diff options
Diffstat (limited to 'gcc/ada/sem_ch4.adb')
| -rw-r--r-- | gcc/ada/sem_ch4.adb | 59 |
1 files changed, 57 insertions, 2 deletions
diff --git a/gcc/ada/sem_ch4.adb b/gcc/ada/sem_ch4.adb index 2fa9c5a..d54d992 100644 --- a/gcc/ada/sem_ch4.adb +++ b/gcc/ada/sem_ch4.adb @@ -3510,6 +3510,9 @@ package body Sem_Ch4 is -- Determine whether if expression If_Expr lacks an else part or if it -- has one, it evaluates to True. + function Referenced (Id : Entity_Id; Expr : Node_Id) return Boolean; + -- Determine whether entity Id is referenced within expression Expr + -------------------- -- Is_Empty_Range -- -------------------- @@ -3561,9 +3564,44 @@ package body Sem_Ch4 is and then Is_True (Expr_Value (Else_Expr))); end No_Else_Or_Trivial_True; + ---------------- + -- Referenced -- + ---------------- + + function Referenced (Id : Entity_Id; Expr : Node_Id) return Boolean is + Seen : Boolean := False; + + function Is_Reference (N : Node_Id) return Traverse_Result; + -- Determine whether node N denotes a reference to Id. If this is the + -- case, set global flag Seen to True and stop the traversal. + + function Is_Reference (N : Node_Id) return Traverse_Result is + begin + if Is_Entity_Name (N) + and then Present (Entity (N)) + and then Entity (N) = Id + then + Seen := True; + return Abandon; + else + return OK; + end if; + end Is_Reference; + + procedure Inspect_Expression is new Traverse_Proc (Is_Reference); + + -- Start of processing for Referenced + + begin + Inspect_Expression (Expr); + + return Seen; + end Referenced; + -- Local variables Cond : constant Node_Id := Condition (N); + Loop_Id : Entity_Id; QE_Scop : Entity_Id; -- Start of processing for Analyze_Quantified_Expression @@ -3590,22 +3628,39 @@ package body Sem_Ch4 is if Present (Iterator_Specification (N)) then Preanalyze (Iterator_Specification (N)); + -- Do not proceed with the analysis when the range of iteration is + -- empty. The appropriate error is issued by Is_Empty_Range. + if Is_Entity_Name (Name (Iterator_Specification (N))) and then Is_Empty_Range (Etype (Name (Iterator_Specification (N)))) then return; end if; - else + else pragma Assert (Present (Loop_Parameter_Specification (N))); Preanalyze (Loop_Parameter_Specification (N)); end if; Preanalyze_And_Resolve (Cond, Standard_Boolean); End_Scope; - Set_Etype (N, Standard_Boolean); + -- Verify that the loop variable is used within the condition of the + -- quantified expression. + + if Present (Iterator_Specification (N)) then + Loop_Id := Defining_Identifier (Iterator_Specification (N)); + else + Loop_Id := Defining_Identifier (Loop_Parameter_Specification (N)); + end if; + + if Warn_On_Suspicious_Contract + and then not Referenced (Loop_Id, Cond) + then + Error_Msg_N ("?T?unused variable &", Loop_Id); + end if; + -- Diagnose a possible misuse of the "some" existential quantifier. When -- we have a quantified expression of the form -- |