CC not resolve to correct arch for xtensa espidf arch by default even if explicitly build targetted

[sansmoraxz]

This actually threw me off and made me go on a wild goose chase. So the packages compiled by setting --target to viz xtensa-esp32s3-espidf, compiles rust code for the target arch but not the dependencies built using C via the cc crate.

So, at the linker stage I was facing issues with mismatch arch for rlib.

Managed to workaround this by explicitly setting env var export CROSS_COMPILE="xtensa-esp32s3-elf", but IMO this should be the default behavior, use the target arch's compiler rather than the host's compiler.

To further make this seamless, it should use the resolved binary name from PATH var, and if not found have some sort of autodiscovery (like how Windows MSVC is done), failing which throw some sort of error message that the required compiler was not found, rather than using a wrong compiler

Ref: mlua-rs/mlua#642

[sansmoraxz]

cargo --version --verbose

cargo 1.88.0-nightly (873a06493 2025-05-10) (1.88.0.0)
release: 1.88.0-nightly
commit-hash: 873a0649350c486caf67be772828a4f36bb4734c
commit-date: 2025-05-10
host: x86_64-unknown-linux-gnu
libgit2: 1.9.0 (sys:0.20.0 vendored)
libcurl: 8.12.1-DEV (sys:0.4.80+curl-8.12.1 vendored ssl:OpenSSL/3.4.1)
ssl: OpenSSL 3.4.1 11 Feb 2025
os: Arch Linux Rolling Release [64-bit]

[NobodyXu]

cc-rs/src/lib.rs

Line 2950 in 1f6ffb1

format!("{prefix}-{cc}")

We already try to do that by adding prefix to the compiler, but xtensa-esp32s3-elf doesn't seem to be names that way

[sansmoraxz]

Hmm, it's still gcc related tools, but with target arch prefixes.

Here's how the compilers are stored:

Arch:

ls ~/.espressif/tools/
esp32ulp-elf  esp-rom-elfs  openocd-esp32  riscv32-esp-elf  riscv32-esp-elf-gdb  xtensa-esp-elf  xtensa-esp-elf-gdb
ls ~/.espressif/tools/xtensa-esp-elf/
esp-13.2.0_20240530  esp-15.1.0_20250607

And the compiler related binaries:

