dawids/lang-bootstrap
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labels, goto

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pommicket 2022-02-13 12:51:21 -05:00
parent a26f0d52d9
commit 5dba28b8ba
2 changed files with 38 additions and 10 deletions
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32
05/codegen.b
View file

@ -2584,6 +2584,8 @@ function generate_statement
if c == STATEMENT_FOR goto gen_stmt_for
if c == STATEMENT_CONTINUE goto gen_stmt_continue
if c == STATEMENT_BREAK goto gen_stmt_break
if c == STATEMENT_LABEL goto gen_stmt_label
if c == STATEMENT_GOTO goto gen_stmt_goto
; @TODO
die(.str_genstmtNI)
@ -2747,7 +2749,35 @@ function generate_statement
emit_jmp_rel32(0) ; jmp +0 (temporary)
add_ref(break_refs, code_output)
return
:gen_stmt_label
if codegen_second_pass != 0 goto gen_label_pass2
ident_list_add(curr_function_labels, dat1, code_output)
return
:gen_label_pass2
addr1 = ident_list_lookup(curr_function_labels, dat1)
if addr1 != code_output goto bad_label_addr
return
:bad_label_addr
die(.str_bad_label_addr)
:str_bad_label_addr
string Internal compiler error: Label address on 2nd pass doesn't match 1st pass.
byte 0
:gen_stmt_goto
if codegen_second_pass == 0 goto gen_goto_pass1
addr0 = ident_list_lookup(curr_function_labels, dat1)
if addr0 == 0 goto bad_label
d = addr0 - code_output
d -= 5 ; subtract length of jmp instruction
emit_jmp_rel32(d)
return
:gen_goto_pass1
emit_jmp_rel32(0) ; we don't know the address of the label; just use 0
return
:bad_label
statement_error(statement, .str_bad_label)
:str_bad_label
string Unrecognized label.
byte 0
function generate_function
argument function_name
argument function_statement

16
05/main.c
View file

@ -23,17 +23,15 @@ long gcd(long a, long b) {
return b;
}
int f() {
lb: goto lb;
}
int main(int argc, char **argv) {
int exp = 0;
int i;
int j;
for (i = 0; i < 10; ++i) {
for (j = 0; j < 10; ++j) {
if (j >= i) break;
exp += 1;
}
if (i >= 5) break;
}
lb:
exp++;
if (exp < 10) goto lb;
return exp ;
}