[PATCH] re-document the ac_cv_prog_cc_c89/ac_cv_prog_cc_c99 variables

[Adrian Bunk]

* doc/autoconf.texi: re-document the ac_cv_prog_cc_c89/ac_cv_prog_cc_c99
variables
---
 doc/autoconf.texi |   18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 08082aa..d11c670 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -7257,16 +7257,26 @@ set to accept Standard C; if not, the shell variable
 @code{ac_cv_prog_cc_stdc} is set to @samp{no}.
 
 When attempting to add compiler options, prefer extended functionality
-modes over strict conformance modes.  Test for C11 support by checking
+modes over strict conformance modes.
+
+Test for C11 support by checking
 for @code{_Alignas}, @code{_Alignof}, @code{_Noreturn},
 @code{_Static_assert}, UTF-8 string literals, duplicate @code{typedef}s,
-and anonymous structures and unions.  Test for C99 support by checking
+and anonymous structures and unions.
+
+Test for C99 support by checking
 for @code{_Bool}, @code{//} comments, flexible array members,
 @code{inline}, signed and unsigned @code{long long int}, mixed code and
 declarations, named initialization of structs, @code{restrict},
 @code{va_copy}, varargs macros, variable declarations in @code{for}
-loops, and variable length arrays.  Test for C89 support by checking for
-function prototypes.
+loops, and variable length arrays.  You can check whether the C compiler
+has been set to accept C99; if not, the shell variable
address@hidden is set to @samp{no}.
+
+Test for C89 support by checking for function prototypes.  You can check
+whether the C compiler has been set to accept ANSI C89; if not, the shell
+variable @code{ac_cv_prog_cc_c89} is set to @samp{no}.
+
 
 If using the GNU C compiler, set shell variable @code{GCC} to
 @samp{yes}.  If output variable @code{CFLAGS} was not already set, set
-- 
1.7.10.4