From be26f4ebf04dd774c665e6e0fbec4b705bc0b53f Mon Sep 17 00:00:00 2001
From: Ruben Kerkhof <ruben@rubenkerkhof.com>
Date: Sat, 27 May 2017 15:27:54 +0200
Subject: [PATCH] configure.ac: detect compiler vendor

I'll use this in followup patches to detect if the compiler supports
various warning flags. For example, a long standing issue is that older
version of the Sun studio compiler doesn't support -Werror.
---
 configure.ac             |  4 +++
 m4/ax_compiler_vendor.m4 | 87 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 91 insertions(+)
 create mode 100644 m4/ax_compiler_vendor.m4

diff --git a/configure.ac b/configure.ac
index a769d492..f54076a4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -27,6 +27,9 @@ AC_SYS_LARGEFILE
 AC_PROG_CC_C99([],
   [AC_MSG_ERROR([No compiler found that supports C99])]
 )
+
+AX_COMPILER_VENDOR
+
 AC_PROG_CXX
 AC_PROG_CPP
 AC_PROG_EGREP
@@ -6814,6 +6817,7 @@ AC_MSG_RESULT()
 AC_MSG_RESULT([Configuration:])
 AC_MSG_RESULT([  Build:])
 AC_MSG_RESULT([    Platform  . . . . . . $ac_system])
+AC_MSG_RESULT([    Compiler vendor . . . $ax_cv_c_compiler_vendor])
 AC_MSG_RESULT([    CC  . . . . . . . . . $CC])
 AC_MSG_RESULT([    CFLAGS  . . . . . . . $AM_CFLAGS $CFLAGS])
 AC_MSG_RESULT([    CXXFLAGS  . . . . . . $AM_CXXFLAGS $CXXFLAGS])
diff --git a/m4/ax_compiler_vendor.m4 b/m4/ax_compiler_vendor.m4
new file mode 100644
index 00000000..ee24c12f
--- /dev/null
+++ b/m4/ax_compiler_vendor.m4
@@ -0,0 +1,87 @@
+# ===========================================================================
+#    http://www.gnu.org/software/autoconf-archive/ax_compiler_vendor.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_COMPILER_VENDOR
+#
+# DESCRIPTION
+#
+#   Determine the vendor of the C/C++ compiler, e.g., gnu, intel, ibm, sun,
+#   hp, borland, comeau, dec, cray, kai, lcc, metrowerks, sgi, microsoft,
+#   watcom, etc. The vendor is returned in the cache variable
+#   $ax_cv_c_compiler_vendor for C and $ax_cv_cxx_compiler_vendor for C++.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu>
+#   Copyright (c) 2008 Matteo Frigo
+#
+#   This program is free software: you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 15
+
+AC_DEFUN([AX_COMPILER_VENDOR],
+[AC_CACHE_CHECK([for _AC_LANG compiler vendor], ax_cv_[]_AC_LANG_ABBREV[]_compiler_vendor,
+  dnl Please add if possible support to ax_compiler_version.m4
+  [# note: don't check for gcc first since some other compilers define __GNUC__
+  vendors="intel:     __ICC,__ECC,__INTEL_COMPILER
+           ibm:       __xlc__,__xlC__,__IBMC__,__IBMCPP__
+           pathscale: __PATHCC__,__PATHSCALE__
+           clang:     __clang__
+           cray:      _CRAYC
+           fujitsu:   __FUJITSU
+           gnu:       __GNUC__
+           sun:       __SUNPRO_C,__SUNPRO_CC
+           hp:        __HP_cc,__HP_aCC
+           dec:       __DECC,__DECCXX,__DECC_VER,__DECCXX_VER
+           borland:   __BORLANDC__,__CODEGEARC__,__TURBOC__
+           comeau:    __COMO__
+           kai:       __KCC
+           lcc:       __LCC__
+           sgi:       __sgi,sgi
+           microsoft: _MSC_VER
+           metrowerks: __MWERKS__
+           watcom:    __WATCOMC__
+           portland:  __PGI
+           tcc:       __TINYC__
+           unknown:   UNKNOWN"
+  for ventest in $vendors; do
+    case $ventest in
+      *:) vendor=$ventest; continue ;;
+      *)  vencpp="defined("`echo $ventest | sed 's/,/) || defined(/g'`")" ;;
+    esac
+    AC_COMPILE_IFELSE([AC_LANG_PROGRAM(,[
+      #if !($vencpp)
+        thisisanerror;
+      #endif
+    ])], [break])
+  done
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_vendor=`echo $vendor | cut -d: -f1`
+ ])
+])
-- 
2.11.0