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| author | Robert Dewar <dewar@adacore.com> | 2008-05-28 15:05:35 +0200 |
|---|---|---|
| committer | Arnaud Charlet <charlet@gcc.gnu.org> | 2008-05-28 15:05:35 +0200 |
| commit | 71a555b3b9c9d741380db25fd2fdc47211b5ecdf (patch) | |
| tree | fb31690627a5834458cdbda545cabae658c2046f | |
| parent | 6765b310618f5ce2cdd780f06b3653ecff8e355c (diff) | |
| download | gcc-71a555b3b9c9d741380db25fd2fdc47211b5ecdf.zip gcc-71a555b3b9c9d741380db25fd2fdc47211b5ecdf.tar.gz gcc-71a555b3b9c9d741380db25fd2fdc47211b5ecdf.tar.bz2 | |
gnat_rm.texi: Add note on Old giving warning when applied to constant
2008-05-28 Robert Dewar <dewar@adacore.com>
* gnat_rm.texi: Add note on Old giving warning when applied to constant
* sem_attr.adb (Analyze_Attribute, case Old): Give warning if prefix is
a constant
From-SVN: r136078
| -rw-r--r-- | gcc/ada/gnat_rm.texi | 4 | ||||
| -rw-r--r-- | gcc/ada/sem_attr.adb | 7 |
2 files changed, 11 insertions, 0 deletions
diff --git a/gcc/ada/gnat_rm.texi b/gcc/ada/gnat_rm.texi index 0d2d0ff..69baaa2 100644 --- a/gcc/ada/gnat_rm.texi +++ b/gcc/ada/gnat_rm.texi @@ -5803,6 +5803,10 @@ package body Old_Pkg is end Old_Pkg; @end smallexample +@noindent +Note that it is allowed to apply 'Old to a constant entity, but this will +result in a warning, since the old and new values will always be the same. + @node Passed_By_Reference @unnumberedsec Passed_By_Reference @cindex Parameters, when passed by reference diff --git a/gcc/ada/sem_attr.adb b/gcc/ada/sem_attr.adb index 0cb2ace..14f9102 100644 --- a/gcc/ada/sem_attr.adb +++ b/gcc/ada/sem_attr.adb @@ -3501,6 +3501,13 @@ package body Sem_Attr is Error_Attr ("attribute % cannot apply to limited objects", P); end if; + if Is_Entity_Name (P) + and then Is_Constant_Object (Entity (P)) + then + Error_Msg_N + ("?attribute Old applied to constant has no effect", P); + end if; + -- Check that the expression does not refer to local entities Check_Local : declare |