Flawed PROVIDE_FUZZ_MAIN_FUNCTION test #28563

1. 
   luke-jr commented at 4:00 am on October 3, 2023: member

   The current test uses AX_CHECK_LINK_FLAG which is buggy in multiple ways:

   1. It prints its own “checking” line, which interrupts the main one.
   2. The AX_CHECK_LINK_FLAG macro is used incorrectly, with a null flag to check. We’re actually testing if the linker accepts the code, which is what AC_LINK_IFELSE is for.
   3. It attempts to use/create a cache based on the provided flags, which in this case are blank and $SANITIZER_LDFLAGS.
   4. The generated code for the cache variable is printf "%s\n" "ax_cv_check_ldflags_$SANITIZER_LDFLAGS_" which will access the wrong variable, SANITIZER_LDFLAGS_, typically undefined, and therefore use a generic cache variable of merely ax_cv_check_ldflags_

   I don’t see any real practical harm in this, but it might be a good idea to fix it, especially since any repetition of this pattern would cause the cache to get used incorrectly.

2. 
   maflcko commented at 6:54 pm on February 8, 2024: member

   I don’t see any real practical harm in this

   Let’s move the discussion to #28564

3. maflcko closed this on Feb 8, 2024

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