Struct cc::Build [−][src]
pub struct Build { /* fields omitted */ }
Expand description
A builder for compilation of a native library.
A Build
is the main type of the cc
crate and is used to control all the
various configuration options and such of a compile. You’ll find more
documentation on each method itself.
Implementations
Construct a new instance of a blank set of configuration.
This builder is finished with the compile
function.
Add a directory to the -I
or include path for headers
Example
use std::path::Path;
let library_path = Path::new("/path/to/library");
cc::Build::new()
.file("src/foo.c")
.include(library_path)
.include("src")
.compile("foo");
Add multiple directories to the -I
include path.
Example
let mut extra_dir = None;
if condition {
extra_dir = Some(Path::new("/path/to"));
}
cc::Build::new()
.file("src/foo.c")
.includes(extra_dir)
.compile("foo");
Specify a -D
variable with an optional value.
Example
cc::Build::new()
.file("src/foo.c")
.define("FOO", "BAR")
.define("BAZ", None)
.compile("foo");
Add an arbitrary object file to link in
Add an arbitrary flag to the invocation of the compiler
Example
cc::Build::new()
.file("src/foo.c")
.flag("-ffunction-sections")
.compile("foo");
Add an arbitrary flag to the invocation of the compiler
Example
cc::Build::new()
.file("src/foo.c")
.file("src/bar.c")
.ar_flag("/NODEFAULTLIB:libc.dll")
.compile("foo");
Run the compiler to test if it accepts the given flag.
For a convenience method for setting flags conditionally,
see flag_if_supported()
.
It may return error if it’s unable to run the compiler with a test file
(e.g. the compiler is missing or a write to the out_dir
failed).
Note: Once computed, the result of this call is stored in the
known_flag_support
field. If is_flag_supported(flag)
is called again, the result will be read from the hash table.
Add an arbitrary flag to the invocation of the compiler if it supports it
Example
cc::Build::new()
.file("src/foo.c")
.flag_if_supported("-Wlogical-op") // only supported by GCC
.flag_if_supported("-Wunreachable-code") // only supported by clang
.compile("foo");
Set the -shared
flag.
When enabled, the compiler will produce a shared object which can then be linked with other objects to form an executable.
Example
cc::Build::new()
.file("src/foo.c")
.shared_flag(true)
.compile("libfoo.so");
Set the -static
flag.
When enabled on systems that support dynamic linking, this prevents linking with the shared libraries.
Example
cc::Build::new()
.file("src/foo.c")
.shared_flag(true)
.static_flag(true)
.compile("foo");
Disables the generation of default compiler flags. The default compiler flags may cause conflicts in some cross compiling scenarios.
Setting the CRATE_CC_NO_DEFAULTS
environment variable has the same
effect as setting this to true
. The presence of the environment
variable and the value of no_default_flags
will be OR’d together.
Add files which will be compiled
Set C++ support.
The other cpp_*
options will only become active if this is set to
true
.
Set CUDA C++ support.
Enabling CUDA will pass the detected C/C++ toolchain as an argument to the CUDA compiler, NVCC. NVCC itself accepts some limited GNU-like args; any other arguments for the C/C++ toolchain will be redirected using “-Xcompiler” flags.
If enabled, this also implicitly enables C++ support.
Link CUDA run-time.
This option mimics the --cudart
NVCC command-line option. Just like
the original it accepts {none|shared|static}
, with default being
static
. The method has to be invoked after .cuda(true)
, or not
at all, if the default is right for the project.
Set warnings into errors flag.
Disabled by default.
Warning: turning warnings into errors only make sense if you are a developer of the crate using cc-rs. Some warnings only appear on some architecture or specific version of the compiler. Any user of this crate, or any other crate depending on it, could fail during compile time.
Example
cc::Build::new()
.file("src/foo.c")
.warnings_into_errors(true)
.compile("libfoo.a");
Set warnings flags.
Adds some flags:
- “-Wall” for MSVC.
- “-Wall”, “-Wextra” for GNU and Clang.
Enabled by default.
Example
cc::Build::new()
.file("src/foo.c")
.warnings(false)
.compile("libfoo.a");
Set extra warnings flags.
Adds some flags:
- nothing for MSVC.
- “-Wextra” for GNU and Clang.
Enabled by default.
Example
// Disables -Wextra, -Wall remains enabled:
cc::Build::new()
.file("src/foo.c")
.extra_warnings(false)
.compile("libfoo.a");
Set the standard library to link against when compiling with C++ support.
See get_cpp_link_stdlib
documentation
for the default value.
If the CXXSTDLIB
environment variable is set, its value will
override the default value, but not the value explicitly set by calling
this function.
A value of None
indicates that no automatic linking should happen,
otherwise cargo will link against the specified library.
The given library name must not contain the lib
prefix.
