Revert the context tracking code

> Do you want to resend your change which revert the context changes?
> Make it base on Josh's git's tree and I will merge your changes in my
> branch.

Below. Or I can give it to you in git if you prefer. I still think we
should redo this in some form so that annotations with different
contexts can work properly, but I don't have time to take care of it
right now.

johannes

>From ca95b62edf1600a2b55ed9ca0515d049807a84fc Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes@sipsolutions.net>
Date: Tue, 23 Dec 2008 10:53:19 +0100
Subject: [PATCH] Revert context tracking code

1 files changed, 10 insertions, 33 deletions

diff --git a/sparse.1 b/sparse.1
index 92a1cae..c44e3a5 100644
--- a/sparse.1
+++ b/sparse.1
@@ -73,43 +73,20 @@ Warn about potential errors in synchronization or other delimited contexts.
 Sparse supports several means of designating functions or statements that
 delimit contexts, such as synchronization.  Functions with the extended
 attribute
-.BI __attribute__((context( [expression ,] in_context , out_context ))
-require the context \fIexpression\fR (for instance, a lock) to have at least the value
+.BI __attribute__((context( expression , in_context , out_context ))
+require the context \fIexpression\fR (for instance, a lock) to have the value
 \fIin_context\fR (a constant nonnegative integer) when called, and return with
-the value adjusted by \fIout_context - in_context\fR (where
-\fIout_context\fR is a constant nonnegative integer).  To change the value
-of a context (for example in macros), use the statement
-.BI __context__( [expression , ]adjust_value[ , required] )
-where \fIadjust_value\fR is a constant integer and \fIrequired\fR is a
-constant nonnegative integer. Not giving \fIrequired\fR is equivalent to
-giving zero and means that the statement does not need the context as a
-precondition, when given it means that the context must at least have the
-value of \fIrequired\fR.
-
-To indicate that a function requires
-.BI exactly
-a certain lock context (not "at least" as above), use the form
-.BI __attribute__((exact_context( [expression ,] in_context , out_context ))
-There currently is no corresponding
-.BI __exact_context__( [expression , ]adjust_value[ , required] )
-statement.
-
-To indicate that a certain function acquires a context depending on its
-return value, use
-.BI __attribute__((conditional_context( [expression ,] in_context , out_success , out_failure ))
-where \fIout_success\fR and \fIout_failure\fR indicate the context change
-done depending on success (non-zero) or failure (zero) return of the
-function. Note that currently, using this attribute on a function means that
-the function itself won't be checked for context handling at all. See the
-testsuite for examples.
-
-Sparse will warn when it sees a function change a
-context without indicating this with a \fBcontext\fR or \fBexact_context\fR attribute, either by
+the value \fIout_context\fR (a constant nonnegative integer).  For APIs
+defined via macros, use the statement form
+.BI __context__( expression , in_value , out_value )
+in the body of the macro.
+
+With \fB-Wcontext\fR Sparse will warn when it sees a function change the
+context without indicating this with a \fBcontext\fR attribute, either by
 decreasing a context below zero (such as by releasing a lock without acquiring
 it), or returning with a changed context (such as by acquiring a lock without
 releasing it).  Sparse will also warn about blocks of code which may
-potentially execute with different contexts and about functions that are
-executed without a lock they require.
+potentially execute with different contexts.
 
 Sparse issues these warnings by default.  To turn them off, use
 \fB\-Wno\-context\fR.