lp_bld_debug.cpp revision 3469715a8a171512cf9b528702e70393f01c6041 
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/MemoryObject.h>
35
36#if HAVE_LLVM >= 0x0300
37#include <llvm/Support/TargetRegistry.h>
38#else /* HAVE_LLVM < 0x0300 */
39#include <llvm/Target/TargetRegistry.h>
40#endif /* HAVE_LLVM < 0x0300 */
41
42#if HAVE_LLVM >= 0x0209
43#include <llvm/Support/Host.h>
44#else /* HAVE_LLVM < 0x0209 */
45#include <llvm/System/Host.h>
46#endif /* HAVE_LLVM < 0x0209 */
47
48#if HAVE_LLVM >= 0x0207
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#endif /* HAVE_LLVM >= 0x0207 */
54#if HAVE_LLVM >= 0x0301
55#include <llvm/MC/MCRegisterInfo.h>
56#endif /* HAVE_LLVM >= 0x0301 */
57
58#include "util/u_math.h"
59#include "util/u_debug.h"
60
61#include "lp_bld_debug.h"
62
63
64
65/**
66 * Check alignment.
67 *
68 * It is important that this check is not implemented as a macro or inlined
69 * function, as the compiler assumptions in respect to alignment of global
70 * and stack variables would often make the check a no op, defeating the
71 * whole purpose of the exercise.
72 */
73extern "C" boolean
74lp_check_alignment(const void *ptr, unsigned alignment)
75{
76   assert(util_is_power_of_two(alignment));
77   return ((uintptr_t)ptr & (alignment - 1)) == 0;
78}
79
80
81class raw_debug_ostream :
82   public llvm::raw_ostream
83{
84   uint64_t pos;
85
86   void write_impl(const char *Ptr, size_t Size);
87
88#if HAVE_LLVM >= 0x207
89   uint64_t current_pos() const { return pos; }
90   size_t preferred_buffer_size() const { return 512; }
91#else
92   uint64_t current_pos() { return pos; }
93   size_t preferred_buffer_size() { return 512; }
94#endif
95};
96
97
98void
99raw_debug_ostream::write_impl(const char *Ptr, size_t Size)
100{
101   if (Size > 0) {
102      char *lastPtr = (char *)&Ptr[Size];
103      char last = *lastPtr;
104      *lastPtr = 0;
105      _debug_printf("%*s", Size, Ptr);
106      *lastPtr = last;
107      pos += Size;
108   }
109}
110
111
112/**
113 * Same as LLVMDumpValue, but through our debugging channels.
114 */
115extern "C" void
116lp_debug_dump_value(LLVMValueRef value)
117{
118#if (defined(PIPE_OS_WINDOWS) && !defined(PIPE_CC_MSVC)) || defined(PIPE_OS_EMBDDED)
119   raw_debug_ostream os;
120   llvm::unwrap(value)->print(os);
121   os.flush();
122#else
123   LLVMDumpValue(value);
124#endif
125}
126
127
128#if HAVE_LLVM >= 0x0207
129/*
130 * MemoryObject wrapper around a buffer of memory, to be used by MC
131 * disassembler.
132 */
133class BufferMemoryObject:
134   public llvm::MemoryObject
135{
136private:
137   const uint8_t *Bytes;
138   uint64_t Length;
139public:
140   BufferMemoryObject(const uint8_t *bytes, uint64_t length) :
141      Bytes(bytes), Length(length)
142   {
143   }
144
145   uint64_t getBase() const
146   {
147      return 0;
148   }
149
150   uint64_t getExtent() const
151   {
152      return Length;
153   }
154
155   int readByte(uint64_t addr, uint8_t *byte) const
156   {
157      if (addr > getExtent())
158         return -1;
159      *byte = Bytes[addr];
160      return 0;
161   }
162};
163#endif /* HAVE_LLVM >= 0x0207 */
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 */
173extern "C" void
174lp_disassemble(const void* func)
175{
176#if HAVE_LLVM >= 0x0207
177   using namespace llvm;
178
179   const uint8_t *bytes = (const uint8_t *)func;
180
181   /*
182    * Limit disassembly to this extent
183    */
184   const uint64_t extent = 96 * 1024;
185
186   uint64_t max_pc = 0;
187
188   /*
189    * Initialize all used objects.
