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-rw-r--r--main.c223
1 files changed, 169 insertions, 54 deletions
diff --git a/main.c b/main.c
index 5e7a8d4..b83669d 100644
--- a/main.c
+++ b/main.c
@@ -40,42 +40,44 @@ int read_all(char* buf) {
#define TK_EOF 0
#define TK_AND 1
-#define TK_ASSIGN 2
-#define TK_BRACE_L 3
-#define TK_BRACE_R 4
-#define TK_BRACKET_L 5
-#define TK_BRACKET_R 6
-#define TK_COMMA 7
-#define TK_EQ 8
-#define TK_GE 9
-#define TK_GT 10
-#define TK_IDENT 11
-#define TK_K_BREAK 12
-#define TK_K_CHAR 13
-#define TK_K_CONTINUE 14
-#define TK_K_ELSE 15
-#define TK_K_FOR 16
-#define TK_K_IF 17
-#define TK_K_INT 18
-#define TK_K_LONG 19
-#define TK_K_RETURN 20
-#define TK_K_SIZEOF 21
-#define TK_K_STRUCT 22
-#define TK_K_VOID 23
-#define TK_LE 24
-#define TK_LT 25
-#define TK_L_INT 26
-#define TK_L_STR 27
-#define TK_MINUS 28
-#define TK_NE 29
-#define TK_NOT 30
-#define TK_PAREN_L 31
-#define TK_PAREN_R 32
-#define TK_PERCENT 33
-#define TK_PLUS 34
-#define TK_SEMICOLON 35
-#define TK_SLASH 36
-#define TK_STAR 37
+#define TK_ARROW 2
+#define TK_ASSIGN 3
+#define TK_BRACE_L 4
+#define TK_BRACE_R 5
+#define TK_BRACKET_L 6
+#define TK_BRACKET_R 7
+#define TK_COMMA 8
+#define TK_DOT 9
+#define TK_EQ 10
+#define TK_GE 11
+#define TK_GT 12
+#define TK_IDENT 13
+#define TK_K_BREAK 14
+#define TK_K_CHAR 15
+#define TK_K_CONTINUE 16
+#define TK_K_ELSE 17
+#define TK_K_FOR 18
+#define TK_K_IF 19
+#define TK_K_INT 20
+#define TK_K_LONG 21
+#define TK_K_RETURN 22
+#define TK_K_SIZEOF 23
+#define TK_K_STRUCT 24
+#define TK_K_VOID 25
+#define TK_LE 26
+#define TK_LT 27
+#define TK_L_INT 28
+#define TK_L_STR 29
+#define TK_MINUS 30
+#define TK_NE 31
+#define TK_NOT 32
+#define TK_PAREN_L 33
+#define TK_PAREN_R 34
+#define TK_PERCENT 35
+#define TK_PLUS 36
+#define TK_SEMICOLON 37
+#define TK_SLASH 38
+#define TK_STAR 39
typedef struct Token {
int kind;
@@ -137,8 +139,14 @@ TOKEN* tokenize(char* src, int len) {
tok += 1;
} else if (c == '-') {
pos += 1;
- tok->kind = TK_MINUS;
- tok += 1;
+ if (src[pos] == '>') {
+ pos += 1;
+ tok->kind = TK_ARROW;
+ tok += 1;
+ } else {
+ tok->kind = TK_MINUS;
+ tok += 1;
+ }
} else if (c == '*') {
pos += 1;
tok->kind = TK_STAR;
@@ -151,6 +159,10 @@ TOKEN* tokenize(char* src, int len) {
pos += 1;
tok->kind = TK_PERCENT;
tok += 1;
+ } else if (c == '.') {
+ pos += 1;
+ tok->kind = TK_DOT;
+ tok += 1;
} else if (c == '!') {
pos += 1;
if (src[pos] == '=') {
@@ -408,19 +420,20 @@ int type_ptr_shift_width(TYPE* ty) {
#define AST_IF_STMT 13
#define AST_INT_LIT_EXPR 14
#define AST_LVAR 15
-#define AST_PARAM 16
-#define AST_PARAM_LIST 17
-#define AST_PROGRAM 18
-#define AST_REF_EXPR 19
-#define AST_RETURN_STMT 20
-#define AST_STRUCT_DECL 21
-#define AST_STRUCT_DEF 22
+#define AST_OFFSETOF 16
+#define AST_PARAM 17
+#define AST_PARAM_LIST 18
+#define AST_PROGRAM 19
+#define AST_REF_EXPR 20
+#define AST_RETURN_STMT 21
+#define AST_STRUCT_DECL 22
+#define AST_STRUCT_DEF 23
#define AST_STRUCT_MEMBER 24
-#define AST_STRUCT_MEMBER_LIST 26
-#define AST_STR_LIT_EXPR 28
-#define AST_TYPE 30
-#define AST_UNARY_EXPR 32
-#define AST_VAR_DECL 34
+#define AST_STRUCT_MEMBER_LIST 25
+#define AST_STR_LIT_EXPR 26
+#define AST_TYPE 27
+#define AST_UNARY_EXPR 28
+#define AST_VAR_DECL 29
typedef struct AstNode {
int kind;
@@ -507,8 +520,62 @@ int type_sizeof_struct(TYPE* ty) {
}
int type_alignof_struct(TYPE* ty) {
- todo();
- return 0;
+ int struct_align = 0;
+
+ AST* member = ty->members->next;
+ while (member) {
+ int align = type_alignof(member->ty);
+
+ if (struct_align < align) {
+ struct_align = align;
+ }
+
+ member = member->next;
+ }
+ return struct_align;
+}
+
