The sysconf function is only available in rtp mode on vxworks. In kernel mode, it is not even declared, but the feature test macro in the testsuite doesn't notice its absence because it's a link test, and vxworks kernel mode uses partial linking.
This patch introduces an alternate test on vxworks targets to check for a declaration and for an often-used sysconf parameter. Bootstrapped on x86_64-linux-gnu. Also tested on ppc- and x86-vx7r2 with gcc-12. for gcc/testsuite/ChangeLog * lib/target-supports.exp (check_effective_target_sysconf): Check for declaration and _SC_PAGESIZE on vxworks. --- gcc/testsuite/lib/target-supports.exp | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp index bd9f432e4a761..263ef35a2e4df 100644 --- a/gcc/testsuite/lib/target-supports.exp +++ b/gcc/testsuite/lib/target-supports.exp @@ -1146,6 +1146,17 @@ proc check_effective_target_mmap {} { # Return 1 if the target supports sysconf, 0 otherwise. proc check_effective_target_sysconf {} { + # VxWorks has sysconf in rtp mode only, but our way to test can't + # tell kernel mode doesn't, as we're doing partial links for + # kernel modules. We can tell by checking for a declaration, or + # for some sysconf parm, because configurations that don't offer + # sysconf don't have either. + if { [istarget *-*-vxworks*] } { + return [check_no_compiler_messages sysconfdecl assembly { + #include <unistd.h> + int f() { return sysconf(_SC_PAGESIZE); } + }]; + } return [check_function_available "sysconf"] } -- Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/ Free Software Activist GNU Toolchain Engineer Disinformation flourishes because many people care deeply about injustice but very few check the facts. Ask me about <https://stallmansupport.org>