switch to yeslogic-fontconfig-sys

instead of servo-fontconfig

servo-fontconfig statically links a vendored fontconfig library if
fontconfig is not found by pkgconfig. Using a vendored fontconfig
library instead of the system fontconfig library doesn't actually work
well though:
slint-ui/slint#88
Building a vendored copy of fontconfig is also problematic because
fontconfig has a lot of C dependencies, which makes it difficult to
cross compile the vendored copy of fontconfig:

$ pkg-config fontconfig --static --libs
-lfontconfig -lfreetype -lz -lbz2 -lpng16 -lm -lm -lz -lharfbuzz -lm
-lglib-2.0 -lm -lpcre -lsysprof-capture-4 -pthread -lgraphite2
-lbrotlidec -lbrotlicommon -lxml2 -lz -llzma -lm

Instead of using a vendored copy, with
yeslogic/fontconfig-rs#12
yeslogic-fontconfig-sys will have a Cargo feature to dlopen fontconfig
at runtime instead of linking it at build time. This is exposed in
font-kit with the new source-fontconfig-dlopen feature, which is
disabled by default. The feature can be enabled by setting the
RUST_FONTCONFIG_DLOPEN environment variable to avoid needing to
propagate the Cargo feature all the way through downstream
Cargo.toml's. This feature makes it considerably easier to cross
compile by avoiding the need to cross compile fontconfig and all its
dependencies.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "font-kit"
-version = "0.10.1"
+version = "0.11.0"
 authors = ["Patrick Walton <pcwalton@mimiga.net>"]
 description = "A cross-platform font loading library"
 license = "MIT/Apache-2.0"
@@ -14,7 +14,8 @@ edition = "2018"
 default = ["source"]
 loader-freetype = ["freetype"]
 loader-freetype-default = ["loader-freetype"]
-source-fontconfig = ["servo-fontconfig"]
+source-fontconfig = ["yeslogic-fontconfig-sys"]
+source-fontconfig-dlopen = ["yeslogic-fontconfig-sys/dlopen"]
 source-fontconfig-default = ["source-fontconfig"]
 source = []
 
@@ -32,8 +33,8 @@ pathfinder_simd = "0.5.1"
 version = "0.7"
 optional = true
 
-[dependencies.servo-fontconfig]
-version = "0.5"
+[dependencies.yeslogic-fontconfig-sys]
+version = "3.0.0"
 optional = true
 
 [dev-dependencies]
@@ -58,7 +59,7 @@ core-text = "19.1.0"
 freetype = "0.7"
 
 [target.'cfg(not(any(target_family = "windows", target_os = "macos", target_os = "ios", target_arch = "wasm32")))'.dependencies]
-servo-fontconfig = "0.5"
+yeslogic-fontconfig-sys = "3.0.0"
 
 [target.'cfg(not(any(target_arch = "wasm32", target_family = "windows", target_os = "android")))'.dependencies]
 dirs-next = "2.0"

build.rs

@@ -0,0 +1,7 @@
+fn main() {
+ println!("cargo:rerun-if-env-changed=RUST_FONTCONFIG_DLOPEN");
+ let dlopen = std::env::var("RUST_FONTCONFIG_DLOPEN").is_ok();
+ if dlopen {
+ println!("cargo:rustc-cfg=feature=\"source-fontconfig-dlopen\"");
+ }
+}

src/sources/fontconfig.rs

@@ -244,7 +244,13 @@ impl Source for FontconfigSource {
 mod fc {
  #![allow(dead_code)]
 
- use fontconfig::fontconfig as ffi;
+ use fontconfig_sys as ffi;
+ use fontconfig_sys::ffi_dispatch;
+
+ #[cfg(feature = "source-fontconfig-dlopen")]
+ use ffi::statics::LIB;
+ #[cfg(not(feature = "source-fontconfig-dlopen"))]
+ use ffi::*;
 
  use std::ffi::{CStr, CString};
  use std::os::raw::{c_char, c_uchar};
@@ -308,7 +314,7 @@ mod fc {
  pub fn new() -> Self {
  unsafe {
  Config {
- d: ffi::FcInitLoadConfigAndFonts(),
+ d: ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcInitLoadConfigAndFonts,),
  }
  }
  }
@@ -317,7 +323,7 @@ mod fc {
  impl Drop for Config {
  fn drop(&mut self) {
  unsafe {
- ffi::FcConfigDestroy(self.d);
+ ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcConfigDestroy, self.d);
  }
  }
  }
@@ -337,23 +343,23 @@ mod fc {
 
  // FcPatternCreate
  pub fn new() -> Self {
- unsafe { Pattern::from_ptr(ffi::FcPatternCreate()) }
+ unsafe { Pattern::from_ptr(ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcPatternCreate,)) }
  }
 
