Re: [PATCH 05/10] meson: Add wasm build in build scripts

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

Cc'ing Pierrick

On 7/4/25 16:45, Kohei Tokunaga wrote:
> has_int128_type is set to false on emscripten as of now to avoid errors by
> libffi. And tests aren't integrated with Wasm execution environment as of
> now so this commit disables tests.
> 
> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
> ---
>   configs/meson/emscripten.txt  |  6 ++++++
>   configure                     |  7 +++++++
>   meson.build                   | 14 ++++++++++----
>   meson_options.txt             |  2 +-
>   scripts/meson-buildoptions.sh |  2 +-
>   5 files changed, 25 insertions(+), 6 deletions(-)
>   create mode 100644 configs/meson/emscripten.txt
> 
> diff --git a/configs/meson/emscripten.txt b/configs/meson/emscripten.txt
> new file mode 100644
> index 0000000000..054b263814
> --- /dev/null
> +++ b/configs/meson/emscripten.txt
> @@ -0,0 +1,6 @@
> +[built-in options]
> +c_args = ['-Wno-unused-command-line-argument','-g','-O3','-pthread']
> +cpp_args = ['-Wno-unused-command-line-argument','-g','-O3','-pthread']
> +objc_args = ['-Wno-unused-command-line-argument','-g','-O3','-pthread']
> +c_link_args = ['-Wno-unused-command-line-argument','-g','-O3','-pthread','-sASYNCIFY=1','-sPROXY_TO_PTHREAD=1','-sFORCE_FILESYSTEM','-sALLOW_TABLE_GROWTH','-sTOTAL_MEMORY=2GB','-sWASM_BIGINT','-sEXPORT_ES6=1','-sASYNCIFY_IMPORTS=ffi_call_js','-sEXPORTED_RUNTIME_METHODS=addFunction,removeFunction,TTY,FS']
> +cpp_link_args = ['-Wno-unused-command-line-argument','-g','-O3','-pthread','-sASYNCIFY=1','-sPROXY_TO_PTHREAD=1','-sFORCE_FILESYSTEM','-sALLOW_TABLE_GROWTH','-sTOTAL_MEMORY=2GB','-sWASM_BIGINT','-sEXPORT_ES6=1','-sASYNCIFY_IMPORTS=ffi_call_js','-sEXPORTED_RUNTIME_METHODS=addFunction,removeFunction,TTY,FS']
> diff --git a/configure b/configure
> index 02f1dd2311..a1fe6e11cd 100755
> --- a/configure
> +++ b/configure
> @@ -360,6 +360,10 @@ elif check_define __NetBSD__; then
>     host_os=netbsd
>   elif check_define __APPLE__; then
>     host_os=darwin
> +elif check_define EMSCRIPTEN ; then
> +  host_os=emscripten
> +  cpu=wasm32
> +  cross_compile="yes"
>   else
>     # This is a fatal error, but don't report it yet, because we
>     # might be going to just print the --help text, or it might
> @@ -526,6 +530,9 @@ case "$cpu" in
>       linux_arch=x86
>       CPU_CFLAGS="-m64"
>       ;;
> +  wasm32)
> +    CPU_CFLAGS="-m32"
> +    ;;
>   esac
>   
>   if test -n "$host_arch" && {
> diff --git a/meson.build b/meson.build
> index 41f68d3806..bcf1e33ddf 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -50,9 +50,9 @@ genh = []
>   qapi_trace_events = []
>   
>   bsd_oses = ['gnu/kfreebsd', 'freebsd', 'netbsd', 'openbsd', 'dragonfly', 'darwin']
> -supported_oses = ['windows', 'freebsd', 'netbsd', 'openbsd', 'darwin', 'sunos', 'linux']
> +supported_oses = ['windows', 'freebsd', 'netbsd', 'openbsd', 'darwin', 'sunos', 'linux', 'emscripten']
>   supported_cpus = ['ppc', 'ppc64', 's390x', 'riscv32', 'riscv64', 'x86', 'x86_64',
> -  'arm', 'aarch64', 'loongarch64', 'mips', 'mips64', 'sparc64']
> +  'arm', 'aarch64', 'loongarch64', 'mips', 'mips64', 'sparc64', 'wasm32']
>   
>   cpu = host_machine.cpu_family()
>   
> @@ -353,6 +353,8 @@ foreach lang : all_languages
>         # endif
>         #endif''')
>       # ok
> +  elif compiler.get_id() == 'emscripten'
> +    # ok
>     else
>       error('You either need GCC v7.4 or Clang v10.0 (or XCode Clang v15.0) to compile QEMU')
>     endif
> @@ -514,6 +516,8 @@ ucontext_probe = '''
>   supported_backends = []
>   if host_os == 'windows'
>     supported_backends += ['windows']
> +elif host_os == 'emscripten'
> +  supported_backends += ['fiber']
>   else
>     if host_os != 'darwin' and cc.links(ucontext_probe)
>       supported_backends += ['ucontext']
> @@ -2962,7 +2966,7 @@ config_host_data.set('CONFIG_ATOMIC64', cc.links('''
>       return 0;
>     }''', args: qemu_isa_flags))
>   
> -has_int128_type = cc.compiles('''
> +has_int128_type = host_os != 'emscripten' and cc.compiles('''
>     __int128_t a;
>     __uint128_t b;
>     int main(void) { b = a; }''')
> @@ -4456,7 +4460,9 @@ subdir('scripts')
>   subdir('tools')
>   subdir('pc-bios')
>   subdir('docs')
> -subdir('tests')
> +if host_os != 'emscripten'
> +  subdir('tests')
> +endif
>   if gtk.found()
>     subdir('po')
>   endif
> diff --git a/meson_options.txt b/meson_options.txt
> index 59d973bca0..6d73aafe91 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -34,7 +34,7 @@ option('fuzzing_engine', type : 'string', value : '',
>   option('trace_file', type: 'string', value: 'trace',
>          description: 'Trace file prefix for simple backend')
>   option('coroutine_backend', type: 'combo',
> -       choices: ['ucontext', 'sigaltstack', 'windows', 'auto'],
> +       choices: ['ucontext', 'sigaltstack', 'windows', 'auto', 'fiber'],
>          value: 'auto', description: 'coroutine backend to use')
>   
>   # Everything else can be set via --enable/--disable-* option
> diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
> index 3e8e00852b..cbba2f248c 100644
> --- a/scripts/meson-buildoptions.sh
> +++ b/scripts/meson-buildoptions.sh
> @@ -80,7 +80,7 @@ meson_options_help() {
>     printf "%s\n" '  --tls-priority=VALUE     Default TLS protocol/cipher priority string'
>     printf "%s\n" '                           [NORMAL]'
>     printf "%s\n" '  --with-coroutine=CHOICE  coroutine backend to use (choices:'
> -  printf "%s\n" '                           auto/sigaltstack/ucontext/windows)'
> +  printf "%s\n" '                           auto/fiber/sigaltstack/ucontext/windows)'
>     printf "%s\n" '  --with-pkgversion=VALUE  use specified string as sub-version of the'
>     printf "%s\n" '                           package'
>     printf "%s\n" '  --with-suffix=VALUE      Suffix for QEMU data/modules/config directories'