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#include <fstream>
30#include <sstream>
31#include <iomanip>
32
33#include <llvm-c/Core.h>
34#include <llvm-c/Disassembler.h>
35#include <llvm/Support/raw_ostream.h>
36#include <llvm/Support/Format.h>
37#include <llvm/Support/Host.h>
38#include <llvm/IR/Module.h>
39
40#include "util/u_math.h"
41#include "util/u_debug.h"
42
43#include "lp_bld_debug.h"
44
45#ifdef __linux__
46#include <sys/stat.h>
47#include <fcntl.h>
48#endif
49
50
51
52/**
53 * Check alignment.
54 *
55 * It is important that this check is not implemented as a macro or inlined
56 * function, as the compiler assumptions in respect to alignment of global
57 * and stack variables would often make the check a no op, defeating the
58 * whole purpose of the exercise.
59 */
60extern "C" boolean
61lp_check_alignment(const void *ptr, unsigned alignment)
62{
63   assert(util_is_power_of_two(alignment));
64   return ((uintptr_t)ptr & (alignment - 1)) == 0;
65}
66
67
68/**
69 * Same as LLVMDumpValue, but through our debugging channels.
70 */
71extern "C" void
72lp_debug_dump_value(LLVMValueRef value)
73{
74#if HAVE_LLVM >= 0x0304
75   char *str = LLVMPrintValueToString(value);
76   if (str) {
77      os_log_message(str);
78      LLVMDisposeMessage(str);
79   }
80#elif defined(PIPE_OS_WINDOWS) || defined(PIPE_OS_EMBEDDED)
81   std::string str;
82   llvm::raw_string_ostream os(str);
83   llvm::unwrap(value)->print(os);
84   os_log_message(str.c_str());
85#else
86   LLVMDumpValue(value);
87#endif
88}
89
90
91/*
92 * Disassemble a function, using the LLVM MC disassembler.
93 *
94 * See also:
95 * - http://blog.llvm.org/2010/01/x86-disassembler.html
96 * - http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html
97 */
98static size_t
99disassemble(const void* func, std::ostream &buffer)
100{
101   const uint8_t *bytes = (const uint8_t *)func;
102
103   /*
104    * Limit disassembly to this extent
105    */
106   const uint64_t extent = 96 * 1024;
107
108   /*
109    * Initialize all used objects.
110    */
111
112   const char *triple = LLVM_HOST_TRIPLE;
113   LLVMDisasmContextRef D = LLVMCreateDisasm(triple, NULL, 0, NULL, NULL);
114   char outline[1024];
115
116   if (!D) {
117      buffer << "error: could not create disassembler for triple "
118             << triple << '\n';
119      return 0;
120   }
121
122   uint64_t pc;
123   pc = 0;
124   while (pc < extent) {
125      size_t Size;
126
127      /*
128       * Print address.  We use addresses relative to the start of the function,
129       * so that between runs.
130       */
131
132      buffer << std::setw(6) << (unsigned long)pc << ":\t";
133
134      Size = LLVMDisasmInstruction(D, (uint8_t *)bytes + pc, extent - pc, 0, outline,
135                                   sizeof outline);
136
137      if (!Size) {
138         buffer << "invalid\n";
139         pc += 1;
140         break;
141      }
142
143      /*
144       * Output the bytes in hexidecimal format.
145       */
146
147      if (0) {
148         unsigned i;
149         for (i = 0; i < Size; ++i) {
150            buffer << std::hex << std::setfill('0') << std::setw(2)
151                   << static_cast<int> (bytes[pc + i]);
152         }
153         for (; i < 16; ++i) {
154            buffer << std::dec << "   ";
155         }
156      }
157
158      /*
159       * Print the instruction.
160       */
161
162      buffer << std::setw(Size) << outline << '\n';
163
164      /*
165       * Stop disassembling on return statements, if there is no record of a
166       * jump to a successive address.
167       *
168       * XXX: This currently assumes x86
169       */
170
171#if defined(PIPE_ARCH_X86) || defined(PIPE_ARCH_X86_64)
172      if (Size == 1 && bytes[pc] == 0xc3) {
173         break;
174      }
175#endif
176
177      /*
178       * Advance.
179       */
180
181      pc += Size;
182
183      if (pc >= extent) {
184         buffer << "disassembly larger than " << extent << " bytes, aborting\n";
185         break;
186      }
187   }
188
189   buffer << '\n';
190
191   LLVMDisasmDispose(D);
192
193   /*
194    * Print GDB command, useful to verify output.
195    */
196   if (0) {
197      buffer << "disassemble " << static_cast<const void*>(bytes) << ' '
198             << static_cast<const void*>(bytes + pc) << '\n';
199   }
200
201   return pc;
202}
203
204
205extern "C" void
206lp_disassemble(LLVMValueRef func, const void *code)
207{
208   std::ostringstream buffer;
209   std::string s;
210
211   buffer << LLVMGetValueName(func) << ":\n";
212   disassemble(code, buffer);
213   s = buffer.str();
214   os_log_message(s.c_str());
215   os_log_message("\n");
216}
217
218
219/*
220 * Linux perf profiler integration.
221 *
222 * See also:
223 * - http://penberg.blogspot.co.uk/2009/06/jato-has-profiler.html
224 * - https://github.com/penberg/jato/commit/73ad86847329d99d51b386f5aba692580d1f8fdc
225 * - http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=80d496be89ed7dede5abee5c057634e80a31c82d
226 */
227extern "C" void
228lp_profile(LLVMValueRef func, const void *code)
229{
230#if defined(__linux__) && defined(PROFILE)
231   static std::ofstream perf_asm_file;
232   static boolean first_time = TRUE;
233   static FILE *perf_map_file = NULL;
234   if (first_time) {
235      /*
236       * We rely on the disassembler for determining a function's size, but
237       * the disassembly is a leaky and slow operation, so avoid running
238       * this except when running inside linux perf, which can be inferred
239       * by the PERF_BUILDID_DIR environment variable.
240       */
241      if (getenv("PERF_BUILDID_DIR")) {
242         pid_t pid = getpid();
243         char filename[256];
244         util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map", (unsigned long long)pid);
245         perf_map_file = fopen(filename, "wt");
246         util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map.asm", (unsigned long long)pid);
247         perf_asm_file.open(filename);
248      }
249      first_time = FALSE;
250   }
251   if (perf_map_file) {
252      const char *symbol = LLVMGetValueName(func);
253      unsigned long addr = (uintptr_t)code;
254      perf_asm_file << symbol << ":\n";
255      unsigned long size = disassemble(code, perf_asm_file);
256      perf_asm_file.flush();
257      fprintf(perf_map_file, "%lx %lx %s\n", addr, size, symbol);
258      fflush(perf_map_file);
259   }
260#else
261   (void)func;
262   (void)code;
263#endif
264}
265
266
267