configure: add -std=c99 conditionally (#45739)
Many users seem to try to override the default CC and/or CFLAGS without
knowing the effect of what they are doing. Our build configuration needs
a confirming C99 compiler, which may require a specific option to select
the language version. This commit adds a dynamic test that makes sure
the compiler is invoked with appropriate options.
yash/trunk/configure (diff)| @@ -395,7 +395,7 @@ | ||
| 395 | 395 | # define options for debugging |
| 396 | 396 | if ${debug} |
| 397 | 397 | then |
| 398 | - cc="${CC-gcc -std=c99}" | |
| 398 | + cc="${CC-gcc}" | |
| 399 | 399 | cflags="${CFLAGS--pedantic -MMD -Wall -Wextra -O1 -fno-inline -ggdb}" |
| 400 | 400 | else |
| 401 | 401 | defconfigh "NDEBUG" |
| @@ -413,12 +413,12 @@ | ||
| 413 | 413 | checked "yes" |
| 414 | 414 | elif |
| 415 | 415 | [ x"${cc}" = x"c99" ] && [ x"${CC+set}" != x"set" ] && ( |
| 416 | - cc='gcc -std=c99' | |
| 416 | + cc='gcc' | |
| 417 | 417 | trymake && tryexec |
| 418 | 418 | ) |
| 419 | 419 | then |
| 420 | - checked "yes (using gcc -std=c99)" | |
| 421 | - cc='gcc -std=c99' | |
| 420 | + checked "yes (using gcc)" | |
| 421 | + cc='gcc' | |
| 422 | 422 | else |
| 423 | 423 | checked "no" |
| 424 | 424 | printf 'Compiler "%s" not found or not working.\n' "${CC-${cc}}" >&2 |
| @@ -447,6 +447,36 @@ | ||
| 447 | 447 | unset savecflags |
| 448 | 448 | fi |
| 449 | 449 | |
| 450 | +# find compiler option for C99 support | |
| 451 | +checking 'additional option to compile C99 code' | |
| 452 | +cat >"${tempsrc}" <<END | |
| 453 | +int main(int argc, char **argv) { | |
| 454 | +if (argc == 0) return 0; | |
| 455 | +int vla[argc]; | |
| 456 | +vla[0] = 42; | |
| 457 | +// one-line comment | |
| 458 | +struct s { int v; } i = { .v = argv[0][0] }; | |
| 459 | +return vla[0] + i.v; | |
| 460 | +} | |
| 461 | +END | |
| 462 | +if | |
| 463 | + trycompile | |
| 464 | +then | |
| 465 | + checked "none needed" | |
| 466 | +elif | |
| 467 | + [ x"${CFLAGS+set}" != x"set" ] && | |
| 468 | + cflags="${cflags} -std=c99" && | |
| 469 | + trycompile | |
| 470 | +then | |
| 471 | + checked "with -std=c99" | |
| 472 | +else | |
| 473 | + checked "failed" | |
| 474 | + printf 'Compiler "%s" does not seem to support C99.\n' "${CC-${cc}}" >&2 | |
| 475 | + printf 'The compiler was tested with these options: %s\n' \ | |
| 476 | + "${CFLAGS-${cflags}} ${CADDS-${null}}" >&2 | |
| 477 | + fail | |
| 478 | +fi | |
| 479 | + | |
| 450 | 480 | # check if make supports include statements |
| 451 | 481 | checking 'whether make supports include statements' |
| 452 | 482 | if |
magicant