lp_bld_debug.cpp revision b61e56756c2d61a94a8dd90abb4dc83e0c0349ae 
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 <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 */
64extern "C" boolean
65lp_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
72class 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
89void
90raw_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 */
106extern "C" void
107lp_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 */
124class BufferMemoryObject:
125   public llvm::MemoryObject
126{
127private:
128   const uint8_t *Bytes;
129   uint64_t Length;
130public:
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 */
164extern "C" void
165lp_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#if HAVE_LLVM >= 0x0300
291      const MCInstrDesc &TID = TII->get(Inst.getOpcode());
292#else
293      const TargetInstrDesc &TID = TII->get(Inst.getOpcode());
294#endif
295
296      /*
297       * Keep track of forward jumps to a nearby address.
298       */
299
300      if (TID.isBranch()) {
301         for (unsigned i = 0; i < Inst.getNumOperands(); ++i) {
302            const MCOperand &operand = Inst.getOperand(i);
303            if (operand.isImm()) {
304               uint64_t jump;
305
306               /*
307                * FIXME: Handle both relative and absolute addresses correctly.
308                * EDInstInfo actually has this info, but operandTypes and
309                * operandFlags enums are not exposed in the public interface.
310                */
311
312               if (1) {
313                  /*
314                   * PC relative addr.
315                   */
316
317                  jump = pc + operand.getImm();
318               } else {
319                  /*
320                   * Absolute addr.
321                   */
322
323                  jump = (uint64_t)operand.getImm();
324               }
325
326               /*
327                * Output the address relative to the function start, given
328                * that MC will print the addresses relative the current pc.
329                */
330               debug_printf("\t\t; %lu", (unsigned long)jump);
331
332               /*
333                * Ignore far jumps given it could be actually a tail return to
334                * a random address.
335                */
336
337               if (jump > max_pc &&
338                   jump < extent) {
339                  max_pc = jump;
340               }
341            }
342         }
343      }
344
345      debug_printf("\n");
346
347      /*
348       * Stop disassembling on return statements, if there is no record of a
349       * jump to a successive address.
350       */
351
352      if (TID.isReturn()) {
353         if (pc > max_pc) {
354            break;
355         }
356      }
357   }
358
359   /*
360    * Print GDB command, useful to verify output.
361    */
362
363   if (0) {
364      debug_printf("disassemble %p %p\n", bytes, bytes + pc);
365   }
366
367   debug_printf("\n");
368#else /* HAVE_LLVM < 0x0207 */
369   (void)func;
370#endif /* HAVE_LLVM < 0x0207 */
371}
372
373