src/gallium/auxiliary/gallivm/lp_bld_debug.cpp

   1 /**************************************************************************
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   3  * Copyright 2009-2011 VMware, Inc.
   4  * All Rights Reserved.
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   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,
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  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
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  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 <llvm-c/Core.h>
  29 #include <llvm/Target/TargetMachine.h>
  30 #include <llvm/Target/TargetRegistry.h>
  31 #include <llvm/Target/TargetSelect.h>
  32 #include <llvm/Target/TargetInstrInfo.h>
  33 #include <llvm/Support/raw_ostream.h>
  34 #include <llvm/Support/MemoryObject.h>
  35 #include <llvm/System/Host.h>
  36
  37 #if HAVE_LLVM >= 0x0207
  38 #include <llvm/MC/MCDisassembler.h>
  39 #include <llvm/MC/MCAsmInfo.h>
  40 #include <llvm/MC/MCInst.h>
  41 #include <llvm/MC/MCInstPrinter.h>
  42 #endif /* HAVE_LLVM >= 0x0207 */
  43
  44 #include "util/u_math.h"
  45 #include "util/u_debug.h"
  46
  47 #include "lp_bld_debug.h"
  48
  49
  50
  51 /**
  52  * Check alignment.
  53  *
  54  * It is important that this check is not implemented as a macro or inlined
  55  * function, as the compiler assumptions in respect to alignment of global
  56  * and stack variables would often make the check a no op, defeating the
  57  * whole purpose of the exercise.
  58  */
  59 extern "C" boolean
  60 lp_check_alignment(const void *ptr, unsigned alignment)
  61 {
  62    assert(util_is_power_of_two(alignment));
  63    return ((uintptr_t)ptr & (alignment - 1)) == 0;
  64 }
  65
  66
  67 class raw_debug_ostream :
  68    public llvm::raw_ostream
  69 {
  70    uint64_t pos;
  71
  72    void write_impl(const char *Ptr, size_t Size);
  73    uint64_t current_pos() { return pos; }
  74    uint64_t current_pos() const { return pos; }
  75
  76 #if HAVE_LLVM >= 0x207
  77    uint64_t preferred_buffer_size() { return 512; }
  78 #else
  79    size_t preferred_buffer_size() { return 512; }
  80 #endif
  81 };
  82
  83
  84 void
  85 raw_debug_ostream::write_impl(const char *Ptr, size_t Size)
  86 {
  87    if (Size > 0) {
  88       char *lastPtr = (char *)&Ptr[Size];
  89       char last = *lastPtr;
  90       *lastPtr = 0;
  91       _debug_printf("%*s", Size, Ptr);
  92       *lastPtr = last;
  93       pos += Size;
  94    }
  95 }
  96
  97
  98 /**
  99  * Same as LLVMDumpValue, but through our debugging channels.
 100  */
 101 extern "C" void
 102 lp_debug_dump_value(LLVMValueRef value)
 103 {
 104 #if (defined(PIPE_OS_WINDOWS) && !defined(PIPE_CC_MSVC)) || defined(PIPE_OS_EMBDDED)
 105    raw_debug_ostream os;
 106    llvm::unwrap(value)->print(os);
 107    os.flush();
 108 #else
 109    LLVMDumpValue(value);
 110 #endif
 111 }
 112
 113
 114 /*
 115  * MemoryObject wrapper around a buffer of memory, to be used by MC
 116  * disassembler.
 117  */
 118 class BufferMemoryObject:
 119    public llvm::MemoryObject
 120 {
 121 private:
 122    const uint8_t *Bytes;
 123    uint64_t Length;
 124 public:
 125    BufferMemoryObject(const uint8_t *bytes, uint64_t length) :
 126       Bytes(bytes), Length(length)
 127    {
 128    }
 129
 130    uint64_t getBase() const
 131    {
 132       return 0;
 133    }
 134
 135    uint64_t getExtent() const
 136    {
 137       return Length;
 138    }
 139
 140    int readByte(uint64_t addr, uint8_t *byte) const
 141    {
 142       if (addr > getExtent())
 143          return -1;
 144       *byte = Bytes[addr];
 145       return 0;
 146    }
 147 };
 148
 149
 150 /*
 151  * Disassemble a function, using the LLVM MC disassembler.
 152  *
 153  * See also:
 154  * - http://blog.llvm.org/2010/01/x86-disassembler.html
 155  * - http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html
 156  */
 157 extern "C" void
 158 lp_disassemble(const void* func)
 159 {
 160 #if HAVE_LLVM >= 0x0207
 161    using namespace llvm;
 162
 163    const uint8_t *bytes = (const uint8_t *)func;
 164
 165    /*
 166     * Limit disassembly to this extent
 167     */
 168    const uint64_t extent = 0x10000;
 169
 170    uint64_t max_pc = 0;
 171
 172    /*
 173     * Initialize all used objects.
