lp_bld_debug.cpp revision 34930facfe11ef6e322c276295ddf884d36de11c 
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#include <llvm/Support/TargetSelect.h>
39#else /* HAVE_LLVM < 0x0300 */
40#include <llvm/Target/TargetRegistry.h>
41#include <llvm/Target/TargetSelect.h>
42#endif /* HAVE_LLVM < 0x0300 */
43
44#if HAVE_LLVM >= 0x0209
45#include <llvm/Support/Host.h>
46#else /* HAVE_LLVM < 0x0209 */
47#include <llvm/System/Host.h>
48#endif /* HAVE_LLVM < 0x0209 */
49
50#if HAVE_LLVM >= 0x0207
51#include <llvm/MC/MCDisassembler.h>
52#include <llvm/MC/MCAsmInfo.h>
53#include <llvm/MC/MCInst.h>
54#include <llvm/MC/MCInstPrinter.h>
55#endif /* HAVE_LLVM >= 0x0207 */
56
57#include "util/u_math.h"
58#include "util/u_debug.h"
59
60#include "lp_bld_debug.h"
61
62
63
64/**
65 * Check alignment.
66 *
67 * It is important that this check is not implemented as a macro or inlined
68 * function, as the compiler assumptions in respect to alignment of global
69 * and stack variables would often make the check a no op, defeating the
70 * whole purpose of the exercise.
71 */
72extern "C" boolean
73lp_check_alignment(const void *ptr, unsigned alignment)
74{
75   assert(util_is_power_of_two(alignment));
76   return ((uintptr_t)ptr & (alignment - 1)) == 0;
77}
78
79
80class raw_debug_ostream :
81   public llvm::raw_ostream
82{
83   uint64_t pos;
84
85   void write_impl(const char *Ptr, size_t Size);
86   uint64_t current_pos() { return pos; }
87   uint64_t current_pos() const { return pos; }
88
89#if HAVE_LLVM >= 0x207
90   uint64_t preferred_buffer_size() { return 512; }
91#else
92   size_t preferred_buffer_size() { return 512; }
93#endif
94};
95
96
97void
98raw_debug_ostream::write_impl(const char *Ptr, size_t Size)
99{
100   if (Size > 0) {
101      char *lastPtr = (char *)&Ptr[Size];
102      char last = *lastPtr;
103      *lastPtr = 0;
104      _debug_printf("%*s", Size, Ptr);
105      *lastPtr = last;
106      pos += Size;
107   }
108}
109
110
111/**
112 * Same as LLVMDumpValue, but through our debugging channels.
113 */
114extern "C" void
115lp_debug_dump_value(LLVMValueRef value)
116{
117#if (defined(PIPE_OS_WINDOWS) && !defined(PIPE_CC_MSVC)) || defined(PIPE_OS_EMBDDED)
118   raw_debug_ostream os;
119   llvm::unwrap(value)->print(os);
120   os.flush();
121#else
122   LLVMDumpValue(value);
123#endif
124}
125
126
127#if HAVE_LLVM >= 0x0207
128/*
129 * MemoryObject wrapper around a buffer of memory, to be used by MC
130 * disassembler.
131 */
132class BufferMemoryObject:
133   public llvm::MemoryObject
134{
135private:
136   const uint8_t *Bytes;
137   uint64_t Length;
138public:
139   BufferMemoryObject(const uint8_t *bytes, uint64_t length) :
140      Bytes(bytes), Length(length)
141   {
142   }
143
144   uint64_t getBase() const
145   {
146      return 0;
147   }
148
149   uint64_t getExtent() const
150   {
151      return Length;
152   }
153
154   int readByte(uint64_t addr, uint8_t *byte) const
155   {
156      if (addr > getExtent())
157         return -1;
158      *byte = Bytes[addr];
159      return 0;
160   }
161};
162#endif /* HAVE_LLVM >= 0x0207 */
163
164
165/*
166 * Disassemble a function, using the LLVM MC disassembler.
167 *
168 * See also:
169 * - http://blog.llvm.org/2010/01/x86-disassembler.html
170 * - http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html
171 */
172extern "C" void
173lp_disassemble(const void* func)
174{
175#if HAVE_LLVM >= 0x0207
176   using namespace llvm;
177
178   const uint8_t *bytes = (const uint8_t *)func;
179
180   /*
181    * Limit disassembly to this extent
182    */
183   const uint64_t extent = 0x10000;
184
185   uint64_t max_pc = 0;
186
187   /*
188    * Initialize all used objects.
