ldc-developers/ldc v1.21.0

LDC 1.21.0

on GitHub

(Changes since 1.21.0-beta1 are marked with (new).)

Big news

• Frontend, druntime and Phobos are at version 2.091.1+, incl. new CLI switches -verror-style and -HC, -HCd, -HCf. (#3333, #3399) (new)
• iOS (incl. watchOS and tvOS) support has landed in druntime and Phobos (thanks Jacob!). All unittests are green on iOS/arm64. The prebuilt macOS package includes prebuilt druntime & Phobos libraries for iOS/arm64, for first -mtriple=arm64-apple-ios12.0 cross-compilation experiments. (#3373)
• LLVM for prebuilt packages upgraded to v10.0.0. Android NDK version bumped to r21. (#3307, #3387, #3398) (new)
• Initial support for GCC/GDC-style inline assembly syntax, besides DMD-style inline asm and LDC-specific __asm, enabling to write inline asm that is portable across GDC/LDC and corresponds to the GCC syntax in C. See ldc-developers/druntime#171 for examples wrt. how to transition from __asm to similar GCC-style asm. (#3304)
• Inline assembly diagnostics have been extended by the D source location. (#3339)
• Android:
  • Revamped druntime initialization, fixing related issues for i686/x86_64 targets, enabling the usage of the ld.gold linker (bfd isn't required anymore) as well as getting rid of the D main() requirement. (#3350, #3357, ldc-developers/druntime#178)
  • Reduced size for shared libraries by compiling druntime and Phobos with hidden visibility. (#3377) (new)

Platform support

• Supports LLVM 3.9 - 10.0.

Bug fixes

• Fixed tail calls in thunks, affecting AArch64 (the debug libraries now work) and possibly other architectures. (#3329, #3332)
• Windows: Do not emit any column infos for CodeView by default (like clang) & add -gcolumn-info. (#3102, #3388) (new)
• Windows: Do not leak MSVC-environment-setup into -run child processes. A new LDC_VSDIR_FORCE environment variable can be used to enforce MSVC toolchain setup. (#3340, #3341)
• Windows: Fix memory leak when throwing exceptions in threads. (#3369, ldc-developers/druntime#181)
• Try to use memcmp for (in)equality of non-mutable static arrays and mutable slices. (#3400, #3401) (new)
• ldc.gccbuiltins_*: Lift 256-bit vector limit, adding 174 AVX512 builtins for x86; 512-bit vector aliases have been added to core.simd. (#3405, #3406) (new)

Internals

• core.bitop.{bts,btr,btc} are now CTFE-able. (ldc-developers/druntime#182) (new)
• Do not fallback to host for critical section size of unknown targets. (#3389) (new)
• Linux: Possibility to avoid passing -fuse-ld to cc via -linker=. (#3382) (new)
• WebAssembly: Switch from legacy linked-list ModuleInfo registry to __minfo section. (#3348)
• Windows: Bundled libcurl upgraded to v7.69.1, incl. the option to link it statically. (#3378) (new)
• Windows: Switch to wide wmain C entry point in druntime. (#3351)
• druntime unittests are now compiled with -checkaction=context.

Known issues

• NEW: When building LDC, old LDC 0.17.*/ltsmaster host compilers miscompile LDC ≥ 1.21, leading to potential segfaults of the built LDC. Ltsmaster can still be used to bootstrap a first compiler and then let that compiler compile itself. (#3354)
• Buggy older ld.bfd linker versions may wrongly strip out required symbols, e.g., ModuleInfos (so that e.g. no module ctors/dtors are run). LDC defaults to ld.gold on Linux.
• LDC does not zero the padding area of a real variable. This may lead to wrong results if the padding area is also considered. See #770. Does not apply to real members inside structs etc.