Fix toplevel comment of attr-fnspec.h

gcc/ChangeLog:

2020-10-15  Jan Hubicka  <hubicka@ucw.cz>
	    Richard Biener  <rguenther@suse.de>

	* attr-fnspec.h: Fix toplevel comment.

diff --git a/gcc/attr-fnspec.h b/gcc/attr-fnspec.h
index 921bb48ae6a0202f2d68cd6f33a234fcd98bc48c..d38b84a969ee5316559ad70519bb4c69930c22f7 100644 (file)
--- a/gcc/attr-fnspec.h
+++ b/gcc/attr-fnspec.h
@@ -30,12 +30,14 @@
 
    character 2+2i specifies properties of argument number i as follows:
      'x' or 'X' specifies that parameter is unused.
-     'r' or 'R' specifies that parameter is only read and memory pointed to is
-               never dereferenced.
-     'w' or 'W' specifies that parameter is only written to.
+     'r' or 'R' specifies that the memory pointed to by the parameter is only
+               read and does not escape
+     'w' or 'W' specifies that the memory pointed to by the parameter does not
+               escape
      '.'       specifies that nothing is known.
-   The uppercase letter in addition specifies that parameter
-   is non-escaping. 
+   The uppercase letter in addition specifies that the memory pointed to
+   by the parameter is not dereferenced.  For 'r' only read applies
+   transitively to pointers read from the pointed-to memory.
 
    character 3+2i specifies additional properties of argument number i
    as follows: