Patch ping.
On 2/19/20 3:30 PM, Alexey Neyman wrote:
Hi all,
Attached is a patch adjusted per discussion in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93751
- The manual is corrected to reflect that DIEs for external variables
are not generated when using DWARF
- A new option is introduced that implements the behavior that was
described in the manual (and is what other debugging formats do).
Please review/apply.
Regards,
Alexey.
>From 7a1b7d99a98416ed8b1c8bf2e4877655fd820fd0 Mon Sep 17 00:00:00 2001
From: Alexey Neyman <sti...@att.net>
Date: Thu, 13 Feb 2020 22:01:10 -0800
Subject: [PATCH] debug/93751 Option to create DIEs for ext. vars
-g1 is described in the manual to generate debug info for functions and
external variables. It does that for older debugging formats but not for
DWARF. This change fixes the manual to describe the current behavior and
introduces a new option, -gexternal-variables, that makes -g1 output the
DIEs for external variables, as it does for older debugging formats.
2020-02-14 Alexey Neyman <sti...@att.net>
PR debug/93751
* gcc/common.opt: New option, -gexternal-variables.
* gcc/doc/invoke.texi: Describe the new option.
* dwarf2out.c (gen_decl_die): Proceed to generating the DIE if
the debug level is terse, DIEs for external variables have been
requested and the declaration is public.
(dwarf2out_decl): Same.
* gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-1: New test.
* gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-2: New test.
* gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-3: New test.
Signed-off-by: Alexey Neyman <sti...@att.net>
---
gcc/common.opt | 4 ++++
gcc/doc/invoke.texi | 13 +++++++++++--
gcc/dwarf2out.c | 14 ++++++++++----
gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-1.c | 7 +++++++
gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-2.c | 7 +++++++
gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-3.c | 7 +++++++
6 files changed, 46 insertions(+), 6 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-1.c
create mode 100644 gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-2.c
create mode 100644 gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-3.c
diff --git a/gcc/common.opt b/gcc/common.opt
index 5692cd04374..aec0aacb116 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -3075,6 +3075,10 @@ gdwarf-
Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
Generate debug information in DWARF v2 (or later) format.
+gexternal-variables
+Common Driver RejectNegative Var(debug_external_variables)
+Generate debug information for external variables.
+
ggdb
Common Driver JoinedOrMissing
Generate debug information in default extended format.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index bd9ecebf103..d09cf298c36 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -443,7 +443,8 @@ Objective-C and Objective-C++ Dialects}.
@item Debugging Options
@xref{Debugging Options,,Options for Debugging Your Program}.
@gccoptlist{-g -g@var{level} -gdwarf -gdwarf-@var{version} @gol
--ggdb -grecord-gcc-switches -gno-record-gcc-switches @gol
+-gexternal-variables -ggdb @gol
+-grecord-gcc-switches -gno-record-gcc-switches @gol
-gstabs -gstabs+ -gstrict-dwarf -gno-strict-dwarf @gol
-gas-loc-support -gno-as-loc-support @gol
-gas-locview-support -gno-as-locview-support @gol
@@ -8649,7 +8650,10 @@ Level 0 produces no debug information at all. Thus,
@option{-g0} negates
Level 1 produces minimal information, enough for making backtraces in
parts of the program that you don't plan to debug. This includes
descriptions of functions and external variables, and line number
-tables, but no information about local variables.
+tables, but no information about local variables. For historical
+reasons, the descriptions of external variables are not generated
+when producing the debugging information in DWARF format; these
+descriptions can be requested using @option{-gexternal-variables}.
Level 3 includes extra information, such as all the macro definitions
present in the program. Some debuggers support macro expansion when
@@ -8663,6 +8667,11 @@ confusion with @option{-gdwarf-@var{level}}.
Instead use an additional @option{-g@var{level}} option to change the
debug level for DWARF.
+@item -gexternal-variables
+@opindex gexternal-variables
+When using level 1 of the debugging information in DWARF format,
+also produce the descriptions of the external variables.
+
@item -fno-eliminate-unused-debug-symbols
@opindex feliminate-unused-debug-symbols
@opindex fno-eliminate-unused-debug-symbols
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index fe46c7e1eee..13c62ad1eec 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -26354,8 +26354,11 @@ gen_decl_die (tree decl, tree origin, struct
vlr_context *ctx,
case VAR_DECL:
case RESULT_DECL:
/* If we are in terse mode, don't generate any DIEs to represent any
- variable declarations or definitions. */
- if (debug_info_level <= DINFO_LEVEL_TERSE)
+ variable declarations or definitions unless it is an external variable
+ and we've been explicitly told to generate them. */
+ if (debug_info_level < DINFO_LEVEL_TERSE
+ || (debug_info_level == DINFO_LEVEL_TERSE
+ && !(debug_external_variables && TREE_PUBLIC(decl_or_origin))))
break;
/* Avoid generating stray type DIEs during late dwarf dumping.
@@ -26831,8 +26834,11 @@ dwarf2out_decl (tree decl)
context_die = lookup_decl_die (DECL_CONTEXT (decl));
/* If we are in terse mode, don't generate any DIEs to represent any
- variable declarations or definitions. */
- if (debug_info_level <= DINFO_LEVEL_TERSE)
+ variable declarations or definitions unless it is an external variable
+ and we've been explicitly told to generate them. */
+ if (debug_info_level < DINFO_LEVEL_TERSE
+ || (debug_info_level == DINFO_LEVEL_TERSE
+ && !(debug_external_variables && TREE_PUBLIC(decl))))
return;
break;
diff --git a/gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-1.c
b/gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-1.c
new file mode 100644
index 00000000000..d9b75cb7537
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-1.c
@@ -0,0 +1,7 @@
+// { dg-do compile }
+// { dg-options "-O -gdwarf-2 -g1 -dA" }
+int foo;
+static int bar;
+
+// Verify that with -g1 we do not generate the DIEs for variables at all
+// { dg-final { scan-assembler-not " DW_TAG_variable" } }
diff --git a/gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-2.c
b/gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-2.c
new file mode 100644
index 00000000000..177256af5c2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-2.c
@@ -0,0 +1,7 @@
+// { dg-do compile }
+// { dg-options "-O -gdwarf-2 -g1 -gexternal-variables -dA" }
+static int bar;
+
+// Verify that with -g1 -gexternal-variables we still do not generate
+// DIEs for static variables.
+// { dg-final { scan-assembler-not " DW_TAG_variable" } }
diff --git a/gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-3.c
b/gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-3.c
new file mode 100644
index 00000000000..8d750498a35
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/debug/dwarf2/pr93751-3.c
@@ -0,0 +1,7 @@
+// { dg-do compile }
+// { dg-options "-O -gdwarf-2 -g1 -gexternal-variables -dA" }
+int foo;
+
+// Verify that with -g1 -gexternal-variables we generate
+// DIEs for external variables.
+// { dg-final { scan-assembler " DW_TAG_variable" } }
--
2.20.1
