glsl/lower_clip_distance: Update symbol table.

This patch modifies the clip distance lowering pass so that the new
symbol it generates (glClipDistanceMESA) is added to the shader's
symbol table.

This will allow a later patch to modify the linker so that it finds
transform feedback varyings using the symbol table rather than having
to iterate through all the declarations in the shader.

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

src/glsl/ir_optimization.h

@@ -72,7 +72,7 @@ bool lower_noise(exec_list *instructions);
 bool lower_variable_index_to_cond_assign(exec_list *instructions,
     bool lower_input, bool lower_output, bool lower_temp, bool lower_uniform);
 bool lower_quadop_vector(exec_list *instructions, bool dont_lower_swz);
-bool lower_clip_distance(exec_list *instructions);
+bool lower_clip_distance(gl_shader *shader);
 void lower_output_reads(exec_list *instructions);
 void lower_ubo_reference(struct gl_shader *shader, exec_list *instructions);
 bool optimize_redundant_jumps(exec_list *instructions);

src/glsl/linker.cpp

@@ -2568,8 +2568,9 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       if (!prog->LinkStatus)
 	 goto done;
 
-      if (ctx->ShaderCompilerOptions[i].LowerClipDistance)
-         lower_clip_distance(prog->_LinkedShaders[i]->ir);
+      if (ctx->ShaderCompilerOptions[i].LowerClipDistance) {
+         lower_clip_distance(prog->_LinkedShaders[i]);
+      }
 
       unsigned max_unroll = ctx->ShaderCompilerOptions[i].MaxUnrollIterations;
 

src/glsl/lower_clip_distance.cpp

@@ -45,6 +45,7 @@
  * LowerClipDistance flag in gl_shader_compiler_options to true.
  */
 
+#include "glsl_symbol_table.h"
 #include "ir_hierarchical_visitor.h"
 #include "ir.h"
 
@@ -334,11 +335,14 @@ lower_clip_distance_visitor::visit_leave(ir_call *ir)
 
 
 bool
-lower_clip_distance(exec_list *instructions)
+lower_clip_distance(gl_shader *shader)
 {
    lower_clip_distance_visitor v;
 
-   visit_list_elements(&v, instructions);
+   visit_list_elements(&v, shader->ir);
+
+   if (v.new_clip_distance_var)
+      shader->symbols->add_variable(v.new_clip_distance_var);
 
    return v.progress;
 }