ARB prog parser: Fix epic memory leak in lexer / parser interface

Anything that matched IDENTIFIER was strdup'ed and returned to the
parser.  However, almost every case of IDENTIFIER in the parser just
dropped the returned string on the floor.  Every swizzle string, every
option string, every use of a variable, etc. leaked memory.

Create a temporary buffer in the parser state (string_dumpster and
dumpster_size).  Return strings from the lexer to the parser in the
buffer.  Grow the buffer as needed.  When the parser needs to keep a
string (i.e., delcaring a new variable), let it make a copy then.

The only leak that valgrind now detects is /occasionally/ the copy of
the program string in gl_program::String is leaked.  I'm not seeing
how. :(

1 files changed, 16 insertions, 0 deletions

diff --git a/src/mesa/shader/program_parser.h b/src/mesa/shader/program_parser.h
index fa47d84565a..8d8b4d89bc4 100644
--- a/src/mesa/shader/program_parser.h
+++ b/src/mesa/shader/program_parser.h
@@ -38,6 +38,13 @@ enum asm_type {
    at_output,
 };
 
+/**
+ * \note
+ * Objects of this type are allocated as the object plus the name of the
+ * symbol.  That is, malloc(sizeof(struct asm_symbol) + strlen(name) + 1).
+ * Alternately, asm_symbol::name could be moved to the bottom of the structure
+ * and declared as 'char name[0];'.
+ */
 struct asm_symbol {
    struct asm_symbol *next;    /**< List linkage for freeing. */
    const char *name;
@@ -158,6 +165,15 @@ struct asm_parser_state {
 
 
    /**
+    * Buffer to hold strings transfered from the lexer to the parser
+    */
+   /*@{*/
+   char *string_dumpster;      /**< String data transfered. */
+   size_t dumpster_size;       /**< Total size, in bytes, of the buffer. */
+   /*@}*/
+
+
+   /**
     * Selected limits copied from gl_constants
     *
     * These are limits from the GL context, but various bits in the program