On Fri, Apr 7, 2017 at 11:42 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> Hi!
>
> The following C and Ada testcases show ICE due to endless recursion in
> dwarf2out.c. The problem is that when processing BLOCK_NONLOCALIZED_VARS,
> we want to treat all the FUNCTION_DECLs in there as mere declarations,
> but gen_subprogram_die does:
> int declaration = (current_function_decl != decl
> || class_or_namespace_scope_p (context_die));
> and thus if there is some self-inlining and we are unlucky enough
> not to reach some early-outs that just ignore the FUNCTION_DECL,
> like:
> /* Detect and ignore this case, where we are trying to output
> something we have already output. */
> if (get_AT (old_die, DW_AT_low_pc)
> || get_AT (old_die, DW_AT_ranges))
> return;
> we will recurse infinitely. The following patch fixes it by
> just ignoring current_function_decl seen from BLOCK_NONLOCALIZED_VARS,
> that implies it is already inlined into somewhere and in the abstract
> origin we emit properly a DW_AT_declaration decl if needed, that is pretty
> much what gen_subprogram_die would do anyway in such cases, because there
> is already old_die, we really don't want to make some child of it its parent
> and otherwise no further action is performed.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok.
Thanks,
Richard.
> Other possibilities include adding some global bool flag that
> gen_subprogram_die's int declaration = ... above should ignore
> decl == current_function_decl that we'd set in decls_for_scope when
> seeing current_function_decl in BLOCK_NONLOCALIZED_VARS (and probably
> save/clear + restore in dwarf2out_abstract_function where we change
> current_function_decl). Or we could pass through from decls_for_scope
> down through process_scope_var, gen_decl_die to gen_subprogram_die
> a bool flag force_declaration.
>
> 2017-04-07 Jakub Jelinek <ja...@redhat.com>
>
> PR debug/80321
> * dwarf2out.c (decls_for_scope): Ignore declarations of
> current_function_decl in BLOCK_NONLOCALIZED_VARS.
>
> * gcc.dg/debug/pr80321.c: New test.
>
> 2017-04-07 Eric Botcazou <ebotca...@adacore.com>
>
> * gnat.dg/debug10.adb: New test.
> * gnat.dg/debug10_pkg.ads: New helper.
>
> --- gcc/dwarf2out.c.jj 2017-04-07 11:46:48.000000000 +0200
> +++ gcc/dwarf2out.c 2017-04-07 20:00:43.503772542 +0200
> @@ -24889,7 +24889,12 @@ decls_for_scope (tree stmt, dw_die_ref c
> for (i = 0; i < BLOCK_NUM_NONLOCALIZED_VARS (stmt); i++)
> {
> decl = BLOCK_NONLOCALIZED_VAR (stmt, i);
> - if (TREE_CODE (decl) == FUNCTION_DECL)
> + if (decl == current_function_decl)
> + /* Ignore declarations of the current function, while they
> + are declarations, gen_subprogram_die would treat them
> + as definitions again, because they are equal to
> + current_function_decl and endlessly recurse. */;
> + else if (TREE_CODE (decl) == FUNCTION_DECL)
> process_scope_var (stmt, decl, NULL_TREE, context_die);
> else
> process_scope_var (stmt, NULL_TREE, decl, context_die);
> --- gcc/testsuite/gcc.dg/debug/pr80321.c.jj 2017-04-07 21:39:01.930615179
> +0200
> +++ gcc/testsuite/gcc.dg/debug/pr80321.c 2017-04-07 21:39:49.722982635
> +0200
> @@ -0,0 +1,26 @@
> +/* PR debug/80321 */
> +/* { dg-do compile } */
> +/* { dg-options "-fkeep-inline-functions" } */
> +
> +void bar (void);
> +
> +static inline void
> +test (int x)
> +{
> + inline void
> + foo (int x)
> + {
> + test (0);
> + asm volatile ("" : : : "memory");
> + }
> + if (x != 0)
> + foo (x);
> + else
> + bar ();
> +}
> +
> +void
> +baz (int x)
> +{
> + test (x);
> +}
> --- gcc/testsuite/gnat.dg/debug10.adb.jj 2017-04-07 20:24:44.232473780
> +0200
> +++ gcc/testsuite/gnat.dg/debug10.adb 2017-04-07 20:26:40.493980722 +0200
> @@ -0,0 +1,68 @@
> +-- PR debug/80321
> +
> +-- { dg-do compile }
> +-- { dg-options "-O2 -g" }
> +
> +with Debug10_Pkg; use Debug10_Pkg;
> +
> +procedure Debug10 (T : Entity_Id) is
> +
> + procedure Inner (E : Entity_Id);
> + pragma Inline (Inner);
> +
> + procedure Inner (E : Entity_Id) is
> + begin
> + if E /= Empty
> + and then not Nodes (E + 3).Flag16
> + then
> + Debug10 (E);
> + end if;
> + end Inner;
> +
> + function Ekind (E : Entity_Id) return Entity_Kind is
> + begin
> + return N_To_E (Nodes (E + 1).Nkind);
> + end Ekind;
> +
> +begin
