Patchwork [8.3,backport] Fix crash in cp_print_value_fields

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Submitter Tom de Vries
Date Aug. 2, 2019, 3:14 p.m.
Message ID <8484cf89-f276-4bed-3fa6-00a21b81ca61@suse.de>
Download mbox | patch
Permalink /patch/33922/
State New
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Comments

Tom de Vries - Aug. 2, 2019, 3:14 p.m.
On 17-05-19 22:18, Tom Tromey wrote:
> From: Tom Tromey <tom@tromey.com>
> 
> PR c++/20020 concerns a crash in cp_print_value_fields.  The immediate
> cause is that cp_print_value_fields does not handle the case where
> value_static_field fails.  This is fixed in this patch by calling
> cp_print_static_field from the "try" block.
> 
> Digging a bit deeper, the error occurs because GCC does not emit a
> DW_AT_const_value for a static constexpr member appearing in a
> template class.  I've filed a GCC bug for this.
> 
> Tested on x86-64 Fedora 29.
> 
> gdb/ChangeLog
> 2019-05-17  Tom Tromey  <tromey@adacore.com>
> 
> 	PR c++/20020:
> 	* cp-valprint.c (cp_print_value_fields): Call
> 	cp_print_static_field inside "try".
> 
> gdb/testsuite/ChangeLog
> 2019-05-17  Tom Tromey  <tromey@adacore.com>
> 
> 	PR c++/20020:
> 	* gdb.cp/constexpr-field.exp: New file.
> 	* gdb.cp/constexpr-field.cc: New file.

OK to backport to 8.3, as well as the followup patch "Fix two buglets in
cp_print_value_fields patch"?

Neither of the patches apply cleanly, so I'm attaching them here.

The difference in test results is:
...
+Running gdb/testsuite/gdb.cp/constexpr-field.exp ...
+XFAIL: gdb.cp/constexpr-field.exp: print x (PRMS gcc/90526)
+PASS: gdb.cp/constexpr-field.exp: print y
...

Thanks,
- Tom
Tom Tromey - Aug. 2, 2019, 5:27 p.m.
>>>>> "Tom" == Tom de Vries <tdevries@suse.de> writes:

Tom> OK to backport to 8.3, as well as the followup patch "Fix two buglets in
Tom> cp_print_value_fields patch"?

Yes, thank you for doing this.

Tom

Patch

Fix buglet in cp_print_value_fields patch

[ Backport of master commit 3d507ff23b. ]

Pedro pointed out an issue in the cp_print_value_fields
patch, aka the fix for PR c++/20020.

This patch addresses the issue.  Tested on x86-64 Fedora 29.

gdb/testsuite/ChangeLog
2019-06-27  Tom Tromey  <tromey@adacore.com>

	* gdb.cp/constexpr-field.exp: Use setup_xfail.

---
 gdb/testsuite/ChangeLog                  | 4 ++++
 gdb/testsuite/gdb.cp/constexpr-field.exp | 3 ++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 5f26daa67e..c51036165c 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@ 
+2019-06-27  Tom Tromey  <tromey@adacore.com>
+
+	* gdb.cp/constexpr-field.exp: Use setup_xfail.
+
 2019-05-29  Tom Tromey  <tromey@adacore.com>
 
 	PR c++/20020:
diff --git a/gdb/testsuite/gdb.cp/constexpr-field.exp b/gdb/testsuite/gdb.cp/constexpr-field.exp
index e4849efeae..2f71cef952 100644
--- a/gdb/testsuite/gdb.cp/constexpr-field.exp
+++ b/gdb/testsuite/gdb.cp/constexpr-field.exp
@@ -31,6 +31,7 @@  if {![runto_main]} {
 
 # "x" sometimes isn't available due to
 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90526
-gdb_test "print x" " = {static f = .*}"
+setup_xfail *-*-* gcc/90526
+gdb_test "print x" " = {static f = true}"
 
 gdb_test "print y" " = {static f = true}"