Import subrepo pkg-config/:pkg-config at a493b0d7c93df68c94d1bad2a1f419389e52c0f5

1 files changed, 510 insertions, 0 deletions

diff --git a/pkg-config/src/lib.rs b/pkg-config/src/lib.rs
new file mode 100644
index 0000000..c88bd34
--- /dev/null
+++ b/pkg-config/src/lib.rs
@@ -0,0 +1,510 @@
+//! A build dependency for Cargo libraries to find system artifacts through the
+//! `pkg-config` utility.
+//!
+//! This library will shell out to `pkg-config` as part of build scripts and
+//! probe the system to determine how to link to a specified library. The
+//! `Config` structure serves as a method of configuring how `pkg-config` is
+//! invoked in a builder style.
+//!
+//! A number of environment variables are available to globally configure how
+//! this crate will invoke `pkg-config`:
+//!
+//! * `PKG_CONFIG_ALLOW_CROSS` - if this variable is not set, then `pkg-config`
+//!   will automatically be disabled for all cross compiles.
+//! * `FOO_NO_PKG_CONFIG` - if set, this will disable running `pkg-config` when
+//!   probing for the library named `foo`.
+//!
+//! There are also a number of environment variables which can configure how a
+//! library is linked to (dynamically vs statically). These variables control
+//! whether the `--static` flag is passed. Note that this behavior can be
+//! overridden by configuring explicitly on `Config`. The variables are checked
+//! in the following order:
+//!
+//! * `FOO_STATIC` - pass `--static` for the library `foo`
+//! * `FOO_DYNAMIC` - do not pass `--static` for the library `foo`
+//! * `PKG_CONFIG_ALL_STATIC` - pass `--static` for all libraries
+//! * `PKG_CONFIG_ALL_DYNAMIC` - do not pass `--static` for all libraries
+//!
+//! After running `pkg-config` all appropriate Cargo metadata will be printed on
+//! stdout if the search was successful.
+//!
+//! # Example
+//!
+//! Find the system library named `foo`, with minimum version 1.2.3:
+//!
+//! ```no_run
+//! extern crate pkg_config;
+//!
+//! fn main() {
+//!     pkg_config::Config::new().atleast_version("1.2.3").probe("foo").unwrap();
+//! }
+//! ```
+//!
+//! Find the system library named `foo`, with no version requirement (not
+//! recommended):
+//!
+//! ```no_run
+//! extern crate pkg_config;
+//!
+//! fn main() {
+//!     pkg_config::probe_library("foo").unwrap();
+//! }
+//! ```
+//!
+//! Configure how library `foo` is linked to.
+//!
+//! ```no_run
+//! extern crate pkg_config;
+//!
+//! fn main() {
+//!     pkg_config::Config::new().atleast_version("1.2.3").statik(true).probe("foo").unwrap();
+//! }
+//! ```
+
+#![doc(html_root_url = "http://alexcrichton.com/pkg-config-rs")]
+#![cfg_attr(test, deny(warnings))]
+
+use std::ascii::AsciiExt;
+use std::env;
+use std::error;
+use std::ffi::{OsStr, OsString};
+use std::fmt;
+use std::fs;
+use std::io;
+use std::path::{PathBuf, Path};
+use std::process::{Command, Output};
+use std::str;
+
+pub fn target_supported() -> bool {
+    let target = env::var("TARGET").unwrap_or(String::new());
+    let host = env::var("HOST").unwrap_or(String::new());
+
+    // Only use pkg-config in host == target situations by default (allowing an
+    // override) and then also don't use pkg-config on MSVC as it's really not
+    // meant to work there but when building MSVC code in a MSYS shell we may be
+    // able to run pkg-config anyway.
+    (host == target || env::var_os("PKG_CONFIG_ALLOW_CROSS").is_some()) &&
+    !target.contains("msvc")
+}
+
+#[derive(Clone)]
+pub struct Config {
+    statik: Option<bool>,
+    atleast_version: Option<String>,
+    extra_args: Vec<OsString>,
+    cargo_metadata: bool,
+    print_system_libs: bool,
+}
+
+#[derive(Debug)]
+pub struct Library {
+    pub libs: Vec<String>,
+    pub link_paths: Vec<PathBuf>,
+    pub frameworks: Vec<String>,
+    pub framework_paths: Vec<PathBuf>,
+    pub include_paths: Vec<PathBuf>,
+    pub version: String,
+    _priv: (),
+}
+
+/// Represents all reasons `pkg-config` might not succeed or be run at all.
