[PATCH] driver: Don't imply -dD for -g3 -g0 [PR97989]

[Jakub Jelinek]

Hi!

The driver enables -dD when preprocessing when -g3 is specified, for obvious reasons
that we need the macros to be preserved somewhere for them to make up the debug
info.  But it enables it even if -g3 is later overridden to -g2, -g1 or -g0,
where we in the end don't emit .debug_mac{ros,info}.

The following patch passes -dD only if we'll need it.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2020-11-26  Jakub Jelinek  <jakub@redhat.com>

	PR debug/97989
	* gcc.c (cpp_unique_options): Add -dD if %:debug-level-gt(2)
	rather than g3|ggdb3|gstabs3|gxcoff3|gvms3.

	* gcc.dg/cpp/pr97989-1.c: New test.
	* gcc.dg/cpp/pr97989-2.c: New test.

--- gcc/gcc.c.jj	2020-11-18 09:40:09.680662345 +0100
+++ gcc/gcc.c	2020-11-25 18:35:29.255919853 +0100
@@ -1212,7 +1212,7 @@ static const char *cpp_unique_options =
  %{MMD:-MMD %{!o:%b.d}%{o*:%.d%*}}\
  %{M} %{MM} %{MF*} %{MG} %{MP} %{MQ*} %{MT*}\
  %{!E:%{!M:%{!MM:%{!MT:%{!MQ:%{MD|MMD:%{o*:-MQ %*}}}}}}}\
- %{remap} %{g3|ggdb3|gstabs3|gxcoff3|gvms3:-dD}\
+ %{remap} %{%:debug-level-gt(2):-dD}\
  %{!iplugindir*:%{fplugin*:%:find-plugindir()}}\
  %{H} %C %{D*&U*&A*} %{i*} %Z %i\
  %{E|M|MM:%W{o*}}";
--- gcc/testsuite/gcc.dg/cpp/pr97989-1.c.jj	2020-11-25 18:30:34.008243484 +0100
+++ gcc/testsuite/gcc.dg/cpp/pr97989-1.c	2020-11-25 18:33:31.504245962 +0100
@@ -0,0 +1,8 @@
+/* PR debug/97989 */
+/* { dg-do preprocess } */
+/* { dg-options "-g3 -g2 -P" } */
+
+#define foo bar
+int i;
+
+/* { dg-final { scan-file-not pr97989-1.i "(^|\\n)#define foo bar($|\\n)" } } */
--- gcc/testsuite/gcc.dg/cpp/pr97989-2.c.jj	2020-11-25 18:32:23.291013634 +0100
+++ gcc/testsuite/gcc.dg/cpp/pr97989-2.c	2020-11-25 18:33:39.467156290 +0100
@@ -0,0 +1,8 @@
+/* PR debug/97989 */
+/* { dg-do preprocess } */
+/* { dg-options "-g2 -g3 -P" } */
+
+#define foo bar
+int i;
+
+/* { dg-final { scan-file pr97989-2.i "(^|\\n)#define foo bar($|\\n)" } } */

	Jakub