diff options
| -rw-r--r-- | gcc/ada/a-tags.adb | 47 |
1 files changed, 44 insertions, 3 deletions
diff --git a/gcc/ada/a-tags.adb b/gcc/ada/a-tags.adb index 0b735be7a44..33f0be3a6be 100644 --- a/gcc/ada/a-tags.adb +++ b/gcc/ada/a-tags.adb @@ -628,9 +628,50 @@ package body Ada.Tags is end loop; if Addr_Last <= External'Last then - Addr := - Integer_Address'Value (External (Addr_First .. Addr_Last)); - return To_Tag (Addr); + + -- Protect the run-time against wrong internal tags. We + -- cannot use exception handlers here because it would + -- disable the use of this run-time compiling with + -- restriction No_Exception_Handler. + + declare + C : Character; + Wrong_Tag : Boolean := False; + + begin + if External (Addr_First) /= '1' + or else External (Addr_First + 1) /= '6' + or else External (Addr_First + 2) /= '#' + then + Wrong_Tag := True; + + else + for J in Addr_First + 3 .. Addr_Last - 1 loop + C := External (J); + + if not (C in '0' .. '9') + and then not (C in 'A' .. 'F') + and then not (C in 'a' .. 'f') + then + Wrong_Tag := True; + exit; + end if; + end loop; + end if; + + -- Convert the numeric value into a tag + + if not Wrong_Tag then + Addr := Integer_Address'Value + (External (Addr_First .. Addr_Last)); + + -- Internal tags never have value 0 + + if Addr /= 0 then + return To_Tag (Addr); + end if; + end if; + end; end if; end; |