Autoconf: Remove 'deeper' checks for AC_CHECK_FUNCS#13830
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Kangie wants to merge 1 commit intocurl:masterfrom
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Autoconf: Remove 'deeper' checks for AC_CHECK_FUNCS#13830Kangie wants to merge 1 commit intocurl:masterfrom
AC_CHECK_FUNCS#13830Kangie wants to merge 1 commit intocurl:masterfrom
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Autoconf check: Note how it fakes out the compiler, because what it is actually interested in is "does this symbol exist". The "deeper" check: -Werror=implicit-function-declarations actually comes from curl-compilers.m4 (it is also in my CFLAGS, so it appears twice). A build system that wants to check for symbols without using the "fake out the prototype" trick requires you supply the header you claim it should exist in; curl isn't providing any headers, which means the check is erroneous as it cannot be used to "check deeper". |
The net effect of the deeper checks is to raise implicit function decls on modern compilers. These checks appear to have been added ~20 years ago, relating to an unverifiable claim about HP-UX. Autoconf support for the platform has grown in leaps and bounds since. It didn't cause a real problem here, but when investigating a FP this came up. No evidence has been identified that this was actually broken in the past, and there is no evidence that this is necessary now. `-Werror=implicit-function-declarations` is enabled for both checks; without a working prototype they will both fail regardless. In the second case there will in fact never be a working prototype and therefore it will always fail unconditionally. `AC_CHECK_FUNCS` does effectively the same thing as the removed checks, except it actually defines a dummy prototype to see if it links. If `AC_CHECK_FUNCS` is broken on a given platform we have bigger problems than trying to build cURL. This should also be faster. Bug: https://bugs.gentoo.org/932827 Reviewed-By: Eli Schwartz <eschwartz93@gmail.com>
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thanks! |
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The net effect of the deeper checks is to raise implicit function decls on modern compilers.
These checks appear to have been added ~20 years ago, relating to an unverifiable claim about HP-UX. Autoconf support for the platform has grown in leaps and bounds since.
It didn't cause a real problem here, but when investigating a FP this came up. No evidence has been identified that this was actually broken in the past, and there is no evidence that this is necessary now.
-Werror=implicit-function-declarationsis enabled for both checks; without a working prototype they will both fail regardless. In the second case there will in fact never be a working prototype and therefore it will always fail unconditionally.AC_CHECK_FUNCSdoes effectively the same thing as the removed checks, except it actually defines a dummy prototype to see if it links.If
AC_CHECK_FUNCSis broken on a given platform we have bigger problems than trying to build cURL. This should also be faster.CC @thesamesam @eli-schwartz
Bug: https://bugs.gentoo.org/932827