summaryrefslogtreecommitdiff
path: root/05
diff options
context:
space:
mode:
Diffstat (limited to '05')
-rw-r--r--05/codegen.b95
-rw-r--r--05/main.c14
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
diff --git a/05/main.c b/05/main.c
index cf2de7e..f26c982 100644
--- a/05/main.c
+++ b/05/main.c
@@ -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 ;
}