From 31c7a68a8c6b44e0a19a5f480425e8c9109ad901 Mon Sep 17 00:00:00 2001 From: Michael Jeanson Date: Mon, 22 Mar 2021 18:02:49 -0400 Subject: [PATCH] configure: enable extended compiler warnings Import the compiler warning flag detection system from Babeltrace and enable extended compiler warnings. Change-Id: Id7d783a946a014b9b0811fbd934377cd9cde93c7 Signed-off-by: Michael Jeanson Signed-off-by: Mathieu Desnoyers --- configure.ac | 56 +++++++++++++++++++++++++++++++++-- m4/ax_append_compile_flags.m4 | 46 ++++++++++++++++++++++++++++ m4/ax_append_flag.m4 | 50 +++++++++++++++++++++++++++++++ m4/ax_check_compile_flag.m4 | 53 +++++++++++++++++++++++++++++++++ m4/ax_require_defined.m4 | 37 +++++++++++++++++++++++ 5 files changed, 240 insertions(+), 2 deletions(-) create mode 100644 m4/ax_append_compile_flags.m4 create mode 100644 m4/ax_append_flag.m4 create mode 100644 m4/ax_check_compile_flag.m4 create mode 100644 m4/ax_require_defined.m4 diff --git a/configure.ac b/configure.ac index 54b00dcc..cf2e0e3e 100644 --- a/configure.ac +++ b/configure.ac @@ -135,6 +135,50 @@ AC_TYPE_UINT64_T 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="${WARN_CFLAGS} -Wold-style-definition -Wstrict-prototypes" + ## ## ## C++ compiler checks ## @@ -143,6 +187,14 @@ AC_CHECK_TYPES([ptrdiff_t]) # Find an optional C++11 compiler without GNU extensions (-std=c++11) AX_CXX_COMPILE_STDCXX([11], [noext], [optional]) +AS_IF([test "$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 ## @@ -492,10 +544,10 @@ AC_SUBST([LTTNG_UST_CTL_LIBRARY_VERSION], ust_ctl_lib_version) # 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. diff --git a/m4/ax_append_compile_flags.m4 b/m4/ax_append_compile_flags.m4 new file mode 100644 index 00000000..9c856356 --- /dev/null +++ b/m4/ax_append_compile_flags.m4 @@ -0,0 +1,46 @@ +# ============================================================================ +# 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 +# +# 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 diff --git a/m4/ax_append_flag.m4 b/m4/ax_append_flag.m4 new file mode 100644 index 00000000..dd6d8b61 --- /dev/null +++ b/m4/ax_append_flag.m4 @@ -0,0 +1,50 @@ +# =========================================================================== +# 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 +# Copyright (c) 2011 Maarten Bosmans +# +# 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 diff --git a/m4/ax_check_compile_flag.m4 b/m4/ax_check_compile_flag.m4 new file mode 100644 index 00000000..bd753b34 --- /dev/null +++ b/m4/ax_check_compile_flag.m4 @@ -0,0 +1,53 @@ +# =========================================================================== +# 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 +# Copyright (c) 2011 Maarten Bosmans +# +# 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 diff --git a/m4/ax_require_defined.m4 b/m4/ax_require_defined.m4 new file mode 100644 index 00000000..17c3eab7 --- /dev/null +++ b/m4/ax_require_defined.m4 @@ -0,0 +1,37 @@ +# =========================================================================== +# 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 +# +# 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 -- 2.34.1