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-rw-r--r--README.md3
-rw-r--r--main.c114
2 files changed, 68 insertions, 49 deletions
diff --git a/README.md b/README.md
index c2ff956..fc7d736 100644
--- a/README.md
+++ b/README.md
@@ -43,7 +43,8 @@ To meet the four-day goal, many design decisions were made to reduce complexity
* Most syntax sugar is not implemented
* No increment/decrement operators
* No compound assignment operators
- * No `while`
+ * ~~No `while`~~
+ * Implemented after self-hosting
* Limited preprocessor
* Supports only simple `#define` that replaces identifiers with integer literals
* No global variables
diff --git a/main.c b/main.c
index 05d2a2e..23e6ba7 100644
--- a/main.c
+++ b/main.c
@@ -22,7 +22,7 @@ void fatal_error(char* msg) {
int read_all(char* buf) {
int c;
int n = 0;
- for (;;) {
+ while (1) {
c = getchar();
if (c == -1) {
break;
@@ -61,21 +61,22 @@ int read_all(char* buf) {
#define TK_K_SIZEOF 24
#define TK_K_STRUCT 25
#define TK_K_VOID 26
-#define TK_LE 27
-#define TK_LT 28
-#define TK_L_INT 29
-#define TK_L_STR 30
-#define TK_MINUS 31
-#define TK_NE 32
-#define TK_NOT 33
-#define TK_OROR 34
-#define TK_PAREN_L 35
-#define TK_PAREN_R 36
-#define TK_PERCENT 37
-#define TK_PLUS 38
-#define TK_SEMICOLON 39
-#define TK_SLASH 40
-#define TK_STAR 41
+#define TK_K_WHILE 27
+#define TK_LE 28
+#define TK_LT 29
+#define TK_L_INT 30
+#define TK_L_STR 31
+#define TK_MINUS 32
+#define TK_NE 33
+#define TK_NOT 34
+#define TK_OROR 35
+#define TK_PAREN_L 36
+#define TK_PAREN_R 37
+#define TK_PERCENT 38
+#define TK_PLUS 39
+#define TK_SEMICOLON 40
+#define TK_SLASH 41
+#define TK_STAR 42
struct Token {
int kind;
@@ -95,7 +96,7 @@ struct Token* tokenize(char* src, int len) {
int pos = 0;
int ch;
int start;
- for (; pos < len; ) {
+ while (pos < len) {
char c = src[pos];
if (c == '(') {
pos = pos + 1;
@@ -231,7 +232,7 @@ struct Token* tokenize(char* src, int len) {
} else if (c == '"') {
pos = pos + 1;
start = pos;
- for (;;) {
+ while (1) {
ch = src[pos];
if (ch == '\\') {
pos = pos + 1;
@@ -247,7 +248,7 @@ struct Token* tokenize(char* src, int len) {
tok = tok + 1;
} else if (isdigit(c)) {
start = pos;
- for (; isdigit(src[pos]); ) {
+ while (isdigit(src[pos])) {
pos = pos + 1;
}
tok->kind = TK_L_INT;
@@ -256,7 +257,7 @@ struct Token* tokenize(char* src, int len) {
tok = tok + 1;
} else if (isalpha(c)) {
start = pos;
- for (; isalnum(src[pos]) || src[pos] == '_'; ) {
+ while (isalnum(src[pos]) || src[pos] == '_') {
pos = pos + 1;
}
int ident_len = pos - start;
@@ -284,11 +285,13 @@ struct Token* tokenize(char* src, int len) {
tok->kind = TK_K_STRUCT;
} else if (ident_len == 4 && strstr(src + start, "void") == src + start) {
tok->kind = TK_K_VOID;
+ } else if (ident_len == 5 && strstr(src + start, "while") == src + start) {
+ tok->kind = TK_K_WHILE;
} else {
tok->value = calloc(ident_len + 1, sizeof(char));
memcpy(tok->value, src + start, ident_len);
int i = 0;
- for (; defines + i != def; ) {
+ while (defines + i != def) {
if (strcmp(tok->value, defines[i].from) == 0) {
tok->kind = defines[i].to->kind;
tok->value = defines[i].to->value;
@@ -306,20 +309,20 @@ struct Token* tokenize(char* src, int len) {
} else if (c == '#') {
pos = pos + 1;
pos = pos + 6;
- for (; isspace(src[pos]); ) {
+ while (isspace(src[pos])) {
pos = pos + 1;
}
start = pos;
- for (; isalnum(src[pos]) || src[pos] == '_'; ) {
+ while (isalnum(src[pos]) || src[pos] == '_') {
pos = pos + 1;
}
def->from = calloc(pos - start + 1, sizeof(char));
memcpy(def->from, src + start, pos - start);
- for (; isspace(src[pos]); ) {
+ while (isspace(src[pos])) {
pos = pos + 1;
}
int start2 = pos;
- for (; isdigit(src[pos]); ) {
+ while (isdigit(src[pos])) {
pos = pos + 1;
}
def->to = calloc(1, sizeof(struct Token));
