Add `signed` keyword

parse.c

@@ -260,6 +260,7 @@ Program *program(void) {
 //
 // Note that "typedef" and "static" can appear anywhere in a basetype.
 // "int" can appear anywhere if type is short, long or long long.
+// "signed" can appear anywhere if type is short, int, long or long long.
 static Type *basetype(StorageClass *sclass) {
   if (!is_typename())
     error_tok(token, "typename expected");
@@ -272,6 +273,7 @@ static Type *basetype(StorageClass *sclass) {
     INT    = 1 << 8,
     LONG   = 1 << 10,
     OTHER  = 1 << 12,
+    SIGNED = 1 << 13,
   };
 
   Type *ty = int_type;
@@ -302,7 +304,8 @@ static Type *basetype(StorageClass *sclass) {
 
     // Handle user-defined types.
     if (!peek("void") && !peek("_Bool") && !peek("char") &&
-        !peek("short") && !peek("int") && !peek("long")) {
+        !peek("short") && !peek("int") && !peek("long") &&
+        !peek("signed")) {
       if (counter)
         break;
 
@@ -333,6 +336,8 @@ static Type *basetype(StorageClass *sclass) {
       counter += INT;
     else if (consume("long"))
       counter += LONG;
+    else if (consume("signed"))
+      counter |= SIGNED;
 
     switch (counter) {
     case VOID:
@@ -342,19 +347,28 @@ static Type *basetype(StorageClass *sclass) {
       ty = bool_type;
       break;
     case CHAR:
+    case SIGNED + CHAR:
       ty = char_type;
       break;
     case SHORT:
     case SHORT + INT:
+    case SIGNED + SHORT:
+    case SIGNED + SHORT + INT:
       ty = short_type;
       break;
     case INT:
+    case SIGNED:
+    case SIGNED + INT:
       ty = int_type;
       break;
     case LONG:
     case LONG + INT:
     case LONG + LONG:
     case LONG + LONG + INT:
+    case SIGNED + LONG:
+    case SIGNED + LONG + INT:
+    case SIGNED + LONG + LONG:
+    case SIGNED + LONG + LONG + INT:
       ty = long_type;
       break;
     default:
@@ -1118,7 +1132,7 @@ static bool is_typename(void) {
   return peek("void") || peek("_Bool") || peek("char") || peek("short") ||
          peek("int") || peek("long") || peek("enum") || peek("struct") ||
          peek("typedef") || peek("static") || peek("extern") ||
-         find_typedef(token);
+         peek("signed") || find_typedef(token);
 }
 
 static Node *stmt(void) {

tests

@@ -709,6 +709,29 @@ int main() {
   assert(6, add_all3(1,2,3,0), "add_all3(1,2,3,0)");
   assert(5, add_all3(1,2,3,-1,0), "add_all3(1,2,3,-1,0)");
 
+  assert(1, sizeof(char), "sizeof(char)");
+  assert(1, sizeof(signed char), "sizeof(signed char)");
+  assert(1, sizeof(signed char signed), "sizeof(signed char signed)");
+
+  assert(2, sizeof(short), "sizeof(short)");
+  assert(2, sizeof(int short), "sizeof(int short)");
+  assert(2, sizeof(short int), "sizeof(short int)");
+  assert(2, sizeof(signed short), "sizeof(signed short)");
+  assert(2, sizeof(int short signed), "sizeof(int short signed)");
+
+  assert(4, sizeof(int), "sizeof(int)");
+  assert(4, sizeof(signed int), "sizeof(signed int)");
+  assert(4, sizeof(signed), "sizeof(signed)");
+  assert(4, sizeof(signed signed), "sizeof(signed signed)");
+
+  assert(8, sizeof(long), "sizeof(long)");
+  assert(8, sizeof(signed long), "sizeof(signed long)");
+  assert(8, sizeof(signed long int), "sizeof(signed long int)");
+
+  assert(8, sizeof(long long), "sizeof(long long)");
+  assert(8, sizeof(signed long long), "sizeof(signed long long)");
+  assert(8, sizeof(signed long long int), "sizeof(signed long long int)");
+
   printf("OK\n");
   return 0;
 }

tokenize.c

@@ -151,7 +151,7 @@ static char *starts_with_reserved(char *p) {
                        "char", "sizeof", "struct", "typedef", "short",
                        "long", "void", "_Bool", "enum", "static", "break",
                        "continue", "goto", "switch", "case", "default",
-                       "extern", "_Alignof", "do"};
+                       "extern", "_Alignof", "do", "signed"};
 
   for (int i = 0; i < sizeof(kw) / sizeof(*kw); i++) {
     int len = strlen(kw[i]);