github.com/jlmucb/cloudproxy@v0.0.0-20170830161738-b5aa0b619bc4/src/third_party/google-glog/m4/.svn/text-base/pc_from_ucontext.m4.svn-base (about)

     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])