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| author | The Phantom Derpstorm <phdofthehouse@gmail.com> | 2024-06-12 03:16:02 -0400 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-06-12 09:16:02 +0200 |
| commit | 5989450e0061dce8cff89d8acfdd5225c14cd065 (patch) | |
| tree | f27a31bdd90497b029718f283d0702fec58e8477 /clang/docs | |
| parent | b83f8c75e4cccf25abbe4ad76406ba0c382bf336 (diff) | |
| download | llvm-5989450e0061dce8cff89d8acfdd5225c14cd065.zip llvm-5989450e0061dce8cff89d8acfdd5225c14cd065.tar.gz llvm-5989450e0061dce8cff89d8acfdd5225c14cd065.tar.bz2 | |
[clang][Sema, Lex, Parse] Preprocessor embed in C and C++ (and Obj-C and Obj-C++ by-proxy) (#68620)
This commit implements the entirety of the now-accepted [N3017 -
Preprocessor
Embed](https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3017.htm) and
its sister C++ paper [p1967](https://wg21.link/p1967). It implements
everything in the specification, and includes an implementation that
drastically improves the time it takes to embed data in specific
scenarios (the initialization of character type arrays). The mechanisms
used to do this are used under the "as-if" rule, and in general when the
system cannot detect it is initializing an array object in a variable
declaration, will generate EmbedExpr AST node which will be expanded
by AST consumers (CodeGen or constant expression evaluators) or
expand embed directive as a comma expression.
---------
Co-authored-by: Aaron Ballman <aaron@aaronballman.com>
Co-authored-by: cor3ntin <corentinjabot@gmail.com>
Co-authored-by: H. Vetinari <h.vetinari@gmx.com>
Co-authored-by: Podchishchaeva, Mariya <mariya.podchishchaeva@intel.com>
Diffstat (limited to 'clang/docs')
| -rw-r--r-- | clang/docs/LanguageExtensions.rst | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst index a49e412..1b5db38 100644 --- a/clang/docs/LanguageExtensions.rst +++ b/clang/docs/LanguageExtensions.rst @@ -1502,6 +1502,7 @@ Attributes on Structured Bindings __cpp_structured_bindings C+ Designated initializers (N494) C99 C89 Array & element qualification (N2607) C23 C89 Attributes (N2335) C23 C89 +``#embed`` (N3017) C23 C89, C++ ============================================ ================================ ============= ============= Type Trait Primitives @@ -5664,3 +5665,26 @@ Compiling different TUs depending on these flags (including use of ``std::hardware_destructive_interference``) with different compilers, macro definitions, or architecture flags will lead to ODR violations and should be avoided. + +``#embed`` Parameters +===================== + +``clang::offset`` +----------------- +The ``clang::offset`` embed parameter may appear zero or one time in the +embed parameter sequence. Its preprocessor argument clause shall be present and +have the form: + +..code-block: text + + ( constant-expression ) + +and shall be an integer constant expression. The integer constant expression +shall not evaluate to a value less than 0. The token ``defined`` shall not +appear within the constant expression. + +The offset will be used when reading the contents of the embedded resource to +specify the starting offset to begin embedding from. The resources is treated +as being empty if the specified offset is larger than the number of bytes in +the resource. The offset will be applied *before* any ``limit`` parameters are +applied. |