From 8114d04fb9291469ce2c5b6781776ec5c41b6949 Mon Sep 17 00:00:00 2001
From: Yaossg <yaossg@outlook.com>
Date: Sat, 30 Nov 2024 11:19:13 +0800
Subject: [PATCH] comma expr

---
 README.md  |  1 +
 boot.c     | 27 ++++++++++++++++++++-------
 demo/add.c |  2 +-
 3 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/README.md b/README.md
index 2b3abe6..86a2024 100644
--- a/README.md
+++ b/README.md
@@ -122,6 +122,7 @@ $ sh boot.sh
 | `&&`                              | 逻辑与                                          | 从左到右 |
 | <code>&#124;&#124;</code>         | 逻辑或                                          | 从左到右 |
 | `=`                               | 赋值                                            | 从右到左 |
+| `,`                               | 逗号                                            | 从左到右 |
 
 - 同级表达式的求值顺序与结合性一致。
 - 加减号支持整数之间，指针与整数，指针之间的运算。
diff --git a/boot.c b/boot.c
index 913acd2..a56a1ac 100644
--- a/boot.c
+++ b/boot.c
@@ -22,7 +22,7 @@ const int TOKEN_EOF = 0;
 const int TOKEN_SEMICOLON = 1;
 const int TOKEN_ADD = 2;
 const int TOKEN_MINUS = 3;
-const int TOKEN_STAR = 4;
+const int TOKEN_MUL = 4;
 const int TOKEN_DIV = 5;
 const int TOKEN_REM = 6;
 const int TOKEN_ASSIGN = 7;
@@ -277,7 +277,7 @@ void next_token() {
             token_type = TOKEN_MINUS;
         }
     } else if (ch == '*') {
-        token_type = TOKEN_STAR;
+        token_type = TOKEN_MUL;
     } else if (ch == '/') {
         int ch2 = getchar();
         if (ch2 == '/') {
@@ -429,7 +429,7 @@ int parse_type() {
         int type = token_type & ~TYPE_TOKEN_MASK;
         next_token();
         ignore_const();
-        if (token_type == TOKEN_STAR) {
+        if (token_type == TOKEN_MUL) {
             next_token();
             ignore_const();
             type = type | TYPE_PTR_MASK;
@@ -1011,6 +1011,8 @@ int addressof(int reg) {
 
 int parse_expr();
 
+int parse_assign_expr();
+
 int parse_function_call(int id) {
     const char* name = id_table + id_lut[id];
     if (global_marker[id] != MARKER_FUNCTION) {
@@ -1029,7 +1031,7 @@ int parse_function_call(int id) {
             eprintf("too many arguments\n");
             exit(1);
         }
-        args[arg++] = parse_expr();
+        args[arg++] = parse_assign_expr();
         next_token();
         if (token_type == TOKEN_COMMA) {
             // continue;
@@ -1128,7 +1130,7 @@ int parse_prefix_expr() {
             exit(1);
         }
         return addressof(reg);
-    } else if (token_type == TOKEN_STAR) {
+    } else if (token_type == TOKEN_MUL) {
         int reg = parse_postfix_expr();
         int type = reg_type[reg];
         if (!(type & TYPE_PTR_MASK)) {
@@ -1167,7 +1169,7 @@ int parse_mul_expr() {
     int lhs = parse_prefix_expr();
     while (1) {
         next_token();
-        if (token_type == TOKEN_STAR) {
+        if (token_type == TOKEN_MUL) {
             int rhs = parse_prefix_expr();
             lhs = asm_rr_arith("mul", lhs, rhs);
         } else if (token_type == TOKEN_DIV) {
@@ -1384,7 +1386,18 @@ int parse_assign_expr() {
 }
 
 int parse_expr() {
-    return parse_assign_expr();
+    int lhs = parse_assign_expr();
+    while (1) {
+        next_token();
+        if (token_type == TOKEN_COMMA) {
+            int rhs = parse_assign_expr();
+            lhs = rhs;
+        } else {
+            unget_token();
+            break;
+        }
+    }
+    return lhs;
 }
 
 void parse_local_variable(int type) {
diff --git a/demo/add.c b/demo/add.c
index 6c54b5f..f42e07e 100644
--- a/demo/add.c
+++ b/demo/add.c
@@ -12,6 +12,6 @@ int f1() {
 int main() {
     int a[15];
     p = a;
-    for (int i = 0; i < 15; ++i) a[i] = i;
+    for (int i = 0; i < 15; a[i] = i, ++i);
     return f1();
 }
\ No newline at end of file