Bug 672157

Summary:	debug info: Missing DW_AT_accessibility
Product:	[Fedora] Fedora	Reporter:	Jan Kratochvil <jan.kratochvil>
Component:	gcc	Assignee:	Jakub Jelinek <jakub>
Status:	CLOSED NOTABUG	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	low	Docs Contact:
Priority:	unspecified
Version:	rawhide	CC:	jakub
Target Milestone:	---	Keywords:	Regression
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-01-24 10:16:06 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Jan Kratochvil 2011-01-24 09:08:20 UTC

Description of problem:
By the upgrade some GDB testsuite cases fail.

Version-Release number of selected component (if applicable):
FAIL gcc-c++-4.6.0-0.3.fc15.x86_64
PASS gcc-c++-4.5.1-4.fc14.x86_64
PASS g++ (GCC) 4.6.0 20110124 (experimental)
PASS g++ (GCC) 4.5.3 20110124 (prerelease)
PASS g++ (GCC) 4.4.6 20110124 (prerelease)

How reproducible:
Always.

Steps to Reproduce:
struct Alpha
{
  virtual void x() { }
};
struct Derived : public Alpha
{
} v;

Actual results:
FAIL:
 <2><41>: Abbrev Number: 3 (DW_TAG_inheritance)
    <42>   DW_AT_type        : <0x70>   
    <46>   DW_AT_data_member_location: 0        

Expected results:
PASS:
 <2><41>: Abbrev Number: 3 (DW_TAG_inheritance)
    <42>   DW_AT_type        : <0x70>   
    <46>   DW_AT_data_member_location: 0        
    <47>   DW_AT_accessibility: 1       (public)

Additional info:
DWARF3:
An inheritance entry may have a DW_AT_accessibility attribute. If no accessibility attribute is present, private access is assumed for an entry of a class [...]

Affects at least:
gdb.cp/casts.exp

Comment 1 Jakub Jelinek 2011-01-24 10:16:06 UTC

You've omitted the important following words:
An inheritance entry may have a DW_AT_accessibility attribute. If no accessibility attribute is present, private access is assumed for an entry of a class and public access is assumed for an entry of an interface, struct or union.

The rule used by GCC now for -gdwarf-3 and above is the default is the natural choice for the language in question, i.e. if source doesn't need explicit public: or private:, then no DW_AT_accessibility is used.  For -gdwarf-2 the old behavior has been preserved.
See http://gcc.gnu.org/PR45124

Upstream GCC behaves exactly the same, the only difference is that GCC 4.6-RH defaults to -gdwarf-3, while GCC 4.6 upstream defaults still to -gdwarf-2.