[Windows] libpthread missing exports, so I can not link

[ctaggart]

I posted How do I use a different libstdc++.a with Rust?, but after some more debugging, it looks like libpthread doesn't have any exports. Why doesn't it?

dumpbin /exports "C:\Users\camer\.rustup\toolchains\nightly-x86_64-pc-windows-gnu\lib\rustlib\x86_64-pc-windows-gnu\lib\libpthread.a"

I was expecting it to have exports like other libraries in the directory do:

dumpbin /exports "C:\Users\camer\.rustup\toolchains\nightly-x86_64-pc-windows-gnu\lib\rustlib\x86_64-pc-windows-gnu\lib\libcrypt32.a"

I was expecting it to have the same exports as other libpthread libraries:

dumpbin /exports "C:\Octave\Octave-4.2.1\lib\libpthread.dll.a"

Looking around at the issues here, it looks like it may be related to:

• [Windows] Enable building rustc with "pthreads" flavor of mingw. [Windows] Enable building rustc with "pthreads" flavor of mingw. #40805

[alexcrichton]

cc @vadimcn

[vadimcn]

@ctaggart: that one is a static lib, did you try dumpbin /symbols ...?

[ctaggart]

@vadimcn, that would explain it. dumpbin /symbols does show the functions that the linker complains about. I'm still not sure why I can't link, but I'll now take a closer look at static vs dynamic dependencies with the "-Wl,-Bstatic" and "-Wl,-Bdynamic" options being passed in to see if I can figure out these errors.

[vadimcn]

I'd try setting RUSTFLAGS=-Clink-arg=-v to see what switches gcc gives to ld.