Submitted by Arnaud Charlet on Nov. 4, 2011, 2:02 p.m.

Message ID | 20111104140215.GA20911@adacore.com |
---|---|

State | New |

Headers | show |

Index: a-cdlili.adb =================================================================== --- a-cdlili.adb (revision 180934) +++ a-cdlili.adb (working copy) @@ -515,10 +515,24 @@ LI, RI : Cursor; begin - if Target'Address = Source'Address then + + -- The semantics of Merge changed slightly per AI05-0021. It was + -- originally the case that if Target and Source denoted the same + -- container object, then the GNAT implementation of Merge did + -- nothing. However, it was argued that RM05 did not precisely + -- specify the semantics for this corner case. The decision of the + -- ARG was that if Target and Source denote the same non-empty + -- container object, then Program_Error is raised. + + if Source.Is_Empty then return; end if; + if Target'Address = Source'Address then + raise Program_Error with + "Target and Source denote same non-empty container"; + end if; + if Target.Busy > 0 then raise Program_Error with "attempt to tamper with cursors of Target (list is busy)"; Index: a-coinve.adb =================================================================== --- a-coinve.adb (revision 180934) +++ a-coinve.adb (working copy) @@ -1268,16 +1268,26 @@ I, J : Index_Type'Base; begin - if Target.Last < Index_Type'First then - Move (Target => Target, Source => Source); + + -- The semantics of Merge changed slightly per AI05-0021. It was + -- originally the case that if Target and Source denoted the same + -- container object, then the GNAT implementation of Merge did + -- nothing. However, it was argued that RM05 did not precisely + -- specify the semantics for this corner case. The decision of the + -- ARG was that if Target and Source denote the same non-empty + -- container object, then Program_Error is raised. + + if Source.Last < Index_Type'First then -- Source is empty return; end if; if Target'Address = Source'Address then - return; + raise Program_Error with + "Target and Source denote same non-empty container"; end if; - if Source.Last < Index_Type'First then + if Target.Last < Index_Type'First then -- Target is empty + Move (Target => Target, Source => Source); return; end if; Index: a-cidlli.adb =================================================================== --- a-cidlli.adb (revision 180934) +++ a-cidlli.adb (working copy) @@ -563,10 +563,24 @@ LI, RI : Cursor; begin - if Target'Address = Source'Address then + + -- The semantics of Merge changed slightly per AI05-0021. It was + -- originally the case that if Target and Source denoted the same + -- container object, then the GNAT implementation of Merge did + -- nothing. However, it was argued that RM05 did not precisely + -- specify the semantics for this corner case. The decision of the + -- ARG was that if Target and Source denote the same non-empty + -- container object, then Program_Error is raised. + + if Source.Is_Empty then return; end if; + if Target'Address = Source'Address then + raise Program_Error with + "Target and Source denote same non-empty container"; + end if; + if Target.Busy > 0 then raise Program_Error with "attempt to tamper with cursors of Target (list is busy)"; Index: a-cobove.adb =================================================================== --- a-cobove.adb (revision 180934) +++ a-cobove.adb (working copy) @@ -788,16 +788,26 @@ I, J : Count_Type; begin - if Target.Is_Empty then - Move (Target => Target, Source => Source); + + -- The semantics of Merge changed slightly per AI05-0021. It was + -- originally the case that if Target and Source denoted the same + -- container object, then the GNAT implementation of Merge did + -- nothing. However, it was argued that RM05 did not precisely + -- specify the semantics for this corner case. The decision of the + -- ARG was that if Target and Source denote the same non-empty + -- container object, then Program_Error is raised. + + if Source.Is_Empty then return; end if; if Target'Address = Source'Address then - return; + raise Program_Error with + "Target and Source denote same non-empty container"; end if; - if Source.Is_Empty then + if Target.Is_Empty then + Move (Target => Target, Source => Source); return; end if; Index: a-convec.adb =================================================================== --- a-convec.adb (revision 180934) +++ a-convec.adb (working copy) @@ -909,16 +909,26 @@ J : Index_Type'Base; begin - if Target.Last < Index_Type'First then - Move (Target => Target, Source => Source); + + -- The semantics of Merge changed slightly per AI05-0021. It was + -- originally the case that if Target and Source denoted the same + -- container object, then the GNAT implementation of Merge did + -- nothing. However, it was argued that RM05 did not precisely + -- specify the semantics for this corner case. The decision of the + -- ARG was that if Target and Source denote the same non-empty + -- container object, then Program_Error is raised. + + if Source.Last < Index_Type'First then -- Source is empty return; end if; if Target'Address = Source'Address then - return; + raise Program_Error with + "Target and Source denote same non-empty container"; end if; - if Source.Last < Index_Type'First then + if Target.Last < Index_Type'First then -- Target is empty + Move (Target => Target, Source => Source); return; end if; Index: a-cbdlli.adb =================================================================== --- a-cbdlli.adb (revision 180934) +++ a-cbdlli.adb (working copy) @@ -713,10 +713,24 @@ LI, RI : Cursor; begin - if Target'Address = Source'Address then + + -- The semantics of Merge changed slightly per AI05-0021. It was + -- originally the case that if Target and Source denoted the same + -- container object, then the GNAT implementation of Merge did + -- nothing. However, it was argued that RM05 did not precisely + -- specify the semantics for this corner case. The decision of the + -- ARG was that if Target and Source denote the same non-empty + -- container object, then Program_Error is raised. + + if Source.Is_Empty then return; end if; + if Target'Address = Source'Address then + raise Program_Error with + "Target and Source denote same non-empty container"; + end if; + if Target.Busy > 0 then raise Program_Error with "attempt to tamper with cursors of Target (list is busy)";