lib: fix function pointers to please UndefinedBehaviorSanitizer - #15289
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Make sure we use functions with the correct prototype. Closes #15289
It makes the callbacks get different signnatures when used from within libcurl vs outside of it by libcurl-using applications (such as the libtests) and this triggers UndefinedBehaviorSanitizer errors. Closes #15289
Make test applications use the correct prototypes for callbacks. Closes #15289
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Make sure we use functions with the correct prototype. Closes curl#15289
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It makes the callbacks get different signnatures when used from within libcurl vs outside of it by libcurl-using applications (such as the libtests) and this triggers UndefinedBehaviorSanitizer errors. Closes curl#15289
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Make test applications use the correct prototypes for callbacks. Closes curl#15289
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Aliasing everything to void has the downside of losing strict type checking. Also it breaks C++ code that defines CURL_STRICTER and contains references to these types. I think it is better to keep struct typedefs in CURL_STRICTER and build everything within curl source tree with it. This will make ubsan happy and API users may still use void aliases on platforms whose ABIs permit it. |
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Use plain typecasts instead to make it more obvious what the code does.
The UndefinedBehaviorSanitizer (ubsan) now errors if a callback pointer is used to a call a function with ever so slight difference in signature. This is annoying because it means that we can no longer use our long established practice of using a different typedef for several handles when building the library vs when using it. We used to have a plain struct pointer for libcurl builds and a
void *for that name when the header is used for applications.