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Differential D41073

Wasm: add support in libcxx
ClosedPublic

Authored by ncw on Dec 11 2017, 10:12 AM.

Details

Reviewers
mclow.lists
sunfish
EricWF
sbc100
Commits
rG5029d676f827: [libcxx] Add WebAssembly support
rCXX320925: [libcxx] Add WebAssembly support
rL320925: [libcxx] Add WebAssembly support
Summary

It turns out that this is the only change required in libcxx for it to compile with the new wasm32-unknown-unknown-wasm target recently added to Clang.

I haven't done much testing of whether libc++ works with Wasm, but committing the compile fix is at least a start.

Adding Marshall Clow and Dan Gohman as reviewers since they landed the last Emscripten-related changes in libcxx.

Diff Detail

Repository
rCXX libc++

Event Timeline

ncw created this revision.Dec 11 2017, 10:12 AM
Herald added a reviewer: EricWF. · View Herald TranscriptDec 11 2017, 10:12 AM
Herald added subscribers: cfe-commits, aheejin, jfb. · View Herald Transcript
sunfish accepted this revision.Dec 11 2017, 11:31 AM

Yes, wasm has its own object format, so this change makes sense.

This revision is now accepted and ready to land.Dec 11 2017, 11:31 AM
sbc100 added a subscriber: sbc100.Dec 13 2017, 12:05 PM

Do you want to land this dan? Or I can if you prefer.

sunfish added a comment.Dec 13 2017, 12:42 PM

Either way. I won't be able to get to it until next week, so feel free to land it earlier.

ncw updated this revision to Diff 127242.Dec 16 2017, 7:06 AM

Although Dan has already reviewed, I've sneakily added in another change here to help compilation against Musl.

Musl is Linux-only, or rather, provides the linux ABI. For Wasm, __linux isn't defined but if we're using Musl then we can provide ELAST and get rid of the associated warnings. Musl is definitely wedded to the 4096 errno limit that's part of the Linux ABI, so I believe this change is safe.

Herald added a subscriber: krytarowski. · View Herald TranscriptDec 16 2017, 7:06 AM
sbc100 accepted this revision.Dec 16 2017, 10:54 AM
Closed by commit rL320925: [libcxx] Add WebAssembly support (authored by sbc). · Explain WhyDec 16 2017, 11:00 AM
This revision was automatically updated to reflect the committed changes.

Revision Contents

PathSize
include/
2 lines
src/
include/
2 lines

Diff 127242

include/__config

Show All 39 Lines
#endif #endif
#if defined(__ELF__) #if defined(__ELF__)
#define _LIBCPP_OBJECT_FORMAT_ELF 1 #define _LIBCPP_OBJECT_FORMAT_ELF 1
#elif defined(__MACH__) #elif defined(__MACH__)
#define _LIBCPP_OBJECT_FORMAT_MACHO 1 #define _LIBCPP_OBJECT_FORMAT_MACHO 1
#elif defined(_WIN32) #elif defined(_WIN32)
#define _LIBCPP_OBJECT_FORMAT_COFF 1 #define _LIBCPP_OBJECT_FORMAT_COFF 1
#elif defined(__wasm__)
#define _LIBCPP_OBJECT_FORMAT_WASM 1
#else #else
#error Unknown object file format #error Unknown object file format
#endif #endif
#if defined(_LIBCPP_ABI_UNSTABLE) || _LIBCPP_ABI_VERSION >= 2 #if defined(_LIBCPP_ABI_UNSTABLE) || _LIBCPP_ABI_VERSION >= 2
// Change short string representation so that string data starts at offset 0, // Change short string representation so that string data starts at offset 0,
// improving its alignment in some cases. // improving its alignment in some cases.
#define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT #define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
▲ Show 20 Lines • Show All 991 Lines • Show Last 20 Lines

src/include/config_elast.h

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#endif #endif
#if defined(ELAST) #if defined(ELAST)
#define _LIBCPP_ELAST ELAST #define _LIBCPP_ELAST ELAST
#elif defined(_NEWLIB_VERSION) #elif defined(_NEWLIB_VERSION)
#define _LIBCPP_ELAST __ELASTERROR #define _LIBCPP_ELAST __ELASTERROR
#elif defined(__Fuchsia__) #elif defined(__Fuchsia__)
// No _LIBCPP_ELAST needed on Fuchsia // No _LIBCPP_ELAST needed on Fuchsia
#elif defined(__linux__) #elif defined(__linux__) || defined(_LIBCPP_HAS_MUSL_LIBC)
#define _LIBCPP_ELAST 4095 #define _LIBCPP_ELAST 4095
#elif defined(__APPLE__) #elif defined(__APPLE__)
// No _LIBCPP_ELAST needed on Apple // No _LIBCPP_ELAST needed on Apple
#elif defined(__sun__) #elif defined(__sun__)
#define _LIBCPP_ELAST ESTALE #define _LIBCPP_ELAST ESTALE
#elif defined(_LIBCPP_MSVCRT) #elif defined(_LIBCPP_MSVCRT)
#define _LIBCPP_ELAST (_sys_nerr - 1) #define _LIBCPP_ELAST (_sys_nerr - 1)
#else #else
// Warn here so that the person doing the libcxx port has an easier time: // Warn here so that the person doing the libcxx port has an easier time:
#warning ELAST for this platform not yet implemented #warning ELAST for this platform not yet implemented
#endif #endif
#endif // _LIBCPP_CONFIG_ELAST #endif // _LIBCPP_CONFIG_ELAST