AC_TYPE_UINT8_T
AC_CHECK_TYPES([ptrdiff_t])
+# Detect warning flags supported by the C compiler and append them to
+# WARN_CFLAGS.
+m4_define([WARN_FLAGS_LIST], [ dnl
+ -Wall dnl
+ -Wextra dnl
+ -Wmissing-prototypes dnl
+ -Wmissing-declarations dnl
+ -Wnull-dereference dnl
+ -Wundef dnl
+ -Wshadow dnl
+ -Wjump-misses-init dnl
+ -Wsuggest-attribute=format dnl
+ -Wtautological-constant-out-of-range-compare dnl
+ -Wnested-externs dnl
+ -Wwrite-strings dnl
+ -Wformat=2 dnl
+ -Wstrict-aliasing dnl
+ -Wmissing-noreturn dnl
+ -Winit-self dnl
+ -Wduplicated-cond dnl
+ -Wduplicated-branches dnl
+ -Wlogical-op dnl
+ dnl These would require reworking the tracepoint macros
+ dnl-Wredundant-decls dnl
+ -Wno-sign-compare dnl
+ -Wno-missing-field-initializers dnl
+ -Wno-null-dereference dnl
+])
+
+# Pass -Werror as an extra flag during the test: this is needed to make the
+# -Wunknown-warning-option diagnostic fatal with clang.
+AC_LANG_PUSH([C])
+AX_APPEND_COMPILE_FLAGS([WARN_FLAGS_LIST], [WARN_CFLAGS], [-Werror])
+AC_LANG_POP([C])
+
+# The test used in AX_APPEND_COMPILE_FLAGS, generated using AC_LANG_PROGRAM, is
+# written in such a way that it triggers warnings with the following warning
+# flags. So they would always end up disabled if we put them there, because
+# the test program would not build.
+#
+# Enable them here unconditionally. They are supported by GCC >= 4.8 and by
+# Clang >= 3.3 (required by the project) and are only valid for C code.
+WARN_CFLAGS="${WARN_CFLAGS} -Wold-style-definition -Wstrict-prototypes"
+
## ##
## C++ compiler checks ##
# Find an optional C++11 compiler without GNU extensions (-std=c++11)
AX_CXX_COMPILE_STDCXX([11], [noext], [optional])
+AS_IF([test "$HAVE_CXX11" = "1"], [
+ # Pass -Werror as an extra flag during the test: this is needed to make the
+ # -Wunknown-warning-option diagnostic fatal with clang.
+ AC_LANG_PUSH([C++])
+ AX_APPEND_COMPILE_FLAGS([WARN_FLAGS_LIST -Wno-undef -Wno-duplicated-branches], [WARN_CXXFLAGS], [-Werror])
+ AC_LANG_POP([C++])
+])
+
## ##
## Header checks ##
# Major soname for python-lttngust
AC_SUBST([LTTNG_UST_LIB_SONAME_MAJOR], [ust_lib_version_current])
-AM_CFLAGS="-Wall $URCU_CFLAGS $PTHREAD_CFLAGS"
+AM_CFLAGS="$WARN_CFLAGS $URCU_CFLAGS $PTHREAD_CFLAGS"
AC_SUBST(AM_CFLAGS)
-AM_CXXFLAGS="$AM_CFLAGS"
+AM_CXXFLAGS="$WARN_CXXFLAGS $URCU_CFLAGS $PTHREAD_CFLAGS"
AC_SUBST(AM_CXXFLAGS)
# The order in which the include folders are searched is important.
--- /dev/null
+# ============================================================================
+# https://www.gnu.org/software/autoconf-archive/ax_append_compile_flags.html
+# ============================================================================
+#
+# SYNOPSIS
+#
+# AX_APPEND_COMPILE_FLAGS([FLAG1 FLAG2 ...], [FLAGS-VARIABLE], [EXTRA-FLAGS], [INPUT])
+#
+# DESCRIPTION
+#
+# For every FLAG1, FLAG2 it is checked whether the compiler works with the
+# flag. If it does, the flag is added FLAGS-VARIABLE
+#
+# If FLAGS-VARIABLE is not specified, the current language's flags (e.g.
+# CFLAGS) is used. During the check the flag is always added to the
+# current language's flags.
+#
+# If EXTRA-FLAGS is defined, it is added to the current language's default
+# flags (e.g. CFLAGS) when the check is done. The check is thus made with
+# the flags: "CFLAGS EXTRA-FLAGS FLAG". This can for example be used to
+# force the compiler to issue an error when a bad flag is given.
+#
+# INPUT gives an alternative input source to AC_COMPILE_IFELSE.
