Add char type

chibicc.h

@@ -125,6 +125,7 @@ Obj *parse(Token *tok);
 //
 
 typedef enum {
+  TY_CHAR,
   TY_INT,
   TY_PTR,
   TY_FUNC,
@@ -157,6 +158,7 @@ struct Type {
   Type *next;
 };
 
+extern Type *ty_char;
 extern Type *ty_int;
 
 bool is_integer(Type *ty);

codegen.c

@@ -1,7 +1,8 @@
 #include "chibicc.h"
 
 static int depth;
-static char *argreg[] = {"%rdi", "%rsi", "%rdx", "%rcx", "%r8", "%r9"};
+static char *argreg8[] = {"%dil", "%sil", "%dl", "%cl", "%r8b", "%r9b"};
+static char *argreg64[] = {"%rdi", "%rsi", "%rdx", "%rcx", "%r8", "%r9"};
 static Obj *current_fn;
 
 static void gen_expr(Node *node);
@@ -60,13 +61,20 @@ static void load(Type *ty) {
     return;
   }
 
-  printf("  mov (%%rax), %%rax\n");
+  if (ty->size == 1)
+    printf("  movsbq (%%rax), %%rax\n");
+  else
+    printf("  mov (%%rax), %%rax\n");
 }
 
 // Store %rax to an address that the stack top is pointing to.
-static void store(void) {
+static void store(Type *ty) {
   pop("%rdi");
-  printf("  mov %%rax, (%%rdi)\n");
+
+  if (ty->size == 1)
+    printf("  mov %%al, (%%rdi)\n");
+  else
+    printf("  mov %%rax, (%%rdi)\n");
 }
 
 // Generate code for a given node.
@@ -94,7 +102,7 @@ static void gen_expr(Node *node) {
     gen_addr(node->lhs);
     push();
     gen_expr(node->rhs);
-    store();
+    store(node->ty);
     return;
   case ND_FUNCALL: {
     int nargs = 0;
@@ -105,7 +113,7 @@ static void gen_expr(Node *node) {
     }
 
     for (int i = nargs - 1; i >= 0; i--)
-      pop(argreg[i]);
+      pop(argreg64[i]);
 
     printf("  mov $0, %%rax\n");
     printf("  call %s\n", node->funcname);
@@ -246,8 +254,12 @@ static void emit_text(Obj *prog) {
 
     // Save passed-by-register arguments to the stack
     int i = 0;
-    for (Obj *var = fn->params; var; var = var->next)
+    for (Obj *var = fn->params; var; var = var->next) {
-      printf("  mov %s, %d(%%rbp)\n", argreg[i++], var->offset);
+      if (var->ty->size == 1)
+        printf("  mov %s, %d(%%rbp)\n", argreg8[i++], var->offset);
+      else
+        printf("  mov %s, %d(%%rbp)\n", argreg64[i++], var->offset);
+    }
 
     // Emit code
     gen_stmt(fn->body);

parse.c

@@ -118,8 +118,13 @@ static int get_number(Token *tok) {
   return tok->val;
 }
 
-// declspec = "int"
+// declspec = "char" | "int"
 static Type *declspec(Token **rest, Token *tok) {
+  if (equal(tok, "char")) {
+    *rest = tok->next;
+    return ty_char;
+  }
+
   *rest = skip(tok, "int");
   return ty_int;
 }
@@ -204,6 +209,11 @@ static Node *declaration(Token **rest, Token *tok) {
   return node;
 }
 
+// Returns true if a given token represents a type.
+static bool is_typename(Token *tok) {
+  return equal(tok, "char") || equal(tok, "int");
+}
+
 // stmt = "return" expr ";"
 //      | "if" "(" expr ")" stmt ("else" stmt)?
 //      | "for" "(" expr-stmt expr? ";" expr? ")" stmt
@@ -270,7 +280,7 @@ static Node *compound_stmt(Token **rest, Token *tok) {
   Node head = {};
   Node *cur = &head;
   while (!equal(tok, "}")) {
-    if (equal(tok, "int"))
+    if (is_typename(tok))
       cur = cur->next = declaration(&tok, tok);
     else
       cur = cur->next = stmt(&tok, tok);

test.sh

@@ -163,4 +163,12 @@ assert 3 'int x[4]; int main() { x[0]=0; x[1]=1; x[2]=2; x[3]=3; return x[3]; }'
 assert 8 'int x; int main() { return sizeof(x); }'
 assert 32 'int x[4]; int main() { return sizeof(x); }'
 
+assert 1 'int main() { char x=1; return x; }'
+assert 1 'int main() { char x=1; char y=2; return x; }'
+assert 2 'int main() { char x=1; char y=2; return y; }'
+
+assert 1 'int main() { char x; return sizeof(x); }'
+assert 10 'int main() { char x[10]; return sizeof(x); }'
+assert 1 'int main() { return sub_char(7, 3, 3); } int sub_char(char a, char b, char c) { return a-b-c; }'
+
 echo OK

tokenize.c

@@ -90,7 +90,7 @@ static int read_punct(char *p) {
 
 static bool is_keyword(Token *tok) {
   static char *kw[] = {
-    "return", "if", "else", "for", "while", "int", "sizeof",
+    "return", "if", "else", "for", "while", "int", "sizeof", "char",
   };
 
   for (int i = 0; i < sizeof(kw) / sizeof(*kw); i++)

type.c

@@ -1,9 +1,10 @@
 #include "chibicc.h"
 
+Type *ty_char = &(Type){TY_CHAR, 1};
 Type *ty_int = &(Type){TY_INT, 8};
 
 bool is_integer(Type *ty) {
-  return ty->kind == TY_INT;
+  return ty->kind == TY_CHAR || ty->kind == TY_INT;
 }
 
 Type *copy_type(Type *ty) {