From 008d12251620366c3972c8884a33c63ddf4843ba Mon Sep 17 00:00:00 2001
From: pacien
Date: Mon, 7 May 2018 14:44:11 +0200
Subject: Extract generator functions (partial commit pt2)

---
 src/generator.c | 161 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 158 insertions(+), 3 deletions(-)

(limited to 'src/generator.c')

diff --git a/src/generator.c b/src/generator.c
index a7a7c72..004e559 100644
--- a/src/generator.c
+++ b/src/generator.c
@@ -7,7 +7,9 @@
 #include <stdio.h>
 #include "symbol_table.h"
 
-void prologue() {
+// ----- GLOBAL FUNCTIONS -----
+
+void gen_prologue() {
   printf("extern printf\n");
   printf("section .data\n");
   printf("format_int db \"%%d\",10,0\n\n");
@@ -27,7 +29,7 @@ void prologue() {
   printf("push rbp\nmov rbp, rsp\n\n");
 }
 
-void const_declaration() {
+void gen_const_declaration() {
   printf("mov rax,60 \n");
   printf("mov rdi,0 \n");
   printf("syscall \n");
@@ -37,7 +39,7 @@ void const_declaration() {
   loc_display_table();
 }
 
-void declaration(const char name[], int type, Scope scope) {
+void gen_declaration(const char name[], int type, Scope scope) {
   switch (scope) {
   case GLOBAL:
     glo_addVar(name, type);
@@ -50,4 +52,157 @@ void declaration(const char name[], int type, Scope scope) {
   printf("push 0\n");
 }
 
+// ----- READ AND PRINT FUNCTIONS -----
+
+void gen_read(const char name[], Scope scope) {
+  switch (scope) {
+  case GLOBAL:
+    glo_lookup(name);
+    break;
+  case LOCAL:
+    loc_lookup(name);
+    break;
+  }
+}
+
+void gen_print() {
+  printf("pop rax\n");
+  printf("call print\n");
+}
+
+// ----- CONDITIONAL BRANCHING ------
+
+void gen_if_label(int idx) {
+  printf(".end_if%d:\n", idx);
+  printf(";ENDIF\n\n");
+}
+
+void gen_if_start(int idx) {
+  printf("\n;BEGINIF\n");
+  printf("pop rax\n");
+  printf("cmp rax,0\n");
+  printf("jz .end_if%d\n", idx);
+}
+
+void gen_if_end(int idx) {
+  printf("jmp .end_ifelse%d\n", idx);
+  printf(".end_if%d:\n", idx);
+}
+
+void gen_ifelse_end(int idx) {
+  printf(".end_ifelse%d:\n", idx);
+  printf("ENDIF\n\n");
+}
+
+// ----- OPERATORS -----
+
+void gen_assign(int ident, Scope scope) {
+  // TODO: what's "$$" and how do we extract it?
+}
+
+void gen_or(int left, int right, int idx) {
+  check_expected_type(left, INT);
+  check_expected_type(right, INT);
+
+  printf(";a OR c\n");
+  printf("pop rax\n");
+  printf("cmp rax,1\n");
+  printf("je .true%d\n", idx);
+  printf("pop rcx\n");
+  printf("cmp rcx,1\n");
+  printf("jz .true%d\n", idx);
+  printf("push 0\n");
+  printf("jmp .false%d\n", idx);
+  printf(".true%d:\n", idx);
+  printf("push 1\n");
+  printf(".false%d:", idx);
+}
+
+void gen_and(int left, int right, int idx) {
+  check_expected_type(left, INT);
+  check_expected_type(right, INT);
+
+  printf(";a AND c\n");
+  printf("pop rax\n");
+  printf("cmp rax,0\n");
+  printf("jz .false%d\n", idx);
+  printf("pop rcx\n");
+  printf("cmp rcx,0\n");
+  printf("jz .false%d\n", idx);
+  printf("push 1\n");
+  printf("jmp .true%d\n", idx);
+  printf(".false%d:\n", idx);
+  printf("push 0\n");
+  printf(".true%d:", idx);
+}
+
+void gen_eq(const char op[], int left, int right, int idx) {
+  check_expected_type(left, INT);
+  check_expected_type(right, INT);
+
+  printf(";a EQ c\npop rax\npop rcx\ncmp rax,rcx\n");
+
+  if (!strcmp(op, "=="))
+    printf("je .true%d\n", idx);
+  else if (!strcmp(op, "!="))
+    printf("jne .true%d\n", idx);
+  else
+    exit(1); // TODO: error on unexpected op
+
+  printf("push 0\njmp .false%d\n.true%d:\npush 1\n.false%d:", idx, idx, idx);
+}
+
+void gen_order(const char op[], int left, int right, int idx) {
+  check_expected_type(left, INT);
+  check_expected_type(right, INT);
+
+  printf(";a ORDER c\npop rcx\npop rax\ncmp rax,rcx\n");
+
+  if (!strcmp(op, "<"))
+    printf("jl .true%d\n", idx);
+  else if (!strcmp(op, "<="))
+    printf("jle .true%d\n", idx);
+  else if(!strcmp(op, ">"))
+    printf("jg .true%d\n", idx);
+  else if(!strcmp(op, "<="))
+    printf("jge .true%d\n", idx);
+  else
+    exit(1); // TODO: error on unexpected op
+
+  printf("push 0\njmp .false%d\n.true%d:\npush 1\n.false%d:", idx, idx, idx);
+}
+
+void gen_addsub(char op, int left, int right) {
+  check_expected_type(left, INT);
+  check_expected_type(right, INT);
+
+  switch (op) {
+  case '+':
+    printf(";E + T\npop rcx\npop rax\nadd rax,rcx\npush rax\n");
+    break;
+  case '-':
+    printf(";E - T\npop rcx\npop rax\nsub rax,rcx\npush rax\n");
+    break;
+  default:
+    exit(1);
+  }
+}
+
+void gen_divstar(char op, int left, int right) {
+  check_expected_type(left, INT);
+  check_expected_type(right, INT);
+
+  switch (op) {
+  case '*':
+    printf(";E * T\npop rax\npop rcx\nimul rax,rcx\npush rax\n");
+    break;
+  case '/':
+  case '%':
+    printf(";E / T\npop rax\npop rcx\nxor rdx,rdx\nidiv rcx\n");
+    printf("push %s\n", op == '/' ? "rax" : "rdx");
+    break;
+  default:
+    exit(1);
+  }
+}
 
-- 
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