Add CC to the GN build, work on GPU more

build/config/linux/BUILD.gn

Index: build/config/linux/BUILD.gn
diff --git a/build/config/linux/BUILD.gn b/build/config/linux/BUILD.gn
index e26e397ec0ed85b84fa4eafaae057490426ea577..18b1da4a6482d0977c57b803e2025cf990964fc3 100644
--- a/build/config/linux/BUILD.gn
+++ b/build/config/linux/BUILD.gn
@@ -82,31 +82,63 @@ pkg_config("gconf") {
   defines = [ "USE_GCONF" ]
 }
 
+# name: Name to use for the value of the --name arg.
+# output_h/output_cc: Names for the generated header/cc file with no dir.
+# header: header file to process. Example: "<foo/bar.h>"
+# functions: List of strings for functions to process.
+# config: Label of the config generated by pkgconfig.
+template("generate_library_loader") {
+  output_h = "$root_gen_dir/library_loaders/" + invoker.output_h
+  output_cc = "$root_gen_dir/library_loaders/" + invoker.output_cc
+
+  action_visibility = ":$target_name"
+  action("${target_name}_loader") {
+    visibility = action_visibility
+
+    script = "//tools/generate_library_loader/generate_library_loader.py"
+    if (defined(invoker.visibility)) {
+      visibility = invoker.visibility
+    }
+
+    outputs = [ output_h, output_cc ]
+
+    args = [
+      "--name", invoker.name,
+      "--output-h", rebase_path(output_h),
+      "--output-cc", rebase_path(output_cc),
+      "--header", invoker.header,
+      # Note GYP build exposes a per-target variable to control this, which, if
+      # manually set to true, will disable dlopen(). Its not clear this is
+      # needed, so here we just leave off. If this can be done globally, we
+      # can expose one switch for this value, otherwise we need to add a template
+      # param for this.
+      "--link-directly=0",
+    ] + invoker.functions
+  }
+
+  source_set(target_name) {
+    direct_dependent_configs = [ invoker.config ]
+    sources = [ output_h, output_cc ]
+    deps = [ ":${target_name}_loader" ]
+  }
+}
+
 pkg_config("gio_config") {
   packages = [ "gio-2.0" ]
   defines = [ "USE_GIO" ]
+  ignore_libs = true  # Loader generated below.
 }
 
-gio_output_h = "$root_gen_dir/library_loaders/libgio.h"
-gio_output_cc = "$root_gen_dir/library_loaders/libgio_loader.cc"
+# This generates a target named "gio".
+generate_library_loader("gio") {
+  name = "LibGioLoader"
+  output_h = "libgio.h"
+  output_cc = "libgio_loader.cc"
+  # TODO(brettw) convert ti "<gio/gio.h>" once GN doesn't mangle <>.
+  header = "\"gio/gio.h\""
+  config = ":gio_config"
 
-action("make_gio_headers") {
-  visibility = ":gio"
-
-  script = "//tools/generate_library_loader/generate_library_loader.py"
-
-  outputs = [ gio_output_h, gio_output_cc ]
-
-  args = [
-    "--name", "LibGioLoader",
-    "--output-h", rebase_path(gio_output_h),
-    "--output-cc", rebase_path(gio_output_cc),
-    # TODO(brettw) convert ti "<gio/gio.h>" once GN doesn't mangle <>.
-    "--header", "\"gio/gio.h\"",
-    # Note GYP build exposes a variable linux_link_gsettings to control this,
-    # which, if manually set to true, will disable dlopen() for this. Its not
-    # clear this is needed, so here we just leave off.
-    "--link-directly=0",
+  functions = [
     "g_settings_new",
     "g_settings_get_child",
     "g_settings_get_string",
@@ -117,8 +149,29 @@ action("make_gio_headers") {
   ]
 }
 
-source_set("gio") {
-  direct_dependent_configs = [ ":gio_config" ]
-  sources = [ gio_output_h, gio_output_cc ]
-  deps = [ ":make_gio_headers" ]
+# pkgconfig doesn't return anything interesting for this other than -lpci
+# on suppotred systems, so we hardcode.
+config("libpci_config") {
+  # This is not needed as long as we're setting link_directly=0 for the library
+  # loaders.
+  #libs = [ "pci" ]
+}
+
+# This generates a target named "libpci".
+generate_library_loader("libpci") {
+  name = "LibPciLoader"
+  output_h = "libpci.h"
+  output_cc = "libpci_loader.cc"
+  # TODO(brettw) convert to "<pci/pci.h>" once GN doesn't mangle <>.
+  header = "\"pci/pci.h\""
+  config = ":libpci_config"
+
+  functions = [
+    "pci_alloc",
+    "pci_init",
+    "pci_cleanup",
+    "pci_scan_bus",
+    "pci_fill_info",
+    "pci_lookup_name",
+  ]
 }