Separate Simple Backend creation from initialization.
[chromium-blink-merge.git] / third_party / tcmalloc / vendor / m4 / pc_from_ucontext.m4
blobdee73a1d62a4eeefe1cf421fb69642bebd017edc
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).
6 # OpenBSD doesn't have ucontext.h, but we can get PC from ucontext_t
7 # by using signal.h.
9 # The first argument of AC_PC_FROM_UCONTEXT will be invoked when we
10 # cannot find a way to obtain PC from ucontext.
12 AC_DEFUN([AC_PC_FROM_UCONTEXT],
13   [AC_CHECK_HEADERS(ucontext.h)
14    # Redhat 7 has <sys/ucontext.h>, but it barfs if we #include it directly
15    # (this was fixed in later redhats).  <ucontext.h> works fine, so use that.
16    if grep "Red Hat Linux release 7" /etc/redhat-release >/dev/null 2>&1; then
17      AC_DEFINE(HAVE_SYS_UCONTEXT_H, 0, [<sys/ucontext.h> is broken on redhat 7])
18      ac_cv_header_sys_ucontext_h=no
19    else
20      AC_CHECK_HEADERS(sys/ucontext.h)       # ucontext on OS X 10.6 (at least)
21    fi
22    AC_CHECK_HEADERS(cygwin/signal.h)        # ucontext on cywgin
23    AC_MSG_CHECKING([how to access the program counter from a struct ucontext])
24    pc_fields="           uc_mcontext.gregs[[REG_PC]]"  # Solaris x86 (32 + 64 bit)
25    pc_fields="$pc_fields uc_mcontext.gregs[[REG_EIP]]" # Linux (i386)
26    pc_fields="$pc_fields uc_mcontext.gregs[[REG_RIP]]" # Linux (x86_64)
27    pc_fields="$pc_fields uc_mcontext.sc_ip"            # Linux (ia64)
28    pc_fields="$pc_fields uc_mcontext.uc_regs->gregs[[PT_NIP]]" # Linux (ppc)
29    pc_fields="$pc_fields uc_mcontext.gregs[[R15]]"     # Linux (arm old [untested])
30    pc_fields="$pc_fields uc_mcontext.arm_pc"           # Linux (arm arch 5)
31    pc_fields="$pc_fields uc_mcontext.gp_regs[[PT_NIP]]"  # Suse SLES 11 (ppc64)
32    pc_fields="$pc_fields uc_mcontext.mc_eip"           # FreeBSD (i386)
33    pc_fields="$pc_fields uc_mcontext.mc_rip"           # FreeBSD (x86_64 [untested])
34    pc_fields="$pc_fields uc_mcontext.__gregs[[_REG_EIP]]"  # NetBSD (i386)
35    pc_fields="$pc_fields uc_mcontext.__gregs[[_REG_RIP]]"  # NetBSD (x86_64)
36    pc_fields="$pc_fields uc_mcontext->ss.eip"          # OS X (i386, <=10.4)
37    pc_fields="$pc_fields uc_mcontext->__ss.__eip"      # OS X (i386, >=10.5)
38    pc_fields="$pc_fields uc_mcontext->ss.rip"          # OS X (x86_64)
39    pc_fields="$pc_fields uc_mcontext->__ss.__rip"      # OS X (>=10.5 [untested])
40    pc_fields="$pc_fields uc_mcontext->ss.srr0"         # OS X (ppc, ppc64 [untested])
41    pc_fields="$pc_fields uc_mcontext->__ss.__srr0"     # OS X (>=10.5 [untested])
42    pc_field_found=false
43    for pc_field in $pc_fields; do
44      if ! $pc_field_found; then
45        # Prefer sys/ucontext.h to ucontext.h, for OS X's sake.
46        if test "x$ac_cv_header_cygwin_signal_h" = xyes; then
47          AC_TRY_COMPILE([#define _GNU_SOURCE 1
48                          #include <cygwin/signal.h>],
49                         [ucontext_t u; return u.$pc_field == 0;],
50                         AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
51                                            How to access the PC from a struct ucontext)
52                         AC_MSG_RESULT([$pc_field])
53                         pc_field_found=true)
54        elif test "x$ac_cv_header_sys_ucontext_h" = xyes; then
55          AC_TRY_COMPILE([#define _GNU_SOURCE 1
56                          #include <sys/ucontext.h>],
57                         [ucontext_t u; return u.$pc_field == 0;],
58                         AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
59                                            How to access the PC from a struct ucontext)
60                         AC_MSG_RESULT([$pc_field])
61                         pc_field_found=true)
62        elif test "x$ac_cv_header_ucontext_h" = xyes; then
63          AC_TRY_COMPILE([#define _GNU_SOURCE 1
64                          #include <ucontext.h>],
65                         [ucontext_t u; return u.$pc_field == 0;],
66                         AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
67                                            How to access the PC from a struct ucontext)
68                         AC_MSG_RESULT([$pc_field])
69                         pc_field_found=true)
70        else     # hope some standard header gives it to us
71          AC_TRY_COMPILE([],
72                         [ucontext_t u; return u.$pc_field == 0;],
73                         AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
74                                            How to access the PC from a struct ucontext)
75                         AC_MSG_RESULT([$pc_field])
76                         pc_field_found=true)
77        fi
78      fi
79    done
80    if ! $pc_field_found; then
81      pc_fields="           sc_eip"  # OpenBSD (i386)
82      pc_fields="$pc_fields sc_rip"  # OpenBSD (x86_64)
83      for pc_field in $pc_fields; do
84        if ! $pc_field_found; then
85          AC_TRY_COMPILE([#include <signal.h>],
86                         [ucontext_t u; return u.$pc_field == 0;],
87                         AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
88                                            How to access the PC from a struct ucontext)
89                         AC_MSG_RESULT([$pc_field])
90                         pc_field_found=true)
91        fi
92      done
93    fi
94    if ! $pc_field_found; then
95      [$1]
96    fi])