Split up headers.

This splits headers into three locations:
include - for backwards compatibility, the global include
include_all - for things system/vendor both use
include_vendor - for things that only vendors use

The goal is to gradually have system things stop referencing
(at least most) of these headers.

Bug: 37280010
Test: build (CL on top adds back in symlinks)

Change-Id: Ibf194276b7faa857e1e7605d7719f4e7d873ecba

Android.bp

@@ -32,6 +32,7 @@ license {
 
 cc_library_headers {
     name: "libhardware_headers",
+
     header_libs: [
         "libaudio_system_headers",
         "libsystem_headers",
@@ -45,11 +46,22 @@ cc_library_headers {
         "libbluetooth-types-header",
     ],
 
-    export_include_dirs: ["include"],
     recovery_available: true,
     vendor_available: true,
     // TODO(b/153609531): remove when no longer needed.
     native_bridge_supported: true,
+
+    // There are three include directories currently:
+    // - include: this directory is the original location of libhardware headers. It is globally
+    //       available (even if you do not depend on libhardware). Many locations also use
+    //       LOCAL_C_INCLUDES or include_dirs to access these from a global namespace. These processes
+    //       should replace this dependency with a direct dependency on libhardware(_headers)?.
+    // - include_all: this directory is for system and vendor include files. Gradually, the number of
+    //       files here should be reduced to 0 by moving them to vendor as old code is phased out.
+    // - include_vendor: this directory is the current designated resting place for these headers.
+    //       They are kept around to try to help insure existing codebases can function.
+    export_include_dirs: ["include_all"],
+
     target: {
         recovery: {
             exclude_header_libs: [
@@ -60,6 +72,12 @@ cc_library_headers {
         windows: {
             enabled: true,
         },
+        vendor: {
+            override_export_include_dirs: [
+                "include_all",
+                "include_vendor",
+            ],
+        },
     },
     apex_available: [
         "//apex_available:platform",

update-includes.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+
+set +ex
+
+if [ ! "$ANDROID_BUILD_TOP" ]; then
+    echo "lunch?"
+    exit 1
+fi
+
+function update-includes() {
+    find -L "$ANDROID_BUILD_TOP/hardware/libhardware/include/hardware" -maxdepth 1 -xtype l -exec rm {} \;
+
+    for f in $ANDROID_BUILD_TOP/hardware/libhardware/include_all/hardware/*; do
+        local bn="$(basename $f)"
+        ln -s "../../include_all/hardware/$bn" "$ANDROID_BUILD_TOP/hardware/libhardware/include/hardware/$bn"
+    done
+}
+
+update-includes