 174     */
 175
 176    std::string Triple = sys::getHostTriple();
 177
 178    std::string Error;
 179    const Target *T = TargetRegistry::lookupTarget(Triple, Error);
 180
 181 #if HAVE_LLVM >= 0x0208
 182    InitializeNativeTargetAsmPrinter();
 183 #else
 184    InitializeAllAsmPrinters();
 185 #endif
 186
 187    InitializeAllDisassemblers();
 188
 189    OwningPtr<const MCAsmInfo> AsmInfo(T->createAsmInfo(Triple));
 190
 191    if (!AsmInfo) {
 192       debug_printf("error: no assembly info for target %s\n", Triple.c_str());
 193       return;
 194    }
 195
 196    OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler());
 197    if (!DisAsm) {
 198       debug_printf("error: no disassembler for target %s\n", Triple.c_str());
 199       return;
 200    }
 201
 202    raw_debug_ostream Out;
 203
 204    int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
 205 #if HAVE_LLVM >= 0x0208
 206    OwningPtr<MCInstPrinter> Printer(
 207          T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo));
 208 #else
 209    OwningPtr<MCInstPrinter> Printer(
 210          T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, Out));
 211 #endif
 212    if (!Printer) {
 213       debug_printf("error: no instruction printer for target %s\n", Triple.c_str());
 214       return;
 215    }
 216
 217    TargetMachine *TM = T->createTargetMachine(Triple, "");
 218
 219    const TargetInstrInfo *TII = TM->getInstrInfo();
 220
 221    /*
 222     * Wrap the data in a MemoryObject
 223     */
 224    BufferMemoryObject memoryObject((const uint8_t *)bytes, extent);
 225
 226    uint64_t pc;
 227    pc = 0;
 228    while (true) {
 229       MCInst Inst;
 230       uint64_t Size;
 231
 232       /*
 233        * Print address.  We use addresses relative to the start of the function,
 234        * so that between runs.
 235        */
 236
 237       debug_printf("%6lu:\t", (unsigned long)pc);
 238
 239       if (!DisAsm->getInstruction(Inst, Size, memoryObject,
 240                                  pc,
 241                                  nulls())) {
 242          debug_printf("invalid\n");
 243          pc += 1;
 244       }
 245
 246       /*
 247        * Output the bytes in hexidecimal format.
 248        */
 249
 250       if (0) {
 251          unsigned i;
 252          for (i = 0; i < Size; ++i) {
 253             debug_printf("%02x ", ((const uint8_t*)bytes)[pc + i]);
 254          }
 255          for (; i < 16; ++i) {
 256             debug_printf("   ");
 257          }
 258       }
 259
 260       /*
 261        * Print the instruction.
 262        */
 263
 264 #if HAVE_LLVM >= 0x208
 265       Printer->printInst(&Inst, Out);
 266 #else
 267       Printer->printInst(&Inst);
 268 #endif
 269       Out.flush();
 270
 271       /*
 272        * Advance.
 273        */
 274
 275       pc += Size;
 276
 277       const TargetInstrDesc &TID = TII->get(Inst.getOpcode());
 278
 279       /*
 280        * Keep track of forward jumps to a nearby address.
 281        */
 282
 283       if (TID.isBranch()) {
 284          for (unsigned i = 0; i < Inst.getNumOperands(); ++i) {
 285             const MCOperand &operand = Inst.getOperand(i);
 286             if (operand.isImm()) {
 287                uint64_t jump;
 288
 289                /*
 290                 * FIXME: Handle both relative and absolute addresses correctly.
 291                 * EDInstInfo actually has this info, but operandTypes and
 292                 * operandFlags enums are not exposed in the public interface.
 293                 */
 294
 295                if (1) {
 296                   /*
 297                    * PC relative addr.
 298                    */
 299
 300                   jump = pc + operand.getImm();
 301                } else {
 302                   /*
 303                    * Absolute addr.
 304                    */
 305
 306                   jump = (uint64_t)operand.getImm();
 307                }
 308
 309                /*
 310                 * Output the address relative to the function start, given
 311                 * that MC will print the addresses relative the current pc.
 312                 */
 313                debug_printf("\t\t; %lu", (unsigned long)jump);
 314
 315                /*
 316                 * Ignore far jumps given it could be actually a tail return to
 317                 * a random address.
 318                 */
 319
 320                if (jump > max_pc &&
 321                    jump < extent) {
 322                   max_pc = jump;
 323                }
 324             }
 325          }
 326       }
 327
 328       debug_printf("\n");
 329
 330       /*
 331        * Stop disassembling on return statements, if there is no record of a
 332        * jump to a successive address.
 333        */
 334
 335       if (TID.isReturn()) {
 336          if (pc > max_pc) {
 337             break;
 338          }
 339       }
 340    }
 341
 342    /*
 343     * Print GDB command, useful to verify output.
 344     */
 345
 346    if (0) {
 347       debug_printf("disassemble %p %p\n", bytes, bytes + pc);
 348    }
 349
 350    debug_printf("\n");
 351 #else
 352    (void)func;
 353 #endif
 354 }
 355