| //! Defines primitive types that match C's type definitions for FFI compatibility. |
| //! |
| //! This module is intentionally standalone to facilitate parsing when retrieving |
| //! core C types. |
| |
| macro_rules! type_alias { |
| { |
| $Docfile:tt, $Alias:ident = $Real:ty; |
| $( $Cfg:tt )* |
| } => { |
| #[doc = include_str!($Docfile)] |
| $( $Cfg )* |
| #[stable(feature = "core_ffi_c", since = "1.64.0")] |
| pub type $Alias = $Real; |
| } |
| } |
| |
| type_alias! { "c_char.md", c_char = c_char_definition::c_char; #[doc(cfg(all()))] } |
| |
| type_alias! { "c_schar.md", c_schar = i8; } |
| type_alias! { "c_uchar.md", c_uchar = u8; } |
| type_alias! { "c_short.md", c_short = i16; } |
| type_alias! { "c_ushort.md", c_ushort = u16; } |
| |
| type_alias! { "c_int.md", c_int = c_int_definition::c_int; #[doc(cfg(all()))] } |
| type_alias! { "c_uint.md", c_uint = c_int_definition::c_uint; #[doc(cfg(all()))] } |
| |
| type_alias! { "c_long.md", c_long = c_long_definition::c_long; #[doc(cfg(all()))] } |
| type_alias! { "c_ulong.md", c_ulong = c_long_definition::c_ulong; #[doc(cfg(all()))] } |
| |
| type_alias! { "c_longlong.md", c_longlong = i64; } |
| type_alias! { "c_ulonglong.md", c_ulonglong = u64; } |
| |
| type_alias! { "c_float.md", c_float = f32; } |
| type_alias! { "c_double.md", c_double = f64; } |
| |
| mod c_char_definition { |
| crate::cfg_select! { |
| // These are the targets on which c_char is unsigned. Usually the |
| // signedness is the same for all target_os values on a given architecture |
| // but there are some exceptions (see isSignedCharDefault() in clang). |
| // aarch64: |
| // Section 10 "Arm C and C++ language mappings" in Procedure Call Standard for the Arm® |
| // 64-bit Architecture (AArch64) says C/C++ char is unsigned byte. |
| // https://github.com/ARM-software/abi-aa/blob/2024Q3/aapcs64/aapcs64.rst#arm-c-and-c-language-mappings |
| // arm: |
| // Section 8 "Arm C and C++ Language Mappings" in Procedure Call Standard for the Arm® |
| // Architecture says C/C++ char is unsigned byte. |
| // https://github.com/ARM-software/abi-aa/blob/2024Q3/aapcs32/aapcs32.rst#arm-c-and-c-language-mappings |
| // csky: |
| // Section 2.1.2 "Primary Data Type" in C-SKY V2 CPU Applications Binary Interface |
| // Standards Manual says ANSI C char is unsigned byte. |
| // https://github.com/c-sky/csky-doc/blob/9f7121f7d40970ba5cc0f15716da033db2bb9d07/C-SKY_V2_CPU_Applications_Binary_Interface_Standards_Manual.pdf |
| // Note: this doesn't seem to match Clang's default (https://github.com/rust-lang/rust/issues/129945). |
| // hexagon: |
| // Section 3.1 "Basic data type" in Qualcomm Hexagon™ Application |
| // Binary Interface User Guide says "By default, the `char` data type is unsigned." |
| // https://docs.qualcomm.com/bundle/publicresource/80-N2040-23_REV_K_Qualcomm_Hexagon_Application_Binary_Interface_User_Guide.pdf |
| // msp430: |
| // Section 2.1 "Basic Types" in MSP430 Embedded Application Binary |
| // Interface says "The char type is unsigned by default". |
| // https://www.ti.com/lit/an/slaa534a/slaa534a.pdf |
| // powerpc/powerpc64: |
| // - PPC32 SysV: "Table 3-1 Scalar Types" in System V Application Binary Interface PowerPC |
| // Processor Supplement says ANSI C char is unsigned byte |
| // https://refspecs.linuxfoundation.org/elf/elfspec_ppc.pdf |
| // - PPC64 ELFv1: Section 3.1.4 "Fundamental Types" in 64-bit PowerPC ELF Application |
| // Binary Interface Supplement 1.9 says ANSI C is unsigned byte |
| // https://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.html#FUND-TYPE |
| // - PPC64 ELFv2: Section 2.1.2.2 "Fundamental Types" in 64-Bit ELF V2 ABI Specification |
| // says char is unsigned byte |
| // https://openpowerfoundation.org/specifications/64bitelfabi/ |
| // - AIX: XL C for AIX Language Reference says "By default, char behaves like an unsigned char." |
| // https://www.ibm.com/docs/en/xl-c-aix/13.1.3?topic=specifiers-character-types |
| // riscv32/riscv64: |
| // C/C++ type representations section in RISC-V Calling Conventions |
| // page in RISC-V ELF psABI Document says "char is unsigned." |
