Squashed commit of the following (st-mesa-per-context-shaders branch):

commit 4f106f44a32eaddb6cf3fea6ba5ee9787bff609a
Author: Brian Paul <brianp@vmware.com>
Date:   Mon Dec 13 14:06:08 2010 -0700

    st/mesa: reorganize vertex program translation code

    Now it looks like the fragment and geometry program code.
    Also remove the serial number fields from programs.  It was used to
    determine when new translations were needed.  Now the variant key is
    used for that.  And the st_program_string_notify() callback removes all
    variants when the program's code is changed.

commit e12d6791c5e4bff60bb2e6c04414b1b4d1325f3e
Author: Brian Paul <brianp@vmware.com>
Date:   Mon Dec 13 13:38:12 2010 -0700

    st/mesa: implement geometry shader varients

    Only needed in order to support per-context gallium shaders.

commit c5751c673644808ab069259a852f24c4c0e92b9d
Author: Brian Paul <brianp@vmware.com>
Date:   Sun Dec 12 15:28:57 2010 -0700

    st/mesa: restore glDraw/CopyPixels using new fragment program variants

    Clean up the logic for fragment programs for glDraw/CopyPixels.  We now
    generate fragment program variants for glDraw/CopyPixels as needed which
    do texture sampling, pixel scale/bias, pixelmap lookups, etc.

commit 7b0bb99bab6547f503a0176b5c0aef1482b02c97
Author: Brian Paul <brianp@vmware.com>
Date:   Fri Dec 10 17:03:23 2010 -0700

    st/mesa: checkpoint: implement fragment program variants

    The fragment programs variants are per-context, as the vertex programs.

    NOTE: glDrawPixels is totally broken at this point.

commit 2cc926183f957f8abac18d71276dd5bbd1f27be2
Author: Brian Paul <brianp@vmware.com>
Date:   Fri Dec 10 14:59:32 2010 -0700

    st/mesa: make vertex shader variants per-context

    Gallium shaders are per-context but OpenGL shaders aren't.  So we need
    to make a different variant for each context.

    During context tear-down we need to walk over all shaders/programs and
    free all variants for the context being destroyed.

1 files changed, 94 insertions, 25 deletions

diff --git a/src/mesa/state_tracker/st_program.h b/src/mesa/state_tracker/st_program.h
index 72dbc715fe..519ee8c0d1 100644
--- a/src/mesa/state_tracker/st_program.h
+++ b/src/mesa/state_tracker/st_program.h
@@ -40,26 +40,60 @@
 #include "st_context.h"
 
 
+/** Fragment program variant key */
+struct st_fp_varient_key
+{
+   struct st_context *st;         /**< variants are per-context */
+
+   /** for glBitmap */
+   GLuint bitmap:1;               /**< glBitmap varient? */
+
+   /** for glDrawPixels */
+   GLuint drawpixels:1;           /**< glDrawPixels varient */
+   GLuint scaleAndBias:1;         /**< glDrawPixels w/ scale and/or bias? */
+   GLuint pixelMaps:1;            /**< glDrawPixels w/ pixel lookup map? */
+   GLuint drawpixels_z:1;         /**< glDrawPixels(GL_DEPTH) */
+   GLuint drawpixels_stencil:1;   /**< glDrawPixels(GL_STENCIL) */
+};
+
+
+/**
+ * Variant of a fragment program.
+ */
+struct st_fp_varient
+{
+   /** Parameters which generated this version of fragment program */
+   struct st_fp_varient_key key;
+
+   /** Driver's compiled shader */
+   void *driver_shader;
+
+   /** For glBitmap variants */
+   struct gl_program_parameter_list *parameters;
+   uint bitmap_sampler;
+
+   /** next in linked list */
+   struct st_fp_varient *next;
+};
+
+
 /**
  * Derived from Mesa gl_fragment_program:
  */
 struct st_fragment_program
 {
    struct gl_fragment_program Base;
-   GLuint serialNo;
 
    struct pipe_shader_state tgsi;
-   void *driver_shader;
 