190    */
191
192#if HAVE_LLVM >= 0x0301
193   std::string Triple = sys::getDefaultTargetTriple();
194#else
195   std::string Triple = sys::getHostTriple();
196#endif
197
198   std::string Error;
199   const Target *T = TargetRegistry::lookupTarget(Triple, Error);
200
201#if HAVE_LLVM >= 0x0300
202   OwningPtr<const MCAsmInfo> AsmInfo(T->createMCAsmInfo(Triple));
203#else
204   OwningPtr<const MCAsmInfo> AsmInfo(T->createAsmInfo(Triple));
205#endif
206
207   if (!AsmInfo) {
208      debug_printf("error: no assembly info for target %s\n", Triple.c_str());
209      return;
210   }
211
212#if HAVE_LLVM >= 0x0300
213   const MCSubtargetInfo *STI = T->createMCSubtargetInfo(Triple, sys::getHostCPUName(), "");
214   OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler(*STI));
215#else
216   OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler());
217#endif
218   if (!DisAsm) {
219      debug_printf("error: no disassembler for target %s\n", Triple.c_str());
220      return;
221   }
222
223   raw_debug_ostream Out;
224
225#if HAVE_LLVM >= 0x0300
226   unsigned int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
227#else
228   int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
229#endif
230
231#if HAVE_LLVM >= 0x0301
232   OwningPtr<const MCRegisterInfo> MRI(T->createMCRegInfo(Triple));
233   if (!MRI) {
234      debug_printf("error: no register info for target %s\n", Triple.c_str());
235      return;
236   }
237
238   OwningPtr<const MCInstrInfo> MII(T->createMCInstrInfo());
239   if (!MII) {
240      debug_printf("error: no instruction info for target %s\n", Triple.c_str());
241      return;
242   }
243#endif
244
245#if HAVE_LLVM >= 0x0301
246   OwningPtr<MCInstPrinter> Printer(
247         T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, *MII, *MRI, *STI));
248#elif HAVE_LLVM == 0x0300
249   OwningPtr<MCInstPrinter> Printer(
250         T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, *STI));
251#elif HAVE_LLVM >= 0x0208
252   OwningPtr<MCInstPrinter> Printer(
253         T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo));
254#else
255   OwningPtr<MCInstPrinter> Printer(
256         T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, Out));
257#endif
258   if (!Printer) {
259      debug_printf("error: no instruction printer for target %s\n", Triple.c_str());
260      return;
261   }
262
263#if HAVE_LLVM >= 0x0301
264   TargetOptions options;
265#if defined(DEBUG)
266   options.JITEmitDebugInfo = true;
267#endif
268#if defined(PIPE_ARCH_X86)
269   options.StackAlignmentOverride = 4;
270#endif
271#if defined(DEBUG) || defined(PROFILE)
272   options.NoFramePointerElim = true;
273#endif
274   TargetMachine *TM = T->createTargetMachine(Triple, sys::getHostCPUName(), "", options);
275#elif HAVE_LLVM == 0x0300
276   TargetMachine *TM = T->createTargetMachine(Triple, sys::getHostCPUName(), "");
277#else
278   TargetMachine *TM = T->createTargetMachine(Triple, "");
279#endif
280
281   const TargetInstrInfo *TII = TM->getInstrInfo();
282
283   /*
284    * Wrap the data in a MemoryObject
285    */
286   BufferMemoryObject memoryObject((const uint8_t *)bytes, extent);
287
288   uint64_t pc;
289   pc = 0;
290   while (true) {
291      MCInst Inst;
292      uint64_t Size;
293
294      /*
295       * Print address.  We use addresses relative to the start of the function,
296       * so that between runs.
297       */
298
299      debug_printf("%6lu:\t", (unsigned long)pc);
300
301      if (!DisAsm->getInstruction(Inst, Size, memoryObject,
302                                 pc,
303#if HAVE_LLVM >= 0x0300
304				  nulls(), nulls())) {
305#else
306				  nulls())) {
307#endif
308         debug_printf("invalid\n");
309         pc += 1;
310      }
311
312      /*
313       * Output the bytes in hexidecimal format.
314       */
315
316      if (0) {
317         unsigned i;
318         for (i = 0; i < Size; ++i) {
319            debug_printf("%02x ", ((const uint8_t*)bytes)[pc + i]);
320         }
321         for (; i < 16; ++i) {
322            debug_printf("   ");
323         }
324      }
325
326      /*
327       * Print the instruction.
328       */
329
330#if HAVE_LLVM >= 0x0300
331      Printer->printInst(&Inst, Out, "");
332#elif HAVE_LLVM >= 0x208
333      Printer->printInst(&Inst, Out);
334#else
335      Printer->printInst(&Inst);
336#endif
337      Out.flush();
338
339      /*
340       * Advance.
341       */
342
343      pc += Size;
344
345#if HAVE_LLVM >= 0x0300
346      const MCInstrDesc &TID = TII->get(Inst.getOpcode());
347#else
348      const TargetInstrDesc &TID = TII->get(Inst.getOpcode());
349#endif
350
351      /*
352       * Keep track of forward jumps to a nearby address.
353       */
354
355      if (TID.isBranch()) {
356         for (unsigned i = 0; i < Inst.getNumOperands(); ++i) {
357            const MCOperand &operand = Inst.getOperand(i);
358            if (operand.isImm()) {
359               uint64_t jump;
360
361               /*
362                * FIXME: Handle both relative and absolute addresses correctly.
363                * EDInstInfo actually has this info, but operandTypes and
364                * operandFlags enums are not exposed in the public interface.
365                */
366
367               if (1) {
368                  /*
369                   * PC relative addr.
370                   */
371
372                  jump = pc + operand.getImm();
373               } else {
374                  /*
375                   * Absolute addr.
376                   */
377
378                  jump = (uint64_t)operand.getImm();
379               }
380
381               /*
382                * Output the address relative to the function start, given
383                * that MC will print the addresses relative the current pc.
384                */
385               debug_printf("\t\t; %lu", (unsigned long)jump);
386
387               /*
388                * Ignore far jumps given it could be actually a tail return to
389                * a random address.
390                */
391
392               if (jump > max_pc &&
393                   jump < extent) {
394                  max_pc = jump;
395               }
396            }
397         }
398      }
399
400      debug_printf("\n");
401
402      /*
403       * Stop disassembling on return statements, if there is no record of a
404       * jump to a successive address.
405       */
406
407      if (TID.isReturn()) {
408         if (pc > max_pc) {
409            break;
410         }
411      }
412   }
413
414   /*
415    * Print GDB command, useful to verify output.
416    */
417
418   if (0) {
419      debug_printf("disassemble %p %p\n", bytes, bytes + pc);
420   }
421
422   debug_printf("\n");
423#else /* HAVE_LLVM < 0x0207 */
424   (void)func;
425#endif /* HAVE_LLVM < 0x0207 */
426}
427
428