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<p>Ok than, will fix, provide tests and submit to phab.<br>
</p>
<br>
<div class="moz-cite-prefix">On 02/27/2017 10:21 PM, Eric
Christopher wrote:<br>
</div>
<blockquote
cite="mid:CALehDX4QoE5ry2ueaX+D1nSwUTQHP9Z9wkK60sc1096PtvWJDg@mail.gmail.com"
type="cite">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<div dir="ltr">FWIW I agree completely with Dave here. We should
show the constness of the data explicitly in the dump.
<div><br>
</div>
<div>Thanks!</div>
<div><br>
</div>
<div>-eric</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr">On Mon, Feb 27, 2017 at 11:13 AM David Blaikie
<<a moz-do-not-send="true" href="mailto:dblaikie@gmail.com">dblaikie@gmail.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr" class="gmail_msg">I tend to think it's more
legible if we include the values there, even if no bytes
were required to produce them. I don't generally look at the
abbreviations when reading a dump & expect to see the
data in the debug_info/debug_types output.<br
class="gmail_msg">
<br class="gmail_msg">
( <a moz-do-not-send="true"
class="m_3395721182541375228GWVZpf m_3395721182541375228gW
gmail_msg" id="m_3395721182541375228IloFPc-3"
href="mailto:aprantl@apple.com" target="_blank">+Adrian
Prantl</a> <a moz-do-not-send="true"
class="m_3395721182541375228GWVZpf m_3395721182541375228gW
gmail_msg" id="m_3395721182541375228IloFPc-2"
href="mailto:echristo@gmail.com" target="_blank">+Eric
Christopher</a> in case they've got thoughts on the
subject)</div>
<div dir="ltr" class="gmail_msg"><br class="gmail_msg">
<br class="gmail_msg">
<div class="gmail_quote gmail_msg">
<div dir="ltr" class="gmail_msg">On Mon, Feb 27, 2017 at
11:09 AM Victor Leschuk <<a moz-do-not-send="true"
href="mailto:vleschuk@accesssoftek.com"
class="gmail_msg" target="_blank">vleschuk@accesssoftek.com</a>>
wrote:<br class="gmail_msg">
</div>
<blockquote class="gmail_quote gmail_msg" style="margin:0
0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000" class="gmail_msg">
<p class="gmail_msg">Yeah, I see, I was wrong. I agree
that we need to make behavior uniform here. However
I still think we shouldn't include the data which is
not really present into dump. It seems more logical
for me to not print flag_present values either.</p>
<p class="gmail_msg">What do you think?</p>
</div>
<div bgcolor="#FFFFFF" text="#000000" class="gmail_msg">
<div
class="m_3395721182541375228m_-1917743091071114938moz-cite-prefix
gmail_msg">On 02/27/2017 09:54 PM, David Blaikie
wrote:<br class="gmail_msg">
</div>
<blockquote type="cite" class="gmail_msg">
<div dir="ltr" class="gmail_msg"><br
class="gmail_msg">
<br class="gmail_msg">
<div class="gmail_quote gmail_msg">
<div dir="ltr" class="gmail_msg">On Mon, Feb 27,
2017 at 10:30 AM Victor Leschuk <<a
moz-do-not-send="true"
href="mailto:vleschuk@accesssoftek.com"
class="gmail_msg" target="_blank">vleschuk@accesssoftek.com</a>>
wrote:<br class="gmail_msg">
</div>
<blockquote class="gmail_quote gmail_msg"
style="margin:0 0 0 .8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"
class="gmail_msg">
<p class="gmail_msg">I think flag_present
and implicit_const attributes shouldn't be
treated as similar here: flag_present
attributes physically do have a record in
.debug_info section,</p>
</div>
</blockquote>
<div class="gmail_msg"><br class="gmail_msg">
I think one of us is confused, because my
understanding is that flag_present attributes
do not have any bit/bytes in the debug_info
representation.<br class="gmail_msg">
<br class="gmail_msg">
To take the same example as before and look at
the assembly:<br class="gmail_msg">
<br class="gmail_msg">
this is the debug_info assembly for that
subprogram:<br class="gmail_msg">
<font class="gmail_msg" face="monospace"><br
class="gmail_msg">
</font>
<div class="gmail_msg"><font class="gmail_msg"
face="monospace"> .byte 2
# Abbrev [2] 0x2a:0x19
DW_TAG_subprogram</font></div>
