LLVM 19 + setjmp/longjmp doc

[yamt]

this is a draft because:

• llvm 19 has not been released yet
• contain another PR Disable tests/benchmarks for libcxx #476
• the necessary wasi-libc changes have not been landed yet
  • fix shared library build with llvm-19 wasi-libc#526
  • Exclude setjmp runtime from LTO wasi-libc#529

[yamt]

currently broken. see WebAssembly/wasi-libc#529

[yamt]

fixed

[yamt]

windows failure needs an investigation.
maybe a regression in WebAssembly/wasi-libc#526 ?

2024-08-23T07:45:02.3027061Z C:/wasi-sdk/install/bin/clang.exe -fdebug-prefix-map=D:/a/wasi-sdk/wasi-sdk=wasisdk://v24.8g43219b2e8914 -resource-dir C:/wasi-sdk/sysroot/install/wasi-resource-dir -O2 -g -DNDEBUG --target=wasm32-wasi -fno-trapping-math -Wall -Wextra -Werror -Wno-null-pointer-arithmetic -Wno-unused-parameter -Wno-sign-compare -Wno-unused-variable -Wno-unused-function -Wno-ignored-attributes -Wno-missing-braces -Wno-ignored-pragmas -Wno-unused-but-set-variable -Wno-unknown-warning-option -mthread-model single -isystem "C:/wasi-sdk/sysroot/install/share/wasi-sysroot/include/wasm32-wasi" -nodefaultlibs -shared --sysroot=C:/wasi-sdk/sysroot/install/share/wasi-sysroot \
2024-08-23T07:45:02.3098443Z -o C:/wasi-sdk/sysroot/install/share/wasi-sysroot/lib/wasm32-wasi/libc.so -Wl,--whole-archive build/wasm32-wasi/libc.so.a -Wl,--no-whole-archive C:/wasi-sdk/sysroot/install/wasi-resource-dir\lib\wasi\libclang_rt.builtins-wasm32.a \
2024-08-23T07:45:02.3150232Z -Wl,--allow-undefined-file=linker-provided-symbols.txt
2024-08-23T07:45:02.3227562Z # Collect symbol information.
2024-08-23T07:45:02.3273237Z # silently dropping the tail.
2024-08-23T07:45:02.3477724Z #
2024-08-23T07:45:02.3511021Z C:/wasi-sdk/install/bin/llvm-ar.exe crs build/wasm32-wasi/libsetjmp.so.a 
2024-08-23T07:45:02.3615937Z clang: error: no such file or directory: 'C:/wasi-sdk/sysroot/install/wasi-resource-dirlibwasilibclang_rt.builtins-wasm32.a'
2024-08-23T07:45:02.4196867Z make: *** [Makefile:624: C:/wasi-sdk/sysroot/install/share/wasi-sysroot/lib/wasm32-wasi/libc.so] Error 1

[yamt]

windows failure needs an investigation. maybe a regression in WebAssembly/wasi-libc#526 ?

2024-08-23T07:45:02.3027061Z C:/wasi-sdk/install/bin/clang.exe -fdebug-prefix-map=D:/a/wasi-sdk/wasi-sdk=wasisdk://v24.8g43219b2e8914 -resource-dir C:/wasi-sdk/sysroot/install/wasi-resource-dir -O2 -g -DNDEBUG --target=wasm32-wasi -fno-trapping-math -Wall -Wextra -Werror -Wno-null-pointer-arithmetic -Wno-unused-parameter -Wno-sign-compare -Wno-unused-variable -Wno-unused-function -Wno-ignored-attributes -Wno-missing-braces -Wno-ignored-pragmas -Wno-unused-but-set-variable -Wno-unknown-warning-option -mthread-model single -isystem "C:/wasi-sdk/sysroot/install/share/wasi-sysroot/include/wasm32-wasi" -nodefaultlibs -shared --sysroot=C:/wasi-sdk/sysroot/install/share/wasi-sysroot \
2024-08-23T07:45:02.3098443Z -o C:/wasi-sdk/sysroot/install/share/wasi-sysroot/lib/wasm32-wasi/libc.so -Wl,--whole-archive build/wasm32-wasi/libc.so.a -Wl,--no-whole-archive C:/wasi-sdk/sysroot/install/wasi-resource-dir\lib\wasi\libclang_rt.builtins-wasm32.a \
2024-08-23T07:45:02.3150232Z -Wl,--allow-undefined-file=linker-provided-symbols.txt
2024-08-23T07:45:02.3227562Z # Collect symbol information.
2024-08-23T07:45:02.3273237Z # silently dropping the tail.
2024-08-23T07:45:02.3477724Z #
2024-08-23T07:45:02.3511021Z C:/wasi-sdk/install/bin/llvm-ar.exe crs build/wasm32-wasi/libsetjmp.so.a 
2024-08-23T07:45:02.3615937Z clang: error: no such file or directory: 'C:/wasi-sdk/sysroot/install/wasi-resource-dirlibwasilibclang_rt.builtins-wasm32.a'
2024-08-23T07:45:02.4196867Z make: *** [Makefile:624: C:/wasi-sdk/sysroot/install/share/wasi-sysroot/lib/wasm32-wasi/libc.so] Error 1

fixed in WebAssembly/wasi-libc#526

[alexcrichton]

Changes here look good to me and with LLVM 19 being release we likely want to do a release of wasi-sdk in the near future, so I'm going to merge this.