MinGW delay load issue

Description

This repository provides a sample to replicate the MinGW delay loading issue.

So far, this issue has been found to happen when trying to link with the wininet, virtdisk, uxtheme libraries. The use of InternetCrackUrlA() from wininet is only provided here as an example, as many more calls and DLLs are affected.

An initial discussion of the issue, on the MinGW mailing list, can be found here.

Workarounds

Two "workarounds" have been found to alleviate the issue:

1. Redefining DECLSPEC_IMPORT to use __attribute__((visibility("hidden"))) instead of __declspec (dllimport). However, this kind of workaround is problematic as, for instance, MinGW's windows.h header doest itself include more headers that use DECLSPEC_IMPORT, which mean redefining the macro before the relevant header inclusion is tricky.

2. Adding explicit references to the symbols that the linker appears to ignore (in this example _InternetCrackUrlA@16) so that they aren't discarded. Likewise, this workaround is problematic, as, even outside of having to identify all the problematic function calls, one must make sure these additional intrinsic function calls are referenced by the application or added as -u parameters when invoking ld, and since the decorations are not the same for 32 and 64 bit, one cannot just use a single common 32 + 64 bit implementation...

Testing

1. Clone https://github.com/pbatard/delayload.git (this repository)
2. From a MinGW32 (32-bit) prompt, issue make.
3. Run ./delayload.exe and observe the crash.
4. To test with the workarounds, issue make clean and then either make WORKAROUND1 or make WORKAROUND2.