+#
+# NOTE: This macro depends on the AX_APPEND_FLAG and
+# AX_CHECK_COMPILE_FLAG. Please keep this macro in sync with
+# AX_APPEND_LINK_FLAGS.
+#
+# LICENSE
+#
+# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+
+#serial 7
+
+AC_DEFUN([AX_APPEND_COMPILE_FLAGS],
+[AX_REQUIRE_DEFINED([AX_CHECK_COMPILE_FLAG])
+AX_REQUIRE_DEFINED([AX_APPEND_FLAG])
+for flag in $1; do
+ AX_CHECK_COMPILE_FLAG([$flag], [AX_APPEND_FLAG([$flag], [$2])], [], [$3], [$4])
+done
+])dnl AX_APPEND_COMPILE_FLAGS
--- /dev/null
+# ===========================================================================
+# https://www.gnu.org/software/autoconf-archive/ax_append_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_APPEND_FLAG(FLAG, [FLAGS-VARIABLE])
+#
+# DESCRIPTION
+#
+# FLAG is appended to the FLAGS-VARIABLE shell variable, with a space
+# added in between.
+#
+# If FLAGS-VARIABLE is not specified, the current language's flags (e.g.
+# CFLAGS) is used. FLAGS-VARIABLE is not changed if it already contains
+# FLAG. If FLAGS-VARIABLE is unset in the shell, it is set to exactly
+# FLAG.
+#
+# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION.
+#
+# LICENSE
+#
+# Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+
+#serial 8
+
+AC_DEFUN([AX_APPEND_FLAG],
+[dnl
+AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_SET_IF
+AS_VAR_PUSHDEF([FLAGS], [m4_default($2,_AC_LANG_PREFIX[FLAGS])])
+AS_VAR_SET_IF(FLAGS,[
+ AS_CASE([" AS_VAR_GET(FLAGS) "],
+ [*" $1 "*], [AC_RUN_LOG([: FLAGS already contains $1])],
+ [
+ AS_VAR_APPEND(FLAGS,[" $1"])
+ AC_RUN_LOG([: FLAGS="$FLAGS"])
+ ])
+ ],
+ [
+ AS_VAR_SET(FLAGS,[$1])
+ AC_RUN_LOG([: FLAGS="$FLAGS"])
+ ])
+AS_VAR_POPDEF([FLAGS])dnl
+])dnl AX_APPEND_FLAG
--- /dev/null
+# ===========================================================================
+# https://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
+#
+# DESCRIPTION
+#
+# Check whether the given FLAG works with the current language's compiler
+# or gives an error. (Warnings, however, are ignored)
+#
+# ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
+# success/failure.
+#
+# If EXTRA-FLAGS is defined, it is added to the current language's default
+# flags (e.g. CFLAGS) when the check is done. The check is thus made with
+# the flags: "CFLAGS EXTRA-FLAGS FLAG". This can for example be used to
+# force the compiler to issue an error when a bad flag is given.
+#
+# INPUT gives an alternative input source to AC_COMPILE_IFELSE.
+#
+# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
+# macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
+#
+# LICENSE
+#
+# Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+
+#serial 6
+
+AC_DEFUN([AX_CHECK_COMPILE_FLAG],
+[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
+AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
+AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [
+ ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS
+ _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"
+ AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
+ [AS_VAR_SET(CACHEVAR,[yes])],
+ [AS_VAR_SET(CACHEVAR,[no])])
+ _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
+AS_VAR_IF(CACHEVAR,yes,
+ [m4_default([$2], :)],
+ [m4_default([$3], :)])
+AS_VAR_POPDEF([CACHEVAR])dnl
+])dnl AX_CHECK_COMPILE_FLAGS
--- /dev/null
+# ===========================================================================
+# https://www.gnu.org/software/autoconf-archive/ax_require_defined.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_REQUIRE_DEFINED(MACRO)
+#
+# DESCRIPTION
+#
+# AX_REQUIRE_DEFINED is a simple helper for making sure other macros have
+# been defined and thus are available for use. This avoids random issues
+# where a macro isn't expanded. Instead the configure script emits a
+# non-fatal:
+#
+# ./configure: line 1673: AX_CFLAGS_WARN_ALL: command not found
+#
+# It's like AC_REQUIRE except it doesn't expand the required macro.
+#
+# Here's an example:
+#
+# AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
+#
+# LICENSE
+#
+# Copyright (c) 2014 Mike Frysinger <vapier@gentoo.org>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+
+#serial 2
+
+AC_DEFUN([AX_REQUIRE_DEFINED], [dnl
+ m4_ifndef([$1], [m4_fatal([macro ]$1[ is not defined; is a m4 file missing?])])
+])dnl AX_REQUIRE_DEFINED