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Merge pull request #134 from Be-ing/library_file_paths
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@thomcc
thomcc committed Oct 25, 2022
2 parents 28b8442 + a9d0132 commit d5e10b7
Showing 1 changed file with 196 additions and 59 deletions.
255 changes: 196 additions & 59 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -38,8 +38,6 @@
//! 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();
//! }
Expand All @@ -49,8 +47,6 @@
//! recommended):
//!
//! ```no_run
//! extern crate pkg_config;
//!
//! fn main() {
//! pkg_config::probe_library("foo").unwrap();
//! }
Expand All @@ -59,8 +55,6 @@
//! 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();
//! }
Expand Down Expand Up @@ -93,14 +87,26 @@ pub struct Config {

#[derive(Clone, Debug)]
pub struct Library {
/// Libraries specified by -l
pub libs: Vec<String>,
/// Library search paths specified by -L
pub link_paths: Vec<PathBuf>,
/// Library file paths specified without -l
pub link_files: Vec<PathBuf>,
/// Darwin frameworks specified by -framework
pub frameworks: Vec<String>,
/// Darwin framework search paths specified by -F
pub framework_paths: Vec<PathBuf>,
/// C/C++ header include paths specified by -I
pub include_paths: Vec<PathBuf>,
/// Linker options specified by -Wl
pub ld_args: Vec<Vec<String>>,
/// C/C++ definitions specified by -D
pub defines: HashMap<String, Option<String>>,
/// Version specified by .pc file's Version field
pub version: String,
/// Ensure that this struct can only be created via its private `[Library::new]` constructor.
/// Users of this crate can only access the struct via `[Config::probe]`.
_priv: (),
}

Expand Down Expand Up @@ -558,6 +564,7 @@ impl Library {
Library {
libs: Vec::new(),
link_paths: Vec::new(),
link_files: Vec::new(),
include_paths: Vec::new(),
ld_args: Vec::new(),
frameworks: Vec::new(),
Expand All @@ -568,9 +575,67 @@ impl Library {
}
}

/// Extract the &str to pass to cargo:rustc-link-lib from a filename (just the file name, not including directories)
/// using target-specific logic.
fn extract_lib_from_filename<'a>(target: &str, filename: &'a str) -> Option<&'a str> {
fn test_suffixes<'b>(filename: &'b str, suffixes: &[&str]) -> Option<&'b str> {
for suffix in suffixes {
if filename.ends_with(suffix) {
return Some(&filename[..filename.len() - suffix.len()]);
}
}
None
}

let prefix = "lib";
if target.contains("msvc") {
// According to link.exe documentation:
// https://learn.microsoft.com/en-us/cpp/build/reference/link-input-files?view=msvc-170
//
// LINK doesn't use file extensions to make assumptions about the contents of a file.
// Instead, LINK examines each input file to determine what kind of file it is.
//
// However, rustc appends `.lib` to the string it receives from the -l command line argument,
// which it receives from Cargo via cargo:rustc-link-lib:
// https://github.com/rust-lang/rust/blob/657f246812ab2684e3c3954b1c77f98fd59e0b21/compiler/rustc_codegen_ssa/src/back/linker.rs#L828
// https://github.com/rust-lang/rust/blob/657f246812ab2684e3c3954b1c77f98fd59e0b21/compiler/rustc_codegen_ssa/src/back/linker.rs#L843
// So the only file extension that works for MSVC targets is `.lib`
return test_suffixes(filename, &[".lib"]);
} else if target.contains("windows") && target.contains("gnu") {
// GNU targets for Windows, including gnullvm, use `LinkerFlavor::Gcc` internally in rustc,
// which tells rustc to use the GNU linker. rustc does not prepend/append to the string it
// receives via the -l command line argument before passing it to the linker:
// https://github.com/rust-lang/rust/blob/657f246812ab2684e3c3954b1c77f98fd59e0b21/compiler/rustc_codegen_ssa/src/back/linker.rs#L446
// https://github.com/rust-lang/rust/blob/657f246812ab2684e3c3954b1c77f98fd59e0b21/compiler/rustc_codegen_ssa/src/back/linker.rs#L457
// GNU ld can work with more types of files than just the .lib files that MSVC's link.exe needs.
// GNU ld will prepend the `lib` prefix to the filename if necessary, so it is okay to remove
// the `lib` prefix from the filename. The `.a` suffix *requires* the `lib` prefix.
// https://sourceware.org/binutils/docs-2.39/ld.html#index-direct-linking-to-a-dll
if filename.starts_with(prefix) {
let filename = &filename[prefix.len()..];
return test_suffixes(filename, &[".dll.a", ".dll", ".lib", ".a"]);
} else {
return test_suffixes(filename, &[".dll.a", ".dll", ".lib"]);
}
} else if target.contains("apple") {
if filename.starts_with(prefix) {
let filename = &filename[prefix.len()..];
return test_suffixes(filename, &[".a", ".so", ".dylib"]);
}
return None;
} else {
if filename.starts_with(prefix) {
let filename = &filename[prefix.len()..];
return test_suffixes(filename, &[".a", ".so"]);
}
return None;
}
}