189    */
190
191#if HAVE_LLVM >= 0x0301
192   std::string Triple = sys::getDefaultTargetTriple();
193#else
194   std::string Triple = sys::getHostTriple();
195#endif
196
197   std::string Error;
198   const Target *T = TargetRegistry::lookupTarget(Triple, Error);
199
200#if HAVE_LLVM >= 0x0208
201   InitializeNativeTargetAsmPrinter();
202#else
203   InitializeAllAsmPrinters();
204#endif
205
206   InitializeAllDisassemblers();
207
208#if HAVE_LLVM >= 0x0300
209   OwningPtr<const MCAsmInfo> AsmInfo(T->createMCAsmInfo(Triple));
210#else
211   OwningPtr<const MCAsmInfo> AsmInfo(T->createAsmInfo(Triple));
212#endif
213
214   if (!AsmInfo) {
215      debug_printf("error: no assembly info for target %s\n", Triple.c_str());
216      return;
217   }
218
219#if HAVE_LLVM >= 0x0300
220   const MCSubtargetInfo *STI = T->createMCSubtargetInfo(Triple, sys::getHostCPUName(), "");
221   OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler(*STI));
222#else
223   OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler());
224#endif
225   if (!DisAsm) {
226      debug_printf("error: no disassembler for target %s\n", Triple.c_str());
227      return;
228   }
229
230   raw_debug_ostream Out;
231
232#if HAVE_LLVM >= 0x0300
233   unsigned int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
234#else
235   int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
236#endif
237
238#if HAVE_LLVM >= 0x0300
239   OwningPtr<MCInstPrinter> Printer(
240         T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, *STI));
241#elif HAVE_LLVM >= 0x0208
242   OwningPtr<MCInstPrinter> Printer(
243         T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo));
244#else
245   OwningPtr<MCInstPrinter> Printer(
246         T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, Out));
247#endif
248   if (!Printer) {
249      debug_printf("error: no instruction printer for target %s\n", Triple.c_str());
250      return;
251   }
252
253#if HAVE_LLVM >= 0x0300
254   TargetMachine *TM = T->createTargetMachine(Triple, sys::getHostCPUName(), "");
255#else
256   TargetMachine *TM = T->createTargetMachine(Triple, "");
257#endif
258
259   const TargetInstrInfo *TII = TM->getInstrInfo();
260
261   /*
262    * Wrap the data in a MemoryObject
263    */
264   BufferMemoryObject memoryObject((const uint8_t *)bytes, extent);
265
266   uint64_t pc;
267   pc = 0;
268   while (true) {
269      MCInst Inst;
270      uint64_t Size;
271
272      /*
273       * Print address.  We use addresses relative to the start of the function,
274       * so that between runs.
275       */
276
277      debug_printf("%6lu:\t", (unsigned long)pc);
278
279      if (!DisAsm->getInstruction(Inst, Size, memoryObject,
280                                 pc,
281#if HAVE_LLVM >= 0x0300
282				  nulls(), nulls())) {
283#else
284				  nulls())) {
285#endif
286         debug_printf("invalid\n");
287         pc += 1;
288      }
289
290      /*
291       * Output the bytes in hexidecimal format.
292       */
293
294      if (0) {
295         unsigned i;
296         for (i = 0; i < Size; ++i) {
297            debug_printf("%02x ", ((const uint8_t*)bytes)[pc + i]);
298         }
299         for (; i < 16; ++i) {
300            debug_printf("   ");
301         }
302      }
303
304      /*
305       * Print the instruction.
306       */
307
308#if HAVE_LLVM >= 0x0300
309      Printer->printInst(&Inst, Out, "");
310#elif HAVE_LLVM >= 0x208
311      Printer->printInst(&Inst, Out);
312#else
313      Printer->printInst(&Inst);
314#endif
315      Out.flush();
316
317      /*
318       * Advance.
319       */
320
321      pc += Size;
322
323#if HAVE_LLVM >= 0x0300
324      const MCInstrDesc &TID = TII->get(Inst.getOpcode());
325#else
326      const TargetInstrDesc &TID = TII->get(Inst.getOpcode());
327#endif
328
329      /*
330       * Keep track of forward jumps to a nearby address.
331       */
332
333      if (TID.isBranch()) {
334         for (unsigned i = 0; i < Inst.getNumOperands(); ++i) {
335            const MCOperand &operand = Inst.getOperand(i);
336            if (operand.isImm()) {
337               uint64_t jump;
338
339               /*
340                * FIXME: Handle both relative and absolute addresses correctly.
341                * EDInstInfo actually has this info, but operandTypes and
342                * operandFlags enums are not exposed in the public interface.
343                */
344
345               if (1) {
346                  /*
347                   * PC relative addr.
348                   */
349
350                  jump = pc + operand.getImm();
351               } else {
352                  /*
353                   * Absolute addr.
354                   */
355
356                  jump = (uint64_t)operand.getImm();
357               }
358
359               /*
360                * Output the address relative to the function start, given
361                * that MC will print the addresses relative the current pc.
362                */
363               debug_printf("\t\t; %lu", (unsigned long)jump);
364
365               /*
366                * Ignore far jumps given it could be actually a tail return to
367                * a random address.
368                */
369
370               if (jump > max_pc &&
371                   jump < extent) {
372                  max_pc = jump;
373               }
374            }
375         }
376      }
377
378      debug_printf("\n");
379
380      /*
381       * Stop disassembling on return statements, if there is no record of a
382       * jump to a successive address.
383       */
384
385      if (TID.isReturn()) {
386         if (pc > max_pc) {
387            break;
388         }
389      }
390   }
391
392   /*
393    * Print GDB command, useful to verify output.
394    */
395
396   if (0) {
397      debug_printf("disassemble %p %p\n", bytes, bytes + pc);
398   }
399
400   debug_printf("\n");
401#else /* HAVE_LLVM < 0x0207 */
402   (void)func;
403#endif /* HAVE_LLVM < 0x0207 */
404}
405
406