ls ~/.espressif/tools/xtensa-esp-elf/esp-15.1.0_20250607/xtensa-esp-elf/bin
xtensa-esp32-elf-addr2line   xtensa-esp32-elf-gprof        xtensa-esp32s2-elf-c++filt     xtensa-esp32s2-elf-objcopy    xtensa-esp32s3-elf-gcc-15.1.0  xtensa-esp32s3-elf-strings  xtensa-esp-elf-gcov-dump
xtensa-esp32-elf-ar          xtensa-esp32-elf-ld           xtensa-esp32s2-elf-cpp         xtensa-esp32s2-elf-objdump    xtensa-esp32s3-elf-gcc-ar      xtensa-esp32s3-elf-strip    xtensa-esp-elf-gcov-tool
xtensa-esp32-elf-as          xtensa-esp32-elf-ld.bfd       xtensa-esp32s2-elf-elfedit     xtensa-esp32s2-elf-ranlib     xtensa-esp32s3-elf-gcc-nm      xtensa-esp-elf-addr2line    xtensa-esp-elf-gprof
xtensa-esp32-elf-c++         xtensa-esp32-elf-lto-dump     xtensa-esp32s2-elf-g++         xtensa-esp32s2-elf-readelf    xtensa-esp32s3-elf-gcc-ranlib  xtensa-esp-elf-ar           xtensa-esp-elf-ld
xtensa-esp32-elf-cc          xtensa-esp32-elf-nm           xtensa-esp32s2-elf-gcc         xtensa-esp32s2-elf-size       xtensa-esp32s3-elf-gcov        xtensa-esp-elf-as           xtensa-esp-elf-ld.bfd
xtensa-esp32-elf-c++filt     xtensa-esp32-elf-objcopy      xtensa-esp32s2-elf-gcc-15.1.0  xtensa-esp32s2-elf-strings    xtensa-esp32s3-elf-gcov-dump   xtensa-esp-elf-c++          xtensa-esp-elf-lto-dump
xtensa-esp32-elf-cpp         xtensa-esp32-elf-objdump      xtensa-esp32s2-elf-gcc-ar      xtensa-esp32s2-elf-strip      xtensa-esp32s3-elf-gcov-tool   xtensa-esp-elf-cc           xtensa-esp-elf-nm
xtensa-esp32-elf-elfedit     xtensa-esp32-elf-ranlib       xtensa-esp32s2-elf-gcc-nm      xtensa-esp32s3-elf-addr2line  xtensa-esp32s3-elf-gprof       xtensa-esp-elf-c++filt      xtensa-esp-elf-objcopy
xtensa-esp32-elf-g++         xtensa-esp32-elf-readelf      xtensa-esp32s2-elf-gcc-ranlib  xtensa-esp32s3-elf-ar         xtensa-esp32s3-elf-ld          xtensa-esp-elf-cpp          xtensa-esp-elf-objdump
xtensa-esp32-elf-gcc         xtensa-esp32-elf-size         xtensa-esp32s2-elf-gcov        xtensa-esp32s3-elf-as         xtensa-esp32s3-elf-ld.bfd      xtensa-esp-elf-elfedit      xtensa-esp-elf-ranlib
xtensa-esp32-elf-gcc-15.1.0  xtensa-esp32-elf-strings      xtensa-esp32s2-elf-gcov-dump   xtensa-esp32s3-elf-c++        xtensa-esp32s3-elf-lto-dump    xtensa-esp-elf-g++          xtensa-esp-elf-readelf
xtensa-esp32-elf-gcc-ar      xtensa-esp32-elf-strip        xtensa-esp32s2-elf-gcov-tool   xtensa-esp32s3-elf-cc         xtensa-esp32s3-elf-nm          xtensa-esp-elf-gcc          xtensa-esp-elf-size
xtensa-esp32-elf-gcc-nm      xtensa-esp32s2-elf-addr2line  xtensa-esp32s2-elf-gprof       xtensa-esp32s3-elf-c++filt    xtensa-esp32s3-elf-objcopy     xtensa-esp-elf-gcc-15.1.0   xtensa-esp-elf-strings
xtensa-esp32-elf-gcc-ranlib  xtensa-esp32s2-elf-ar         xtensa-esp32s2-elf-ld          xtensa-esp32s3-elf-cpp        xtensa-esp32s3-elf-objdump     xtensa-esp-elf-gcc-ar       xtensa-esp-elf-strip
xtensa-esp32-elf-gcov        xtensa-esp32s2-elf-as         xtensa-esp32s2-elf-ld.bfd      xtensa-esp32s3-elf-elfedit    xtensa-esp32s3-elf-ranlib      xtensa-esp-elf-gcc-nm
xtensa-esp32-elf-gcov-dump   xtensa-esp32s2-elf-c++        xtensa-esp32s2-elf-lto-dump    xtensa-esp32s3-elf-g++        xtensa-esp32s3-elf-readelf     xtensa-esp-elf-gcc-ranlib
xtensa-esp32-elf-gcov-tool   xtensa-esp32s2-elf-cc         xtensa-esp32s2-elf-nm          xtensa-esp32s3-elf-gcc        xtensa-esp32s3-elf-size        xtensa-esp-elf-gcov

Debuggers:

ls ~/.espressif/tools/xtensa-esp-elf-gdb/16.2_20250324/xtensa-esp-elf-gdb/bin
xtensa-esp32-elf-gdb    xtensa-esp32s3-elf-gdb   xtensa-esp-elf-gdb-3.11  xtensa-esp-elf-gdb-3.13  xtensa-esp-elf-gdb-3.9        xtensa-esp-elf-gdb-no-python  xtensa-esp-elf-gstack
xtensa-esp32s2-elf-gdb  xtensa-esp-elf-gdb-3.10  xtensa-esp-elf-gdb-3.12  xtensa-esp-elf-gdb-3.8   xtensa-esp-elf-gdb-add-index  xtensa-esp-elf-gprof

[NobodyXu]

Thanks, I would accept a PR to hardcode that for that particular target.

I would like a new function where all these hardcodes (that might come in the future) can be put into.

Sorry I was busy recently and didn't get to reply