Add #include <...>

chibicc.h

@@ -346,4 +346,6 @@ int align_to(int n, int align);
 // main.c
 //
 
+bool file_exists(char *path);
+
 extern char *base_file;

main.c

@@ -224,7 +224,7 @@ static char *find_file(char *pattern) {
 }
 
 // Returns true if a given file exists.
-static bool file_exists(char *path) {
+bool file_exists(char *path) {
   struct stat st;
   return !stat(path, &st);
 }

preprocess.c

@@ -421,10 +421,10 @@ static MacroArg *find_arg(MacroArg *args, Token *tok) {
 }
 
 // Concatenates all tokens in `tok` and returns a new string.
-static char *join_tokens(Token *tok) {
+static char *join_tokens(Token *tok, Token *end) {
   // Compute the length of the resulting token.
   int len = 1;
-  for (Token *t = tok; t && t->kind != TK_EOF; t = t->next) {
+  for (Token *t = tok; t != end && t->kind != TK_EOF; t = t->next) {
     if (t != tok && t->has_space)
       len++;
     len += t->len;
@@ -434,7 +434,7 @@ static char *join_tokens(Token *tok) {
 
   // Copy token texts.
   int pos = 0;
-  for (Token *t = tok; t && t->kind != TK_EOF; t = t->next) {
+  for (Token *t = tok; t != end && t->kind != TK_EOF; t = t->next) {
     if (t != tok && t->has_space)
       buf[pos++] = ' ';
     strncpy(buf + pos, t->loc, t->len);
@@ -450,7 +450,7 @@ static Token *stringize(Token *hash, Token *arg) {
   // Create a new string token. We need to set some value to its
   // source location for error reporting function, so we use a macro
   // name token as a template.
-  char *s = join_tokens(arg);
+  char *s = join_tokens(arg, NULL);
   return new_str_token(s, hash);
 }
 
@@ -596,6 +596,54 @@ static bool expand_macro(Token **rest, Token *tok) {
   return true;
 }
 
+// Read an #include argument.
+static char *read_include_filename(Token **rest, Token *tok, bool *is_dquote) {
+  // Pattern 1: #include "foo.h"
+  if (tok->kind == TK_STR) {
+    // A double-quoted filename for #include is a special kind of
+    // token, and we don't want to interpret any escape sequences in it.
+    // For example, "\f" in "C:\foo" is not a formfeed character but
+    // just two non-control characters, backslash and f.
+    // So we don't want to use token->str.
+    *is_dquote = true;
+    *rest = skip_line(tok->next);
+    return strndup(tok->loc + 1, tok->len - 2);
+  }
+
+  // Pattern 2: #include <foo.h>
+  if (equal(tok, "<")) {
+    // Reconstruct a filename from a sequence of tokens between
+    // "<" and ">".
+    Token *start = tok;
+
+    // Find closing ">".
+    for (; !equal(tok, ">"); tok = tok->next)
+      if (tok->at_bol || tok->kind == TK_EOF)
+        error_tok(tok, "expected '>'");
+
+    *is_dquote = false;
+    *rest = skip_line(tok->next);
+    return join_tokens(start->next, tok);
+  }
+
+  // Pattern 3: #include FOO
+  // In this case FOO must be macro-expanded to either
+  // a single string token or a sequence of "<" ... ">".
+  if (tok->kind == TK_IDENT) {
+    Token *tok2 = preprocess2(copy_line(rest, tok));
+    return read_include_filename(&tok2, tok2, is_dquote);
+  }
+
+  error_tok(tok, "expected a filename");
+}
+
+static Token *include_file(Token *tok, char *path, Token *filename_tok) {
+  Token *tok2 = tokenize_file(path);
+  if (!tok2)
+    error_tok(filename_tok, "%s: cannot open file: %s", path, strerror(errno));
+  return append(tok2, tok);
+}
+
 // Visit all tokens in `tok` while evaluating preprocessing
 // macros and directives.
 static Token *preprocess2(Token *tok) {
@@ -618,22 +666,19 @@ static Token *preprocess2(Token *tok) {
     tok = tok->next;
 
     if (equal(tok, "include")) {
-      tok = tok->next;
+      bool is_dquote;
+      char *filename = read_include_filename(&tok, tok->next, &is_dquote);
 
-      if (tok->kind != TK_STR)
-        error_tok(tok, "expected a filename");
+      if (filename[0] != '/') {
+        char *path = format("%s/%s", dirname(strdup(start->file->name)), filename);
+        if (file_exists(path)) {
+          tok = include_file(tok, path, start->next->next);
+          continue;
+        }
+      }
 
-      char *path;
-      if (tok->str[0] == '/')
-        path = tok->str;
-      else
-        path = format("%s/%s", dirname(strdup(tok->file->name)), tok->str);
-
-      Token *tok2 = tokenize_file(path);
-      if (!tok2)
-        error_tok(tok, "%s", strerror(errno));
-      tok = skip_line(tok->next);
-      tok = append(tok2, tok);
+      // TODO: Search a file from the include paths.
+      tok = include_file(tok, filename, start->next->next);
       continue;
     }
 

self.py

@@ -94,6 +94,7 @@ int atexit(void (*)(void));
 FILE *open_memstream(char **ptr, size_t *sizeloc);
 char *dirname(char *path);
 char *strncpy(char *dest, char *src, long n);
+int stat(char *pathname, struct stat *statbuf);
 """)
 
 for path in sys.argv[1:]:

test/include3.h

@@ -0,0 +1 @@
+#define foo 3

test/include4.h

@@ -0,0 +1 @@
+#define foo 4

test/macro.c

@@ -306,6 +306,22 @@ int main() {
 #define M14(x) M13(x. M12)
   ASSERT(0, strcmp(M14(bar), "bar. foo"));
 
+#include "include3.h"
+  ASSERT(3, foo);
+
+#include "include4.h"
+  ASSERT(4, foo);
+
+#define M13 "include3.h"
+#include M13
+  ASSERT(3, foo);
+
+#define M13 < include4.h
+#include M13 >
+  ASSERT(4, foo);
+
+#undef foo
+
   printf("OK\n");
   return 0;
 }