> +
> + if T = Empty then
> + return;
> + end if;
> +
> + Nodes (T + 3).Flag16 := True;
> +
> + if Ekind (T) in Object_Kind then
> + Inner (T);
> +
> + elsif Ekind (T) in Type_Kind then
> + Inner (T);
> +
> + if Ekind (T) in Record_Kind then
> +
> + if Ekind (T) = E_Class_Wide_Subtype then
> + Inner (T);
> + end if;
> +
> + elsif Ekind (T) in Array_Kind then
> + Inner (T);
> +
> + elsif Ekind (T) in Access_Kind then
> + Inner (T);
> +
> + elsif Ekind (T) in Scalar_Kind then
> +
> + if My_Scalar_Range (T) /= Empty
> + and then My_Test (My_Scalar_Range (T))
> + then
> + if My_Is_Entity_Name (T) then
> + Inner (T);
> + end if;
> +
> + if My_Is_Entity_Name (T) then
> + Inner (T);
> + end if;
> + end if;
> + end if;
> + end if;
> +end;
> --- gcc/testsuite/gnat.dg/debug10_pkg.ads.jj 2017-04-07 20:24:47.384433302
> +0200
> +++ gcc/testsuite/gnat.dg/debug10_pkg.ads 2017-04-07 20:24:22.000000000
> +0200
> @@ -0,0 +1,138 @@
> +with Unchecked_Conversion;
> +
> +package Debug10_Pkg is
> +
> + type Node_Id is range 0 .. 99_999_999;
> +
> + Empty : constant Node_Id := 0;
> +
> + subtype Entity_Id is Node_Id;
> +
> + type Union_Id is new Integer;
> +
> + function My_Is_Entity_Name (N : Node_Id) return Boolean;
> +
> + function My_Scalar_Range (Id : Entity_Id) return Node_Id;
> +
> + function My_Test (N : Node_Id) return Boolean;
> +
> + type Node_Kind is (N_Unused_At_Start, N_Unused_At_End);
> +
> + type Entity_Kind is (
> +
> + E_Void,
> + E_Component,
> + E_Constant,
> + E_Discriminant,
> + E_Loop_Parameter,
> + E_Variable,
> + E_Out_Parameter,
> + E_In_Out_Parameter,
> + E_In_Parameter,
> + E_Generic_In_Out_Parameter,
> + E_Generic_In_Parameter,
> + E_Named_Integer,
> + E_Named_Real,
> + E_Enumeration_Type,
> + E_Enumeration_Subtype,
> + E_Signed_Integer_Type,
> + E_Signed_Integer_Subtype,
> + E_Modular_Integer_Type,
> + E_Modular_Integer_Subtype,
> + E_Ordinary_Fixed_Point_Type,
> + E_Ordinary_Fixed_Point_Subtype,
> + E_Decimal_Fixed_Point_Type,
> + E_Decimal_Fixed_Point_Subtype,
> + E_Floating_Point_Type,
> + E_Floating_Point_Subtype,
> + E_Access_Type,
> + E_Access_Subtype,
> + E_Access_Attribute_Type,
> + E_Allocator_Type,
> + E_General_Access_Type,
> + E_Access_Subprogram_Type,
> + E_Anonymous_Access_Subprogram_Type,
> + E_Access_Protected_Subprogram_Type,
> + E_Anonymous_Access_Protected_Subprogram_Type,
> + E_Anonymous_Access_Type,
> + E_Array_Type,
> + E_Array_Subtype,
> + E_String_Literal_Subtype,
> + E_Class_Wide_Type,
> + E_Class_Wide_Subtype,
> + E_Record_Type,
> + E_Record_Subtype,
> + E_Record_Type_With_Private,
> + E_Record_Subtype_With_Private,
> + E_Private_Type,
> + E_Private_Subtype,
> + E_Limited_Private_Type,
> + E_Limited_Private_Subtype,
> + E_Incomplete_Type,
> + E_Incomplete_Subtype,
> + E_Task_Type,
> + E_Task_Subtype,
> + E_Protected_Type,
> + E_Protected_Subtype,
> + E_Exception_Type,
> + E_Subprogram_Type,
> + E_Enumeration_Literal,
> + E_Function,
> + E_Operator,
> + E_Procedure,
> + E_Abstract_State,
> + E_Entry,
> + E_Entry_Family,
> + E_Block,
> + E_Entry_Index_Parameter,
> + E_Exception,
> + E_Generic_Function,
> + E_Generic_Procedure,
> + E_Generic_Package,
> + E_Label,
> + E_Loop,
> + E_Return_Statement,
> + E_Package,
> + E_Package_Body,
> + E_Protected_Object,
> + E_Protected_Body,
> + E_Task_Body,
> + E_Subprogram_Body
> + );
> +
> + subtype Access_Kind is Entity_Kind range
> + E_Access_Type ..
> + E_Anonymous_Access_Type;
> +
> + subtype Array_Kind is Entity_Kind range
> + E_Array_Type ..
> + E_String_Literal_Subtype;
> +
> + subtype Object_Kind is Entity_Kind range
> + E_Component ..
> + E_Generic_In_Parameter;
> +
> + subtype Record_Kind is Entity_Kind range
> + E_Class_Wide_Type ..
> + E_Record_Subtype_With_Private;
> +
> + subtype Scalar_Kind is Entity_Kind range
> + E_Enumeration_Type ..
> + E_Floating_Point_Subtype;
> +
> + subtype Type_Kind is Entity_Kind range
> + E_Enumeration_Type ..
> + E_Subprogram_Type;
> +
> + type Node_Record (Is_Extension : Boolean := False) is record
> + Flag16 : Boolean;
> + Nkind : Node_Kind;
> + end record;
> +
> + function N_To_E is new Unchecked_Conversion (Node_Kind, Entity_Kind);
> +
> + type Arr is array (Node_Id) of Node_Record;
> +
> + Nodes : Arr;
> +
> +end Debug10_Pkg;
>
> Jakub
