Struct bindgen::Builder[][src]

pub struct Builder { /* fields omitted */ }
Expand description

Configure and generate Rust bindings for a C/C++ header.

This is the main entry point to the library.

use bindgen::builder;

// Configure and generate bindings.
let bindings = builder().header("path/to/input/header")
    .allowlist_type("SomeCoolClass")
    .allowlist_function("do_some_cool_thing")
    .generate()?;

// Write the generated bindings to an output file.
bindings.write_to_file("path/to/output.rs")?;

Enums

Bindgen can map C/C++ enums into Rust in different ways. The way bindgen maps enums depends on the pattern passed to several methods:

  1. constified_enum_module()
  2. bitfield_enum()
  3. newtype_enum()
  4. rustified_enum()

For each C enum, bindgen tries to match the pattern in the following order:

  1. Constified enum module
  2. Bitfield enum
  3. Newtype enum
  4. Rustified enum

If none of the above patterns match, then bindgen will generate a set of Rust constants.

Clang arguments

Extra arguments can be passed to with clang:

  1. clang_arg(): takes a single argument
  2. clang_args(): takes an iterator of arguments
  3. BINDGEN_EXTRA_CLANG_ARGS environment variable: whitespace separate environment variable of arguments

Clang arguments specific to your crate should be added via the clang_arg()/clang_args() methods.

End-users of the crate may need to set the BINDGEN_EXTRA_CLANG_ARGS environment variable to add additional arguments. For example, to build against a different sysroot a user could set BINDGEN_EXTRA_CLANG_ARGS to --sysroot=/path/to/sysroot.

Implementations

Generates the command line flags use for creating Builder.

Add an input C/C++ header to generate bindings for.

This can be used to generate bindings to a single header:

let bindings = bindgen::Builder::default()
    .header("input.h")
    .generate()
    .unwrap();

Or you can invoke it multiple times to generate bindings to multiple headers:

let bindings = bindgen::Builder::default()
    .header("first.h")
    .header("second.h")
    .header("third.h")
    .generate()
    .unwrap();

Add a depfile output which will be written alongside the generated bindings.

Add contents as an input C/C++ header named name.

The file name will be added to the clang arguments.

Specify the rust target

The default is the latest stable Rust version

Disable support for native Rust unions, if supported.

Disable insertion of bindgen’s version identifier into generated bindings.

Set the output graphviz file.

Whether the generated bindings should contain documentation comments (docstrings) or not. This is set to true by default.

Note that clang by default excludes comments from system headers, pass -fretain-comments-from-system-headers as clang_arg to include them. It can also be told to process all comments (not just documentation ones) using the -fparse-all-comments flag. See slides on clang comment parsing for background and examples.

Whether to allowlist recursively or not. Defaults to true.

Given that we have explicitly allowlisted the “initiate_dance_party” function in this C header:

typedef struct MoonBoots {
    int bouncy_level;
} MoonBoots;

void initiate_dance_party(MoonBoots* boots);

We would normally generate bindings to both the initiate_dance_party function and the MoonBoots struct that it transitively references. By configuring with allowlist_recursively(false), bindgen will not emit bindings for anything except the explicitly allowlisted items, and there would be no emitted struct definition for MoonBoots. However, the initiate_dance_party function would still reference MoonBoots!

Disabling this feature will almost certainly cause bindgen to emit bindings that will not compile! If you disable this feature, then it is your responsibility to provide definitions for every type that is referenced from an explicitly allowlisted item. One way to provide the definitions is by using the Builder::raw_line method, another would be to define them in Rust and then include!(...) the bindings immediately afterwards.

👎 Deprecated:

Use allowlist_recursively instead

Deprecated alias for allowlist_recursively.

Generate #[macro_use] extern crate objc; instead of use objc; in the prologue of the files generated from objective-c files

Generate proper block signatures instead of void pointers.

Generate #[macro_use] extern crate block; instead of use block; in the prologue of the files generated from apple block files

Whether to use the clang-provided name mangling. This is true by default and probably needed for C++ features.

However, some old libclang versions seem to return incorrect results in some cases for non-mangled functions, see 1, so we allow disabling it.

👎 Deprecated:

Use blocklist_type instead

Hide the given type from the generated bindings. Regular expressions are supported.

👎 Deprecated:

Use blocklist_type instead

Hide the given type from the generated bindings. Regular expressions are supported.

Hide the given type from the generated bindings. Regular expressions are supported.

To blocklist types prefixed with “mylib” use "mylib_.*". For more complicated expressions check regex docs

👎 Deprecated:

Use blocklist_function instead

Hide the given function from the generated bindings. Regular expressions are supported.

Hide the given function from the generated bindings. Regular expressions are supported.

To blocklist functions prefixed with “mylib” use "mylib_.*". For more complicated expressions check regex docs

👎 Deprecated:

Use blocklist_item instead

Hide the given item from the generated bindings, regardless of whether it’s a type, function, module, etc. Regular expressions are supported.

