一文字のローカル変数

9cc.c

@@ -1,12 +1,8 @@
-#include <ctype.h>
-#include <stdarg.h>
-#include <stdbool.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
+#include "9cc.h"
 
 typedef enum {
     TK_RESERVED,
+    TK_IDENT,
     TK_NUM,
     TK_EOF,
 } TokenKind;
@@ -70,6 +66,12 @@ int expect_number() {
     return val;
 }
 
+int get_offset() {
+    int offset = (token->str[0] - 'a' + 1) * 8;
+    token = token->next;
+    return offset;
+}
+
 bool at_eof() {
     return token->kind == TK_EOF;
 }
@@ -104,7 +106,7 @@ Token *tokenize(char *p) {
             continue;
         }
 
-        if (strchr("+-*/()<>", *p)) {
+        if (strchr("+-*/()<>=;", *p)) {
             cur = new_token(TK_RESERVED, cur, p++, 1);
             continue;
         }
@@ -115,6 +117,11 @@ Token *tokenize(char *p) {
             continue;
         }
 
+        if('a' <= *p && *p <= 'z') {
+            cur = new_token(TK_IDENT, cur, p++, 1);
+            continue;
+        }
+
         error_at(p, "トークナイズできません");
     }
 
@@ -131,7 +138,9 @@ typedef enum {
     ND_EQ,
     ND_NEQ,
     ND_LT,
-    ND_LTE
+    ND_LTE,
+    ND_ASSIGN,
+    ND_LVAR,
 } NodeKind;
 
 typedef struct Node Node;
@@ -141,6 +150,7 @@ struct Node {
     Node *lhs;
     Node *rhs;
     int val;
+    int offset;
 };
 
 Node *new_node(NodeKind kind, Node *lhs, Node *rhs) {
@@ -158,16 +168,48 @@ Node *new_node_num(int val) {
     return node;
 }
 
+Node *new_node_ident(int offset) {
+    Node *node = calloc(1,sizeof(Node));
+    node->kind = ND_LVAR;
+    node->offset = offset;
+    return node;
+}
+
+Node *code[100];
+
+Node *program();
+Node *stmt();
 Node *expr();
+Node *assign();
 Node *equality();
 Node *relational();
 Node *add();
 Node *mul();
 Node *primary();
 Node *unary();
 
+Node *program() {
+    int i = 0;
+    while (!at_eof())
+        code[i++] = stmt();
+    code[i] = NULL;
+}
+
+Node *stmt() {
+    Node *node = expr();
+    expect(";");
+    return node;
+}
+
 Node *expr() {
+    return assign();
+}
+
+Node *assign() {
     Node *node = equality();
+    if (consume("="))
+        node = new_node(ND_ASSIGN, node, assign());
+    return node;
 }
 
 Node *equality() {
@@ -233,6 +275,10 @@ Node *primary() {
         return node;
     }
 
+    if (token->kind == TK_IDENT) {
+        return new_node_ident(get_offset());
+    }
+
     return new_node_num(expect_number());
 }
 
@@ -244,10 +290,36 @@ Node *unary() {
     return primary();
 }
 
+void gen_lval(Node *node) {
+    if (node->kind != ND_LVAR)
+        error("代入の左辺値が変数ではありません");
+
+    printf("  mov rax, rbp\n");
+    printf("  sub rax, %d\n", node->offset);
+    printf("  push rax\n");
+}
+
 void gen(Node *node) {
-    if (node->kind == ND_NUM) {
+    switch (node->kind)
+    {
+    case ND_NUM:
         printf("  push %d\n", node->val);
         return;
+    case ND_LVAR:
+        gen_lval(node);
+        printf("  pop rax\n");
+        printf("  mov rax, [rax]\n");
+        printf("  push rax\n");
+        return;
+    case ND_ASSIGN:
+        gen_lval(node->lhs);
+        gen(node->rhs);
+
+        printf("  pop rdi\n");
+        printf("  pop rax\n");
+        printf("  mov [rax], rdi\n");
+        printf("  push rdi\n");
+        return;
     }
 
     gen(node->lhs);
@@ -304,15 +376,24 @@ int main(int argc, char **argv) {
     user_input = argv[1];
     token = tokenize(user_input);
 
-    Node *node = expr();
+    program();
 
     printf(".intel_syntax noprefix\n");
     printf(".globl main\n");
     printf("main:\n");
 
-    gen(node);
+    printf("  push rbp\n");
+    printf("  mov rbp, rsp\n");
+    printf("  sub rsp, 208\n");
 
-    printf("  pop rax\n");
+    for (int i = 0; code[i]; i++) {
+        gen(code[i]);
+
+        printf("  pop rax\n");
+    }
+
+    printf("  mov rsp, rbp\n");
+    printf("  pop rbp\n");
     printf("  ret\n");
     return 0;
 }

9cc.h

@@ -0,0 +1,6 @@
+#include <ctype.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>

Makefile

@@ -1,6 +1,11 @@
 CFLAGS=-std=c11 -g -static
+SRCS=$(wildcard *.c)
+OBJS=$(SRCS:.c=.o)
 
-9cc: 9cc.c
+9cc: $(OBJS)
+		$(CC) -o 9cc $(OBJS) $(LDFLAGS)
+
+$(OBJS): 9cc.h
 
 test: 9cc
 	./test.sh

test.sh

@@ -16,35 +16,39 @@ assert() {
     fi 
 }
 
-assert 0 0
-assert 42 42
-assert 21 "5+20-4"
-assert 41 " 12 + 34 - 5"
-assert 47 '5+6*7'
-assert 15 '5*(9-6)'
-assert 4 '(3+5)/2'
-assert 5 '6 + -1'
-assert 1 '- - 1'
-assert 1 '-5 + 6'
-
-assert 0 '0==1'
-assert 1 '42==42'
-assert 1 '0!=1'
-assert 0 '42!=42'
-
-assert 1 '0<1'
-assert 0 '1<1'
-assert 0 '2<1'
-assert 1 '0<=1'
-assert 1 '1<=1'
-assert 0 '2<=1'
-
-assert 1 '1>0'
-assert 0 '1>1'
-assert 0 '1>2'
-assert 1 '1>=0'
-assert 1 '1>=1'
-assert 0 '1>=2'
-assert 1 '100-50*2 == 10*3-15*2'
+assert 0 '0;'
+assert 42 '42;'
+assert 21 "5+20-4;"
+assert 41 " 12 + 34 - 5;"
+assert 47 '5+6*7;'
+assert 15 '5*(9-6);'
+assert 4 '(3+5)/2;'
+assert 5 '6 + -1;'
+assert 1 '- - 1;'
+assert 1 '-5 + 6;'
+
+assert 0 '0==1;'
+assert 1 '42==42;'
+assert 1 '0!=1;'
+assert 0 '42!=42;'
+
+assert 1 '0<1;'
+assert 0 '1<1;'
+assert 0 '2<1;'
+assert 1 '0<=1;'
+assert 1 '1<=1;'
+assert 0 '2<=1;'
+
+assert 1 '1>0;'
+assert 0 '1>1;'
+assert 0 '1>2;'
+assert 1 '1>=0;'
+assert 1 '1>=1;'
+assert 0 '1>=2;'
+assert 1 '100-50*2 == 10*3-15*2;'
+assert 3 'a=3;'
+assert 10 'z=2*5;'
+assert 13 'z=2*5;a=3;c=a+z;'
+
 
 echo OK