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, 13 insertions, 4 deletions

diff --git a/src/mesa/shader/program_parse.y b/src/mesa/shader/program_parse.y
index c3152aa2f88..a23625d3fb5 100644
--- a/src/mesa/shader/program_parse.y
+++ b/src/mesa/shader/program_parse.y
@@ -1919,7 +1919,7 @@ ALIAS_statement: ALIAS IDENTIFIER '=' IDENTIFIER
 		      "undefined variable binding in ALIAS statement");
 	      YYERROR;
 	   } else {
-	      _mesa_symbol_table_add_symbol(state->st, 0, $2, target);
+	      _mesa_symbol_table_add_symbol(state->st, 0, strdup($2), target);
 	   }
 	}
 	;
@@ -2027,10 +2027,14 @@ declare_variable(struct asm_parser_state *state, char *name, enum asm_type t,
    if (exist != NULL) {
       yyerror(locp, state, "redeclared identifier");
    } else {
-      s = calloc(1, sizeof(struct asm_symbol));
-      s->name = name;
+      const size_t name_len = strlen(name);
+
+      s = calloc(1, sizeof(struct asm_symbol) + name_len + 1);
+      s->name = (char *)(s + 1);
       s->type = t;
 
+      memcpy((char *) s->name, name, name_len + 1);
+
       switch (t) {
       case at_temp:
 	 if (state->prog->NumTemporaries >= state->limits->MaxTemps) {
@@ -2280,6 +2284,7 @@ _mesa_parse_arb_program(GLcontext *ctx, GLenum target, const GLubyte *str,
 
    if (state->prog->String != NULL) {
       _mesa_free(state->prog->String);
+      state->prog->String = NULL;
    }
 
    state->prog->String = strz;
@@ -2371,7 +2376,6 @@ error:
    for (sym = state->sym; sym != NULL; sym = temp) {
       temp = sym->next;
 
-      _mesa_free((void *) sym->name);
       _mesa_free(sym);
    }
    state->sym = NULL;
@@ -2379,5 +2383,10 @@ error:
    _mesa_symbol_table_dtor(state->st);
    state->st = NULL;
 
+   if (state->string_dumpster != NULL) {
+      _mesa_free(state->string_dumpster);
+      state->dumpster_size = 0;
+   }
+
    return result;
 }