fn parse_libs_cflags(&mut self, name: &str, output: &[u8], config: &Config) {
let mut is_msvc = false;
if let Ok(target) = env::var("TARGET") {
let target = env::var("TARGET");
if let Ok(target) = &target {
if target.contains("msvc") {
is_msvc = true;
}
Expand Down Expand Up @@ -670,7 +735,36 @@ impl Library {
self.include_paths.push(PathBuf::from(inc));
}
}
_ => (),
_ => {
let path = std::path::Path::new(part);
if path.is_file() {
// Cargo doesn't have a means to directly specify a file path to link,
// so split up the path into the parent directory and library name.
// TODO: pass file path directly when link-arg library type is stabilized
// https://github.com/rust-lang/rust/issues/99427
if let (Some(dir), Some(file_name), Ok(target)) =
(path.parent(), path.file_name(), &target)
{
match Self::extract_lib_from_filename(
target,
&file_name.to_string_lossy(),
) {
Some(lib_basename) => {
let link_search =
format!("rustc-link-search={}", dir.display());
config.print_metadata(&link_search);

let link_lib = format!("rustc-link-lib={}", lib_basename);
config.print_metadata(&link_lib);
self.link_files.push(PathBuf::from(path));
}
None => {
println!("cargo:warning=File path {} found in pkg-config file for {}, but could not extract library base name to pass to linker command line", path.display(), name);
}
}
}
}
}
}
}

Expand Down Expand Up @@ -776,60 +870,103 @@ fn split_flags(output: &[u8]) -> Vec<String> {
words
}

#[test]
#[cfg(target_os = "macos")]
fn system_library_mac_test() {
use std::path::Path;

let system_roots = vec![PathBuf::from("/Library"), PathBuf::from("/System")];

assert!(!is_static_available(
"PluginManager",
&system_roots,
&[PathBuf::from("/Library/Frameworks")]
));
assert!(!is_static_available(
"python2.7",
&system_roots,
&[PathBuf::from(
"/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/config"
)]
));
assert!(!is_static_available(
"ffi_convenience",
&system_roots,
&[PathBuf::from(
"/Library/Ruby/Gems/2.0.0/gems/ffi-1.9.10/ext/ffi_c/libffi-x86_64/.libs"
)]
));

// Homebrew is in /usr/local, and it's not a part of the OS
if Path::new("/usr/local/lib/libpng16.a").exists() {
assert!(is_static_available(
"png16",
#[cfg(test)]
mod tests {
use super::*;

#[test]
#[cfg(target_os = "macos")]
fn system_library_mac_test() {
use std::path::Path;

let system_roots = vec![PathBuf::from("/Library"), PathBuf::from("/System")];

assert!(!is_static_available(
"PluginManager",
&system_roots,
&[PathBuf::from("/usr/local/lib")]
&[PathBuf::from("/Library/Frameworks")]
));
assert!(!is_static_available(
"python2.7",
&system_roots,
&[PathBuf::from(
"/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/config"
)]
));
assert!(!is_static_available(
"ffi_convenience",
&system_roots,
&[PathBuf::from(
"/Library/Ruby/Gems/2.0.0/gems/ffi-1.9.10/ext/ffi_c/libffi-x86_64/.libs"
)]
));

// Homebrew is in /usr/local, and it's not a part of the OS
if Path::new("/usr/local/lib/libpng16.a").exists() {
assert!(is_static_available(
"png16",
&system_roots,
&[PathBuf::from("/usr/local/lib")]
));

let libpng = Config::new()
.range_version("1".."99")
.probe("libpng16")
.unwrap();
assert!(libpng.version.find('\n').is_none());
}
}

let libpng = Config::new()
.range_version("1".."99")
.probe("libpng16")
.unwrap();
assert!(libpng.version.find('\n').is_none());
#[test]
#[cfg(target_os = "linux")]
fn system_library_linux_test() {
assert!(!is_static_available(
"util",
&[PathBuf::from("/usr")],
&[PathBuf::from("/usr/lib/x86_64-linux-gnu")]
));
assert!(!is_static_available(
"dialog",
&[PathBuf::from("/usr")],
&[PathBuf::from("/usr/lib")]
));
}
}

#[test]
#[cfg(target_os = "linux")]
fn system_library_linux_test() {
assert!(!is_static_available(
"util",
&[PathBuf::from("/usr")],
&[PathBuf::from("/usr/lib/x86_64-linux-gnu")]
));
assert!(!is_static_available(
"dialog",
&[PathBuf::from("/usr")],
&[PathBuf::from("/usr/lib")]
));
fn test_library_filename(target: &str, filename: &str) {
assert_eq!(
Library::extract_lib_from_filename(target, filename),
Some("foo")
);
}

#[test]
fn link_filename_linux() {
let target = "x86_64-unknown-linux-gnu";
test_library_filename(target, "libfoo.a");
test_library_filename(target, "libfoo.so");
}

#[test]
fn link_filename_apple() {
let target = "x86_64-apple-darwin";
test_library_filename(target, "libfoo.a");
test_library_filename(target, "libfoo.so");
test_library_filename(target, "libfoo.dylib");
}

#[test]
fn link_filename_msvc() {
let target = "x86_64-pc-windows-msvc";
// static and dynamic libraries have the same .lib suffix
test_library_filename(target, "foo.lib");
}

#[test]
fn link_filename_mingw() {
let target = "x86_64-pc-windows-gnu";
test_library_filename(target, "foo.lib");
test_library_filename(target, "libfoo.a");
test_library_filename(target, "foo.dll");
test_library_filename(target, "foo.dll.a");
}
}

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