Add ! operator

chibicc.h

@@ -103,6 +103,7 @@ typedef enum {
   ND_MEMBER,    // . (struct member access)
   ND_ADDR,      // unary &
   ND_DEREF,     // unary *
+  ND_NOT,       // !
   ND_RETURN,    // "return"
   ND_IF,        // "if"
   ND_WHILE,     // "while"

codegen.c

@@ -222,6 +222,14 @@ void gen(Node *node) {
     if (node->ty->kind != TY_ARRAY)
       load(node->ty);
     return;
+  case ND_NOT:
+    gen(node->lhs);
+    printf("  pop rax\n");
+    printf("  cmp rax, 0\n");
+    printf("  sete al\n");
+    printf("  movzb rax, al\n");
+    printf("  push rax\n");
+    return;
   case ND_IF: {
     int seq = labelseq++;
     if (node->els) {

examples/nqueen.c

@@ -38,8 +38,7 @@ int solve(int (*board)[10], int row) {
     return 0;
   }
   for (int i = 0; i < 10; i++) {
-    if (conflict(board, row, i)) {
-    } else {
+    if (!conflict(board, row, i)) {
       board[row][i] = 1;
       solve(board, row + 1);
       board[row][i] = 0;

parse.c

@@ -781,7 +781,7 @@ Node *cast() {
   return unary();
 }
 
-// unary = ("+" | "-" | "*" | "&")? cast
+// unary = ("+" | "-" | "*" | "&" | "!")? cast
 //       | ("++" | "--") unary
 //       | postfix
 Node *unary() {
@@ -794,6 +794,8 @@ Node *unary() {
     return new_unary(ND_ADDR, cast(), tok);
   if (tok = consume("*"))
     return new_unary(ND_DEREF, cast(), tok);
+  if (tok = consume("!"))
+    return new_unary(ND_NOT, cast(), tok);
   if (tok = consume("++"))
     return new_unary(ND_PRE_INC, unary(), tok);
   if (tok = consume("--"))

tests

@@ -377,6 +377,10 @@ int main() {
   assert(3, ({ int i=6; i/=2; i; }), "int i=6; i/=2; i;");
   assert(3, ({ int i=6; i/=2; }), "int i=6; i/=2;");
 
+  assert(0, !1, "!1");
+  assert(0, !2, "!2");
+  assert(1, !0, "!0");
+
   printf("OK\n");
   return 0;
 }

tokenize.c

@@ -279,7 +279,7 @@ Token *tokenize() {
     }
 
     // Single-letter punctuator
-    if (strchr("+-*/()<>;={},&[].,", *p)) {
+    if (strchr("+-*/()<>;={},&[].,!", *p)) {
       cur = new_token(TK_RESERVED, cur, p++, 1);
       continue;
     }

type.c

@@ -117,6 +117,7 @@ void visit(Node *node) {
   case ND_NE:
   case ND_LT:
   case ND_LE:
+  case ND_NOT:
     node->ty = int_type();
     return;
   case ND_NUM: