ci: Make compiler warning into errors on CI

[secp256k1.git] / configure.ac

diff --git a/configure.ac b/configure.ac
index aaca5343063c3818371b65ca13e8dfd584337f3d..7172a9f22a257faf564525caeca9b13362b5a0ff 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -8,10 +8,6 @@ AH_TOP([#define LIBSECP256K1_CONFIG_H])
 AH_BOTTOM([#endif /*LIBSECP256K1_CONFIG_H*/])
 AM_INIT_AUTOMAKE([foreign subdir-objects])
 
-# Set -g if CFLAGS are not already set, which matches the default autoconf
-# behavior (see PROG_CC in the Autoconf manual) with the exception that we don't
-# set -O2 here because we set it in any case (see further down).
-: ${CFLAGS="-g"}
 LT_INIT
 
 # Make the compilation flags quiet unless V=1 is used.
@@ -84,7 +80,6 @@ esac
 # These executables are compiled from C source file for which our flags may not be appropriate,
 # e.g., -std=c89 flag has lead to undesirable warnings in the past.
 #
-# TODO We still touch the CFLAGS for --coverage and -O0/-O2.
 # TODO We should analogously not touch CPPFLAGS and LDFLAGS but currently there are no issues.
 AC_DEFUN([SECP_TRY_APPEND_DEFAULT_CFLAGS], [
     # Try to append -Werror=unknown-warning-option to CFLAGS temporarily. Otherwise clang will
@@ -99,6 +94,7 @@ AC_DEFUN([SECP_TRY_APPEND_DEFAULT_CFLAGS], [
     SECP_TRY_APPEND_CFLAGS([-Wno-unused-function], $1) # GCC >= 3.0, -Wunused-function is implied by -Wall.
     SECP_TRY_APPEND_CFLAGS([-Wextra], $1) # GCC >= 3.4, this is the newer name of -W, which we don't use because older GCCs will warn about unused functions.
     SECP_TRY_APPEND_CFLAGS([-Wcast-align], $1) # GCC >= 2.95
+    SECP_TRY_APPEND_CFLAGS([-Wcast-align=strict], $1) # GCC >= 8.0
     SECP_TRY_APPEND_CFLAGS([-Wconditional-uninitialized], $1) # Clang >= 3.0 only
     SECP_TRY_APPEND_CFLAGS([-fvisibility=hidden], $1) # GCC >= 4.0
 
@@ -219,10 +215,14 @@ AM_CONDITIONAL([VALGRIND_ENABLED],[test "$enable_valgrind" = "yes"])
 
 if test x"$enable_coverage" = x"yes"; then
     AC_DEFINE(COVERAGE, 1, [Define this symbol to compile out all VERIFY code])
-    CFLAGS="-O0 --coverage $CFLAGS"
+    SECP_CFLAGS="-O0 --coverage $SECP_CFLAGS"
     LDFLAGS="--coverage $LDFLAGS"
 else
-    CFLAGS="-O2 $CFLAGS"
+    # Most likely the CFLAGS already contain -O2 because that is autoconf's default.
+    # We still add it here because passing it twice is not an issue, and handling
+    # this case would just add unnecessary complexity (see #896).
+    SECP_CFLAGS="-O2 $SECP_CFLAGS"
+    SECP_CFLAGS_FOR_BUILD="-O2 $SECP_CFLAGS_FOR_BUILD"
 fi
 
 if test x"$req_asm" = x"auto"; then
@@ -357,6 +357,9 @@ if test x"$enable_valgrind" = x"yes"; then
   SECP_INCLUDES="$SECP_INCLUDES $VALGRIND_CPPFLAGS"
 fi
 
