i965g: add lots of error checks and early returns

Any allocation that may fail should be checked, and propogate the
error upwards.  At the highest level we will flush batch and retry.

This is an alternate strategy to what the original DRI driver did of
attempting to flush batch from the lowest levels (eg inside
BEGIN_BATCH).  The trouble with that strategy was that flushes could
occur at unexpected times, and additionally there was a need for a
wierd notification mechanism to propogate the 'lost context' state
back up to higher levels.

Propogating the errors directly gives us a lot of flexibility how to
deal with these states, at the expense of a lot more checking in the
code.

Will add some sanity checks later to make sure that out-of-memory
conditions are properly escalated and not lost halfway up the stack.

1 files changed, 10 insertions, 3 deletions

diff --git a/src/gallium/drivers/i965/brw_eu.c b/src/gallium/drivers/i965/brw_eu.c
index de43b14512d..a8fcb5f97eb 100644
--- a/src/gallium/drivers/i965/brw_eu.c
+++ b/src/gallium/drivers/i965/brw_eu.c
@@ -118,16 +118,23 @@ void brw_init_compile( struct brw_context *brw, struct brw_compile *p )
 }
 
 
-const GLuint *brw_get_program( struct brw_compile *p,
-			       GLuint *sz )
+enum pipe_error brw_get_program( struct brw_compile *p,
+                                 const GLuint **data,
+                                 GLuint *sz )
 {
    GLuint i;
 
    for (i = 0; i < 8; i++)
       brw_NOP(p);
 
+   /* Is the generated program malformed for some reason?
+    */
+   if (p->error)
+      return PIPE_ERROR_BAD_INPUT;
+
    *sz = p->nr_insn * sizeof(struct brw_instruction);
-   return (const GLuint *)p->store;
+   *data = (const GLuint *)p->store;
+   return PIPE_OK;
 }