src/gallium/auxiliary/gallivm/lp_bld_debug.cpp

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   3  * Copyright 2009-2011 VMware, Inc.
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  11  * permit persons to whom the Software is furnished to do so, subject to
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  13  *
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  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
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  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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  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
  36 #if HAVE_LLVM >= 0x0209
  37 #include <llvm/Support/Host.h>
  38 #else
  39 #include <llvm/System/Host.h>
  40 #endif
  41
  42 #if HAVE_LLVM >= 0x0207
  43 #include <llvm/MC/MCDisassembler.h>
  44 #include <llvm/MC/MCAsmInfo.h>
  45 #include <llvm/MC/MCInst.h>
  46 #include <llvm/MC/MCInstPrinter.h>
  47 #endif /* HAVE_LLVM >= 0x0207 */
  48
  49 #include "util/u_math.h"
  50 #include "util/u_debug.h"
  51
  52 #include "lp_bld_debug.h"
  53
  54
  55
  56 /**
  57  * Check alignment.
  58  *
  59  * It is important that this check is not implemented as a macro or inlined
  60  * function, as the compiler assumptions in respect to alignment of global
  61  * and stack variables would often make the check a no op, defeating the
  62  * whole purpose of the exercise.
  63  */
  64 extern "C" boolean
  65 lp_check_alignment(const void *ptr, unsigned alignment)
  66 {
  67    assert(util_is_power_of_two(alignment));
  68    return ((uintptr_t)ptr & (alignment - 1)) == 0;
  69 }
  70
  71
  72 class raw_debug_ostream :
  73    public llvm::raw_ostream
  74 {
  75    uint64_t pos;
  76
  77    void write_impl(const char *Ptr, size_t Size);
  78    uint64_t current_pos() { return pos; }
  79    uint64_t current_pos() const { return pos; }
  80
  81 #if HAVE_LLVM >= 0x207
  82    uint64_t preferred_buffer_size() { return 512; }
  83 #else
  84    size_t preferred_buffer_size() { return 512; }
  85 #endif
  86 };
  87
  88
  89 void
  90 raw_debug_ostream::write_impl(const char *Ptr, size_t Size)
  91 {
  92    if (Size > 0) {
  93       char *lastPtr = (char *)&Ptr[Size];
  94       char last = *lastPtr;
  95       *lastPtr = 0;
  96       _debug_printf("%*s", Size, Ptr);
  97       *lastPtr = last;
  98       pos += Size;
  99    }
 100 }
 101
 102
 103 /**
 104  * Same as LLVMDumpValue, but through our debugging channels.
 105  */
 106 extern "C" void
 107 lp_debug_dump_value(LLVMValueRef value)
 108 {
 109 #if (defined(PIPE_OS_WINDOWS) && !defined(PIPE_CC_MSVC)) || defined(PIPE_OS_EMBDDED)
 110    raw_debug_ostream os;
 111    llvm::unwrap(value)->print(os);
 112    os.flush();
 113 #else
 114    LLVMDumpValue(value);
 115 #endif
 116 }
 117
 118
 119 #if HAVE_LLVM >= 0x0207
 120 /*
 121  * MemoryObject wrapper around a buffer of memory, to be used by MC
 122  * disassembler.
 123  */
 124 class BufferMemoryObject:
 125    public llvm::MemoryObject
 126 {
 127 private:
 128    const uint8_t *Bytes;
 129    uint64_t Length;
 130 public:
 131    BufferMemoryObject(const uint8_t *bytes, uint64_t length) :
 132       Bytes(bytes), Length(length)
 133    {
 134    }
 135
 136    uint64_t getBase() const
 137    {
 138       return 0;
 139    }
 140
 141    uint64_t getExtent() const
 142    {
 143       return Length;
 144    }
 145
 146    int readByte(uint64_t addr, uint8_t *byte) const
 147    {
 148       if (addr > getExtent())
 149          return -1;
 150       *byte = Bytes[addr];
 151       return 0;
 152    }
 153 };
 154 #endif /* HAVE_LLVM >= 0x0207 */
 155
 156
 157 /*
 158  * Disassemble a function, using the LLVM MC disassembler.
 159  *
 160  * See also:
 161  * - http://blog.llvm.org/2010/01/x86-disassembler.html
 162  * - http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html
 163  */
 164 extern "C" void
 165 lp_disassemble(const void* func)
 166 {
 167 #if HAVE_LLVM >= 0x0207
 168    using namespace llvm;
 169
 170    const uint8_t *bytes = (const uint8_t *)func;
 171
 172    /*
 173     * Limit disassembly to this extent
 174     */
 175    const uint64_t extent = 0x10000;
 176
 177    uint64_t max_pc = 0;
 178
 179    /*
 180     * Initialize all used objects.