+# Add -Werror and similar flags passed from the outside (for testing, e.g., in CI)
+SECP_CFLAGS="$SECP_CFLAGS $WERROR_CFLAGS"
+
 # Handle static precomputation (after everything which modifies CFLAGS and friends)
 if test x"$use_ecmult_static_precomputation" != x"no"; then
   if test x"$cross_compiling" = x"no"; then
@@ -366,8 +369,8 @@ if test x"$use_ecmult_static_precomputation" != x"no"; then
     fi
     # If we're not cross-compiling, simply use the same compiler for building the static precompation code.
     CC_FOR_BUILD="$CC"
-    SECP_CFLAGS_FOR_BUILD="$SECP_CFLAGS"
     CPPFLAGS_FOR_BUILD="$CPPFLAGS"
+    SECP_CFLAGS_FOR_BUILD="$SECP_CFLAGS"
     CFLAGS_FOR_BUILD="$CFLAGS"
     LDFLAGS_FOR_BUILD="$LDFLAGS"
   else
@@ -378,10 +381,10 @@ if test x"$use_ecmult_static_precomputation" != x"no"; then
     cross_compiling=no
     SAVE_CC="$CC"
     CC="$CC_FOR_BUILD"
-    SAVE_CFLAGS="$CFLAGS"
-    CFLAGS="$CFLAGS_FOR_BUILD"
     SAVE_CPPFLAGS="$CPPFLAGS"
     CPPFLAGS="$CPPFLAGS_FOR_BUILD"
+    SAVE_CFLAGS="$CFLAGS"
+    CFLAGS="$CFLAGS_FOR_BUILD"
     SAVE_LDFLAGS="$LDFLAGS"
     LDFLAGS="$LDFLAGS_FOR_BUILD"
 
@@ -396,14 +399,14 @@ if test x"$use_ecmult_static_precomputation" != x"no"; then
     # Restore the environment
     cross_compiling=$save_cross_compiling
     CC="$SAVE_CC"
-    CFLAGS="$SAVE_CFLAGS"
     CPPFLAGS="$SAVE_CPPFLAGS"
+    CFLAGS="$SAVE_CFLAGS"
     LDFLAGS="$SAVE_LDFLAGS"
 
     if test x"$working_native_cc" = x"no"; then
       AC_MSG_RESULT([no])
       set_precomp=no
-      m4_define([please_set_for_build], [Please set CC_FOR_BUILD, CFLAGS_FOR_BUILD, CPPFLAGS_FOR_BUILD, and/or LDFLAGS_FOR_BUILD.])
+      m4_define([please_set_for_build], [Please set CC_FOR_BUILD, CPPFLAGS_FOR_BUILD, CFLAGS_FOR_BUILD, and/or LDFLAGS_FOR_BUILD.])
       if test x"$use_ecmult_static_precomputation" = x"yes";  then
         AC_MSG_ERROR([native compiler ${CC_FOR_BUILD} does not produce working binaries. please_set_for_build])
       else
@@ -416,9 +419,9 @@ if test x"$use_ecmult_static_precomputation" != x"no"; then
   fi
 
   AC_SUBST(CC_FOR_BUILD)
+  AC_SUBST(CPPFLAGS_FOR_BUILD)
   AC_SUBST(SECP_CFLAGS_FOR_BUILD)
   AC_SUBST(CFLAGS_FOR_BUILD)
-  AC_SUBST(CPPFLAGS_FOR_BUILD)
   AC_SUBST(LDFLAGS_FOR_BUILD)
 else
   set_precomp=no
@@ -531,15 +534,15 @@ fi
 echo
 echo "  valgrind                = $enable_valgrind"
 echo "  CC                      = $CC"
+echo "  CPPFLAGS                = $CPPFLAGS"
 echo "  SECP_CFLAGS             = $SECP_CFLAGS"
 echo "  CFLAGS                  = $CFLAGS"
-echo "  CPPFLAGS                = $CPPFLAGS"
 echo "  LDFLAGS                 = $LDFLAGS"
 echo
 if test x"$set_precomp" = x"yes"; then
 echo "  CC_FOR_BUILD            = $CC_FOR_BUILD"
+echo "  CPPFLAGS_FOR_BUILD      = $CPPFLAGS_FOR_BUILD"
 echo "  SECP_CFLAGS_FOR_BUILD   = $SECP_CFLAGS_FOR_BUILD"
 echo "  CFLAGS_FOR_BUILD        = $CFLAGS_FOR_BUILD"
-echo "  CPPFLAGS_FOR_BUILD      = $CPPFLAGS_FOR_BUILD"
 echo "  LDFLAGS_FOR_BUILD       = $LDFLAGS_FOR_BUILD"
 fi