The Tor Browser / file comparison
comparison: xpcom/reflect/xptcall/src/md/unix/vtable_layout_x86.cpp
xpcom/reflect/xptcall/src/md/unix/vtable_layout_x86.cpp
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
equal
deleted
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replaced
| -1:000000000000 | 0:515a7e061fc1 |
|---|---|
| 1 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 2 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 4 | |
| 5 /* this code contributed by Bert Driehuis <bert_driehuis@nl.compuware.com> */ | |
| 6 | |
| 7 #include <stdio.h> | |
| 8 | |
| 9 // Try to determine the vtable layout generated by G++ | |
| 10 // Produces the offset at which the first vtable entry can be | |
| 11 // found, and the factor to apply for subsequent entries on stdout. | |
| 12 // Example output: | |
| 13 // #define GCC_VTABLE_START 0xc | |
| 14 // #define GCC_VTABLE_FACTOR 0x8 | |
| 15 | |
| 16 class test { | |
| 17 public: | |
| 18 virtual int t1(void); | |
| 19 virtual int t2(void); | |
| 20 int x; | |
| 21 }; | |
| 22 | |
| 23 test::test() { this->x = 0x12121212; }; | |
| 24 | |
| 25 int test::t1(void) { return 1; } | |
| 26 int test::t2(void) { return 2; } | |
| 27 | |
| 28 void die(char *x) { | |
| 29 fprintf(stderr, "%s\n", x); | |
| 30 exit(1); | |
| 31 } | |
| 32 | |
| 33 int | |
| 34 main() | |
| 35 { | |
| 36 int i; | |
| 37 test *t = new test(); | |
| 38 int *tp = (int *) t; | |
| 39 int off1 = -1; | |
| 40 int off2 = -1; | |
| 41 int factor; | |
| 42 int factorshift; | |
| 43 | |
| 44 if (*tp++ != 0x12121212) | |
| 45 die("Integer element test::x not found!"); | |
| 46 tp = (int *) *tp; | |
| 47 for (i = 0; i < 10; i++) { | |
| 48 if (tp[i] == (int) t->t1) | |
| 49 off1 = i; | |
| 50 if (tp[i] == (int) t->t2) | |
| 51 off2 = i; | |
| 52 } | |
| 53 if (off1 == -1 || off2 == -1) | |
| 54 die("Could not determine offset into vtable!"); | |
| 55 factor = (off2 - off1) * 4; | |
| 56 factorshift = -1; | |
| 57 while (factor) { | |
| 58 factorshift++; | |
| 59 factor >>= 1; | |
| 60 } | |
| 61 printf("/* Automatically generated by vtable_layout_x86.cpp */\n"); | |
| 62 printf("#define GCC_VTABLE_START\t0x%x\n", off1 * 4); | |
| 63 printf("#define GCC_VTABLE_FACTOR\t0x%x\n", (off2 - off1) * 4); | |
| 64 printf("#define GCC_VTABLE_SHIFT\t0x%x\n", factorshift); | |
| 65 exit(0); | |
| 66 } |