 181     */
 182
 183    std::string Triple = sys::getHostTriple();
 184
 185    std::string Error;
 186    const Target *T = TargetRegistry::lookupTarget(Triple, Error);
 187
 188 #if HAVE_LLVM >= 0x0208
 189    InitializeNativeTargetAsmPrinter();
 190 #else
 191    InitializeAllAsmPrinters();
 192 #endif
 193
 194    InitializeAllDisassemblers();
 195
 196    OwningPtr<const MCAsmInfo> AsmInfo(T->createAsmInfo(Triple));
 197
 198    if (!AsmInfo) {
 199       debug_printf("error: no assembly info for target %s\n", Triple.c_str());
 200       return;
 201    }
 202
 203    OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler());
 204    if (!DisAsm) {
 205       debug_printf("error: no disassembler for target %s\n", Triple.c_str());
 206       return;
 207    }
 208
 209    raw_debug_ostream Out;
 210    TargetMachine *TM = T->createTargetMachine(Triple, "");
 211
 212 #if HAVE_LLVM >= 0x0300
 213    unsigned int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
 214 #else
 215    int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
 216 #endif
 217 #if HAVE_LLVM >= 0x0300
 218    OwningPtr<MCInstPrinter> Printer(
 219          T->createMCInstPrinter(*TM, AsmPrinterVariant, *AsmInfo));
 220 #elif HAVE_LLVM >= 0x0208
 221    OwningPtr<MCInstPrinter> Printer(
 222          T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo));
 223 #else
 224    OwningPtr<MCInstPrinter> Printer(
 225          T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, Out));
 226 #endif
 227    if (!Printer) {
 228       debug_printf("error: no instruction printer for target %s\n", Triple.c_str());
 229       return;
 230    }
 231
 232    const TargetInstrInfo *TII = TM->getInstrInfo();
 233
 234    /*
 235     * Wrap the data in a MemoryObject
 236     */
 237    BufferMemoryObject memoryObject((const uint8_t *)bytes, extent);
 238
 239    uint64_t pc;
 240    pc = 0;
 241    while (true) {
 242       MCInst Inst;
 243       uint64_t Size;
 244
 245       /*
 246        * Print address.  We use addresses relative to the start of the function,
 247        * so that between runs.
 248        */
 249
 250       debug_printf("%6lu:\t", (unsigned long)pc);
 251
 252       if (!DisAsm->getInstruction(Inst, Size, memoryObject,
 253                                  pc,
 254                                  nulls())) {
 255          debug_printf("invalid\n");
 256          pc += 1;
 257       }
 258
 259       /*
 260        * Output the bytes in hexidecimal format.
 261        */
 262
 263       if (0) {
 264          unsigned i;
 265          for (i = 0; i < Size; ++i) {
 266             debug_printf("%02x ", ((const uint8_t*)bytes)[pc + i]);
 267          }
 268          for (; i < 16; ++i) {
 269             debug_printf("   ");
 270          }
 271       }
 272
 273       /*
 274        * Print the instruction.
 275        */
 276
 277 #if HAVE_LLVM >= 0x208
 278       Printer->printInst(&Inst, Out);
 279 #else
 280       Printer->printInst(&Inst);
 281 #endif
 282       Out.flush();
 283
 284       /*
 285        * Advance.
 286        */
 287
 288       pc += Size;
 289
 290       const TargetInstrDesc &TID = TII->get(Inst.getOpcode());
 291
 292       /*
 293        * Keep track of forward jumps to a nearby address.
 294        */
 295
 296       if (TID.isBranch()) {
 297          for (unsigned i = 0; i < Inst.getNumOperands(); ++i) {
 298             const MCOperand &operand = Inst.getOperand(i);
 299             if (operand.isImm()) {
 300                uint64_t jump;
 301
 302                /*
 303                 * FIXME: Handle both relative and absolute addresses correctly.
 304                 * EDInstInfo actually has this info, but operandTypes and
 305                 * operandFlags enums are not exposed in the public interface.
 306                 */
 307
 308                if (1) {
 309                   /*
 310                    * PC relative addr.
 311                    */
 312
 313                   jump = pc + operand.getImm();
 314                } else {
 315                   /*
 316                    * Absolute addr.
 317                    */
 318
 319                   jump = (uint64_t)operand.getImm();
 320                }
 321
 322                /*
 323                 * Output the address relative to the function start, given
 324                 * that MC will print the addresses relative the current pc.
 325                 */
 326                debug_printf("\t\t; %lu", (unsigned long)jump);
 327
 328                /*
 329                 * Ignore far jumps given it could be actually a tail return to
 330                 * a random address.
 331                 */
 332
 333                if (jump > max_pc &&
 334                    jump < extent) {
 335                   max_pc = jump;
 336                }
 337             }
 338          }
 339       }
 340
 341       debug_printf("\n");
 342
 343       /*
 344        * Stop disassembling on return statements, if there is no record of a
 345        * jump to a successive address.
 346        */
 347
 348       if (TID.isReturn()) {
 349          if (pc > max_pc) {
 350             break;
 351          }
 352       }
 353    }
 354
 355    /*
 356     * Print GDB command, useful to verify output.
 357     */
 358
 359    if (0) {
 360       debug_printf("disassemble %p %p\n", bytes, bytes + pc);
 361    }
 362
 363    debug_printf("\n");
 364 #else /* HAVE_LLVM < 0x0207 */
 365    (void)func;
 366 #endif /* HAVE_LLVM < 0x0207 */
 367 }
 368