bytes, uint64_t length) :
 142       Bytes(bytes), Length(length)
 143    {
 144    }
 145
 146    uint64_t getBase() const
 147    {
 148       return 0;
 149    }
 150
 151    uint64_t getExtent() const
 152    {
 153       return Length;
 154    }
 155
 156    int readByte(uint64_t addr, uint8_t *byte) const
 157    {
 158       if (addr > getExtent())
 159          return -1;
 160       *byte = Bytes[addr];
 161       return 0;
 162    }
 163 };
 164
 165
 166 /*
 167  * Disassemble a function, using the LLVM MC disassembler.
 168  *
 169  * See also:
 170  * - http://blog.llvm.org/2010/01/x86-disassembler.html
 171  * - http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html
 172  */
 173 static size_t
 174 disassemble(const void* func, llvm::raw_ostream & Out)
 175 {
 176    using namespace llvm;
 177
 178    const uint8_t *bytes = (const uint8_t *)func;
 179
 180    /*
 181     * Limit disassembly to this extent
 182     */
 183    const uint64_t extent = 96 * 1024;
 184
 185    uint64_t max_pc = 0;
 186
 187    /*
 188     * Initialize all used objects.
 189     */
 190
 191    std::string Triple = sys::getDefaultTargetTriple();
 192
 193    std::string Error;
 194    const Target *T = TargetRegistry::lookupTarget(Triple, Error);
 195
 196 #if HAVE_LLVM >= 0x0304
 197    OwningPtr<const MCAsmInfo> AsmInfo(T->createMCAsmInfo(*T->createMCRegInfo(Triple), Triple));
 198 #else
 199    OwningPtr<const MCAsmInfo> AsmInfo(T->createMCAsmInfo(Triple));
 200 #endif
 201
 202    if (!AsmInfo) {
 203       Out << "error: no assembly info for target " << Triple << "\n";
 204       Out.flush();
 205       return 0;
 206    }
 207
 208    unsigned int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
 209
 210    OwningPtr<const MCRegisterInfo> MRI(T->createMCRegInfo(Triple));
 211    if (!MRI) {
 212       Out << "error: no register info for target " << Triple.c_str() << "\n";
 213       Out.flush();
 214       return 0;
 215    }
 216
 217    OwningPtr<const MCInstrInfo> MII(T->createMCInstrInfo());
 218    if (!MII) {
 219       Out << "error: no instruction info for target " << Triple.c_str() << "\n";
 220       Out.flush();
 221       return 0;
 222    }
 223
 224 #if HAVE_LLVM >= 0x0305
 225    OwningPtr<const MCSubtargetInfo> STI(T->createMCSubtargetInfo(Triple, sys::getHostCPUName(), ""));
 226    OwningPtr<MCContext> MCCtx(new MCContext(AsmInfo.get(), MRI.get(), 0));
 227    OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler(*STI, *MCCtx));
 228 #else
 229    OwningPtr<const MCSubtargetInfo> STI(T->createMCSubtargetInfo(Triple, sys::getHostCPUName(), ""));
 230    OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler(*STI));
 231 #endif
 232    if (!DisAsm) {
 233       Out << "error: no disassembler for target " << Triple << "\n";
 234       Out.flush();
 235       return 0;
 236    }
 237
 238
 239    OwningPtr<MCInstPrinter> Printer(
 240          T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, *MII, *MRI, *STI));
 241    if (!Printer) {
 242       Out << "error: no instruction printer for target " << Triple.c_str() << "\n";
 243       Out.flush();
 244       return 0;
 245    }
 246
 247    TargetOptions options;
 248 #if defined(DEBUG)
 249    options.JITEmitDebugInfo = true;
 250 #endif
 251 #if defined(PIPE_ARCH_X86)
 252    options.StackAlignmentOverride = 4;
 253 #endif
 254 #if defined(DEBUG) || defined(PROFILE)
 255    options.NoFramePointerElim = true;
 256 #endif
 257    OwningPtr<TargetMachine> TM(T->createTargetMachine(Triple, sys::getHostCPUName(), "", options));
 258
 259    const TargetInstrInfo *TII = TM->getInstrInfo();
 260
 261    /*
 262     * Wrap the data in a MemoryObject
 263     */
 264    BufferMemoryObject memoryObject((const uint8_t *)bytes, extent);
 265
 266    uint64_t pc;
 267    pc = 0;
 268    while (true) {
 269       MCInst Inst;
 270       uint64_t Size;
 271
 272       /*
 273        * Print address.  We use addresses relative to the start of the function,
 274        * so that between runs.
 275        */
 276
 277       Out << llvm::format("%6lu:\t", (unsigned long)pc);
 278
 279       if (!DisAsm->getInstruction(Inst, Size, memoryObject,
 280                                  pc,
 281                                   nulls(), nulls())) {
 282          Out << "invalid";
 283          pc += 1;
 284       }
 285
 286       /*
 287        * Output the bytes in hexidecimal format.
