[PR97714] final: accept markers at line 0

[PR97714] final: accept markers at line 0

[Alexandre Oliva]

Back when I introduced debug markers, I seem to have been under the
impression that location line 0 would only ever occur for unknown and
builtin locations.

Though line 0 never comes up in normal processing of source files, and
debug info formats often cannot represent them, I suppose there's no
need to preemptively discard them during final.

Regstrapped on x86_64-linux-gnu.  Ok to install?


for  gcc/ChangeLog

	PR debug/97714
	* final.c (notice_source_line): Narrow down the condition to
	skip a line-0 marker.

for  gcc/testsuite/ChangeLog

	PR debug/97714
	* gcc.dg/pr97714.c: New.
---
 gcc/final.c                          |   11 +++++------
 gcc/testsuite/gcc.dg/debug/pr97714.c |   11 +++++++++++
 2 files changed, 16 insertions(+), 6 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/debug/pr97714.c

diff --git a/gcc/final.c b/gcc/final.c
index fc9a05e335f47..45f7f39f0885b 100644
--- a/gcc/final.c
+++ b/gcc/final.c
@@ -3250,12 +3250,11 @@ notice_source_line (rtx_insn *insn, bool *is_stmt)
     {
       location_t loc = NOTE_MARKER_LOCATION (insn);
       expanded_location xloc = expand_location (loc);
-      if (xloc.line == 0)
-	{
-	  gcc_checking_assert (LOCATION_LOCUS (loc) == UNKNOWN_LOCATION
-			       || LOCATION_LOCUS (loc) == BUILTINS_LOCATION);
-	  return false;
-	}
+      if (xloc.line == 0
+	  && (LOCATION_LOCUS (loc) == UNKNOWN_LOCATION
+	      || LOCATION_LOCUS (loc) == BUILTINS_LOCATION))
+	return false;
+
       filename = xloc.file;
       linenum = xloc.line;
       columnnum = xloc.column;
diff --git a/gcc/testsuite/gcc.dg/debug/pr97714.c b/gcc/testsuite/gcc.dg/debug/pr97714.c
new file mode 100644
index 0000000000000..dba17831d6943
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/debug/pr97714.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O -g" } */
+
+void
+function ()
+{
+  if (0)
+    {
+#line 0 "whatever"
+    }
+}

-- 
Alexandre Oliva, happy hacker  https://FSFLA.org/blogs/lxo/
   Free Software Activist         GNU Toolchain Engineer
        Vim, Vi, Voltei pro Emacs -- GNUlius Caesar

Re: [PR97714] final: accept markers at line 0

[Richard Biener]

On Wed, Dec 23, 2020 at 12:56 AM Alexandre Oliva via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
>
> Back when I introduced debug markers, I seem to have been under the
> impression that location line 0 would only ever occur for unknown and
> builtin locations.
>
> Though line 0 never comes up in normal processing of source files, and
> debug info formats often cannot represent them, I suppose there's no
> need to preemptively discard them during final.
>
> Regstrapped on x86_64-linux-gnu.  Ok to install?

OK.

>
> for  gcc/ChangeLog
>
>         PR debug/97714
>         * final.c (notice_source_line): Narrow down the condition to
>         skip a line-0 marker.
>
> for  gcc/testsuite/ChangeLog
>
>         PR debug/97714
>         * gcc.dg/pr97714.c: New.
> ---
>  gcc/final.c                          |   11 +++++------
>  gcc/testsuite/gcc.dg/debug/pr97714.c |   11 +++++++++++
>  2 files changed, 16 insertions(+), 6 deletions(-)
>  create mode 100644 gcc/testsuite/gcc.dg/debug/pr97714.c
>
> diff --git a/gcc/final.c b/gcc/final.c
> index fc9a05e335f47..45f7f39f0885b 100644
> --- a/gcc/final.c
> +++ b/gcc/final.c
> @@ -3250,12 +3250,11 @@ notice_source_line (rtx_insn *insn, bool *is_stmt)
>      {
>        location_t loc = NOTE_MARKER_LOCATION (insn);
>        expanded_location xloc = expand_location (loc);
> -      if (xloc.line == 0)
> -       {
> -         gcc_checking_assert (LOCATION_LOCUS (loc) == UNKNOWN_LOCATION
> -                              || LOCATION_LOCUS (loc) == BUILTINS_LOCATION);
> -         return false;
> -       }
> +      if (xloc.line == 0
> +         && (LOCATION_LOCUS (loc) == UNKNOWN_LOCATION
> +             || LOCATION_LOCUS (loc) == BUILTINS_LOCATION))
> +       return false;
> +
>        filename = xloc.file;
>        linenum = xloc.line;
>        columnnum = xloc.column;
> diff --git a/gcc/testsuite/gcc.dg/debug/pr97714.c b/gcc/testsuite/gcc.dg/debug/pr97714.c
> new file mode 100644
> index 0000000000000..dba17831d6943
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/debug/pr97714.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -g" } */
> +
> +void
> +function ()
> +{
> +  if (0)
> +    {
> +#line 0 "whatever"
> +    }
> +}
>
> --
> Alexandre Oliva, happy hacker  https://FSFLA.org/blogs/lxo/
>    Free Software Activist         GNU Toolchain Engineer
>         Vim, Vi, Voltei pro Emacs -- GNUlius Caesar