clang-9 and wasm32-unknown-unknown

Project Infrastructure LLVM Dev List Archives
1

Hi,
I'm not sure if this is a bug or not, but would appreciate
understanding what's going on and what's the right way to fix it.
Running `clang --target=wasm32-unknown-unknown test.c` on a sample C
file with `include <string.h>` returns: "fatal error: 'string.h' file
not found". but without the target it works just fine.

With some help of @jdoerfert in IRC I found this difference:
`clang test.c -v` returns:

#include <...> search starts here:
 /usr/local/include
 /usr/local/lib/clang/9.0.1/include
 /usr/include
End of search list.

But `clang --target=wasm32-unknown-unknown test.c -v` returns:

#include <...> search starts here:
 /usr/local/lib/clang/9.0.1/include
End of search list.

Why are the other include paths missing? what's the right way to make this work?
FWIW I'm pretty sure it worked to me in the past with older clang versions.

Thanks.
Elichai.

2

My understanding is that wasm32-unknown-unknown does not make assumptions about that layout of the host system and needs to be explicitly configured with a sysroot (with -isysroot). Both wasi-sdk and Emscripten ship with their own sysroots and pass this flag for you.