<div class="gmail_msg"><font class="gmail_msg"
face="monospace"> .quad
.Lfunc_begin0 # DW_AT_low_pc</font></div>
<div class="gmail_msg"><font class="gmail_msg"
face="monospace"> .long
.Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc</font></div>
<div class="gmail_msg"><font class="gmail_msg"
face="monospace"> .byte 1
# DW_AT_frame_base</font></div>
<div class="gmail_msg"><font class="gmail_msg"
face="monospace"> .byte 86</font></div>
<div class="gmail_msg"><font class="gmail_msg"
face="monospace"> .long
.Linfo_string3 #
DW_AT_linkage_name</font></div>
<div class="gmail_msg"><font class="gmail_msg"
face="monospace"> .long
.Linfo_string4 # DW_AT_name</font></div>
<div class="gmail_msg"><font class="gmail_msg"
face="monospace"> .byte 1
# DW_AT_decl_file</font></div>
<div class="gmail_msg"><font class="gmail_msg"
face="monospace"> .byte 1
# DW_AT_decl_line</font></div>
<div class="gmail_msg"><font class="gmail_msg"
face="monospace">
# DW_AT_external</font></div>
<div class="gmail_msg"><font class="gmail_msg"
face="monospace"> .byte 0
# End Of Children Mark</font></div>
<br class="gmail_msg">
Note that no bytes were produced for the
DW_AT_external (using DW_FORM_flag_present in
the abbrev) attribute.<br class="gmail_msg">
<br class="gmail_msg">
From the DWARF4 spec:<br class="gmail_msg">
<br class="gmail_msg">
"A flag is represented explicitly as a single
byte of data (DW_FORM_flag) or implicitly
(DW_FORM_flag_present). In the first case, if
the flag has value zero, it indicates the
absence of the attribute; if the flag has a
non-zero value, it indicates the presence of
the attribute. In the second case, the
attribute is implicitly indicated as present,
and no value is encoded in the debugging
information entry itself."<br
class="gmail_msg">
</div>
<blockquote class="gmail_quote gmail_msg"
style="margin:0 0 0 .8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"
class="gmail_msg">
<p class="gmail_msg"> while implicit_const
attributes are not physically mentioned
there. Printing implicit_const values
when dumping .debug_info can be more
convenient for reader but it will actually
violate the definition of dump. When
dumping section contents we expect to see
what is actually there, don't we?<br
class="gmail_msg">
</p>
</div>
<div bgcolor="#FFFFFF" text="#000000"
class="gmail_msg"> <br class="gmail_msg">
<div
class="m_3395721182541375228m_-1917743091071114938m_-7804286437102967308moz-cite-prefix
gmail_msg">On 02/27/2017 09:04 PM, David
Blaikie wrote:<br class="gmail_msg">
</div>
<blockquote type="cite" class="gmail_msg">
<div dir="ltr" class="gmail_msg"><br
class="gmail_msg">
<br class="gmail_msg">
<div class="gmail_quote gmail_msg">
<div dir="ltr" class="gmail_msg">On
Mon, Feb 27, 2017 at 10:00 AM Victor
Leschuk <<a
moz-do-not-send="true"
href="mailto:vleschuk@accesssoftek.com"
class="gmail_msg" target="_blank">vleschuk@accesssoftek.com</a>>
wrote:<br class="gmail_msg">
</div>
<blockquote class="gmail_quote
gmail_msg" style="margin:0 0 0
.8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div bgcolor="#FFFFFF"
text="#000000" class="gmail_msg">
<p class="gmail_msg"><br
class="gmail_msg">
</p>
<br class="gmail_msg">
<div
class="m_3395721182541375228m_-1917743091071114938m_-7804286437102967308m_-7636712434836838175moz-cite-prefix
gmail_msg">On 02/27/2017 08:04
PM, David Blaikie wrote:<br
class="gmail_msg">
</div>
<blockquote type="cite"
class="gmail_msg">
<div dir="ltr" class="gmail_msg">Skipping
these values doesn't seem to
be correct - in the case of
flag_present, I think the
value is still rendered in the
dump, is it not?</div>
</blockquote>
</div>
<div bgcolor="#FFFFFF"
text="#000000" class="gmail_msg">
Do you mean that the value is
somehow mentioned in .debug_info
section? It is not.</div>
</blockquote>
<div class="gmail_msg"><br
class="gmail_msg">
Looks to me like it is:<br
class="gmail_msg">
<br class="gmail_msg">
dumping debug info for this code:
