How do I create a static library in Rust to link with C code in Windows?
c, gcc, rust, windows
Solution
TL;DR: Install a different flavor of GCC
pacman -R local/gcc
pacman -S mingw-w64-i686-gcc
Half-informed guessing follows...
After some help on Rust IRC, it sounds like the issue is that the MSYS2 / MinGW `gcc` is a "stock" compiler, one without special knowledge of MSYS / MinGW / Windows special features.
`mingw-w64-i686-gcc` (or `mingw-w64-x86_64-gcc`) does know about Windows-specific symbols, which libbacktrace, a part of the Rust distribution, requires.
The "correct" GCC build should have the string "Built by MSYS2 project" in the `gcc --version` output.
With that, the full process looks like:
$ rustc --version --verbose
rustc 1.17.0 (56124baa9 2017-04-24)
host: i686-pc-windows-gnu
$ gcc --version
gcc.exe (Rev2, Built by MSYS2 project) 6.3.0
$ rustc --crate-type=staticlib func.rs
note: link against the following native artifacts when linking against this static library
note: the order and any duplication can be significant on some platforms, and so may need to be preserved
note: library: advapi32
note: library: ws2_32
note: library: userenv
note: library: shell32
note: library: gcc_eh
$ gcc -o main main.c func.lib -ladvapi32 -lws2_32 -luserenv -lshell32 -lgcc_eh
$ ./main
4 * 2 = 8
Problem
I have 2 files: func.rs ``` #[no_mangle] pub extern fn double_input(input: i32) -> i32 { input * 2 } ``` main.c ``` #include <stdint.h> #include <stdio.h> extern int32_t double_input(int32_t input); int main() { int input = 4; int output = double_input(input); printf("%d * 2 = %d\n", input, output); return 0; } ``` I want to create static lib in Rust and link the library to main.c. My active toolchain is `stable-i686-pc-windows-gnu`. I'm doing this in cmd: ``` rustc --crate-type=staticlib func.rs ``` But the file func.lib is created, so I do: ``` gcc -o myprog main.c func.lib -lgcc_eh -lshell32 -luserenv -lws2_32 -ladvapi32 ``` But I get an error: ``` undefined reference to __ms_vsnprintf' ``` If I do: ``` rustc --crate-type=staticlib --target=i686-unknown-linux-gnu lib.rs ``` Then libfunc.a is created, but when I do: ``` gcc -o myprog main.c libfunc.a ``` I get an error: ``` main.c:(.text+0x1e): undefined reference to `double_input' ``` What am I doing wrong?