src/gallium/auxiliary/gallivm/lp_bld_debug.cpp

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   3  * Copyright 2009-2011 VMware, Inc.
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   7  * copy of this software and associated documentation files (the
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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
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
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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 #if HAVE_LLVM >= 0x0300
 211    TargetMachine *TM = T->createTargetMachine(Triple, sys::getHostCPUName(), "");
 212 #else
 213    TargetMachine *TM = T->createTargetMachine(Triple, "");
 214 #endif
 215
 216 #if HAVE_LLVM >= 0x0300
 217    unsigned int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
 218 #else
 219    int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
 220 #endif
 221 #if HAVE_LLVM >= 0x0300
 222    OwningPtr<MCInstPrinter> Printer(
 223          T->createMCInstPrinter(*TM, AsmPrinterVariant, *AsmInfo));
 224 #elif HAVE_LLVM >= 0x0208
 225    OwningPtr<MCInstPrinter> Printer(
 226          T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo));
 227 #else
 228    OwningPtr<MCInstPrinter> Printer(
 229          T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, Out));
 230 #endif
 231    if (!Printer) {
 232       debug_printf("error: no instruction printer for target %s\n", Triple.c_str());
 233       return;
 234    }
 235
 236    const TargetInstrInfo *TII = TM->getInstrInfo();
 237
 238    /*
 239     * Wrap the data in a MemoryObject
 240     */
 241    BufferMemoryObject memoryObject((const uint8_t *)bytes, extent);
 242
 243    uint64_t pc;
 244    pc = 0;
 245    while (true) {
 246       MCInst Inst;
 247       uint64_t Size;
 248
 249       /*
 250        * Print address.  We use addresses relative to the start of the function,
 251        * so that between runs.
 252        */
 253
 254       debug_printf("%6lu:\t", (unsigned long)pc);
 255
 256       if (!DisAsm->getInstruction(Inst, Size, memoryObject,
 257                                  pc,
 258                                  nulls())) {
 259          debug_printf("invalid\n");
 260          pc += 1;
 261       }
 262
 263       /*
 264        * Output the bytes in hexidecimal format.
 265        */
 266
 267       if (0) {
 268          unsigned i;
 269          for (i = 0; i < Size; ++i) {
 270             debug_printf("%02x ", ((const uint8_t*)bytes)[pc + i]);
 271          }
 272          for (; i < 16; ++i) {
 273             debug_printf("   ");
 274          }
 275       }
 276
 277       /*
 278        * Print the instruction.
 279        */
 280
 281 #if HAVE_LLVM >= 0x208
 282       Printer->printInst(&Inst, Out);
 283 #else
 284       Printer->printInst(&Inst);
 285 #endif
 286       Out.flush();
 287
 288       /*
 289        * Advance.
 290        */
 291
 292       pc += Size;
 293
 294 #if HAVE_LLVM >= 0x0300
 295       const MCInstrDesc &TID = TII->get(Inst.getOpcode());
 296 #else
 297       const TargetInstrDesc &TID = TII->get(Inst.getOpcode());
 298 #endif
 299
 300       /*
 301        * Keep track of forward jumps to a nearby address.
 302        */
 303
 304       if (TID.isBranch()) {
 305          for (unsigned i = 0; i < Inst.getNumOperands(); ++i) {
 306             const MCOperand &operand = Inst.getOperand(i);
 307             if (operand.isImm()) {
 308                uint64_t jump;
 309
 310                /*
 311                 * FIXME: Handle both relative and absolute addresses correctly.
 312                 * EDInstInfo actually has this info, but operandTypes and
 313                 * operandFlags enums are not exposed in the public interface.
 314                 */
 315
 316                if (1) {
 317                   /*
 318                    * PC relative addr.
 319                    */
 320
 321                   jump = pc + operand.getImm();
 322                } else {
 323                   /*
 324                    * Absolute addr.
 325                    */
 326
 327                   jump = (uint64_t)operand.getImm();
 328                }
 329
 330                /*
 331                 * Output the address relative to the function start, given
 332                 * that MC will print the addresses relative the current pc.
 333                 */
 334                debug_printf("\t\t; %lu", (unsigned long)jump);
 335
 336                /*
 337                 * Ignore far jumps given it could be actually a tail return to
 338                 * a random address.
 339                 */
 340
 341                if (jump > max_pc &&
 342                    jump < extent) {
 343                   max_pc = jump;
 344                }
 345             }
 346          }
 347       }
 348
 349       debug_printf("\n");
 350
 351       /*
 352        * Stop disassembling on return statements, if there is no record of a
 353        * jump to a successive address.
 354        */
 355
 356       if (TID.isReturn()) {
 357          if (pc > max_pc) {
 358             break;
 359          }
 360       }
 361    }
 362
 363    /*
 364     * Print GDB command, useful to verify output.
 365     */
 366
 367    if (0) {
 368       debug_printf("disassemble %p %p\n", bytes, bytes + pc);
 369    }
 370
 371    debug_printf("\n");
 372 #else /* HAVE_LLVM < 0x0207 */
 373    (void)func;
 374 #endif /* HAVE_LLVM < 0x0207 */
 375 }
 376