diff options
Diffstat (limited to 'lib/compiler/src')
| -rw-r--r-- | lib/compiler/src/v3_core.erl | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl index 54f6834dd5..e1a593fffa 100644 --- a/lib/compiler/src/v3_core.erl +++ b/lib/compiler/src/v3_core.erl @@ -1820,7 +1820,21 @@ upattern_list([], _, St) -> {[],[],[],[],St}. %% upat_bin([Pat], [KnownVar], State) -> %% {[Pat],[GuardTest],[NewVar],[UsedVar],State}. upat_bin(Es0, Ks, St0) -> - upat_bin(Es0, Ks, [], St0). + {Es1,Pg,Pv,Pu0,St1} = upat_bin(Es0, Ks, [], St0), + + %% In a clause such as <<Sz:8,V:Sz>> in a function head, Sz will both + %% be new and used; a situation that is not handled properly by + %% uclause/4. (Basically, since Sz occurs in two sets that are + %% subtracted from each other, Sz will not be added to the list of + %% known variables and will seem to be new the next time it is + %% used in a match.) + %% Since the variable Sz really is new (it does not use a + %% value bound prior to the binary matching), Sz should only be + %% included in the set of new variables. Thus we should take it + %% out of the set of used variables. + + Pu1 = subtract(Pu0, intersection(Pv, Pu0)), + {Es1,Pg,Pv,Pu1,St1}. %% upat_bin([Pat], [KnownVar], [LocalVar], State) -> %% {[Pat],[GuardTest],[NewVar],[UsedVar],State}. |