glsl: Generate readable unique names at print time.

Since GLSL IR allows multiple ir_variables to share the same name, we
need to generate unique names when printing the IR.  Previously, we
always used %s@%p, appending the ir_variable's memory address.

While this worked, it had two drawbacks:
- When there aren't duplicates, the extra "@0x669a3e88" is useless
  and makes the code harder to read.
- Real duplicates were hard to tell apart:
  channel_expressions@0x6699e3c8 vs. channel_expressions@0x6699ddd8

We now append @2, @3, @4, and so on, but only where necessary to
distinguish duplicates.  Since we only do this at print time, any
performance impact is irrelevant.

Signed-off-by: Kenneth Graunke <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>
Reviewed-by: Ian Romanick <[email protected]>

1 files changed, 20 insertions, 9 deletions

diff --git a/src/glsl/ir_print_visitor.h b/src/glsl/ir_print_visitor.h
index 4feeb8c184d..c7136f11a3b 100644
--- a/src/glsl/ir_print_visitor.h
+++ b/src/glsl/ir_print_visitor.h
@@ -29,6 +29,10 @@
 #include "ir.h"
 #include "ir_visitor.h"
 
+extern "C" {
+#include "program/symbol_table.h"
+}
+
 extern void _mesa_print_ir(exec_list *instructions,
 			   struct _mesa_glsl_parse_state *state);
 
@@ -37,15 +41,8 @@ extern void _mesa_print_ir(exec_list *instructions,
  */
 class ir_print_visitor : public ir_visitor {
 public:
-   ir_print_visitor()
-   {
-      indentation = 0;
-   }
-
-   virtual ~ir_print_visitor()
-   {
-      /* empty */
-   }
+   ir_print_visitor();
+   virtual ~ir_print_visitor();
 
    void indent(void);
 
@@ -77,6 +74,20 @@ public:
    /*@}*/
 
 private:
+   /**
+    * Fetch/generate a unique name for ir_variable.
+    *
+    * GLSL IR permits multiple ir_variables to share the same name.  This works
+    * fine until we try to print it, when we really need a unique one.
+    */
+   const char *unique_name(ir_variable *var);
+
+   /** A mapping from ir_variable * -> unique printable names. */
+   hash_table *printable_names;
+   _mesa_symbol_table *symbols;
+
+   void *mem_ctx;
+
    int indentation;
 };