6 commits

Author	SHA1	Message	Date
Daniel Bertalan	cf3c8a216b	CMake: Disable Clang 18+ -Wvla-cxx-extension warning ... This warning warns about variable-length arrays being a non-standard extension to the C++ language. We still have a few instances of VLAs, so let's disable the warning for now. This does not interfere with `-Wvla`, which we use to completely forbid this (potentially dangerous) feature in the Kernel and LibCrypto.	2023-11-05 13:41:13 -07:00
Daniel Bertalan	c0cf6e3744	CMake: Set -fvisibility-inlines-hidden on ELF platforms ... The C++ semantics of `inline` dictate that such functions might be defined in multiple translation units. As with all other functions, they must have the same address in all TUs. Because of this, the compiler emits `inline` functions as weak symbols, which the dynamic linker can then resolve to the same address everywhere. This rule is responsible for a significant overhead at startup, as such lookups happen by name. Namely, 86'000 of the 114'000 by-name symbol lookups when loading LibWeb can be attributed to this. Most of these are only ever defined in a single object, making this even more pointless. As nothing in our code relies on either ELF symbol interposition rules or function address equality, we can use the -fvisibility-inlines-hidden escape hatch, which causes this rule to be disregarded. As the symbols are now hidden, no load-time symbol lookup is needed. This flag is used without issues in other large C++ codebases like Chromium and LLVM. Some relevant light reading, suggested by Nico: - https://ridiculousfish.com/blog/posts/i-didnt-order-that-so-why-is-it-on-my-bill-episode-1.html - https://www.cs.dartmouth.edu/~sergey/cs258/ABI/UlrichDrepper-How-To-Write-Shared-Libraries.pdf - https://blog.llvm.org/2018/11/30-faster-windows-builds-with-clang-cl_14.html - https://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Dialect-Options.html#index-fvisibility-inlines-hidden	2023-08-12 05:14:20 +02:00
Daniel Bertalan	00b4976f2c	Everywhere: Make Lagom build with GCC 13 ... GCC 13 was released on 2023-04-26. This commit fixes Lagom build errors when using an updated host toolchain: - Adds a workaround for a bug in constraint handling, which made LibJS fail to compile: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109683 - Silences the new `-Wdangling-reference` diagnostic globally. It produces multiple false positives with no clear way to silence them without `#pragmas`. - Silences `-Wself-move` in `RefPtr` tests as GCC 13 adds this previously Clang-exclusive warning.	2023-05-02 07:03:57 -04:00
Nico Weber	8f988b7bae	Meta: Move more common flags to common_compile_options.cmake ... For the most part no behavior change, except that we now pass -Wno-implicit-const-int-float-conversion and -Wno-literal-suffix only to clang and gcc each in both lagom and serenity builds, while we previously passed them to both in lagom builds (and passed them to one each in serenity builds). The former is a clang flag, the latter a gcc flag, but since we also use -Wno-unknown-warning-option it doesn't really matter.	2023-04-18 10:05:49 +02:00
Nico Weber	4aaefeb1d5	Meta: Move some flags to common_compile_options.cmake ... No behavior change.	2023-04-17 00:52:21 +02:00
Linus Groh	ee721978f6	Meta: Move compiler flags into standalone CMake files ... This way we can have all of them in a single place, similar to how we structure options added via the serenity_option() macro.	2022-05-14 17:53:06 +02:00