4a9b204920
Christoph Reiter reported on the Git for Windows issue tracker[1], that mingw_strftime() imports strftime() from ucrtbase.dll with the wrong calling convention. It should be __cdecl instead of WINAPI, which we always use in DECLARE_PROC_ADDR(). The MSYS2 project encountered cmake sefaults on x86 Windows caused by the same issue in the cmake source. [2] There are no known git crashes that where caused by this, yet, but we should try to prevent them. We import two other non-WINAPI functions via DECLARE_PROC_ADDR(), too. * NtSetSystemInformation() (NTAPI) * GetUserNameExW() (SEC_ENTRY) NTAPI, SEC_ENTRY and WINAPI are all ususally defined as __stdcall, but there are circumstances where they're defined differently. Teach DECLARE_PROC_ADDR() about calling conventions and be explicit about when we want to use which calling convention. Import winnt.h for the definition of NTAPI and sspi.h for SEC_ENTRY near their respective only users. [1] https://github.com/git-for-windows/git/issues/3560 [2] https://github.com/msys2/MINGW-packages/issues/10152 Reported-By: Christoph Reiter <reiter.christoph@gmail.com> Signed-off-by: Matthias Aßhauer <mha1993@live.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
62 lines
1.7 KiB
C
62 lines
1.7 KiB
C
#ifndef LAZYLOAD_H
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#define LAZYLOAD_H
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/*
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* A pair of macros to simplify loading of DLL functions. Example:
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*
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* DECLARE_PROC_ADDR(kernel32.dll, BOOL, WINAPI, CreateHardLinkW,
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* LPCWSTR, LPCWSTR, LPSECURITY_ATTRIBUTES);
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*
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* if (!INIT_PROC_ADDR(CreateHardLinkW))
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* return error("Could not find CreateHardLinkW() function";
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*
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* if (!CreateHardLinkW(source, target, NULL))
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* return error("could not create hardlink from %S to %S",
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* source, target);
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*/
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typedef void (*FARVOIDPROC)(void);
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struct proc_addr {
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const char *const dll;
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const char *const function;
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FARVOIDPROC pfunction;
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unsigned initialized : 1;
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};
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/* Declares a function to be loaded dynamically from a DLL. */
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#define DECLARE_PROC_ADDR(dll, rettype, convention, function, ...) \
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static struct proc_addr proc_addr_##function = \
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{ #dll, #function, NULL, 0 }; \
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typedef rettype (convention *proc_type_##function)(__VA_ARGS__); \
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static proc_type_##function function
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/*
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* Loads a function from a DLL (once-only).
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* Returns non-NULL function pointer on success.
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* Returns NULL + errno == ENOSYS on failure.
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* This function is not thread-safe.
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*/
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#define INIT_PROC_ADDR(function) \
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(function = (proc_type_##function)get_proc_addr(&proc_addr_##function))
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static inline FARVOIDPROC get_proc_addr(struct proc_addr *proc)
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{
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/* only do this once */
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if (!proc->initialized) {
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HANDLE hnd;
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proc->initialized = 1;
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hnd = LoadLibraryExA(proc->dll, NULL,
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LOAD_LIBRARY_SEARCH_SYSTEM32);
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if (hnd)
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proc->pfunction = (FARVOIDPROC)GetProcAddress(hnd,
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proc->function);
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}
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/* set ENOSYS if DLL or function was not found */
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if (!proc->pfunction)
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errno = ENOSYS;
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return proc->pfunction;
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}
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#endif
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