scanner: memory leak free scanner generator.

**Issue:**
Scanner generation leaks memory for transition tables when invoked
without `--tables-file` option.

**Root cause:**
`gentabs` function has different memory acquire/release conditions.

**Solution:**
Reclaim memory at the same scope where it was alloacated.

diff --git a/src/gen.c b/src/gen.c
index 590e5d8d1cc787fd61c69d5ba22e9fea02bc507a..ec0e0141f881e4d4266210f27f835a4849aed242 100644 (file)
--- a/src/gen.c
+++ b/src/gen.c
@@ -1234,9 +1234,9 @@ void gentabs (void)
                yytbl_data_compress (yyacc_tbl);
                if (yytbl_data_fwrite (&tableswr, yyacc_tbl) < 0)
                        flexerror (_("Could not write yyacc_tbl"));
-               yytbl_data_destroy (yyacc_tbl);
-               yyacc_tbl = NULL;
        }
+       yytbl_data_destroy (yyacc_tbl);
+       yyacc_tbl = NULL;
        /* End generating yy_accept */
 
        if (useecs) {
@@ -1289,11 +1289,10 @@ void gentabs (void)
                if (tablesext) {
                        yytbl_data_compress (yymeta_tbl);
                        if (yytbl_data_fwrite (&tableswr, yymeta_tbl) < 0)
-                               flexerror (_
-                                          ("Could not write yymeta_tbl"));
-                       yytbl_data_destroy (yymeta_tbl);
-                       yymeta_tbl = NULL;
+                               flexerror (_("Could not write yymeta_tbl"));
                }
+               yytbl_data_destroy (yymeta_tbl);
+               yymeta_tbl = NULL;
                /* End generating yy_meta */
        }
 
@@ -1350,9 +1349,9 @@ void gentabs (void)
                yytbl_data_compress (yybase_tbl);
                if (yytbl_data_fwrite (&tableswr, yybase_tbl) < 0)
                        flexerror (_("Could not write yybase_tbl"));
-               yytbl_data_destroy (yybase_tbl);
-               yybase_tbl = NULL;
        }
+       yytbl_data_destroy (yybase_tbl);
+       yybase_tbl = NULL;
        /* End generating yy_base */
 
 
@@ -1382,9 +1381,9 @@ void gentabs (void)
                yytbl_data_compress (yydef_tbl);
                if (yytbl_data_fwrite (&tableswr, yydef_tbl) < 0)
                        flexerror (_("Could not write yydef_tbl"));
-               yytbl_data_destroy (yydef_tbl);
-               yydef_tbl = NULL;
        }
+       yytbl_data_destroy (yydef_tbl);
+       yydef_tbl = NULL;
        /* End generating yy_def */
 
 
@@ -1420,9 +1419,9 @@ void gentabs (void)
                yytbl_data_compress (yynxt_tbl);
                if (yytbl_data_fwrite (&tableswr, yynxt_tbl) < 0)
                        flexerror (_("Could not write yynxt_tbl"));
-               yytbl_data_destroy (yynxt_tbl);
-               yynxt_tbl = NULL;
        }
+       yytbl_data_destroy (yynxt_tbl);
+       yynxt_tbl = NULL;
        /* End generating yy_nxt */
 
        /* Begin generating yy_chk */
@@ -1454,9 +1453,9 @@ void gentabs (void)
                yytbl_data_compress (yychk_tbl);
                if (yytbl_data_fwrite (&tableswr, yychk_tbl) < 0)
                        flexerror (_("Could not write yychk_tbl"));
-               yytbl_data_destroy (yychk_tbl);
-               yychk_tbl = NULL;
        }
+       yytbl_data_destroy (yychk_tbl);
+       yychk_tbl = NULL;
        /* End generating yy_chk */
 
        free(acc_array);