Build FreeType with HarfBuzz support

third_party/harfbuzz-ng/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/features.gni")
 import("//build/config/linux/pkg_config.gni")
+import("//build/config/freetype/freetype.gni")
 import("//build/config/ui.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
-
-declare_args() {
-  # Blink uses a cutting-edge version of Harfbuzz; most Linux distros do not
-  # contain a new enough version of the code to work correctly. However,
-  # ChromeOS chroots (i.e, real ChromeOS builds for devices) do contain a
-  # new enough version of the library, and so this variable exists so that
-  # ChromeOS can build against the system lib and keep binary sizes smaller.
-  use_system_harfbuzz = false
-}
+import("//third_party/harfbuzz-ng/harfbuzz.gni")
 
 if (use_system_harfbuzz) {
   import("//build/config/linux/pkg_config.gni")
   pkg_config("harfbuzz_pkgconfig") {
     packages = [ "harfbuzz" ]
   }
   group("harfbuzz-ng") {
     public_configs = [ ":harfbuzz_pkgconfig" ]
   }
 } else {
@@ skipping 14 matching lines @@
       ]
     }
     if (is_win) {
       # Result of 32-bit shift implicitly converted to 64 bits.
       cflags += [ "/wd4334" ]
     }
   }
 
   # See also chrome/browser/ui/libgtkui/BUILD.gn which pulls this.
   config("pangoft2_link_hack") {
-    if (is_linux && use_pango && !is_chromeos && !is_official_build &&
-        current_cpu != "arm" && current_cpu != "mipsel" && !is_component_build) {
+    if (is_linux && use_pango && !use_system_harfbuzz && !is_component_build) {
       # These symbols are referenced from libpangoft2, which will be
       # dynamically linked later.
       ldflags = [ "-Wl,-uhb_ft_face_create_cached,-uhb_glib_get_unicode_funcs" ]
     }
   }
 
   static_library("harfbuzz-ng") {
     sources = [
       "src/hb-atomic-private.hh",
       "src/hb-blob.cc",
@@ skipping 99 matching lines @@
       "src/hb.h",
     ]
 
     defines = [
       "HAVE_OT",
       "HAVE_ICU",
       "HAVE_ICU_BUILTIN",
       "HB_NO_MT",
     ]
 
+    configs -= [ "//build/config/gcc:symbol_visibility_hidden" ]
+    configs += [ "//build/config/gcc:symbol_visibility_default" ]
+
     configs -= [ "//build/config/compiler:chromium_code" ]
     configs += [
       "//build/config/compiler:no_chromium_code",
 
       # Must be after no_chromium_code for warning flags to be ordered
       # correctly.
       ":harfbuzz_warnings",
     ]
     public_configs = [ ":harfbuzz-ng_config" ]
 
     deps = [
       "//third_party/icu:icuuc",
     ]
 
     if (is_mac) {
       sources += [
         "src/hb-coretext.cc",
         "src/hb-coretext.h",
       ]
       defines += [ "HAVE_CORETEXT" ]
       libs = [
         "CoreFoundation.framework",
         "CoreGraphics.framework",
         "CoreText.framework",
       ]
     }
 
-    # When without -fvisibility=hidden for pango to use the harfbuzz
-    # in the tree, all symbols pango needs must be included, or
-    # pango uses mixed versions of harfbuzz and leads to crash.
-    # See crbug.com/462689.
-    if (is_linux && use_pango && !is_chromeos && !is_official_build &&
-        current_cpu != "arm" && current_cpu != "mipsel") {
-      deps += [ "//build/config/freetype" ]
-      configs -= [ "//build/config/gcc:symbol_visibility_hidden" ]
-      configs += [ "//build/config/gcc:symbol_visibility_default" ]
-      sources += [
-        "src/hb-ft.cc",
-        "src/hb-ft.h",
-      ]
-    }
     if (use_glib) {
       configs += [ "//build/config/linux:glib" ]
       sources += [
         "src/hb-glib.cc",
         "src/hb-glib.h",
       ]
     }
   }
+
+  config("harfbuzz-ng-ft-deferred-linkage") {
+    # Use this in //third_party/freetype2 to link without the hb_ft* symbols
+    # existing yet.
+
+    # Use this in harbuzz-ng-ft to link without the regular hb_* symbols
+    # existing yet.
+
+    # The dependency circle is as follows: FreeType depends on HarfBuzz for the
+    # autofitter, HarfBuzz depends on FreeType for the hb_ft functions that
+    # pangocairo depends on. We can solve this by linking //third_party/freetype
+    # incompletely, with leaving the hb_ft_font_create function undefined.  Then
+    # linking harfbuzz-ng-ft incompletely, with leaving the standard harfbuzz
+    # symbols undefined, then using the freetype group in
+    # //build/config/freetype which binds everything together: harfbuzz-ng,
+    # freetype-without-harfbuzz, and harfbuzz-ng-ft.
+    ldflags = [ "-Wl,--unresolved-symbols=ignore-all" ]
+  }
+
+  if (is_linux && use_pango && !use_system_harfbuzz) {
+    static_library("harfbuzz-ng-ft") {
+      sources = [
+        "src/hb-ft.cc",
+        "src/hb-ft.h",
+      ]
+
+      configs -= [ "//build/config/gcc:symbol_visibility_hidden" ]
+      configs += [ "//build/config/gcc:symbol_visibility_default" ]
+
+      configs -= [ "//build/config/compiler:chromium_code" ]
+      configs += [
+        "//build/config/compiler:no_chromium_code",
+        ":harfbuzz-ng-ft-deferred-linkage",
+
+        # Must be after no_chromium_code for warning flags to be ordered
+        # correctly.
+        ":harfbuzz_warnings",
+      ]
+      public_configs = [ ":harfbuzz-ng_config" ]
+
+      defines = [
+        "HAVE_OT",
+        "HAVE_ICU",
+        "HAVE_ICU_BUILTIN",
+        "HB_NO_MT",
+      ]
+
+      deps = [
+        "//build/config/freetype:freetype-without-harfbuzz",
+      ]
+    }
+  }
 }
 
 fuzzer_test("harfbuzz_fuzzer") {
   sources = [
     "fuzz/harfbuzz_fuzzer.cc",
   ]
   deps = [
     ":harfbuzz-ng",
   ]
   libfuzzer_options = [ "max_len=16800" ]
   seed_corpus = "fuzz/seed_corpus"
 }