re PR fortran/81344 (Can't disable -ffpe-trap (or not documented))

2019-02-02  Dominique d'Humieres  <dominiq@gcc.gnu.org>

	PR fortran/81344
	* invoke.texi: Document the behavior of repeated -ffpe-trap
	and -ffpe-summary.

From-SVN: r268480

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 622af1e39020b84fb0c2fde15044e59196f4314f..6f0e9e694955f2295aa71ed4856364b72d50e25c 100644 (file)
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,9 @@
+2019-02-02  Dominique d'Humieres  <dominiq@gcc.gnu.org>
+
+       PR fortran/81344
+       * invoke.texi: Document the behavior of repeated -ffpe-trap
+       and -ffpe-summary.
+
 2019-02-02  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
        PR fortran/88298

diff --git a/gcc/fortran/invoke.texi b/gcc/fortran/invoke.texi
index deaf8eba102a69932e2a6d3198af6862d0453422..0e0c2bcb20da1c2a5ec3b575e5f1cf1915a3c5ae 100644 (file)
--- a/gcc/fortran/invoke.texi
+++ b/gcc/fortran/invoke.texi
@@ -1203,6 +1203,12 @@ The first three exceptions (@samp{invalid}, @samp{zero}, and
 has provisions for dealing with these exceptions, enabling traps for
 these three exceptions is probably a good idea.
 
+If the option is used more than once in the command line, the lists will
+be joined: '@code{ffpe-trap=}@var{list1} @code{ffpe-trap=}@var{list2}'
+is equivalent to @code{ffpe-trap=}@var{list1,list2}.
+
+Note that once enabled an exception cannot be disabled (no negative form).
+
 Many, if not most, floating point operations incur loss of precision
 due to rounding, and hence the @code{ffpe-trap=inexact} is likely to
 be uninteresting in practice.
@@ -1218,6 +1224,9 @@ of the following exceptions: @samp{invalid}, @samp{zero}, @samp{overflow},
 @samp{underflow}, @samp{inexact} and @samp{denormal}. (See
 @option{-ffpe-trap} for a description of the exceptions.)
 
+If the option is used more than once in the command line, only the
+last one will be used.
+
 By default, a summary for all exceptions but @samp{inexact} is shown.
 
 @item -fno-backtrace