How do I figure out what code will user a given permission?

For instance, let's take android.permission.GET_PACKAGE_SIZE.

Searching for this string in Android 1.6 *.xml source files only points to a single application that uses it, frameworks\base\tests\AndroidTests.

So the next step is to search through the开发者_运维百科 .java files in a hope that I'll eventually find the code that might look like it queries for package size.

Is this the supposed way of discovering permission use?

The Manage Applications UI uses the API protected by this permission. It probably doesn't request the permission in its manifest because it runs as the system user ID so is implicitly getting the permission.

For applications in general, yes you can look at their AndroidManifest.xml to find the permissions. This is complicated by shared user IDs, which allow multiple applications to run as the same uid, and thus share permissions; any such app requesting a permission grants that permission to all such apps. The settings app, which has the Manage Applications UI, uses the "system" shared user ID so gets all such permissions available to the system.

Generally speaking, you find out what permissions you need because they are referenced from APIs you want to use, normally in the docs, occasionally by exceptions.

Conversely, if a given permission is not cited in the docs, except where it is named (e.g., on Manifest.permission), then it is probably a system permission that you are ineligible to hold unless you are working on alternative firmware.

And, if you are working on alternative firmware, you'd be well-versed in searching the source code. I use Google Code Search, personally, such as this search for your desired permission.

So, in the case of GET_PACKAGE_SIZE, the only place you find it in the docs is in Manifest.permission, and the only place the source code requires it is in a non-SDK method, so I suspect you cannot hold it.

Just check the docs.

GET_PACKAGE_SIZE : Allows an application to find out the space used by any package.

http://developer.android.com/reference/android/Manifest.permission.html

EDIT

I may have mis-understood the question. If you want to know what code is using a permission value. Then you will in fact have to dig through the source yourself.