feat: implement array type

4 files changed, 71 insertions, 3 deletions

diff --git a/ast.c b/ast.c
index d67bb01..0326855 100644
--- a/ast.c
+++ b/ast.c
@@ -6,6 +6,7 @@ enum TypeKind {
     TypeKind_long,
     TypeKind_void,
     TypeKind_ptr,
+    TypeKind_array,
     TypeKind_enum,
     TypeKind_struct,
 };
@@ -16,6 +17,7 @@ struct AstNode;
 struct Type {
     TypeKind kind;
     struct Type* to;
+    int array_size;
     struct AstNode* def;
 };
 typedef struct Type Type;
@@ -33,6 +35,18 @@ Type* type_new_ptr(Type* to) {
     return ty;
 }
 
+Type* type_new_array(Type* elem, int size) {
+    Type* ty = calloc(1, sizeof(Type));
+    ty->kind = TypeKind_array;
+    ty->to = elem;
+    ty->array_size = size;
+    return ty;
+}
+
+Type* type_array_to_ptr(Type* ty) {
+    return type_new_ptr(ty->to);
+}
+
 int type_is_unsized(Type* ty) {
     return ty->kind != TypeKind_void;
 }
@@ -57,6 +71,8 @@ int type_sizeof(Type* ty) {
         return 8;
     } else if (ty->kind == TypeKind_enum) {
         return 4;
+    } else if (ty->kind == TypeKind_array) {
+        return type_sizeof(ty->to) * ty->array_size;
     } else {
         return type_sizeof_struct(ty);
     }
@@ -77,6 +93,8 @@ int type_alignof(Type* ty) {
         return 8;
     } else if (ty->kind == TypeKind_enum) {
         return 4;
+    } else if (ty->kind == TypeKind_array) {
+        return type_alignof(ty->to);
     } else {
         return type_alignof_struct(ty);
     }
@@ -209,14 +227,20 @@ AstNode* ast_new_binary_expr(int op, AstNode* lhs, AstNode* rhs) {
     if (op == TokenKind_plus) {
         if (lhs->ty->kind == TypeKind_ptr) {
             e->ty = lhs->ty;
+        } else if (lhs->ty->kind == TypeKind_array) {
+            e->ty = type_array_to_ptr(lhs->ty);
         } else if (rhs->ty->kind == TypeKind_ptr) {
             e->ty = rhs->ty;
+        } else if (rhs->ty->kind == TypeKind_array) {
+            e->ty = type_array_to_ptr(rhs->ty);
         } else {
             e->ty = type_new(TypeKind_int);
         }
     } else if (op == TokenKind_minus) {
         if (lhs->ty->kind == TypeKind_ptr) {
             e->ty = lhs->ty;
+        } else if (lhs->ty->kind == TypeKind_array) {
+            e->ty = type_array_to_ptr(lhs->ty);
         } else {
             e->ty = type_new(TypeKind_int);
         }
@@ -236,16 +260,16 @@ AstNode* ast_new_assign_expr(int op, AstNode* lhs, AstNode* rhs) {
 }
 
 AstNode* ast_new_assign_add_expr(AstNode* lhs, AstNode* rhs) {
-    if (lhs->ty->kind == TypeKind_ptr) {
+    if (lhs->ty->kind == TypeKind_ptr || lhs->ty->kind == TypeKind_array) {
         rhs = ast_new_binary_expr(TokenKind_star, rhs, ast_new_int(type_sizeof(lhs->ty->to)));
-    } else if (rhs->ty->kind == TypeKind_ptr) {
+    } else if (rhs->ty->kind == TypeKind_ptr || rhs->ty->kind == TypeKind_array) {
         lhs = ast_new_binary_expr(TokenKind_star, lhs, ast_new_int(type_sizeof(rhs->ty->to)));
     }
     return ast_new_assign_expr(TokenKind_assign_add, lhs, rhs);
 }
 
 AstNode* ast_new_assign_sub_expr(AstNode* lhs, AstNode* rhs) {
-    if (lhs->ty->kind == TypeKind_ptr) {
+    if (lhs->ty->kind == TypeKind_ptr || lhs->ty->kind == TypeKind_array) {
         rhs = ast_new_binary_expr(TokenKind_star, rhs, ast_new_int(type_sizeof(lhs->ty->to)));
     }
     return ast_new_assign_expr(TokenKind_assign_sub, lhs, rhs);
diff --git a/codegen.c b/codegen.c
index 0a90602..5b6f4c8 100644
--- a/codegen.c
+++ b/codegen.c
@@ -88,6 +88,10 @@ void codegen_ref_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) {
 }
 
 void codegen_lval2rval(Type* ty) {
+    if (ty->kind == TypeKind_array) {
+        return;
+    }
+
     int size = type_sizeof(ty);
 
     printf("  pop rax\n");
diff --git a/parse.c b/parse.c
index d08269e..0b682e2 100644
--- a/parse.c
+++ b/parse.c
@@ -702,6 +702,17 @@ AstNode* parse_var_decl(Parser* p) {
     }
     String* name = parse_ident(p);
 
+    if (peek_token(p)->kind == TokenKind_bracket_l) {
+        next_token(p);
+        AstNode* size_expr = parse_expr(p);
+        if (size_expr->kind != AstNodeKind_int_expr) {
+            fatal_error("parse_var_decl: invalid array size");
+        }
+        int size = size_expr->node_int_value;
+        expect(p, TokenKind_bracket_r);
+        ty = type_new_array(ty, size);
+    }
+
     AstNode* init = NULL;
     if (peek_token(p)->kind == TokenKind_assign) {
         next_token(p);
diff --git a/tests/068.sh b/tests/068.sh
new file mode 100644
index 0000000..648e822
--- /dev/null
+++ b/tests/068.sh
@@ -0,0 +1,29 @@
+set -e
+
+cat <<'EOF' > expected
+0
+1
+4
+9
+16
+25
+36
+49
+64
+81
+EOF
+
+bash ../../test_diff.sh <<'EOF'
+int printf();
+
+int main() {
+    int i;
+    int a[10];
+    for (i = 0; i < 10; ++i) {
+        a[i] = i * i;
+    }
+    for (i = 0; i < 10; ++i) {
+        printf("%d\n", a[i]);
+    }
+}
+EOF