+pub enum Error {
+    /// Aborted because of `*_NO_PKG_CONFIG` environment variable.
+    ///
+    /// Contains the name of the responsible environment variable.
+    EnvNoPkgConfig(String),
+
+    /// Cross compilation detected.
+    ///
+    /// Override with `PKG_CONFIG_ALLOW_CROSS=1`.
+    CrossCompilation,
+
+    /// Attempted to compile using the MSVC ABI build
+    MSVC,
+
+    /// Failed to run `pkg-config`.
+    ///
+    /// Contains the command and the cause.
+    Command { command: String, cause: io::Error },
+
+    /// `pkg-config` did not exit sucessfully.
+    ///
+    /// Contains the command and output.
+    Failure { command: String, output: Output },
+
+    #[doc(hidden)]
+    // please don't match on this, we're likely to add more variants over time
+    __Nonexhaustive,
+}
+
+impl error::Error for Error {
+    fn description(&self) -> &str {
+        match *self {
+            Error::EnvNoPkgConfig(_) => "pkg-config requested to be aborted",
+            Error::CrossCompilation => {
+                "pkg-config doesn't handle cross compilation. \
+                 Use PKG_CONFIG_ALLOW_CROSS=1 to override"
+            }
+            Error::MSVC => "pkg-config is incompatible with the MSVC ABI build.",
+            Error::Command { .. } => "failed to run pkg-config",
+            Error::Failure { .. } => "pkg-config did not exit sucessfully",
+            Error::__Nonexhaustive => panic!(),
+        }
+    }
+
+    fn cause(&self) -> Option<&error::Error> {
+        match *self {
+            Error::Command { ref cause, .. } => Some(cause),
+            _ => None,
+        }
+    }
+}
+
+// Workaround for temporary lack of impl Debug for Output in stable std
+struct OutputDebugger<'a>(&'a Output);
+
+// Lifted from 1.7 std
+impl<'a> fmt::Debug for OutputDebugger<'a> {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        let stdout_utf8 = str::from_utf8(&self.0.stdout);
+        let stdout_debug: &fmt::Debug = match stdout_utf8 {
+            Ok(ref str) => str,
+            Err(_) => &self.0.stdout
+        };
+
+        let stderr_utf8 = str::from_utf8(&self.0.stderr);
+        let stderr_debug: &fmt::Debug = match stderr_utf8 {
+            Ok(ref str) => str,
+            Err(_) => &self.0.stderr
+        };
+
+        fmt.debug_struct("Output")
+           .field("status", &self.0.status)
+           .field("stdout", stdout_debug)
+           .field("stderr", stderr_debug)
+           .finish()
+    }
+}
+
+// Workaround for temporary lack of impl Debug for Output in stable std, continued
+impl fmt::Debug for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        match *self {
+            Error::EnvNoPkgConfig(ref name) => {
+                f.debug_tuple("EnvNoPkgConfig")
+                 .field(name)
+                 .finish()
+            }
+            Error::CrossCompilation => write!(f, "CrossCompilation"),
+            Error::MSVC => write!(f, "MSVC"),
+            Error::Command { ref command, ref cause } => {
+                f.debug_struct("Command")
+                 .field("command", command)
+                 .field("cause", cause)
+                 .finish()
+            }
+            Error::Failure { ref command, ref output } => {
+                f.debug_struct("Failure")
+                 .field("command", command)
+                 .field("output", &OutputDebugger(output))
+                 .finish()
+            }
+            Error::__Nonexhaustive => panic!(),
+        }
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        match *self {
+            Error::EnvNoPkgConfig(ref name) => {
+                write!(f, "Aborted because {} is set", name)
+            }
+            Error::CrossCompilation => {
+                write!(f, "Cross compilation detected. \
+                       Use PKG_CONFIG_ALLOW_CROSS=1 to override")
+            }
+            Error::MSVC => {
+                write!(f, "MSVC target detected. If you are using the MSVC ABI \
+                       rust build, please use the GNU ABI build instead.")
+            }
+            Error::Command { ref command, ref cause } => {
+                write!(f, "Failed to run `{}`: {}", command, cause)
+            }
+            Error::Failure { ref command, ref output } => {
+                let stdout = str::from_utf8(&output.stdout).unwrap();
+                let stderr = str::from_utf8(&output.stderr).unwrap();
+                try!(write!(f, "`{}` did not exit successfully: {}", command, output.status));
+                if !stdout.is_empty() {
+                    try!(write!(f, "\n--- stdout\n{}", stdout));
+                }
+                if !stderr.is_empty() {
+                    try!(write!(f, "\n--- stderr\n{}", stderr));
+                }
+                Ok(())
+            }
+            Error::__Nonexhaustive => panic!(),
+        }
+    }
+}
+
+/// Deprecated in favor of the probe_library function
+#[doc(hidden)]
+pub fn find_library(name: &str) -> Result<Library, String> {
+    probe_library(name).map_err(|e| e.to_string())
+}
+
+/// Simple shortcut for using all default options for finding a library.
