Add floating constant

cc.h

@@ -34,6 +34,7 @@ FILE *fopen(char *filename, char *modes);
 void *calloc(size_t nmemb, size_t size);
 void *realloc(void *ptr, size_t size);
 void exit(int status);
+double strtod(char *s, char *endpoint);
 
 int strcmp(char *s1, char *s2);
 
@@ -146,7 +147,7 @@ typedef enum token_type {
 typedef struct token {
   TokenType type;
   int int_value;
-  char *float_pattern;
+  double double_value;
   String *string_value;
   char *identifier;
 } Token;
@@ -278,7 +279,7 @@ typedef struct node {
   enum node_type type;
   Type *value_type;
   int int_value;
-  char *float_pattern;
+  double double_value;
   String *string_value;
   int string_label, float_label;
   char *identifier;

gen.c

@@ -100,7 +100,8 @@ void gen_int_const(Node *node) {
 }
 
 void gen_float_const(Node *node) {
-  printf("  movq $%s, %%rax\n", node->float_pattern);
+  int *d = (int *) &node->double_value;
+  printf("  movq $0x%08x%08x, %%rax\n", d[1], d[0]);
   gen_push("rax");
 }
 

lex.c

@@ -67,24 +67,24 @@ Token *lex() {
   Token *token = token_new();
 
   if (isdigit(peek_char())) {
-    int int_value = 0;
+    String *s = string_new();
     while (isdigit(peek_char())) {
-      int_value = int_value * 10 + (get_char() - '0');
+      string_push(s, get_char());
     }
-    if (!read_char('.')) {
-      token->type = tINT_CONST;
-      token->int_value = int_value;
-    } else {
-      int float_value = 0;
+    if (peek_char() == '.') {
+      string_push(s, get_char());
       while (isdigit(peek_char())) {
-        float_value = float_value * 10 + (get_char() - '0');
+        string_push(s, get_char());
       }
-      if (int_value == 123 && float_value == 456) {
-        token->type = tFLOAT_CONST;
-        token->float_pattern = "4638387859538109000";
-      } else {
-        error("unexpected foating constant.");
+      token->type = tFLOAT_CONST;
+      token->double_value = strtod(s->buffer, NULL);
+    } else {
+      int int_value = 0;
+      for (int i = 0; i < s->length; i++) {
+        int_value = int_value * 10 + (s->buffer[i] - '0');
       }
+      token->type = tINT_CONST;
+      token->int_value = int_value;
     }
   } else if (read_char('\'')) {
     int int_value;

parse.c

@@ -158,7 +158,7 @@ Node *primary_expression() {
   if (token->type == tFLOAT_CONST) {
     Node *node = node_new();
     node->type = FLOAT_CONST;
-    node->float_pattern = token->float_pattern;
+    node->double_value = token->double_value;
     return node;
   }
 

tests/test.sh

@@ -227,6 +227,7 @@ test_stdout "int main() { printf(\"%7.3f\n\", 123.456); }" "123.456"
 test_stdout "int main() { double d = 123.456; printf(\"%7.3f\n\", d); }" "123.456"
 test_stdout "int main() { double d[2] = { 123.456, 123.456 }; printf(\"%7.3f\n\", d[1]); }" "123.456"
 test_stdout "double test_double(double d); int main() { printf(\"%7.3f\n\", test_double(123.456)); }" "246.912"
+test_stdout "int main() { double d = 13211.5673; printf(\"%.4f\n\", d); }" "13211.5673"
 
 test_error "int main() { 2 * (3 + 4; }" "tRPAREN is expected."
 test_error "int main() { 5 + *; }" "unexpected primary expression."