| Austin Schuh | 906616c | 2019-01-21 20:25:11 -0800 | [diff] [blame^] | 1 | # We want to access the "PC" (Program Counter) register from a struct |
| 2 | # ucontext. Every system has its own way of doing that. We try all the |
| 3 | # possibilities we know about. Note REG_PC should come first (REG_RIP |
| 4 | # is also defined on solaris, but does the wrong thing). |
| 5 | |
| 6 | # OpenBSD doesn't have ucontext.h, but we can get PC from ucontext_t |
| 7 | # by using signal.h. |
| 8 | |
| 9 | # The first argument of AC_PC_FROM_UCONTEXT will be invoked when we |
| 10 | # cannot find a way to obtain PC from ucontext. |
| 11 | |
| 12 | AC_DEFUN([AC_PC_FROM_UCONTEXT], |
| 13 | [AC_CHECK_HEADERS(ucontext.h) |
| 14 | AC_CHECK_HEADERS(sys/ucontext.h) # ucontext on OS X 10.6 (at least) |
| 15 | AC_MSG_CHECKING([how to access the program counter from a struct ucontext]) |
| 16 | pc_fields=" uc_mcontext.gregs[[REG_PC]]" # Solaris x86 (32 + 64 bit) |
| 17 | pc_fields="$pc_fields uc_mcontext.gregs[[REG_EIP]]" # Linux (i386) |
| 18 | pc_fields="$pc_fields uc_mcontext.gregs[[REG_RIP]]" # Linux (x86_64) |
| 19 | pc_fields="$pc_fields uc_mcontext.sc_ip" # Linux (ia64) |
| 20 | pc_fields="$pc_fields uc_mcontext.uc_regs->gregs[[PT_NIP]]" # Linux (ppc) |
| 21 | pc_fields="$pc_fields uc_mcontext.gregs[[R15]]" # Linux (arm old [untested]) |
| 22 | pc_fields="$pc_fields uc_mcontext.arm_pc" # Linux (arm new [untested]) |
| 23 | pc_fields="$pc_fields uc_mcontext.mc_eip" # FreeBSD (i386) |
| 24 | pc_fields="$pc_fields uc_mcontext.mc_rip" # FreeBSD (x86_64 [untested]) |
| 25 | pc_fields="$pc_fields uc_mcontext.__gregs[[_REG_EIP]]" # NetBSD (i386) |
| 26 | pc_fields="$pc_fields uc_mcontext.__gregs[[_REG_RIP]]" # NetBSD (x86_64) |
| 27 | pc_fields="$pc_fields uc_mcontext->ss.eip" # OS X (i386, <=10.4) |
| 28 | pc_fields="$pc_fields uc_mcontext->__ss.__eip" # OS X (i386, >=10.5) |
| 29 | pc_fields="$pc_fields uc_mcontext->ss.rip" # OS X (x86_64) |
| 30 | pc_fields="$pc_fields uc_mcontext->__ss.__rip" # OS X (>=10.5 [untested]) |
| 31 | pc_fields="$pc_fields uc_mcontext->ss.srr0" # OS X (ppc, ppc64 [untested]) |
| 32 | pc_fields="$pc_fields uc_mcontext->__ss.__srr0" # OS X (>=10.5 [untested]) |
| 33 | pc_field_found=false |
| 34 | for pc_field in $pc_fields; do |
| 35 | if ! $pc_field_found; then |
| 36 | if test "x$ac_cv_header_sys_ucontext_h" = xyes; then |
| 37 | AC_TRY_COMPILE([#define _GNU_SOURCE 1 |
| 38 | #include <sys/ucontext.h>], |
| 39 | [ucontext_t u; return u.$pc_field == 0;], |
| 40 | AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field, |
| 41 | How to access the PC from a struct ucontext) |
| 42 | AC_MSG_RESULT([$pc_field]) |
| 43 | pc_field_found=true) |
| 44 | else |
| 45 | AC_TRY_COMPILE([#define _GNU_SOURCE 1 |
| 46 | #include <ucontext.h>], |
| 47 | [ucontext_t u; return u.$pc_field == 0;], |
| 48 | AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field, |
| 49 | How to access the PC from a struct ucontext) |
| 50 | AC_MSG_RESULT([$pc_field]) |
| 51 | pc_field_found=true) |
| 52 | fi |
| 53 | fi |
| 54 | done |
| 55 | if ! $pc_field_found; then |
| 56 | pc_fields=" sc_eip" # OpenBSD (i386) |
| 57 | pc_fields="$pc_fields sc_rip" # OpenBSD (x86_64) |
| 58 | for pc_field in $pc_fields; do |
| 59 | if ! $pc_field_found; then |
| 60 | AC_TRY_COMPILE([#include <signal.h>], |
| 61 | [ucontext_t u; return u.$pc_field == 0;], |
| 62 | AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field, |
| 63 | How to access the PC from a struct ucontext) |
| 64 | AC_MSG_RESULT([$pc_field]) |
| 65 | pc_field_found=true) |
| 66 | fi |
| 67 | done |
| 68 | fi |
| 69 | if ! $pc_field_found; then |
| 70 | [$1] |
| 71 | fi]) |