+pub fn probe_library(name: &str) -> Result<Library, Error> {
+    Config::new().probe(name)
+}
+
+/// Run `pkg-config` to get the value of a variable from a package using
+/// --variable.
+pub fn get_variable(package: &str, variable: &str) -> Result<String, Error> {
+    let arg = format!("--variable={}", variable);
+    let cfg = Config::new();
+    Ok(try!(run(cfg.command(package, &[&arg]))).trim_right().to_owned())
+}
+
+impl Config {
+    /// Creates a new set of configuration options which are all initially set
+    /// to "blank".
+    pub fn new() -> Config {
+        Config {
+            statik: None,
+            atleast_version: None,
+            extra_args: vec![],
+            print_system_libs: true,
+            cargo_metadata: true,
+        }
+    }
+
+    /// Indicate whether the `--static` flag should be passed.
+    ///
+    /// This will override the inference from environment variables described in
+    /// the crate documentation.
+    pub fn statik(&mut self, statik: bool) -> &mut Config {
+        self.statik = Some(statik);
+        self
+    }
+
+    /// Indicate that the library must be at least version `vers`.
+    pub fn atleast_version(&mut self, vers: &str) -> &mut Config {
+        self.atleast_version = Some(vers.to_string());
+        self
+    }
+
+    /// Add an argument to pass to pkg-config.
+    ///
+    /// It's placed after all of the arguments generated by this library.
+    pub fn arg<S: AsRef<OsStr>>(&mut self, arg: S) -> &mut Config {
+        self.extra_args.push(arg.as_ref().to_os_string());
+        self
+    }
+
+    /// Define whether metadata should be emitted for cargo allowing it to
+    /// automatically link the binary. Defaults to `true`.
+    pub fn cargo_metadata(&mut self, cargo_metadata: bool) -> &mut Config {
+        self.cargo_metadata = cargo_metadata;
+        self
+    }
+
+    /// Enable or disable the `PKG_CONFIG_ALLOW_SYSTEM_LIBS` environment
+    /// variable.
+    ///
+    /// This env var is enabled by default.
+    pub fn print_system_libs(&mut self, print: bool) -> &mut Config {
+        self.print_system_libs = print;
+        self
+    }
+
+    /// Deprecated in favor fo the `probe` function
+    #[doc(hidden)]
+    pub fn find(&self, name: &str) -> Result<Library, String> {
+        self.probe(name).map_err(|e| e.to_string())
+    }
+
+    /// Run `pkg-config` to find the library `name`.
+    ///
+    /// This will use all configuration previously set to specify how
+    /// `pkg-config` is run.
+    pub fn probe(&self, name: &str) -> Result<Library, Error> {
+        let abort_var_name = format!("{}_NO_PKG_CONFIG", envify(name));
+        if env::var_os(&abort_var_name).is_some() {
+            return Err(Error::EnvNoPkgConfig(abort_var_name))
+        } else if !target_supported() {
+            if env::var("TARGET").unwrap_or(String::new()).contains("msvc") {
+                return Err(Error::MSVC);
+            }
+            else {
+                return Err(Error::CrossCompilation);
+            }
+        }
+
+        let mut library = Library::new();
+
+        let output = try!(run(self.command(name, &["--libs", "--cflags"])));
+        library.parse_libs_cflags(name, &output, self);
+
+        let output = try!(run(self.command(name, &["--modversion"])));
+        library.parse_modversion(&output);
+
+        Ok(library)
+    }
+
+    /// Deprecated in favor of the top level `get_variable` function
+    #[doc(hidden)]
+    pub fn get_variable(package: &str, variable: &str) -> Result<String, String> {
+        get_variable(package, variable).map_err(|e| e.to_string())
+    }
+
+    fn is_static(&self, name: &str) -> bool {
+        self.statik.unwrap_or_else(|| infer_static(name))
+    }
+
+    fn command(&self, name: &str, args: &[&str]) -> Command {
+        let exe = env::var("PKG_CONFIG").unwrap_or(String::from("pkg-config"));
+        let mut cmd = Command::new(exe);
+        if self.is_static(name) {
+            cmd.arg("--static");
+        }
+        cmd.args(args)
+           .args(&self.extra_args);
+
+        if self.print_system_libs {
+            cmd.env("PKG_CONFIG_ALLOW_SYSTEM_LIBS", "1");
+        }
+        if let Some(ref version) = self.atleast_version {
+            cmd.arg(&format!("{} >= {}", name, version));
+        } else {
+            cmd.arg(name);
+        }
+        cmd
+    }
+
+    fn print_metadata(&self, s: &str) {
+        if self.cargo_metadata {
+            println!("cargo:{}", s);
+        }
+    }
+}
+
+impl Library {
+    fn new() -> Library {
+        Library {
+            libs: Vec::new(),
+            link_paths: Vec::new(),
+            include_paths: Vec::new(),
+            frameworks: Vec::new(),
+            framework_paths: Vec::new(),
+            version: String::new(),
+            _priv: (),
+        }
+    }
+
+    fn parse_libs_cflags(&mut self, name: &str, output: &str, config: &Config) {
+        let parts = output.trim_right()
+                          .split(' ')
+                          .filter(|l| l.len() > 2)
+                          .map(|arg| (&arg[0..2], &arg[2..]))
