[llvm-commits] [PATCH] fix illegal impicit cast from const void* to void*

[Stephen Canon]

On Mar 3, 2012, at 5:56 PM, Joerg Sonnenberger <joerg at britannica.bec.de> wrote:
> On Sat, Mar 03, 2012 at 11:14:33PM +0100, John Spencer wrote:
>> more context:
>> void* DynamicLibrary::SearchForAddressOfSymbol(const char
>> *symbolName) calls the macro
>> 
>> EXPLICIT_SYMBOL
>> 
>> to return a (void*) pointer to a FILE* from a named argument which
>> is either stderr, stdin, or stdout.
>> 
>> the musl libc defines these symbols as const FILE* (which is
>> perfectly legal), so the implicit cast to void* fails.
> 
> Is it really legal? stdin and friends are supposed to be passed to
> functions taking FILE * as argument, so it would force const violations
> all the time.

C11, 7.21.1 says:

>          stderr
>          stdin
>          stdout
> 
> which are expressions of type ‘‘pointer to FILE’’ that point to the FILE objects associated, respectively, with the standard error, input, and output streams.

so that would not seem to be allowed by the standard.

- steve