glsl: Clean up shading language mixing check for GLSL 3.00 ES.

Previously, we prohibited mixing of shading language versions if
min_version == 100 or max_version >= 130.  This was technically
correct (since desktop GLSL 1.30 and beyond prohibit mixing of shading
language versions, as does GLSL 1.00 ES), but it was confusing.  Also,
we asserted that all shading language versions were between 1.00 and
1.40, which was unnecessary (since the parser already checks shading
language versions) and doesn't work for GLSL 3.00 ES.

This patch changes the code to explicitly check that (a) ES shaders
aren't mixed with desktop shaders, (b) shaders aren't mixed between ES
versions, and (c) shaders aren't mixed between desktop GLSL versions
when at least one shader is GLSL 1.30 or greater.  Also, it removes
the unnecessary assertion.

[v2, idr]: Slightly tweak the is_es_prog detection to occur outside the loop
instead of doing something special on the first loop iteration.  Suggested by
Ken.

[v3, idr]: s/IsEs(Shader|Prog)/IsES/  Suggested by Ken and Eric.

Reviewed-by: Ian Romanick <[email protected]> [v1]
Reviewed-by: Kenneth Graunke <[email protected]>
Acked-by: Carl Worth <[email protected]>

1 files changed, 11 insertions, 3 deletions

diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index 3b2ab962b4e..311df6579f2 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -2421,10 +2421,18 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
 
    unsigned min_version = UINT_MAX;
    unsigned max_version = 0;
+   const bool is_es_prog =
+      (prog->NumShaders > 0 && prog->Shaders[0]->IsES) ? true : false;
    for (unsigned i = 0; i < prog->NumShaders; i++) {
       min_version = MIN2(min_version, prog->Shaders[i]->Version);
       max_version = MAX2(max_version, prog->Shaders[i]->Version);
 
+      if (prog->Shaders[i]->IsES != is_es_prog) {
+	 linker_error(prog, "all shaders must use same shading "
+		      "language version\n");
+	 goto done;
+      }
+
       switch (prog->Shaders[i]->Type) {
       case GL_VERTEX_SHADER:
 	 vert_shader_list[num_vert_shaders] = prog->Shaders[i];
@@ -2444,10 +2452,10 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
    /* Previous to GLSL version 1.30, different compilation units could mix and
     * match shading language versions.  With GLSL 1.30 and later, the versions
     * of all shaders must match.
+    *
+    * GLSL ES has never allowed mixing of shading language versions.
     */
-   assert(min_version >= 100);
-   assert(max_version <= 140);
-   if ((max_version >= 130 || min_version == 100)
+   if ((is_es_prog || max_version >= 130)
        && min_version != max_version) {
       linker_error(prog, "all shaders must use same shading "
 		   "language version\n");