Improve CC_FOR_BUILD detection

This commits simply uses CC as CC_FOR_BUILD and the same for
corresponding flags if we're not cross-compiling. This has a number of
benefits in this common case:
 - It avoids strange cases where very old compilers are used (#768).
 - Flags are consistently set for CC and CC_FOR_BUILD.
 - ./configure is faster.
 - You get compiler x consistently if you set CC=x; we got this wrong
   in CI in the past.

./configure warns if a _FOR_BUILD variable is set but ignored because
we're not cross-compiling.

The change exposed that //-style comments are used in gen_context.c,
which is also fixed by this commit.

This commit also reorganizes code in configure.ac to have a cleaner
separation of sections.
This commit is contained in:
Tim Ruffing
2021-01-02 15:15:21 +01:00
parent 47802a4762
commit 3c15130709
2 changed files with 75 additions and 51 deletions

View File

@@ -4,8 +4,8 @@
* file COPYING or https://www.opensource.org/licenses/mit-license.php.*
***********************************************************************/
// Autotools creates libsecp256k1-config.h, of which ECMULT_GEN_PREC_BITS is needed.
// ifndef guard so downstream users can define their own if they do not use autotools.
/* Autotools creates libsecp256k1-config.h, of which ECMULT_GEN_PREC_BITS is needed.
ifndef guard so downstream users can define their own if they do not use autotools. */
#if !defined(ECMULT_GEN_PREC_BITS)
#include "libsecp256k1-config.h"
#endif