@@ -502,7 +505,7 @@ int type_sizeof_struct(struct Type* ty) {
int padding;
struct AstNode* member = ty->struct_def->node1->next;
- for (; member; ) {
+ while (member) {
int size = type_sizeof(member->ty);
int align = type_alignof(member->ty);
@@ -528,7 +531,7 @@ int type_alignof_struct(struct Type* ty) {
int struct_align = 0;
struct AstNode* member = ty->struct_def->node1->next;
- for (; member; ) {
+ while (member) {
int align = type_alignof(member->ty);
if (struct_align < align) {
@@ -548,7 +551,7 @@ int type_offsetof(struct Type* ty, char* name) {
int next_offset = 0;
struct AstNode* member = ty->struct_def->node1->next;
- for (; member; ) {
+ while (member) {
int size = type_sizeof(member->ty);
int align = type_alignof(member->ty);
@@ -573,7 +576,7 @@ struct Type* type_member_typeof(struct Type* ty, char* name) {
}
struct AstNode* member = ty->struct_def->node1->next;
- for (; member; ) {
+ while (member) {
if (strcmp(member->name, name) == 0) {
return member->ty;
}
@@ -729,7 +732,7 @@ struct AstNode* parse_primary_expr(struct Parser* p) {
struct AstNode* parse_arg_list(struct Parser* p) {
struct AstNode* list = ast_new_list(AST_ARG_LIST);
- for (; peek_token(p)->kind != TK_PAREN_R; ) {
+ while (peek_token(p)->kind != TK_PAREN_R) {
struct AstNode* arg = parse_expr(p);
list->last->next = arg;
list->last = arg;
@@ -750,7 +753,7 @@ struct AstNode* parse_postfix_expr(struct Parser* p) {
struct AstNode* offset_node;
int offset;
char* name;
- for (;;) {
+ while (1) {
int tk = peek_token(p)->kind;
if (tk == TK_PAREN_L) {
next_token(p);
@@ -848,7 +851,7 @@ struct Type* parse_type(struct Parser* p) {
} else {
fatal_error("unreachable");
}
- for (;;) {
+ while (1) {
struct Token* t2 = peek_token(p);
if (t2->kind == TK_STAR) {
next_token(p);
@@ -908,7 +911,7 @@ struct AstNode* parse_prefix_expr(struct Parser* p) {
struct AstNode* parse_multiplicative_expr(struct Parser* p) {
struct AstNode* lhs = parse_prefix_expr(p);
- for (;;) {
+ while (1) {
int op = peek_token(p)->kind;
if (op == TK_STAR || op == TK_SLASH || op == TK_PERCENT) {
next_token(p);
@@ -926,7 +929,7 @@ struct AstNode* parse_additive_expr(struct Parser* p) {
struct AstNode* lhs = parse_multiplicative_expr(p);
struct AstNode* rhs;
struct Type* result_type;
- for (;;) {
+ while (1) {
int op = peek_token(p)->kind;
if (op == TK_PLUS) {
next_token(p);
@@ -960,7 +963,7 @@ struct AstNode* parse_additive_expr(struct Parser* p) {
struct AstNode* parse_relational_expr(struct Parser* p) {
struct AstNode* lhs = parse_additive_expr(p);
struct AstNode* rhs;
- for (;;) {
+ while (1) {
int op = peek_token(p)->kind;
if (op == TK_LT || op == TK_LE) {
next_token(p);
@@ -986,7 +989,7 @@ struct AstNode* parse_relational_expr(struct Parser* p) {
struct AstNode* parse_equality_expr(struct Parser* p) {
struct AstNode* lhs = parse_relational_expr(p);
- for (;;) {
+ while (1) {
int op = peek_token(p)->kind;
if (op == TK_EQ || op == TK_NE) {
next_token(p);
@@ -1002,7 +1005,7 @@ struct AstNode* parse_equality_expr(struct Parser* p) {
struct AstNode* parse_logical_and_expr(struct Parser* p) {
struct AstNode* lhs = parse_equality_expr(p);
- for (;;) {
+ while (1) {
int op = peek_token(p)->kind;
if (op == TK_ANDAND) {
next_token(p);
@@ -1018,7 +1021,7 @@ struct AstNode* parse_logical_and_expr(struct Parser* p) {
struct AstNode* parse_logical_or_expr(struct Parser* p) {
struct AstNode* lhs = parse_logical_and_expr(p);
- for (;;) {
+ while (1) {
int op = peek_token(p)->kind;
if (op == TK_OROR) {
next_token(p);
@@ -1034,7 +1037,7 @@ struct AstNode* parse_logical_or_expr(struct Parser* p) {
struct AstNode* parse_assignment_expr(struct Parser *p) {
struct AstNode* lhs = parse_logical_or_expr(p);
- for (;;) {
+ while (1) {
int op = peek_token(p)->kind;
