* [Bug translator/11815] New: SDT_V2 sdt.h broken for modern gcc on x86-64, cxxclass.exp
@ 2010-07-13 18:59 fche at redhat dot com
2010-07-13 19:03 ` [Bug translator/11815] " fche at redhat dot com
0 siblings, 1 reply; 2+ messages in thread
From: fche at redhat dot com @ 2010-07-13 18:59 UTC (permalink / raw)
To: systemtap
With gcc 4.5ish on x86-64, SDT_V2 gets super optimized,
and gives us this ditty in the .probes section assembly code:
3:
.asciz "$.LC0 $64 $24" #,,
.balign 8
where $.LC0 is a reference to a string literal. This symbol
does not get propagated past the assembler, so stap has no
hope of resolving this particular operand.
Secondarily, the regexp magic in tapsets.cxx:4651ish
// this pattern matches 0xD(%R) | (%R) | %R
const char *pattern =
"\\([0x]*-*[0-9]*\\)\\([(]*\\)\\(%*[0-9a-z][0-9a-z]*\\)\\([)]*\\)";
this unfortunately appears to match each of the above quoted operands, and
leads to wrong code generation (fetch_register(0)).
--
Summary: SDT_V2 sdt.h broken for modern gcc on x86-64,
cxxclass.exp
Product: systemtap
Version: unspecified
Status: NEW
Severity: normal
Priority: P2
Component: translator
AssignedTo: systemtap at sources dot redhat dot com
ReportedBy: fche at redhat dot com
http://sourceware.org/bugzilla/show_bug.cgi?id=11815
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* [Bug translator/11815] SDT_V2 sdt.h broken for modern gcc on x86-64, cxxclass.exp
2010-07-13 18:59 [Bug translator/11815] New: SDT_V2 sdt.h broken for modern gcc on x86-64, cxxclass.exp fche at redhat dot com
@ 2010-07-13 19:03 ` fche at redhat dot com
0 siblings, 0 replies; 2+ messages in thread
From: fche at redhat dot com @ 2010-07-13 19:03 UTC (permalink / raw)
To: systemtap
------- Additional Comments From fche at redhat dot com 2010-07-13 19:02 -------
re. problem#1, jakub advises that passing -L to the assembler may preserve
those symbols into the final object files, at the cost of considerable
extra storage.
--
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|systemtap at sources dot |fche at redhat dot com
|redhat dot com |
Status|NEW |ASSIGNED
http://sourceware.org/bugzilla/show_bug.cgi?id=11815
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2010-07-13 18:59 [Bug translator/11815] New: SDT_V2 sdt.h broken for modern gcc on x86-64, cxxclass.exp fche at redhat dot com
2010-07-13 19:03 ` [Bug translator/11815] " fche at redhat dot com
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