[src/mpfr.h] Use the underscore version of the attribute names.

[doc/README.dev] Added information on this subject.

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@13723 280ebfd0-de03-0410-8827-d642c229c3f4

2 files changed, 10 insertions, 3 deletions

diff --git a/doc/README.dev b/doc/README.dev
index d180428cd..1ee7ee641 100644
--- a/doc/README.dev
+++ b/doc/README.dev
@@ -681,6 +681,13 @@ user-defined string literal in C++11:
   https://en.cppreference.com/w/cpp/language/user_literal
   https://stackoverflow.com/a/6402166/3782797
 
+In at least mpfr.h, use the underscore version of the attribute names
+(e.g. "__sentinel__" instead of "sentinel"), otherwise user code could
+fail to compile with GCC when it defines macros such as "sentinel"
+(before the #include's or via the -D command-line option). See
+
+  https://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html
+
    =====================================================================
 
 Setting errno is safe to signal some error information (as in the
diff --git a/src/mpfr.h b/src/mpfr.h
index a26a59640..c434a6526 100644
--- a/src/mpfr.h
+++ b/src/mpfr.h
@@ -272,7 +272,7 @@ typedef enum {
 #if defined (__GNUC__)
 # if __GNUC__ >= 4
 #  undef __MPFR_SENTINEL_ATTR
-#  define __MPFR_SENTINEL_ATTR __attribute__ ((sentinel))
+#  define __MPFR_SENTINEL_ATTR __attribute__ ((__sentinel__))
 # endif
 #endif
 
@@ -331,7 +331,7 @@ typedef enum {
 */
 #if defined(__GNUC__) && \
   (__GNUC__ >= 4 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
-# define MPFR_DEPRECATED __attribute__ ((deprecated))
+# define MPFR_DEPRECATED __attribute__ ((__deprecated__))
 #elif defined(_MSC_VER) && _MSC_VER >= 1300
 # define MPFR_DEPRECATED __declspec(deprecated)
 #else
@@ -345,7 +345,7 @@ typedef enum {
 
 #if defined(__GNUC__) && \
   (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9))
-# define MPFR_RETURNS_NONNULL __attribute__ ((returns_nonnull))
+# define MPFR_RETURNS_NONNULL __attribute__ ((__returns_nonnull__))
 #else
 # define MPFR_RETURNS_NONNULL
 #endif