Struct bindgen::Builder

pub struct Builder { /* fields omitted */ }

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")
    .whitelist_type("SomeCoolClass")
    .whitelist_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

impl Builder

pub fn command_line_flags(&self) -> Vec<String>

Generates the command line flags use for creating Builder.

pub fn header<T: Into<String>>(mut self: Self, header: T) -> 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();

pub fn header_contents(mut self: Self, name: &str, contents: &str) -> Builder

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

The file name will be added to the clang arguments.

pub fn rust_target(mut self: Self, rust_target: RustTarget) -> Self

Specify the rust target

The default is the latest stable Rust version

pub fn disable_untagged_union(mut self: Self) -> Self

Disable support for native Rust unions, if supported.

pub fn disable_header_comment(mut self: Self) -> Self

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

pub fn emit_ir_graphviz<T: Into<String>>(mut self: Self, path: T) -> Builder

Set the output graphviz file.

pub fn generate_comments(mut self: Self, doit: bool) -> Self

Whether the generated bindings should contain documentation comments (docstrings) or not.

This ideally will always be true, but it may need to be false until we implement some processing on comments to work around issues as described in rust-bindgen issue #426.

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.

pub fn whitelist_recursively(mut self: Self, doit: bool) -> Self

Whether to whitelist recursively or not. Defaults to true.

Given that we have explicitly whitelisted 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 whitelist_recursively(false), bindgen will not emit bindings for anything except the explicitly whitelisted 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 whitelisted 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.

pub fn objc_extern_crate(mut self: Self, doit: bool) -> Self

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

pub fn generate_block(mut self: Self, doit: bool) -> Self

Generate proper block signatures instead of void pointers.

pub fn block_extern_crate(mut self: Self, doit: bool) -> Self

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

pub fn trust_clang_mangling(mut self: Self, doit: bool) -> Self

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.

pub fn hide_type<T: AsRef<str>>(self, arg: T) -> Builder

👎 Deprecated:

Use blacklist_type instead

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

pub fn blacklist_type<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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

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

pub fn blacklist_function<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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

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

pub fn blacklist_item<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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

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

pub fn opaque_type<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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

pub fn whitelisted_type<T: AsRef<str>>(self, arg: T) -> Builder

👎 Deprecated:

use whitelist_type instead

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

pub fn whitelist_type<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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

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

pub fn whitelist_function<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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

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

pub fn whitelisted_function<T: AsRef<str>>(self, arg: T) -> Builder

👎 Deprecated:

use whitelist_function instead

Whitelist the given function.

Deprecated: use whitelist_function instead.

pub fn whitelist_var<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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

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

pub fn whitelisted_var<T: AsRef<str>>(self, arg: T) -> Builder

👎 Deprecated:

use whitelist_var instead

Whitelist the given variable.

Deprecated: use whitelist_var instead.

pub fn default_enum_style(mut self: Self, arg: EnumVariation) -> Builder

Set the default style of code to generate for enums

pub fn bitfield_enum<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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.

pub fn newtype_enum<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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.

pub fn rustified_enum<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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.

pub fn rustified_non_exhaustive_enum<T: AsRef<str>>(
    mut self: Self,
    arg: T
) -> Builder

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.

pub fn constified_enum<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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.

pub fn constified_enum_module<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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.

pub fn default_macro_constant_type(
    mut self: Self,
    arg: MacroTypeVariation
) -> Builder

Set the default type for macro constants

pub fn default_alias_style(mut self: Self, arg: AliasVariation) -> Builder

Set the default style of code to generate for typedefs

pub fn type_alias<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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.

pub fn new_type_alias<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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.

pub fn new_type_alias_deref<T: AsRef<str>>(mut self: Self, arg: T) -> Builder

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.

pub fn raw_line<T: Into<String>>(mut self: Self, arg: T) -> Self

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

pub fn module_raw_line<T, U>(mut self: Self, mod_: T, line: U) -> Self where
    T: Into<String>,
    U: Into<String>, 

Add a given line to the beginning of module mod.

pub fn module_raw_lines<T, I>(mut self: Self, mod_: T, lines: I) -> Self where
    T: Into<String>,
    I: IntoIterator,
    I::Item: Into<String>, 

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

pub fn clang_arg<T: Into<String>>(mut self: Self, arg: T) -> Builder

Add an argument to be passed straight through to clang.

pub fn clang_args<I>(mut self: Self, iter: I) -> Builder where
    I: IntoIterator,
    I::Item: AsRef<str>, 

Add arguments to be passed straight through to clang.

pub fn emit_builtins(mut self: Self) -> Builder

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

pub fn no_convert_floats(mut self: Self) -> Self

Avoid converting floats to f32/f64 by default.

