Make it possible to build libhardware.

third_party/hwcplus/src/hardware.c

 /*
  * Copyright (C) 2008 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 
 #include <hardware/hardware.h>
 
 #include <cutils/properties.h>
 
+#include <stdlib.h>
 #include <dlfcn.h>
 #include <string.h>
 #include <pthread.h>
 #include <errno.h>
 #include <limits.h>
 
 #define LOG_TAG "HAL"
 #include <utils/Log.h>
 
 /** Base path of the hal modules */
-#if defined(__LP64__)
-#define HAL_LIBRARY_PATH1 "/system/lib64/hw"
-#define HAL_LIBRARY_PATH2 "/vendor/lib64/hw"
-#else
-#define HAL_LIBRARY_PATH1 "/system/lib/hw"
-#define HAL_LIBRARY_PATH2 "/vendor/lib/hw"
+#if !defined(DEFAULT_HAL_LIBRARY_PATH)
+#define DEFAULT_HAL_LIBRARY_PATH "/usr/lib/hwcplus"
 #endif
 
 /**
  * There are a set of variant filename for modules. The form of the filename
  * is "<MODULE_ID>.variant.so" so for the led module the Dream variants 
  * of base "ro.product.board", "ro.board.platform" and "ro.arch" would be:
  *
  * led.trout.so
  * led.msm7k.so
  * led.ARMV6.so
@@ skipping 75 matching lines @@
     return status;
 }
 
 /*
  * Check if a HAL with given name and subname exists, if so return 0, otherwise
  * otherwise return negative.  On success path will contain the path to the HAL.
  */
 static int hw_module_exists(char *path, size_t path_len, const char *name,
                             const char *subname)
 {
-    snprintf(path, path_len, "%s/%s.%s.so",
-             HAL_LIBRARY_PATH2, name, subname);
+    char *base = getenv("HAL_LIBRARY_PATH");

[rjkroege, 2014/04/25 21:28:07]

you could be less intrusive and preserve more of the original code with just the
addition of the code to read from the environment variable? And defaults for
CrOS in a #ifdef?

+    if (!base)
+        base = DEFAULT_HAL_LIBRARY_PATH;
+    snprintf(path, path_len, "%s/%s.%s.so", base, name, subname);
     if (access(path, R_OK) == 0)
         return 0;
 
-    snprintf(path, path_len, "%s/%s.%s.so",
-             HAL_LIBRARY_PATH1, name, subname);
-    if (access(path, R_OK) == 0)
-        return 0;
-
     return -ENOENT;
 }
 
 int hw_get_module_by_class(const char *class_id, const char *inst,
                            const struct hw_module_t **module)
 {
     int i;
     char prop[PATH_MAX];
     char path[PATH_MAX];
     char name[PATH_MAX];
@@ skipping 39 matching lines @@
 found:
     /* load the module, if this fails, we're doomed, and we should not try
      * to load a different variant. */
     return load(class_id, path, module);
 }
 
 int hw_get_module(const char *id, const struct hw_module_t **module)
 {
     return hw_get_module_by_class(id, NULL, module);
 }