+                          .collect::<Vec<_>>();
+
+        let mut dirs = Vec::new();
+        let statik = config.is_static(name);
+        for &(flag, val) in parts.iter() {
+            match flag {
+                "-L" => {
+                    let meta = format!("rustc-link-search=native={}", val);
+                    config.print_metadata(&meta);
+                    dirs.push(PathBuf::from(val));
+                    self.link_paths.push(PathBuf::from(val));
+                }
+                "-F" => {
+                    let meta = format!("rustc-link-search=framework={}", val);
+                    config.print_metadata(&meta);
+                    self.framework_paths.push(PathBuf::from(val));
+                }
+                "-I" => {
+                    self.include_paths.push(PathBuf::from(val));
+                }
+                "-l" => {
+                    self.libs.push(val.to_string());
+                    if statik && !is_system(val, &dirs) {
+                        let meta = format!("rustc-link-lib=static={}", val);
+                        config.print_metadata(&meta);
+                    } else {
+                        let meta = format!("rustc-link-lib={}", val);
+                        config.print_metadata(&meta);
+                    }
+                }
+                _ => {}
+            }
+        }
+
+        let mut iter = output.trim_right().split(' ');
+        while let Some(part) = iter.next() {
+            if part != "-framework" {
+                continue
+            }
+            if let Some(lib) = iter.next() {
+                let meta = format!("rustc-link-lib=framework={}", lib);
+                config.print_metadata(&meta);
+                self.frameworks.push(lib.to_string());
+            }
+        }
+    }
+
+    fn parse_modversion(&mut self, output: &str) {
+        self.version.push_str(output.trim());
+    }
+}
+
+fn infer_static(name: &str) -> bool {
+    let name = envify(name);
+    if env::var_os(&format!("{}_STATIC", name)).is_some() {
+        true
+    } else if env::var_os(&format!("{}_DYNAMIC", name)).is_some() {
+        false
+    } else if env::var_os("PKG_CONFIG_ALL_STATIC").is_some() {
+        true
+    } else if env::var_os("PKG_CONFIG_ALL_DYNAMIC").is_some() {
+        false
+    } else {
+        false
+    }
+}
+
+fn envify(name: &str) -> String {
+    name.chars().map(|c| c.to_ascii_uppercase()).map(|c| {
+        if c == '-' {'_'} else {c}
+    }).collect()
+}
+
+fn is_system(name: &str, dirs: &[PathBuf]) -> bool {
+    let libname = format!("lib{}.a", name);
+    let root = Path::new("/usr");
+    !dirs.iter().any(|d| {
+        !d.starts_with(root) && fs::metadata(&d.join(&libname)).is_ok()
+    })
+}
+
+fn run(mut cmd: Command) -> Result<String, Error> {
+    match cmd.output() {
+        Ok(output) => {
+            if output.status.success() {
+                let stdout = String::from_utf8(output.stdout).unwrap();
+                Ok(stdout)
+            } else {
+                Err(Error::Failure {
+                    command: format!("{:?}", cmd),
+                    output: output,
+                })
+            }
+        }
+        Err(cause) => Err(Error::Command {
+            command: format!("{:?}", cmd),
+            cause: cause,
+        }),
+    }
+}