interpreter for "little"

git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@119 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e

1 files changed, 62 insertions, 0 deletions

diff --git a/test/littlesemantics/little.y b/test/littlesemantics/little.y
new file mode 100644
index 0000000..1bf4e8e
--- /dev/null
+++ b/test/littlesemantics/little.y
@@ -0,0 +1,62 @@
+%{
+#include <stdio.h>
+#include <string.h>
+#include "little.h"
+#define YYSTYPE term *
+
+  char *lextext;
+  int lexnum;
+
+  term *revert_env(term *t) {
+    term *r = NULL, *t1;
+    while(NULL != t) {
+      t1 = r;
+      r = t;
+      t = child(t,2);
+      r->term_body.children[1] = t1;
+    }
+    return r;
+  }
+
+  void yyerror(char const *s) {
+    fprintf(stderr, "%s\n", s);
+  }
+%}
+
+%token T_VARIABLES T_IN T_END T_WHILE T_DO T_DONE T_GT
+%token T_ASSIGN T_PLUS T_SCOLUMN T_OPEN T_CLOSE T_OPEN_B T_CLOSE_B
+%token T_SKIP NUM ID 
+%left T_PLUS
+%right T_SCOLUMN
+%%
+program : T_VARIABLES environment T_IN inst T_END
+{ print_env(execute(revert_env($2),$4)); exit(0) }
+;
+b_exp: exp T_GT exp {$$=greater($1, $3); }
+;
+num : NUM { $$=numeral(lexnum); }
+;
+identifier : ID { $$=variable(lextext); }
+;
+variable_value : identifier num { $$=variable_value($1,$2);}
+;
+environment : variable_value { $$ = variable_list($1, NULL); }
+| environment T_SCOLUMN variable_value { $$ = variable_list($3, $1);
+   printf ("foo\n"); }
+;
+inst: identifier T_ASSIGN exp {$$ = assignment($1,$3); }
+|  inst T_SCOLUMN inst {$$ = sequence($1,$3); }
+|  T_WHILE b_exp T_DO inst T_DONE {$$ = term_while($2,$4); } 
+|  T_SKIP { $$ = skip(); }
+|  T_OPEN_B exp T_CLOSE_B { $$ = $2; }
+;
+exp: num {$$= $1;}
+|    identifier {$$=$1; }
+|    exp T_PLUS exp {$$=addition($1, $3); }
+|    T_OPEN exp T_CLOSE { $$= $2; }
+;
+%%
+
+main(int argc, char **argv) {
+  yyparse();
+}