Comments added

diff --git a/util/ceg/as_parser/pars.g b/util/ceg/as_parser/pars.g
index 81f0ac7..5a9e2de 100644 (file)
--- a/util/ceg/as_parser/pars.g
+++ b/util/ceg/as_parser/pars.g
@@ -1,3 +1,42 @@
+/* This file contains the description of the 'as_table' parser.
+ * It transforms every entry into a C-funtion, for example :
+ *
+ *     and dst:REG, src:EADDR  ==>     @text1( 0x23);
+ *                                     mod_RM( dst->reg, src).
+ *
+ *     ... dst:ACCU, src:DATA  ==>     @text1( 0x25);
+ *                                     @text2(
+ *                                     %$(src->expr)).
+ *
+ * Will be transformed into :
+ *
+ *     and_instr( dst, src)
+ *     struct t_operand *dst, *src;
+ *     {
+ *             if (  REG( dst) && EADDR( src)) {
+ *                      cur_pos += 1;
+ *                      fprint( outfile, "text1( 0x23)");
+ *                      fprint( outfile, ";");
+ *                      mod_RM( dst->reg, src);
+ *             }
+ *             else if ( ACCU( dst) && DATA( src)) {
+ *                     cur_pos += 1;
+ *                     fprint( outfile, "text1( 0x25)");
+ *                     fprint( outfile, ";");
+ *                     cur_pos += 2;
+ *                     fprint( outfile, "text2( ");
+ *                     eval( src->expr);
+ *                     fprint( outfile, ")");
+ *                     fprint( outfile, ";");
+ *             }
+ *             else
+ *                     error( "No match for and");
+ *     }
+ * 
+ * At the end of the table a list is generated enumerating all the assembler
+ * mnemonics and their corresponding function names.
+ */
+
 {
 
 #include "decl.h"
@@ -57,6 +96,10 @@ action               : if_statement
                | subroutine
                ;
 
+/* A function call is just an identifier followed by an expression surrounded
+ * by '(' and ')'. CONDITION is a token that matches this construct;
+ */
+
 subroutine     : IDENTIFIER            { yymorfg=1;}
                  CONDITION             { pr_subroutine( yytext);}
                ;