Hide the given item from the generated bindings, regardless of whether it’s a type, function, module, etc. Regular expressions are supported.

To blocklist items prefixed with “mylib” use "mylib_.*". For more complicated expressions check regex docs

Hide any contents of the given file from the generated bindings, regardless of whether it’s a type, function, module etc.

Treat the given type as opaque in the generated bindings. Regular expressions are supported.

To change types prefixed with “mylib” into opaque, use "mylib_.*". For more complicated expressions check regex docs

👎 Deprecated:

use allowlist_type instead

Allowlist the given type so that it (and all types that it transitively refers to) appears in the generated bindings. Regular expressions are supported.

👎 Deprecated:

use allowlist_type instead

Allowlist the given type so that it (and all types that it transitively refers to) appears in the generated bindings. Regular expressions are supported.

Allowlist the given type so that it (and all types that it transitively refers to) appears in the generated bindings. Regular expressions are supported.

To allowlist types prefixed with “mylib” use "mylib_.*". For more complicated expressions check regex docs

Allowlist the given function so that it (and all types that it transitively refers to) appears in the generated bindings. Regular expressions are supported.

To allowlist functions prefixed with “mylib” use "mylib_.*". For more complicated expressions check regex docs

👎 Deprecated:

use allowlist_function instead

Allowlist the given function.

Deprecated: use allowlist_function instead.

👎 Deprecated:

use allowlist_function instead

Allowlist the given function.

Deprecated: use allowlist_function instead.

Allowlist the given variable so that it (and all types that it transitively refers to) appears in the generated bindings. Regular expressions are supported.

To allowlist variables prefixed with “mylib” use "mylib_.*". For more complicated expressions check regex docs

👎 Deprecated:

use allowlist_var instead

Deprecated: use allowlist_var instead.

👎 Deprecated:

use allowlist_var instead

Allowlist the given variable.

Deprecated: use allowlist_var instead.

Set the default style of code to generate for enums

Mark the given enum (or set of enums, if using a pattern) as being bitfield-like. Regular expressions are supported.

This makes bindgen generate a type that isn’t a rust enum. Regular expressions are supported.

This is similar to the newtype enum style, but with the bitwise operators implemented.

Mark the given enum (or set of enums, if using a pattern) as a newtype. Regular expressions are supported.

This makes bindgen generate a type that isn’t a Rust enum. Regular expressions are supported.

Mark the given enum (or set of enums, if using a pattern) as a Rust enum.

This makes bindgen generate enums instead of constants. Regular expressions are supported.

Use this with caution, creating this in unsafe code (including FFI) with an invalid value will invoke undefined behaviour. You may want to use the newtype enum style instead.

Mark the given enum (or set of enums, if using a pattern) as a Rust enum with the #[non_exhaustive] attribute.

This makes bindgen generate enums instead of constants. Regular expressions are supported.

Use this with caution, creating this in unsafe code (including FFI) with an invalid value will invoke undefined behaviour. You may want to use the newtype enum style instead.

Mark the given enum (or set of enums, if using a pattern) as a set of constants that are not to be put into a module.

Mark the given enum (or set of enums, if using a pattern) as a set of constants that should be put into a module.

This makes bindgen generate modules containing constants instead of just constants. Regular expressions are supported.

Set the default type for macro constants

Set the default style of code to generate for typedefs

Mark the given typedef alias (or set of aliases, if using a pattern) to use regular Rust type aliasing.

This is the default behavior and should be used if default_alias_style was set to NewType or NewTypeDeref and you want to override it for a set of typedefs.

Mark the given typedef alias (or set of aliases, if using a pattern) to be generated as a new type by having the aliased type be wrapped in a #[repr(transparent)] struct.

Used to enforce stricter type checking.

Mark the given typedef alias (or set of aliases, if using a pattern) to be generated as a new type by having the aliased type be wrapped in a #[repr(transparent)] struct and also have an automatically generated impl’s of Deref and DerefMut to their aliased type.

Add a string to prepend to the generated bindings. The string is passed through without any modification.

Add a given line to the beginning of module mod.

Add a given set of lines to the beginning of module mod.

Add an argument to be passed straight through to clang.

Add arguments to be passed straight through to clang.

Emit bindings for builtin definitions (for example __builtin_va_list) in the generated Rust.

Avoid converting floats to f32/f64 by default.

Set whether layout tests should be generated.

Set whether Debug should be implemented, if it can not be derived automatically.

Set whether PartialEq should be implemented, if it can not be derived automatically.

Set whether Copy should be derived by default.

Set whether Debug should be derived by default.

Set whether Default should be derived by default.

Set whether Hash should be derived by default.

Set whether PartialOrd should be derived by default. If we don’t compute partialord, we also cannot compute ord. Set the derive_ord to false when doit is false.