-   /** Program prefixed with glBitmap prologue */
-   struct st_fragment_program *bitmap_program;
-   uint bitmap_sampler;
+   struct st_fp_varient *varients;
 };
 
 
 
 struct st_vp_varient_key
 {
+   struct st_context *st;          /**< variants are per-context */
    boolean passthrough_edgeflags;
 };
 
@@ -101,7 +135,6 @@ struct st_vp_varient
 struct st_vertex_program
 {
    struct gl_vertex_program Base;  /**< The Mesa vertex program */
-   GLuint serialNo, lastSerialNo;
 
    /** maps a Mesa VERT_ATTRIB_x to a packed TGSI input index */
    GLuint input_to_index[VERT_ATTRIB_MAX];
@@ -120,13 +153,35 @@ struct st_vertex_program
    struct st_vp_varient *varients;
 };
 
+
+
+struct st_gp_varient_key
+{
+   struct st_context *st;          /**< variants are per-context */
+   /* no other fields yet */
+};
+
+
+/**
+ * Geometry program variant.
+ */
+struct st_gp_varient
+{
+   /* Parameters which generated this translated version of a vertex */
+   struct st_gp_varient_key key;
+
+   void *driver_shader;
+
+   struct st_gp_varient *next;
+};
+
+
 /**
  * Derived from Mesa gl_geometry_program:
  */
 struct st_geometry_program
 {
    struct gl_geometry_program Base;  /**< The Mesa geometry program */
-   GLuint serialNo;
 
    /** map GP input back to VP output */
    GLuint input_map[PIPE_MAX_SHADER_INPUTS];
@@ -145,9 +200,12 @@ struct st_geometry_program
    ubyte input_semantic_index[PIPE_MAX_SHADER_INPUTS];
 
    struct pipe_shader_state tgsi;
-   void *driver_shader;
+
+   struct st_gp_varient *varients;
 };
 
+
+
 static INLINE struct st_fragment_program *
 st_fragment_program( struct gl_fragment_program *fp )
 {
@@ -198,32 +256,43 @@ st_reference_fragprog(struct st_context *st,
 }
 
 
-extern void
-st_translate_fragment_program(struct st_context *st,
-                              struct st_fragment_program *fp);
+extern struct st_vp_varient *
+st_get_vp_varient(struct st_context *st,
+                  struct st_vertex_program *stvp,
+                  const struct st_vp_varient_key *key);
 
-extern void
-st_translate_geometry_program(struct st_context *st,
-                              struct st_geometry_program *stgp);
 
-/* Called after program string change, discard all previous
- * compilation results.
- */
-extern void
-st_prepare_vertex_program(struct st_context *st,
-                          struct st_vertex_program *stvp);
+extern struct st_fp_varient *
+st_get_fp_varient(struct st_context *st,
+                  struct st_fragment_program *stfp,
+                  const struct st_fp_varient_key *key);
 
-extern struct st_vp_varient *
-st_translate_vertex_program(struct st_context *st,
-                            struct st_vertex_program *stvp,
-                            const struct st_vp_varient_key *key);
 
-void
+extern struct st_gp_varient *
+st_get_gp_varient(struct st_context *st,
+                  struct st_geometry_program *stgp,
+                  const struct st_gp_varient_key *key);
+
+
+
+extern void
 st_vp_release_varients( struct st_context *st,
                         struct st_vertex_program *stvp );
 
 extern void
+st_fp_release_varients( struct st_context *st,
+                        struct st_fragment_program *stfp );
+
+extern void
+st_gp_release_varients(struct st_context *st,
+                       struct st_geometry_program *stgp);
+
+
+extern void
 st_print_shaders(struct gl_context *ctx);
 
+extern void
+st_destroy_program_variants(struct st_context *st);
+
 
 #endif