Use pc_from_ucontext.m4 from Google Performance Tools

This M4 module lets us learn the right way (out of at least 18
possibilities) to extract the current PC for stack-trace-fixup-in-signal
purposes.  The Google Performance Tools license is 3-clause BSD.

1 files changed, 131 insertions, 0 deletions

diff --git a/m4/pc_from_ucontext.m4 b/m4/pc_from_ucontext.m4
new file mode 100644
index 000000000..6bedcbb2d
--- /dev/null
+++ b/m4/pc_from_ucontext.m4
@@ -0,0 +1,131 @@
+# This file is from Google Performance Tools, svn revision r226.
+#
+# The Google Performance Tools license is:
+########
+# Copyright (c) 2005, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+########
+# Original file follows below.
+
+# We want to access the "PC" (Program Counter) register from a struct
+# ucontext.  Every system has its own way of doing that.  We try all the
+# possibilities we know about.  Note REG_PC should come first (REG_RIP
+# is also defined on solaris, but does the wrong thing).
+
+# OpenBSD doesn't have ucontext.h, but we can get PC from ucontext_t
+# by using signal.h.
+
+# The first argument of AC_PC_FROM_UCONTEXT will be invoked when we
+# cannot find a way to obtain PC from ucontext.
+
+AC_DEFUN([AC_PC_FROM_UCONTEXT],
+  [AC_CHECK_HEADERS(ucontext.h)
+   # Redhat 7 has <sys/ucontext.h>, but it barfs if we #include it directly
+   # (this was fixed in later redhats).  <ucontext.h> works fine, so use that.
+   if grep "Red Hat Linux release 7" /etc/redhat-release >/dev/null 2>&1; then
+     AC_DEFINE(HAVE_SYS_UCONTEXT_H, 0, [<sys/ucontext.h> is broken on redhat 7])
+     ac_cv_header_sys_ucontext_h=no
+   else
+     AC_CHECK_HEADERS(sys/ucontext.h)       # ucontext on OS X 10.6 (at least)
+   fi
+   AC_CHECK_HEADERS(cygwin/signal.h)        # ucontext on cywgin
+   AC_MSG_CHECKING([how to access the program counter from a struct ucontext])
+   pc_fields="           uc_mcontext.gregs[[REG_PC]]"  # Solaris x86 (32 + 64 bit)
+   pc_fields="$pc_fields uc_mcontext.gregs[[REG_EIP]]" # Linux (i386)
+   pc_fields="$pc_fields uc_mcontext.gregs[[REG_RIP]]" # Linux (x86_64)
+   pc_fields="$pc_fields uc_mcontext.sc_ip"            # Linux (ia64)
+   pc_fields="$pc_fields uc_mcontext.uc_regs->gregs[[PT_NIP]]" # Linux (ppc)
+   pc_fields="$pc_fields uc_mcontext.gregs[[R15]]"     # Linux (arm old [untested])
+   pc_fields="$pc_fields uc_mcontext.arm_pc"           # Linux (arm arch 5)
+   pc_fields="$pc_fields uc_mcontext.gp_regs[[PT_NIP]]"  # Suse SLES 11 (ppc64)
+   pc_fields="$pc_fields uc_mcontext.mc_eip"           # FreeBSD (i386)
+   pc_fields="$pc_fields uc_mcontext.mc_rip"           # FreeBSD (x86_64 [untested])
+   pc_fields="$pc_fields uc_mcontext.__gregs[[_REG_EIP]]"  # NetBSD (i386)
+   pc_fields="$pc_fields uc_mcontext.__gregs[[_REG_RIP]]"  # NetBSD (x86_64)
+   pc_fields="$pc_fields uc_mcontext->ss.eip"          # OS X (i386, <=10.4)
+   pc_fields="$pc_fields uc_mcontext->__ss.__eip"      # OS X (i386, >=10.5)
+   pc_fields="$pc_fields uc_mcontext->ss.rip"          # OS X (x86_64)
+   pc_fields="$pc_fields uc_mcontext->__ss.__rip"      # OS X (>=10.5 [untested])
+   pc_fields="$pc_fields uc_mcontext->ss.srr0"         # OS X (ppc, ppc64 [untested])
+   pc_fields="$pc_fields uc_mcontext->__ss.__srr0"     # OS X (>=10.5 [untested])
+   pc_field_found=false
+   for pc_field in $pc_fields; do
+     if ! $pc_field_found; then
+       # Prefer sys/ucontext.h to ucontext.h, for OS X's sake.
+       if test "x$ac_cv_header_cygwin_signal_h" = xyes; then
+         AC_TRY_COMPILE([#define _GNU_SOURCE 1
+                         #include <cygwin/signal.h>],
+                        [ucontext_t u; return u.$pc_field == 0;],
+                        AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
+                                           How to access the PC from a struct ucontext)
+                        AC_MSG_RESULT([$pc_field])
+                        pc_field_found=true)
+       elif test "x$ac_cv_header_sys_ucontext_h" = xyes; then
+         AC_TRY_COMPILE([#define _GNU_SOURCE 1
+                         #include <sys/ucontext.h>],
+                        [ucontext_t u; return u.$pc_field == 0;],
+                        AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
+                                           How to access the PC from a struct ucontext)
+                        AC_MSG_RESULT([$pc_field])
+                        pc_field_found=true)
+       elif test "x$ac_cv_header_ucontext_h" = xyes; then
+         AC_TRY_COMPILE([#define _GNU_SOURCE 1
+                         #include <ucontext.h>],
+                        [ucontext_t u; return u.$pc_field == 0;],
+                        AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
+                                           How to access the PC from a struct ucontext)
+                        AC_MSG_RESULT([$pc_field])
+                        pc_field_found=true)
+       else     # hope some standard header gives it to us
+         AC_TRY_COMPILE([],
+                        [ucontext_t u; return u.$pc_field == 0;],
+                        AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
+                                           How to access the PC from a struct ucontext)
+                        AC_MSG_RESULT([$pc_field])
+                        pc_field_found=true)
+       fi
+     fi
+   done
+   if ! $pc_field_found; then
+     pc_fields="           sc_eip"  # OpenBSD (i386)
+     pc_fields="$pc_fields sc_rip"  # OpenBSD (x86_64)
+     for pc_field in $pc_fields; do
+       if ! $pc_field_found; then
+         AC_TRY_COMPILE([#include <signal.h>],
+                        [ucontext_t u; return u.$pc_field == 0;],
+                        AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
+                                           How to access the PC from a struct ucontext)
+                        AC_MSG_RESULT([$pc_field])
+                        pc_field_found=true)
+       fi
+     done
+   fi
+   if ! $pc_field_found; then
+     [$1]
+   fi])