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author | Piotr Trojanek <trojanek@adacore.com> | 2022-06-03 15:18:24 +0200 |
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committer | Pierre-Marie de Rodat <derodat@adacore.com> | 2022-07-12 12:24:11 +0000 |
commit | 1710ba9e5d09493690c5f474a5c37b5c8f5d7b19 (patch) | |
tree | 8e0d8ef1e695dcbd46c435df9b6c1dee75a90edd | |
parent | 2148f2996ae76a7773eb7d8e30c02bd036ec7b3c (diff) | |
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[Ada] Warn about unreachable code after calls with No_Return
GNAT was already warning about unreachable code after raise/goto/exit
statements, but not after calls to procedures with No_Return. Now this
warning is extended.
Also, previously the warning was suppressed for unreachable RETURN after
RAISE statements. Now this suppression is narrowed to functions, because
only in function such a RETURN statement might be indeed needed (where
it is the only RETURN statement of a function).
gcc/ada/
* sem_ch5.adb (Check_Unreachable_Code): Extend suppression to
calls with No_Return aspect, but narrow it to functions.
* sem_res.adb (Resolve_Call): Warn about unreachable code after
calls with No_Return.
-rw-r--r-- | gcc/ada/sem_ch5.adb | 20 | ||||
-rw-r--r-- | gcc/ada/sem_res.adb | 9 |
2 files changed, 23 insertions, 6 deletions
diff --git a/gcc/ada/sem_ch5.adb b/gcc/ada/sem_ch5.adb index 891c57a..f38c213 100644 --- a/gcc/ada/sem_ch5.adb +++ b/gcc/ada/sem_ch5.adb @@ -4418,12 +4418,20 @@ package body Sem_Ch5 is elsif Comes_From_Source (Nxt) and then Is_Statement (Nxt) then - -- Special very annoying exception. If we have a return that - -- follows a raise, then we allow it without a warning, since - -- the Ada RM annoyingly requires a useless return here. - - if Nkind (Original_Node (N)) /= N_Raise_Statement - or else Nkind (Nxt) /= N_Simple_Return_Statement + -- Special very annoying exception. Ada RM 6.5(5) annoyingly + -- requires functions to have at least one return statement, so + -- don't complain about a simple return that follows a raise or a + -- call to procedure with No_Return. + + if not (Present (Current_Subprogram) + and then Ekind (Current_Subprogram) = E_Function + and then (Nkind (Original_Node (N)) = N_Raise_Statement + or else + (Nkind (N) = N_Procedure_Call_Statement + and then Is_Entity_Name (Name (N)) + and then Present (Entity (Name (N))) + and then No_Return (Entity (Name (N))))) + and then Nkind (Nxt) = N_Simple_Return_Statement) then -- The rather strange shenanigans with the warning message -- here reflects the fact that Kill_Dead_Code is very good at diff --git a/gcc/ada/sem_res.adb b/gcc/ada/sem_res.adb index 1053cec..4335940 100644 --- a/gcc/ada/sem_res.adb +++ b/gcc/ada/sem_res.adb @@ -62,6 +62,7 @@ with Sem_Case; use Sem_Case; with Sem_Cat; use Sem_Cat; with Sem_Ch3; use Sem_Ch3; with Sem_Ch4; use Sem_Ch4; +with Sem_Ch5; use Sem_Ch5; with Sem_Ch6; use Sem_Ch6; with Sem_Ch8; use Sem_Ch8; with Sem_Ch13; use Sem_Ch13; @@ -7193,6 +7194,14 @@ package body Sem_Res is Analyze_Dimension_Call (N, Nam); + -- Check unreachable code after calls to procedures with No_Return + + if Ekind (Nam) = E_Procedure + and then No_Return (Nam) + then + Check_Unreachable_Code (N); + end if; + -- All done, evaluate call and deal with elaboration issues Eval_Call (N); |