pub fn layout_tests(mut self: Self, doit: bool) -> Self

Set whether layout tests should be generated.

pub fn impl_debug(mut self: Self, doit: bool) -> Self

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

pub fn impl_partialeq(mut self: Self, doit: bool) -> Self

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

pub fn derive_copy(mut self: Self, doit: bool) -> Self

Set whether Copy should be derived by default.

pub fn derive_debug(mut self: Self, doit: bool) -> Self

Set whether Debug should be derived by default.

pub fn derive_default(mut self: Self, doit: bool) -> Self

Set whether Default should be derived by default.

pub fn derive_hash(mut self: Self, doit: bool) -> Self

Set whether Hash should be derived by default.

pub fn derive_partialord(mut self: Self, doit: bool) -> Self

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.

pub fn derive_ord(mut self: Self, doit: bool) -> Self

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.

pub fn derive_partialeq(mut self: Self, doit: bool) -> Self

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.

pub fn derive_eq(mut self: Self, doit: bool) -> Self

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.

pub fn time_phases(mut self: Self, doit: bool) -> Self

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

pub fn emit_clang_ast(mut self: Self) -> Builder

Emit Clang AST.

pub fn emit_ir(mut self: Self) -> Builder

Emit IR.

pub fn enable_cxx_namespaces(mut self: Self) -> Builder

Enable C++ namespaces.

pub fn enable_function_attribute_detection(mut self: Self) -> Self

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].

pub fn disable_name_namespacing(mut self: Self) -> Builder

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 whitelisting and blacklisting, which should still be mangled with the namespaces.

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

pub fn disable_nested_struct_naming(mut self: Self) -> Builder

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.

pub fn conservative_inline_namespaces(mut self: Self) -> Builder

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.

pub fn generate_inline_functions(mut self: Self, doit: bool) -> Self

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.

pub fn ignore_functions(mut self: Self) -> Builder

Ignore functions.

pub fn ignore_methods(mut self: Self) -> Builder

Ignore methods.

pub fn unstable_rust(self, doit: bool) -> Self

👎 Deprecated:

please use rust_target instead

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

pub fn use_core(mut self: Self) -> Builder

Use core instead of libstd in the generated bindings.

pub fn ctypes_prefix<T: Into<String>>(mut self: Self, prefix: T) -> Builder

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

pub fn anon_fields_prefix<T: Into<String>>(mut self: Self, prefix: T) -> Builder

Use the given prefix for the anon fields.

pub fn parse_callbacks(mut self: Self, cb: Box<dyn ParseCallbacks>) -> Self

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

pub fn with_codegen_config(mut self: Self, config: CodegenConfig) -> Self

Choose what to generate using a CodegenConfig.

pub fn detect_include_paths(mut self: Self, doit: bool) -> Self

Whether to detect include paths using clang_sys.

pub fn fit_macro_constants(mut self: Self, doit: bool) -> Self

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

pub fn prepend_enum_name(mut self: Self, doit: bool) -> Self

Prepend the enum name to constant or newtype variants.

pub fn size_t_is_usize(mut self: Self, is: bool) -> Self

Set whether size_t should be translated to usize automatically.

pub fn rustfmt_bindings(mut self: Self, doit: bool) -> Self

Set whether rustfmt should format the generated bindings.

pub fn record_matches(mut self: Self, doit: bool) -> Self

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

pub fn rustfmt_configuration_file(mut self: Self, path: Option<PathBuf>) -> Self

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

pub fn with_rustfmt<P: Into<PathBuf>>(mut self: Self, path: P) -> Self

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

pub fn generate(mut self: Self) -> Result<Bindings, ()>

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

pub fn dump_preprocessed_input(&self) -> Result<()>

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

pub fn no_partialeq<T: Into<String>>(mut self: Self, arg: T) -> Builder

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

pub fn no_copy<T: Into<String>>(mut self: Self, arg: T) -> Self

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

pub fn no_debug<T: Into<String>>(mut self: Self, arg: T) -> Self

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

pub fn no_default<T: Into<String>>(mut self: Self, arg: T) -> Self

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

pub fn no_hash<T: Into<String>>(mut self: Self, arg: T) -> Builder

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

pub fn array_pointers_in_arguments(mut self: Self, doit: bool) -> Self

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

pub fn wasm_import_module_name<T: Into<String>>(
    mut self: Self,
    import_name: T
) -> Self

Set the wasm import module name

pub fn dynamic_library_name<T: Into<String>>(
    mut self: Self,
    dynamic_library_name: T
) -> Self

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

pub fn respect_cxx_access_specs(mut self: Self, doit: bool) -> Self

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

Trait Implementations

impl Debug for Builder

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Builder

fn default() -> Builder

Returns the "default value" for a type.