if (op == TK_ASSIGN) {
next_token(p);
@@ -1118,6 +1121,19 @@ struct AstNode* parse_for_stmt(struct Parser* p) {
return stmt;
}
+struct AstNode* parse_while_stmt(struct Parser* p) {
+ expect(p, TK_K_WHILE);
+ expect(p, TK_PAREN_L);
+ struct AstNode* cond = parse_expr(p);
+ expect(p, TK_PAREN_R);
+ struct AstNode* body = parse_stmt(p);
+
+ struct AstNode* stmt = ast_new(AST_FOR_STMT);
+ stmt->expr2 = cond;
+ stmt->node1 = body;
+ return stmt;
+}
+
struct AstNode* parse_break_stmt(struct Parser* p) {
expect(p, TK_K_BREAK);
expect(p, TK_SEMICOLON);
@@ -1180,7 +1196,7 @@ struct AstNode* parse_expr_stmt(struct Parser* p) {
struct AstNode* parse_block_stmt(struct Parser* p) {
struct AstNode* list = ast_new_list(AST_BLOCK);
expect(p, TK_BRACE_L);
- for (; peek_token(p)->kind != TK_BRACE_R; ) {
+ while (peek_token(p)->kind != TK_BRACE_R) {
struct AstNode* stmt = parse_stmt(p);
list->last->next = stmt;
list->last = stmt;
@@ -1197,6 +1213,8 @@ struct AstNode* parse_stmt(struct Parser* p) {
return parse_if_stmt(p);
} else if (t->kind == TK_K_FOR) {
return parse_for_stmt(p);
+ } else if (t->kind == TK_K_WHILE) {
+ return parse_while_stmt(p);
} else if (t->kind == TK_K_BREAK) {
return parse_break_stmt(p);
} else if (t->kind == TK_K_CONTINUE) {
@@ -1217,7 +1235,7 @@ void enter_func(struct Parser* p) {
void register_params(struct Parser* p, struct AstNode* params) {
struct AstNode* param = params->next;
- for (; param; ) {
+ while (param) {
p->locals[p->n_locals].name = param->name;
p->locals[p->n_locals].ty = param->ty;
p->n_locals = p->n_locals + 1;
@@ -1245,7 +1263,7 @@ struct AstNode* parse_param(struct Parser* p) {
struct AstNode* parse_param_list(struct Parser* p) {
struct AstNode* list = ast_new_list(AST_PARAM_LIST);
- for (; peek_token(p)->kind != TK_PAREN_R; ) {
+ while (peek_token(p)->kind != TK_PAREN_R) {
struct AstNode* param = parse_param(p);
list->last->next = param;
list->last = param;
@@ -1293,7 +1311,7 @@ struct AstNode* parse_struct_member(struct Parser* p) {
struct AstNode* parse_struct_members(struct Parser* p) {
struct AstNode* list = ast_new_list(AST_STRUCT_MEMBER_LIST);
- for (; peek_token(p)->kind != TK_BRACE_R; ) {
+ while (peek_token(p)->kind != TK_BRACE_R) {
struct AstNode* member = parse_struct_member(p);
list->last->next = member;
list->last = member;
@@ -1348,7 +1366,7 @@ struct AstNode* parse_toplevel(struct Parser* p) {
struct AstNode* parse(struct Parser* p) {
struct AstNode* list = ast_new_list(AST_PROGRAM);
- for (; eof(p); ) {
+ while (eof(p)) {
struct AstNode* n = parse_toplevel(p);
list->last->next = n;
list->last = n;
@@ -1396,7 +1414,7 @@ void gen_func_prologue(struct CodeGen* g, struct AstNode* ast) {
printf(" mov rbp, rsp\n");
int param_index = 0;
struct AstNode* param = ast->func_params->next;
- for (; param; ) {
+ while (param) {
if (param_index == 0) {
printf(" push rdi\n");
} else if (param_index == 1) {
@@ -1626,7 +1644,7 @@ void gen_func_call(struct CodeGen* g, struct AstNode* ast) {
struct AstNode* args = ast->expr1;
struct AstNode* arg = args->next;
int n_args = 0;
- for (; arg; ) {
+ while (arg) {
n_args = n_args + 1;
gen_expr(g, arg, GEN_RVAL);
arg = arg->next;
@@ -1798,7 +1816,7 @@ void gen_var_decl(struct CodeGen* g, struct AstNode* ast) {
void gen_block_stmt(struct CodeGen* g, struct AstNode* ast) {
assert_ast_kind(ast, AST_BLOCK);
struct AstNode* stmt = ast->next;
- for (; stmt; ) {
+ while (stmt) {
gen_stmt(g, stmt);
stmt = stmt->next;
}
@@ -1852,7 +1870,7 @@ void gen(struct CodeGen* g, struct AstNode* ast) {
printf(".globl main\n\n");
struct AstNode* func = ast->next;
- for (; func; ) {
+ while (func) {
if (func->kind == AST_FUNC_DEF) {
gen_func(g, func);
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-30 23:24:30 +0000