This change introduces generation of a null statement in alternatives appearing in various forms of select statement, when they do not have trailing statements. The purpose of the additional null statement is to allow a nop to be generated with an appropriate source location indication in debug information, for coverage analysis purposes.
Tested on x86_64-pc-linux-gnu, committed on trunk 2012-07-16 Thomas Quinot <qui...@adacore.com> * exp_ch9.adb (Ensure_Statement_Present): New subprogram. (Expand_N_Asynchronous_Select, Expand_N_Selective_Accept.Process_Accept_Alternative, Expand_N_Selective_Accept.Process_Delay_Alternative, Expand_N_Timed_Entry_Call): For an alternative with no trailing statements, introduce a null statement to carry the sloc of the initial special statement (accept, delay, or entry call) in the alternative, for coverage analysis purposes.
Index: exp_ch9.adb =================================================================== --- exp_ch9.adb (revision 189534) +++ exp_ch9.adb (revision 189535) @@ -339,6 +339,17 @@ -- step of the expansion must to be done after private data has been moved -- to its final resting scope to ensure proper visibility of debug objects. + procedure Ensure_Statement_Present (Loc : Source_Ptr; Alt : Node_Id); + -- If control flow optimizations are suppressed, and Alt is an accept, + -- delay, or entry call alternative with no trailing statements, insert a + -- null trailing statement with the given Loc (which is the sloc of the + -- accept, delay, or entry call statement). There might not be any + -- generated code for the accept, delay, or entry call itself (the + -- effect of these statements is part of the general processsing done + -- for the enclosing selective accept, timed entry call, or asynchronous + -- select), and the null statement is there to carry the sloc of that + -- statement to the back-end for trace-based coverage analysis purposes. + procedure Extract_Dispatching_Call (N : Node_Id; Call_Ent : out Entity_Id; @@ -5468,6 +5479,19 @@ end loop; end Debug_Private_Data_Declarations; + ------------------------------ + -- Ensure_Statement_Present -- + ------------------------------ + + procedure Ensure_Statement_Present (Loc : Source_Ptr; Alt : Node_Id) is + begin + if Opt.Suppress_Control_Flow_Optimizations + and then Is_Empty_List (Statements (Alt)) + then + Set_Statements (Alt, New_List (Make_Null_Statement (Loc))); + end if; + end Ensure_Statement_Present; + ---------------------------- -- Entry_Index_Expression -- ---------------------------- @@ -6587,7 +6611,7 @@ Abortable_Block : Node_Id; Actuals : List_Id; Astats : List_Id; - Blk_Ent : Entity_Id; + Blk_Ent : constant Entity_Id := Make_Temporary (Loc, 'A'); Blk_Typ : Entity_Id; Call : Node_Id; Call_Ent : Entity_Id; @@ -6632,15 +6656,16 @@ Process_Statements_For_Controlled_Objects (Trig); Process_Statements_For_Controlled_Objects (Abrt); + Ecall := Triggering_Statement (Trig); + + Ensure_Statement_Present (Sloc (Ecall), Trig); + -- Retrieve Astats and Tstats now because the finalization machinery may -- wrap them in blocks. Astats := Statements (Abrt); Tstats := Statements (Trig); - Blk_Ent := Make_Temporary (Loc, 'A'); - Ecall := Triggering_Statement (Trig); - -- The arguments in the call may require dynamic allocation, and the -- call statement may have been transformed into a block. The block -- may contain additional declarations for internal entities, and the @@ -10301,6 +10326,8 @@ Alt_Stats := New_List; end if; + Ensure_Statement_Present (Sloc (Astmt), Alt); + -- After the call, if any, branch to trailing statements, if any. -- We create a label for each, as well as the corresponding label -- declaration. @@ -10330,6 +10357,7 @@ ------------------------------- procedure Process_Delay_Alternative (Alt : Node_Id; Index : Int) is + Dloc : constant Source_Ptr := Sloc (Delay_Statement (Alt)); Choices : List_Id; Cond : Node_Id; Delay_Alt : List_Id; @@ -10433,6 +10461,8 @@ Append_List (Delay_Alt, Delay_List); + Ensure_Statement_Present (Dloc, Alt); + -- If the delay alternative has a statement part, add choice to the -- case statements for delays. @@ -11884,6 +11914,8 @@ Process_Statements_For_Controlled_Objects (E_Alt); Process_Statements_For_Controlled_Objects (D_Alt); + Ensure_Statement_Present (Sloc (D_Stat), D_Alt); + -- Retrieve E_Stats and D_Stats now because the finalization machinery -- may wrap them in blocks.