diff options
Diffstat (limited to '05')
| -rw-r--r-- | 05/codegen.b | 95 | ||||
| -rw-r--r-- | 05/main.c | 14 |
2 files changed, 104 insertions, 5 deletions
diff --git a/05/codegen.b b/05/codegen.b index 6c8728a..2c0ceaf 100644 --- a/05/codegen.b +++ b/05/codegen.b @@ -1,3 +1,13 @@ +; @TODO : declarations need to be done differently. +; this should work, but doesn't currently; +; goto lbl1; +; { +; int x; +; lbl1: ... +; } + + + ; CALLING CONVENTION: ; Here is the process for calling a function: ; - the caller pushes the arguments on to the stack, from right to left @@ -26,6 +36,10 @@ global curr_function_return_type global break_refs ; 0-terminated array of pointers to be filled in with the break offset global continue_refs +; address of previous "case" label +global prev_case_addr + + #define REG_RAX 0 #define REG_RBX 3 #define REG_RCX 1 @@ -2586,6 +2600,9 @@ function generate_statement if c == STATEMENT_BREAK goto gen_stmt_break if c == STATEMENT_LABEL goto gen_stmt_label if c == STATEMENT_GOTO goto gen_stmt_goto + if c == STATEMENT_SWITCH goto gen_stmt_switch + if c == STATEMENT_CASE goto gen_stmt_case + if c == STATEMENT_DEFAULT goto gen_stmt_default ; @TODO die(.str_genstmtNI) @@ -2742,13 +2759,25 @@ function generate_statement *4p = d return :gen_stmt_continue + if continue_refs == 0 goto continue_outside_of_loop emit_jmp_rel32(0) ; jmp +0 (temporary) add_ref(continue_refs, code_output) return + :continue_outside_of_loop + statement_error(statement, .str_continue_outside_of_loop) + :str_continue_outside_of_loop + string continue statement not inside loop. + byte 0 :gen_stmt_break + if break_refs == 0 goto break_outside_of_loop emit_jmp_rel32(0) ; jmp +0 (temporary) add_ref(break_refs, code_output) return + :break_outside_of_loop + statement_error(statement, .str_break_outside_of_loop) + :str_break_outside_of_loop + string break statement not inside loop or switch. + byte 0 :gen_stmt_label if codegen_second_pass != 0 goto gen_label_pass2 ident_list_add(curr_function_labels, dat1, code_output) @@ -2778,6 +2807,72 @@ function generate_statement :str_bad_label string Unrecognized label. byte 0 + :gen_stmt_switch + break_refs = malloc(8000) + + local old_prev_case_addr + old_prev_case_addr = prev_case_addr + + generate_push_expression_casted(statement, dat1, TYPE_UNSIGNED_LONG) + emit_pop_rax() ; pop rax + emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax + + emit_jmp_rel32(0) ; jmp +0 (temporary) + prev_case_addr = code_output + + generate_statement(dat2) + + addr1 = code_output + handle_refs(&break_refs, prev_break_refs, addr1) + + ; fill in last jump, if any + if prev_case_addr == 0 goto switch_had_default + d = addr1 - prev_case_addr + p = prev_case_addr - 4 + *4p = d + :switch_had_default + prev_case_addr = old_prev_case_addr + return + :gen_stmt_case + if prev_case_addr == 0 goto gen_bad_case + emit_jmp_rel32(0) ; jump over the part where we deal with this case label + addr0 = code_output + + ; fill in previous jump + d = addr0 - prev_case_addr + p = prev_case_addr - 4 + *4p = d + + emit_mov_rax_imm64(dat1) + emit_cmp_rax_rbx() + emit_jne_rel32(0) + prev_case_addr = code_output + + addr1 = code_output + ; fill in jump over comparison + d = addr1 - addr0 + p = addr0 - 4 + *4p = d + return + + :gen_bad_case + ; @NONSTANDARD: we don't allow `case X:` after `default:` + ; it's very annoying that the C standard allows that + statement_error(statement, .str_gen_bad_case) + :str_gen_bad_case + string Either case outside of switch, or case following default. + byte 0 + :gen_stmt_default + addr0 = code_output + + ; fill in previous jump + d = addr0 - prev_case_addr + p = prev_case_addr - 4 + *4p = d + + prev_case_addr = 0 + return + function generate_function argument function_name argument function_statement @@ -28,10 +28,14 @@ int f() { } int main(int argc, char **argv) { - int exp = 0; - lb: - exp++; - if (exp < 10) goto lb; - return exp ; + int a = 5; + switch(a++){ + case 5: a++; + case 3: a++; + case 4: a++; + default: a++; + } + + return a ; } |