  // FcNameParse
  pub fn from_name(name: &str) -> Self {
  let c_name = CString::new(name).unwrap();
- unsafe { Pattern::from_ptr(ffi::FcNameParse(c_name.as_ptr() as *mut c_uchar)) }
+ unsafe { Pattern::from_ptr(ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcNameParse, c_name.as_ptr() as *mut c_uchar)) }
  }
 
  // FcPatternAddString
  pub fn push_string(&mut self, object: Object, value: String) {
  unsafe {
  let c_string = CString::new(value).unwrap();
- ffi::FcPatternAddString(
+ ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcPatternAddString,
  self.d,
  object.as_ptr(),
- c_string.as_ptr() as *const c_uchar,
+ c_string.as_ptr() as *const c_uchar
  );
 
  // We have to keep this string, because `FcPattern` has a pointer to it now.
@@ -364,21 +370,21 @@ mod fc {
  // FcConfigSubstitute
  pub fn config_substitute(&mut self, match_kind: MatchKind) {
  unsafe {
- ffi::FcConfigSubstitute(ptr::null_mut(), self.d, match_kind.to_u32());
+ ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcConfigSubstitute, ptr::null_mut(), self.d, match_kind.to_u32());
  }
  }
 
  // FcDefaultSubstitute
  pub fn default_substitute(&mut self) {
  unsafe {
- ffi::FcDefaultSubstitute(self.d);
+ ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcDefaultSubstitute, self.d);
  }
  }
 
  // FcFontSort
  pub fn sorted(&self, config: &Config) -> Result<FontSet, Error> {
  let mut res = ffi::FcResultMatch;
- let d = unsafe { ffi::FcFontSort(config.d, self.d, 1, ptr::null_mut(), &mut res) };
+ let d = unsafe { ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcFontSort, config.d, self.d, 1, ptr::null_mut(), &mut res) };
 
  match res {
  ffi::FcResultMatch => Ok(FontSet { d, idx: 0 }),
@@ -391,7 +397,7 @@ mod fc {
 
  // FcFontList
  pub fn list(&self, config: &Config, set: ObjectSet) -> Result<FontSet, Error> {
- let d = unsafe { ffi::FcFontList(config.d, self.d, set.d) };
+ let d = unsafe { ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcFontList, config.d, self.d, set.d) };
  if !d.is_null() {
  Ok(FontSet { d, idx: 0 })
  } else {
@@ -403,7 +409,7 @@ mod fc {
  impl Drop for Pattern {
  #[inline]
  fn drop(&mut self) {
- unsafe { ffi::FcPatternDestroy(self.d) }
+ unsafe { ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcPatternDestroy, self.d) }
  }
  }
 
@@ -417,7 +423,7 @@ mod fc {
  pub fn get_string(&self, object: Object) -> Option<String> {
  unsafe {
  let mut string = ptr::null_mut();
- let res = ffi::FcPatternGetString(self.d, object.as_ptr(), 0, &mut string);
+ let res = ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcPatternGetString, self.d, object.as_ptr(), 0, &mut string);
  if res != ffi::FcResultMatch {
  return None;
  }
@@ -437,7 +443,7 @@ mod fc {
  pub fn get_integer(&self, object: Object) -> Option<i32> {
  unsafe {
  let mut integer = 0;
- let res = ffi::FcPatternGetInteger(self.d, object.as_ptr(), 0, &mut integer);
+ let res = ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcPatternGetInteger, self.d, object.as_ptr(), 0, &mut integer);
  if res != ffi::FcResultMatch {
  return None;
  }
@@ -484,7 +490,7 @@ mod fc {
 
  impl Drop for FontSet {
  fn drop(&mut self) {
- unsafe { ffi::FcFontSetDestroy(self.d) }
+ unsafe { ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcFontSetDestroy, self.d) }
  }
  }
 
@@ -497,7 +503,7 @@ mod fc {
  pub fn new() -> Self {
  unsafe {
  ObjectSet {
- d: ffi::FcObjectSetCreate(),
+ d: ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcObjectSetCreate,),
  }
  }
  }
@@ -507,14 +513,14 @@ mod fc {
  unsafe {
  // Returns `false` if the property name cannot be inserted
  // into the set (due to allocation failure).
- assert_eq!(ffi::FcObjectSetAdd(self.d, object.as_ptr()), 1);
+ assert_eq!(ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcObjectSetAdd, self.d, object.as_ptr()), 1);
  }
  }
  }
 
  impl Drop for ObjectSet {
  fn drop(&mut self) {
- unsafe { ffi::FcObjectSetDestroy(self.d) }
+ unsafe { ffi_dispatch!(feature="source-fontconfig-dlopen", LIB, FcObjectSetDestroy, self.d) }
  }
  }
 }