diff options
Diffstat (limited to 'awkgram.y')
| -rw-r--r-- | awkgram.y | 37 |
1 files changed, 31 insertions, 6 deletions
@@ -84,7 +84,7 @@ static int one_line_close(int fd); static int want_source = FALSE; static int want_regexp; /* lexical scanning kludge */ -static int can_return; /* parsing kludge */ +static char *in_function; /* parsing kludge */ static int rule = 0; const char *const ruletab[] = { @@ -229,7 +229,7 @@ rule } | function_prologue action { - can_return = FALSE; + in_function = NULL; (void) mk_function($1, $2); yyerrok; } @@ -358,11 +358,11 @@ function_prologue $1->source_file = source; if (install_function($2->lextok, $1, $4) < 0) YYABORT; + in_function = $2->lextok; $2->lextok = NULL; bcfree($2); /* $4 already free'd in install_function */ $$ = $1; - can_return = TRUE; } ; @@ -817,15 +817,27 @@ non_compound_stmt } | LEX_RETURN { - if (! can_return) + if (! in_function) yyerror(_("`return' used outside function context")); } opt_exp statement_term { if ($3 == NULL) { $$ = list_create($1); (void) list_prepend($$, instruction(Op_push_i)); $$->nexti->memory = dupnode(Nnull_string); - } else + } else { + if (do_optimize > 1 + && $3->lasti->opcode == Op_func_call + && STREQ($3->lasti->func_name, in_function) + ) { + /* Do tail recursion optimization. Tail + * call without a return value is recognized + * in mk_function(). + */ + ($3->lasti + 1)->tail_call = TRUE; + } + $$ = list_append($3, $1); + } } | simple_stmt statement_term ; @@ -3899,6 +3911,19 @@ mk_function(INSTRUCTION *fi, INSTRUCTION *def) thisfunc = fi->func_body; assert(thisfunc != NULL); + if (do_optimize > 1 && def->lasti->opcode == Op_pop) { + /* tail call which does not return any value. */ + + INSTRUCTION *t; + + for (t = def->nexti; t->nexti != def->lasti; t = t->nexti) + ; + if (t->opcode == Op_func_call + && STREQ(t->func_name, thisfunc->vname) + ) + (t + 1)->tail_call = TRUE; + } + /* add an implicit return at end; * also used by 'return' command in debugger */ @@ -4773,7 +4798,7 @@ optimize_assignment(INSTRUCTION *exp) if ( ! do_optimize || ( i1->opcode != Op_assign && i1->opcode != Op_field_assign) - ) + ) return list_append(exp, instruction(Op_pop)); for (i2 = exp->nexti; i2 != i1; i2 = i2->nexti) { |