* c.opt (Wmissing-include-dirs): New.

	* c-opts.c (c_common_handle_option): Pass true for user_supplied_p
	to add_path () for -I, but false for OPT_idirafter, OPT_iquote and
	OPT_isystem. Handle case OPT_Wmissing_include_dirs.
	* c-incpath.h (add_path): Add fourth (bool) argument.
	* c-incpath.c (add_env_var_paths): Pass false to add_path ().
	(add_standard_paths): Likewise.
	(remove_duplicates) [REASON_NOENT]: Warn if -Wmissing-include-dirs
	is used and the directory was user-supplied via -I.
	(add_path): Set p->user_supplied_p.  Remove duplicated code by
	using add_cpp_dir_path ().
	* cpplib.h (struct cpp_options): Add warn_missing_include_dirs.
	(struct cpp_dir): Add user_supplied_p.
	* doc/invoke.texi (Warning Options): Document new option.

[testsuite]
	* gcc.dg/cpp/Wmissingdirs.c: New.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@82121 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 13 insertions, 10 deletions

diff --git a/gcc/c-incpath.c b/gcc/c-incpath.c
index b4da86fb7ba..ea83c1a18b4 100644
--- a/gcc/c-incpath.c
+++ b/gcc/c-incpath.c
@@ -114,7 +114,7 @@ add_env_var_paths (const char *env_var, int chain)
 	  path[q - p] = '\0';
 	}
 
-      add_path (path, chain, chain == SYSTEM);
+      add_path (path, chain, chain == SYSTEM, false);
     }
 }
 
@@ -142,7 +142,7 @@ add_standard_paths (const char *sysroot, const char *iprefix, int cxx_stdinc)
 	      if (!strncmp (p->fname, cpp_GCC_INCLUDE_DIR, len))
 		{
 		  char *str = concat (iprefix, p->fname + len, NULL);
-		  add_path (str, SYSTEM, p->cxx_aware);
+		  add_path (str, SYSTEM, p->cxx_aware, false);
 		}
 	    }
 	}
@@ -160,7 +160,7 @@ add_standard_paths (const char *sysroot, const char *iprefix, int cxx_stdinc)
 	  else
 	    str = update_path (p->fname, p->component);
 
-	  add_path (str, SYSTEM, p->cxx_aware);
+	  add_path (str, SYSTEM, p->cxx_aware, false);
 	}
     }
 }
@@ -192,7 +192,13 @@ remove_duplicates (cpp_reader *pfile, struct cpp_dir *head,
 	  if (errno != ENOENT)
 	    cpp_errno (pfile, CPP_DL_ERROR, cur->name);
 	  else
-	    reason = REASON_NOENT;
+	    {
+	      /* If -Wmissing-include-dirs is given, warn. */
+	      cpp_options *opts = cpp_get_options (pfile);
+	      if (opts->warn_missing_include_dirs && cur->user_supplied_p)
+		cpp_errno (pfile, CPP_DL_WARNING, cur->name);
+	      reason = REASON_NOENT;
+	    }
 	}
       else if (!S_ISDIR (st.st_mode))
 	cpp_error_with_line (pfile, CPP_DL_ERROR, 0, 0,
@@ -317,7 +323,7 @@ add_cpp_dir_path (cpp_dir *p, int chain)
 /* Add PATH to the include chain CHAIN. PATH must be malloc-ed and
    NUL-terminated.  */
 void
-add_path (char *path, int chain, int cxx_aware)
+add_path (char *path, int chain, int cxx_aware, bool user_supplied_p)
 {
   cpp_dir *p;
 
@@ -329,12 +335,9 @@ add_path (char *path, int chain, int cxx_aware)
   else
     p->sysp = 0;
   p->construct = 0;
+  p->user_supplied_p = user_supplied_p;
 
-  if (tails[chain])
-    tails[chain]->next = p;
-  else
-    heads[chain] = p;
-  tails[chain] = p;
+  add_cpp_dir_path (p, chain);
 }
 
 /* Exported function to handle include chain merging, duplicate