Common values:
stdc++
for GNUc++
for Clangc++_shared
orc++_static
for Android
Example
cc::Build::new()
.file("src/foo.c")
.shared_flag(true)
.cpp_link_stdlib("stdc++")
.compile("libfoo.so");
Force the C++ compiler to use the specified standard library.
Setting this option will automatically set cpp_link_stdlib
to the same
value.
The default value of this option is always None
.
This option has no effect when compiling for a Visual Studio based target.
This option sets the -stdlib
flag, which is only supported by some
compilers (clang, icc) but not by others (gcc). The library will not
detect which compiler is used, as such it is the responsibility of the
caller to ensure that this option is only used in conjunction with a
compiler which supports the -stdlib
flag.
A value of None
indicates that no specific C++ standard library should
be used, otherwise -stdlib
is added to the compile invocation.
The given library name must not contain the lib
prefix.
Common values:
stdc++
for GNUc++
for Clang
Example
cc::Build::new()
.file("src/foo.c")
.cpp_set_stdlib("c++")
.compile("libfoo.a");
Configures the target this configuration will be compiling for.
This option is automatically scraped from the TARGET
environment
variable by build scripts, so it’s not required to call this function.
Example
cc::Build::new()
.file("src/foo.c")
.target("aarch64-linux-android")
.compile("foo");
Configures the host assumed by this configuration.
This option is automatically scraped from the HOST
environment
variable by build scripts, so it’s not required to call this function.
Example
cc::Build::new()
.file("src/foo.c")
.host("arm-linux-gnueabihf")
.compile("foo");
Configures the optimization level of the generated object files.
This option is automatically scraped from the OPT_LEVEL
environment
variable by build scripts, so it’s not required to call this function.
Configures the optimization level of the generated object files.
This option is automatically scraped from the OPT_LEVEL
environment
variable by build scripts, so it’s not required to call this function.
Configures whether the compiler will emit debug information when generating object files.
This option is automatically scraped from the DEBUG
environment
variable by build scripts, so it’s not required to call this function.
Configures whether the compiler will emit instructions to store frame pointers during codegen.
This option is automatically enabled when debug information is emitted. Otherwise the target platform compiler’s default will be used. You can use this option to force a specific setting.
Configures the output directory where all object files and static libraries will be located.
This option is automatically scraped from the OUT_DIR
environment
variable by build scripts, so it’s not required to call this function.
Configures the compiler to be used to produce output.
This option is automatically determined from the target platform or a number of environment variables, so it’s not required to call this function.
Configures the tool used to assemble archives.
This option is automatically determined from the target platform or a number of environment variables, so it’s not required to call this function.
Define whether metadata should be emitted for cargo allowing it to
automatically link the binary. Defaults to true
.
The emitted metadata is:
rustc-link-lib=static=
compiled librustc-link-search=native=
target folder- When target is MSVC, the ATL-MFC libs are added via
rustc-link-search=native=
- When C++ is enabled, the C++ stdlib is added via
rustc-link-lib
Configures whether the compiler will emit position independent code.
This option defaults to false
for windows-gnu
and bare metal targets and
to true
for all other targets.
Configures whether the Procedure Linkage Table is used for indirect calls into shared libraries.
The PLT is used to provide features like lazy binding, but introduces
a small performance loss due to extra pointer indirection. Setting
use_plt
to false
can provide a small performance increase.
Note that skipping the PLT requires a recent version of GCC/Clang.
This only applies to ELF targets. It has no effect on other platforms.
Configures whether the /MT flag or the /MD flag will be passed to msvc build tools.
This option defaults to false
, and affect only msvc targets.
Run the compiler, generating the file output
This will return a result instead of panicing; see compile() for the complete description.
Run the compiler, generating the file output
The name output
should be the name of the library. For backwards compatibility,
the output
may start with lib
and end with .a
. The Rust compiler will create
the assembly with the lib prefix and .a extension. MSVC will create a file without prefix,
ending with .lib
.
Panics
Panics if output
is not formatted correctly or if one of the underlying
compiler commands fails. It can also panic if it fails reading file names
or creating directories.
This will return a result instead of panicing; see expand() for the complete description.
Get the compiler that’s in use for this configuration.
This function will return a Tool
which represents the culmination
of this configuration at a snapshot in time. The returned compiler can
be inspected (e.g. the path, arguments, environment) to forward along to
other tools, or the to_command
method can be used to invoke the
compiler itself.
This method will take into account all configuration such as debug information, optimization level, include directories, defines, etc. Additionally, the compiler binary in use follows the standard conventions for this path, e.g. looking at the explicitly set compiler, environment variables (a number of which are inspected here), and then falling back to the default configuration.
Panics
Panics if an error occurred while determining the architecture.
Get the compiler that’s in use for this configuration.
This will return a result instead of panicing; see get_compiler() for the complete description.
Trait Implementations
Auto Trait Implementations
impl RefUnwindSafe for Build
impl UnwindSafe for Build
Blanket Implementations
Mutably borrows from an owned value. Read more