Set whether Ord should be derived by default. We can’t compute Ord without computing PartialOrd, so we set the same option to derive_partialord.

Set whether PartialEq should be derived by default.

If we don’t derive PartialEq, we also cannot derive Eq, so deriving Eq is also disabled when doit is false.

Set whether Eq should be derived by default.

We can’t derive Eq without also deriving PartialEq, so we also enable deriving PartialEq when doit is true.

Set whether or not to time bindgen phases, and print information to stderr.

Emit Clang AST.

Emit IR.

Enable C++ namespaces.

Enable detecting must_use attributes on C functions.

This is quite slow in some cases (see #1465), so it’s disabled by default.

Note that for this to do something meaningful for now at least, the rust target version has to have support for #[must_use].

Disable name auto-namespacing.

By default, bindgen mangles names like foo::bar::Baz to look like foo_bar_Baz instead of just Baz.

This method disables that behavior.

Note that this intentionally does not change the names used for allowlisting and blocklisting, which should still be mangled with the namespaces.

Note, also, that this option may cause bindgen to generate duplicate names.

Disable nested struct naming.

The following structs have different names for C and C++. In case of C they are visible as foo and bar. In case of C++ they are visible as foo and foo::bar.

struct foo {
    struct bar {
    } b;
};

Bindgen wants to avoid duplicate names by default so it follows C++ naming and it generates foo/foo_bar instead of just foo/bar.

This method disables this behavior and it is indented to be used only for headers that were written for C.

Treat inline namespaces conservatively.

This is tricky, because in C++ is technically legal to override an item defined in an inline namespace:

inline namespace foo {
    using Bar = int;
}
using Bar = long;

Even though referencing Bar is a compiler error.

We want to support this (arguably esoteric) use case, but we don’t want to make the rest of bindgen users pay an usability penalty for that.

To support this, we need to keep all the inline namespaces around, but then bindgen usage is a bit more difficult, because you cannot reference, e.g., std::string (you’d need to use the proper inline namespace).

We could complicate a lot of the logic to detect name collisions, and if not detected generate a pub use inline_ns::* or something like that.

That’s probably something we can do if we see this option is needed in a lot of cases, to improve it’s usability, but my guess is that this is not going to be too useful.

Whether inline functions should be generated or not.

Note that they will usually not work. However you can use -fkeep-inline-functions or -fno-inline-functions if you are responsible of compiling the library to make them callable.

Ignore functions.

Ignore methods.

👎 Deprecated:

please use rust_target instead

Avoid generating any unstable Rust, such as Rust unions, in the generated bindings.

Use core instead of libstd in the generated bindings.

Use the given prefix for the raw types instead of ::std::os::raw.

Use the given prefix for the anon fields.

Allows configuring types in different situations, see the ParseCallbacks documentation.

Choose what to generate using a CodegenConfig.

Whether to detect include paths using clang_sys.

Whether to try to fit macro constants to types smaller than u32/i32

Prepend the enum name to constant or newtype variants.

Set whether size_t should be translated to usize automatically.

Set whether rustfmt should format the generated bindings.

Set whether we should record matched items in our regex sets.

Set the absolute path to the rustfmt configuration file, if None, the standard rustfmt options are used.

Sets an explicit path to rustfmt, to be used when rustfmt is enabled.

If true, always emit explicit padding fields.

If a struct needs to be serialized in its native format (padding bytes and all), for example writing it to a file or sending it on the network, then this should be enabled, as anything reading the padding bytes of a struct may lead to Undefined Behavior.

Generate the Rust bindings using the options built up thus far.

Preprocess and dump the input header files to disk.

This is useful when debugging bindgen, using C-Reduce, or when filing issues. The resulting file will be named something like __bindgen.i or __bindgen.ii

Don’t derive PartialEq for a given type. Regular expressions are supported.

Don’t derive Copy for a given type. Regular expressions are supported.

Don’t derive Debug for a given type. Regular expressions are supported.

Don’t derive/impl Default for a given type. Regular expressions are supported.

Don’t derive Hash for a given type. Regular expressions are supported.

Add #[must_use] for the given type. Regular expressions are supported.

Set whether arr[size] should be treated as *mut T or *mut [T; size] (same for mut)

Set the wasm import module name

Specify the dynamic library name if we are generating bindings for a shared library.

Require successful linkage for all routines in a shared library. This allows us to optimize function calls by being able to safely assume function pointers are valid.

Generate bindings as pub only if the bound item is publically accessible by C++.

Always translate enum integer types to native Rust integer types.

This will result in enums having types such as u32 and i16 instead of c_uint and c_short. Types for Rustified enums are always translated.

Generate types with C style naming.

This will add prefixes to the generated type names. For example instead of a struct A we will generate struct struct_A. Currently applies to structs, unions, and enums.

Trait Implementations

Formats the value using the given formatter. Read more

Returns the “default value” for a type. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Performs the conversion.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.