 288        */
 289
 290       if (0) {
 291          unsigned i;
 292          for (i = 0; i < Size; ++i) {
 293             Out << llvm::format("%02x ", ((const uint8_t*)bytes)[pc + i]);
 294          }
 295          for (; i < 16; ++i) {
 296             Out << "   ";
 297          }
 298       }
 299
 300       /*
 301        * Print the instruction.
 302        */
 303       Printer->printInst(&Inst, Out, "");
 304
 305       /*
 306        * Advance.
 307        */
 308
 309       pc += Size;
 310
 311       const MCInstrDesc &TID = TII->get(Inst.getOpcode());
 312
 313       /*
 314        * Keep track of forward jumps to a nearby address.
 315        */
 316
 317       if (TID.isBranch()) {
 318          for (unsigned i = 0; i < Inst.getNumOperands(); ++i) {
 319             const MCOperand &operand = Inst.getOperand(i);
 320             if (operand.isImm()) {
 321                uint64_t jump;
 322
 323                /*
 324                 * FIXME: Handle both relative and absolute addresses correctly.
 325                 * EDInstInfo actually has this info, but operandTypes and
 326                 * operandFlags enums are not exposed in the public interface.
 327                 */
 328
 329                if (1) {
 330                   /*
 331                    * PC relative addr.
 332                    */
 333
 334                   jump = pc + operand.getImm();
 335                } else {
 336                   /*
 337                    * Absolute addr.
 338                    */
 339
 340                   jump = (uint64_t)operand.getImm();
 341                }
 342
 343                /*
 344                 * Output the address relative to the function start, given
 345                 * that MC will print the addresses relative the current pc.
 346                 */
 347                Out << "\t\t; " << jump;
 348
 349                /*
 350                 * Ignore far jumps given it could be actually a tail return to
 351                 * a random address.
 352                 */
 353
 354                if (jump > max_pc &&
 355                    jump < extent) {
 356                   max_pc = jump;
 357                }
 358             }
 359          }
 360       }
 361
 362       Out << "\n";
 363
 364       /*
 365        * Stop disassembling on return statements, if there is no record of a
 366        * jump to a successive address.
 367        */
 368
 369       if (TID.isReturn()) {
 370          if (pc > max_pc) {
 371             break;
 372          }
 373       }
 374    }
 375
 376    /*
 377     * Print GDB command, useful to verify output.
 378     */
 379
 380    if (0) {
 381       _debug_printf("disassemble %p %p\n", bytes, bytes + pc);
 382    }
 383
 384    Out << "\n";
 385    Out.flush();
 386
 387    return pc;
 388 }
 389
 390
 391 extern "C" void
 392 lp_disassemble(LLVMValueRef func, const void *code) {
 393    raw_debug_ostream Out;
 394    disassemble(code, Out);
 395 }
 396
 397
 398 /*
 399  * Linux perf profiler integration.
 400  *
 401  * See also:
 402  * - http://penberg.blogspot.co.uk/2009/06/jato-has-profiler.html
 403  * - https://github.com/penberg/jato/commit/73ad86847329d99d51b386f5aba692580d1f8fdc
 404  * - http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=80d496be89ed7dede5abee5c057634e80a31c82d
 405  */
 406 extern "C" void
 407 lp_profile(LLVMValueRef func, const void *code)
 408 {
 409 #if defined(__linux__) && (defined(DEBUG) || defined(PROFILE))
 410    static boolean first_time = TRUE;
 411    static FILE *perf_map_file = NULL;
 412    static int perf_asm_fd = -1;
 413    if (first_time) {
 414       /*
 415        * We rely on the disassembler for determining a function's size, but
 416        * the disassembly is a leaky and slow operation, so avoid running
 417        * this except when running inside linux perf, which can be inferred
 418        * by the PERF_BUILDID_DIR environment variable.
 419        */
 420       if (getenv("PERF_BUILDID_DIR")) {
 421          pid_t pid = getpid();
 422          char filename[256];
 423          util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map", (unsigned long long)pid);
 424          perf_map_file = fopen(filename, "wt");
 425          util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map.asm", (unsigned long long)pid);
 426          mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
 427          perf_asm_fd = open(filename, O_WRONLY | O_CREAT, mode);
 428       }
 429       first_time = FALSE;
 430    }
 431    if (perf_map_file) {
 432       const char *symbol = LLVMGetValueName(func);
 433       unsigned long addr = (uintptr_t)code;
 434       llvm::raw_fd_ostream Out(perf_asm_fd, false);
 435       Out << symbol << ":\n";
 436       unsigned long size = disassemble(code, Out);
 437       fprintf(perf_map_file, "%lx %lx %s\n", addr, size, symbol);
 438       fflush(perf_map_file);
 439    }
 440 #else
 441    (void)func;
 442    (void)code;
 443 #endif
 444 }
 445
 446