glsl: Throw an error when faced with a duplicated switch() case label.

The error message I chose matches gcc's error.  Fixes piglit
switch-case-duplicated.vert.

NOTE: This is a candidate for the 8.0 branch.

Reviewed-by: Ian Romanick <[email protected]>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/glsl/glsl_parser_extras.h b/src/glsl/glsl_parser_extras.h
index 35d1e3aee26..d5d5101a820 100644
--- a/src/glsl/glsl_parser_extras.h
+++ b/src/glsl/glsl_parser_extras.h
@@ -48,6 +48,10 @@ struct glsl_switch_state {
    ir_variable *is_fallthru_var;
    ir_variable *is_break_var;
    class ast_switch_statement *switch_nesting_ast;
+
+   /** Table of constant values already used in case labels */
+   struct hash_table *labels_ht;
+
    bool is_switch_innermost; // if switch stmt is closest to break, ...
 };