+int type_offsetof(TYPE* ty, char* name) {
+ if (ty->kind != TY_STRUCT) {
+ fatal_error("type_offsetof: type is not a struct");
+ }
+
+ int next_offset = 0;
+
+ AST* member = ty->members->next;
+ while (member) {
+ int size = type_sizeof(member->ty);
+ int align = type_alignof(member->ty);
+
+ if (next_offset % align != 0) {
+ int padding = align - next_offset % align;
+ next_offset += padding;
+ }
+ if (strcmp(member->name, name) == 0) {
+ return next_offset;
+ }
+ next_offset += size;
+
+ member = member->next;
+ }
+
+ fatal_error("type_offsetof: member not found");
+}
+
+TYPE* type_member_typeof(TYPE* ty, char* name) {
+ if (ty->kind != TY_STRUCT) {
+ fatal_error("type_offsetof: type is not a struct");
+ }
+
+ AST* member = ty->members->next;
+ while (member) {
+ if (strcmp(member->name, name) == 0) {
+ return member->ty;
+ }
+ member = member->next;
+ }
+
+ fatal_error("type_offsetof: member not found");
}
#define LVAR_MAX 32
@@ -678,6 +745,41 @@ AST* parse_postfix_expr(PARSER* p) {
AST* args = parse_arg_list(p);
expect(p, TK_PAREN_R);
ret->expr1 = args;
+ } else if (tk == TK_DOT) {
+ next_token(p);
+ char* name = parse_ident(p);
+
+ // a.b == *(&a + offsetof(b))
+ AST* e = ast_new(AST_DEREF_EXPR);
+ AST* ref_of_ret = ast_new(AST_REF_EXPR);
+ ref_of_ret->expr1 = ret;
+ ref_of_ret->ty = type_new_ptr(ret->ty);
+ int offset = type_offsetof(ret->ty, name);
+ AST* offset_node = ast_new(AST_OFFSETOF);
+ offset_node->int_value = offset;
+ offset_node->ty = type_new(TY_INT);
+ AST* ptr_expr = ast_new_binary_expr(TK_PLUS, ref_of_ret, offset_node);
+ ptr_expr->ty = ref_of_ret->ty;
+ e->expr1 = ptr_expr;
+ e->ty = type_member_typeof(ret->ty, name);
+
+ ret = e;
+ } else if (tk == TK_ARROW) {
+ next_token(p);
+ char* name = parse_ident(p);
+
+ // a->b == *(a + offsetof(b))
+ AST* e = ast_new(AST_DEREF_EXPR);
+ int offset = type_offsetof(ret->ty->to, name);
+ AST* offset_node = ast_new(AST_OFFSETOF);
+ offset_node->int_value = offset;
+ offset_node->ty = type_new(TY_INT);
+ AST* ptr_expr = ast_new_binary_expr(TK_PLUS, ret, offset_node);
+ ptr_expr->ty = ret->ty;
+ e->expr1 = ptr_expr;
+ e->ty = type_member_typeof(ret->ty->to, name);
+
+ ret = e;
} else {
break;
}
@@ -1230,6 +1332,13 @@ void gen_int_lit_expr(CODEGEN* g, AST* ast) {
printf(" push %d\n", ast->int_value);
}
+void gen_offsetof(CODEGEN* g, AST* ast) {
+ assert_ast_kind(ast, AST_OFFSETOF);
+ printf(" # gen_offsetof\n");
+
+ printf(" push %d\n", ast->int_value);
+}
+
void gen_str_lit_expr(CODEGEN* g, AST* ast) {
assert_ast_kind(ast, AST_STR_LIT_EXPR);
printf(" # gen_str_lit_expr\n");
@@ -1275,10 +1384,14 @@ void gen_binary_expr(CODEGEN* g, AST* ast, int gen_mode) {
printf(" pop rax\n");
if (ast->op == TK_PLUS) {
if (ast->expr1->ty->kind == TY_PTR) {
- printf(" shl rdi, %d\n", type_ptr_shift_width(ast->expr1->ty));
+ if (ast->expr2->kind != AST_OFFSETOF) {
+ printf(" shl rdi, %d\n", type_ptr_shift_width(ast->expr1->ty));
+ }
printf(" add rax, rdi\n");
} else if (ast->expr2->ty->kind == TY_PTR) {
- printf(" shl rdi, %d\n", type_ptr_shift_width(ast->expr2->ty));
+ if (ast->expr1->kind != AST_OFFSETOF) {
+ printf(" shl rdi, %d\n", type_ptr_shift_width(ast->expr2->ty));
+ }
printf(" add rax, rdi\n");
} else {
printf(" add rax, rdi\n");
@@ -1393,6 +1506,8 @@ void gen_lvar(CODEGEN* g, AST* ast, int gen_mode) {
void gen_expr(CODEGEN* g, AST* ast, int gen_mode) {
if (ast->kind == AST_INT_LIT_EXPR) {
gen_int_lit_expr(g, ast);
+ } else if (ast->kind == AST_OFFSETOF) {
+ gen_offsetof(g, ast);
} else if (ast->kind == AST_STR_LIT_EXPR) {
gen_str_lit_expr(g, ast);
} else if (ast->kind == AST_UNARY_EXPR) {
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-30 21:46:31 +0000