[PATCH] c++, debug: Fix up locus of DW_TAG_imported_module [PR108716]

[PATCH] c++, debug: Fix up locus of DW_TAG_imported_module [PR108716]

[Jakub Jelinek]

Hi!

Before IMPORTED_DECL has been introduced in PR37410, we used to emit correct
DW_AT_decl_line on DW_TAG_imported_module on the testcase below, after that
change we haven't emitted it at all for a while and after some time
started emitting incorrect locus, in particular the location of } closing
the function.

The problem is that while we have correct EXPR_LOCATION on the USING_STMT,
when genericizing that USING_STMT into IMPORTED_DECL we don't copy the
location to DECL_SOURCE_LOCATION, so it gets whatever input_location happens
to be when it is created.

The following patch fixes that, bootstrapped/regtested on x86_64-linux and
i686-linux, ok for trunk?

2023-02-09  Jakub Jelinek  <jakub@redhat.com>

	PR debug/108716
	* cp-gimplify.cc (cp_genericize_r) <case USING_STMT>: Set
	DECL_SOURCE_LOCATION on IMPORTED_DECL to expression location
	of USING_STMT or input_location.

	* g++.dg/debug/dwarf2/pr108716.C: New test.

--- gcc/cp/cp-gimplify.cc.jj	2023-02-01 10:19:43.038140336 +0100
+++ gcc/cp/cp-gimplify.cc	2023-02-08 10:36:00.301501540 +0100
@@ -1514,6 +1514,8 @@ cp_genericize_r (tree *stmt_p, int *walk
 		tree using_directive = make_node (IMPORTED_DECL);
 		TREE_TYPE (using_directive) = void_type_node;
 		DECL_CONTEXT (using_directive) = current_function_decl;
+		DECL_SOURCE_LOCATION (using_directive)
+		  = cp_expr_loc_or_input_loc (stmt);
 
 		IMPORTED_DECL_ASSOCIATED_DECL (using_directive) = decl;
 		DECL_CHAIN (using_directive) = BLOCK_VARS (block);
--- gcc/testsuite/g++.dg/debug/dwarf2/pr108716.C.jj	2023-02-08 11:48:39.667385750 +0100
+++ gcc/testsuite/g++.dg/debug/dwarf2/pr108716.C	2023-02-08 11:48:57.998115610 +0100
@@ -0,0 +1,14 @@
+// PR debug/108716
+// { dg-options "-O0 -gdwarf-5 -dA -fno-merge-debug-strings" }
+// { dg-final { scan-assembler "DIE \\(\[^\n\r\]*\\) DW_TAG_imported_module\[^\n\r\]*\[\n\r]*\[^\n\r\]* DW_AT_decl_file\[^\n\r\]*\[\n\r]*\[^\n\r\]*0xc\[^\n\r\]* DW_AT_decl_line\[^\n\r\]*\[\n\r]*(\[^\n\r\]*0x13\[^\n\r\]* DW_AT_decl_column\[^\n\r\]*\[\n\r]*)?" } }
+
+namespace M {
+  int x = 1;
+}
+
+int
+main ()
+{
+  using namespace M;
+  return 0;
+}

	Jakub

Re: [PATCH] c++, debug: Fix up locus of DW_TAG_imported_module [PR108716]

[Jason Merrill]

On 2/9/23 03:41, Jakub Jelinek wrote:
> Hi!
> 
> Before IMPORTED_DECL has been introduced in PR37410, we used to emit correct
> DW_AT_decl_line on DW_TAG_imported_module on the testcase below, after that
> change we haven't emitted it at all for a while and after some time
> started emitting incorrect locus, in particular the location of } closing
> the function.
> 
> The problem is that while we have correct EXPR_LOCATION on the USING_STMT,
> when genericizing that USING_STMT into IMPORTED_DECL we don't copy the
> location to DECL_SOURCE_LOCATION, so it gets whatever input_location happens
> to be when it is created.
> 
> The following patch fixes that, bootstrapped/regtested on x86_64-linux and
> i686-linux, ok for trunk?

OK.

> 2023-02-09  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR debug/108716
> 	* cp-gimplify.cc (cp_genericize_r) <case USING_STMT>: Set
> 	DECL_SOURCE_LOCATION on IMPORTED_DECL to expression location
> 	of USING_STMT or input_location.
> 
> 	* g++.dg/debug/dwarf2/pr108716.C: New test.
> 
> --- gcc/cp/cp-gimplify.cc.jj	2023-02-01 10:19:43.038140336 +0100
> +++ gcc/cp/cp-gimplify.cc	2023-02-08 10:36:00.301501540 +0100
> @@ -1514,6 +1514,8 @@ cp_genericize_r (tree *stmt_p, int *walk
>   		tree using_directive = make_node (IMPORTED_DECL);
>   		TREE_TYPE (using_directive) = void_type_node;
>   		DECL_CONTEXT (using_directive) = current_function_decl;
> +		DECL_SOURCE_LOCATION (using_directive)
> +		  = cp_expr_loc_or_input_loc (stmt);
>   
>   		IMPORTED_DECL_ASSOCIATED_DECL (using_directive) = decl;
>   		DECL_CHAIN (using_directive) = BLOCK_VARS (block);
> --- gcc/testsuite/g++.dg/debug/dwarf2/pr108716.C.jj	2023-02-08 11:48:39.667385750 +0100
> +++ gcc/testsuite/g++.dg/debug/dwarf2/pr108716.C	2023-02-08 11:48:57.998115610 +0100
> @@ -0,0 +1,14 @@
> +// PR debug/108716
> +// { dg-options "-O0 -gdwarf-5 -dA -fno-merge-debug-strings" }
> +// { dg-final { scan-assembler "DIE \\(\[^\n\r\]*\\) DW_TAG_imported_module\[^\n\r\]*\[\n\r]*\[^\n\r\]* DW_AT_decl_file\[^\n\r\]*\[\n\r]*\[^\n\r\]*0xc\[^\n\r\]* DW_AT_decl_line\[^\n\r\]*\[\n\r]*(\[^\n\r\]*0x13\[^\n\r\]* DW_AT_decl_column\[^\n\r\]*\[\n\r]*)?" } }
> +
> +namespace M {
> +  int x = 1;
> +}
> +
> +int
> +main ()
> +{
> +  using namespace M;
> +  return 0;
> +}
> 
> 	Jakub
>