| // https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/draft-20240829-13bfa9f54634cb60d86b9b333e109f077805b4b3/riscv-cc.adoc#cc-type-representations |
| // s390x: |
| // - ELF: "Table 1.1.: Scalar types" in ELF Application Binary Interface s390x Supplement |
| // Version 1.6.1 categorize ISO C char in unsigned integer |
| // https://github.com/IBM/s390x-abi/releases/tag/v1.6.1 |
| // - z/OS: XL C/C++ Language Reference says: "By default, char behaves like an unsigned char." |
| // https://www.ibm.com/docs/en/zos/3.1.0?topic=specifiers-character-types |
| // xtensa: |
| // Section 2.17.1 "Data Types and Alignment" of Xtensa LX Microprocessor Overview handbook |
| // says "`char` type is unsigned by default". |
| // https://loboris.eu/ESP32/Xtensa_lx%20Overview%20handbook.pdf |
| // |
| // On the following operating systems, c_char is signed by default, regardless of architecture. |
| // Darwin (macOS, iOS, etc.): |
| // Apple targets' c_char is signed by default even on arm |
| // https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms#Handle-data-types-and-data-alignment-properly |
| // Windows: |
| // Windows MSVC C++ Language Reference says "Microsoft-specific: Variables of type char |
| // are promoted to int as if from type signed char by default, unless the /J compilation |
| // option is used." |
| // https://learn.microsoft.com/en-us/cpp/cpp/fundamental-types-cpp?view=msvc-170#character-types |
| // Vita: |
| // Chars are signed by default on the Vita, and VITASDK follows that convention. |
| // https://github.com/vitasdk/buildscripts/blob/09c533b771591ecde88864b6acad28ffb688dbd4/patches/gcc/0001-gcc-10.patch#L33-L34 |
| // |
| // L4Re: |
| // The kernel builds with -funsigned-char on all targets (but userspace follows the |
| // architecture defaults). As we only have a target for userspace apps so there are no |
| // special cases for L4Re below. |
| // https://github.com/rust-lang/rust/pull/132975#issuecomment-2484645240 |
| all( |
| not(windows), |
| not(target_vendor = "apple"), |
| not(target_os = "vita"), |
| any( |
| target_arch = "aarch64", |
| target_arch = "arm", |
| target_arch = "csky", |
| target_arch = "hexagon", |
| target_arch = "msp430", |
| target_arch = "powerpc", |
| target_arch = "powerpc64", |
| target_arch = "riscv32", |
| target_arch = "riscv64", |
| target_arch = "s390x", |
| target_arch = "xtensa", |
| ) |
| ) => { |
| pub(super) type c_char = u8; |
| } |
| // On every other target, c_char is signed. |
| _ => { |
| pub(super) type c_char = i8; |
| } |
| } |
| } |
| |
| mod c_long_definition { |
| crate::cfg_select! { |
| any( |
| all(target_pointer_width = "64", not(windows)), |
| // wasm32 Linux ABI uses 64-bit long |
| all(target_arch = "wasm32", target_os = "linux") |
| ) => { |
| pub(super) type c_long = i64; |
| pub(super) type c_ulong = u64; |
| } |
| _ => { |
| // The minimal size of `long` in the C standard is 32 bits |
| pub(super) type c_long = i32; |
| pub(super) type c_ulong = u32; |
| } |
| } |
| } |
| |
| /// Equivalent to C's `size_t` type, from `stddef.h` (or `cstddef` for C++). |
| /// |
| /// This type is currently always [`usize`], however in the future there may be |
| /// platforms where this is not the case. |
| #[unstable(feature = "c_size_t", issue = "88345")] |
| pub type c_size_t = usize; |
| |
| /// Equivalent to C's `ptrdiff_t` type, from `stddef.h` (or `cstddef` for C++). |
| /// |
| /// This type is currently always [`isize`], however in the future there may be |
| /// platforms where this is not the case. |
| #[unstable(feature = "c_size_t", issue = "88345")] |
| pub type c_ptrdiff_t = isize; |
| |
| /// Equivalent to C's `ssize_t` (on POSIX) or `SSIZE_T` (on Windows) type. |
| /// |
| /// This type is currently always [`isize`], however in the future there may be |
| /// platforms where this is not the case. |
| #[unstable(feature = "c_size_t", issue = "88345")] |
| pub type c_ssize_t = isize; |
| |
| mod c_int_definition { |
| crate::cfg_select! { |
| any(target_arch = "avr", target_arch = "msp430") => { |
| pub(super) type c_int = i16; |
| pub(super) type c_uint = u16; |
| } |
| _ => { |
| pub(super) type c_int = i32; |
| pub(super) type c_uint = u32; |
| } |
| } |
| } |