void f1() { }<br class="gmail_msg">
<br class="gmail_msg">
produces this:<br class="gmail_msg">
<br class="gmail_msg">
<font class="gmail_msg"
face="monospace"> .debug_abbrev
contents:<br class="gmail_msg">
...<br class="gmail_msg">
</font>
<div class="gmail_msg"><font
class="gmail_msg"
face="monospace"> [2]
DW_TAG_subprogram
DW_CHILDREN_no</font></div>
<div class="gmail_msg"><font
class="gmail_msg"
face="monospace"> ...</font></div>
<div class="gmail_msg"><font
class="gmail_msg"
face="monospace">
DW_AT_external
DW_FORM_flag_present<br
class="gmail_msg">
<br class="gmail_msg">
.debug_info contents:<br
class="gmail_msg">
...<br class="gmail_msg">
0x0000002a:
DW_TAG_subprogram [2]<br
class="gmail_msg">
...<br
class="gmail_msg">
DW_AT_external
[DW_FORM_flag_present] (true)</font></div>
<br class="gmail_msg">
</div>
<div class="gmail_msg">I would expect
similar behavior for const_value -
that the attribute and its constant
value is printed in the debug_info
dump.<br class="gmail_msg">
<br class="gmail_msg">
</div>
<blockquote class="gmail_quote
gmail_msg" style="margin:0 0 0
.8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div bgcolor="#FFFFFF"
text="#000000" class="gmail_msg"><br
class="gmail_msg">
<blockquote type="cite"
class="gmail_msg">
<div dir="ltr" class="gmail_msg">
I would expect the same for
implicit_const values. (also,
this needs test coverage
either way)</div>
</blockquote>
</div>
<div bgcolor="#FFFFFF"
text="#000000" class="gmail_msg">
Yes, you are correct. I will
create tests when we decide what's
right behavior here. <br
class="gmail_msg">
<br class="gmail_msg">
I think skipping is correct here:
we are dumping .debug_info data
based on attributes stored in
AbbrevDecl, this code was based on
assumption that every attribute
has representation in .debug_info
section, that was before
implicit_const form was
introduced.</div>
<div bgcolor="#FFFFFF"
text="#000000" class="gmail_msg"><br
class="gmail_msg">
<blockquote type="cite"
class="gmail_msg"><br
class="gmail_msg">
<div class="gmail_quote
gmail_msg">
<div dir="ltr"
class="gmail_msg">On Sat,
Feb 25, 2017 at 5:27 AM
Victor Leschuk via
llvm-commits <<a
moz-do-not-send="true"
href="mailto:llvm-commits@lists.llvm.org"
class="gmail_msg"
target="_blank">llvm-commits@lists.llvm.org</a>>
wrote:<br class="gmail_msg">
</div>
<blockquote class="gmail_quote
gmail_msg" style="margin:0 0
0 .8ex;border-left:1px #ccc
solid;padding-left:1ex">Author:
vleschuk<br
class="gmail_msg">
Date: Sat Feb 25 07:15:57
2017<br class="gmail_msg">
New Revision: 296253<br
class="gmail_msg">
<br class="gmail_msg">
URL: <a
moz-do-not-send="true"
href="http://llvm.org/viewvc/llvm-project?rev=296253&view=rev"
rel="noreferrer"
class="gmail_msg"
target="_blank">http://llvm.org/viewvc/llvm-project?rev=296253&view=rev</a><br
class="gmail_msg">
Log:<br class="gmail_msg">
[DebugInfo] Skip
implicit_const attributes
when dumping .debug_info.
NFC.<br class="gmail_msg">
<br class="gmail_msg">
When dumping .debug_info
section we loop through all
attributes mentioned in<br
class="gmail_msg">
.debug_abbrev section and
dump values using
DWARFFormValue::extractValue().<br
class="gmail_msg">
We need to skip
implicit_const attributes
here as their values are not<br
class="gmail_msg">
really located in
.debug_info but directly in
.debug_abbrev. This patch
fixes<br class="gmail_msg">
triggered assert() in
DWARFFormValue::extractValue()
caused by trying to<br
class="gmail_msg">
access implicit_const values
from .debug_info.<br
class="gmail_msg">
<br class="gmail_msg">
Modified:<br
class="gmail_msg">
llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp<br
class="gmail_msg">
<br class="gmail_msg">
Modified:
llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp<br
class="gmail_msg">
URL: <a
moz-do-not-send="true"
href="http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp?rev=296253&r1=296252&r2=296253&view=diff"
rel="noreferrer"
class="gmail_msg"
target="_blank">http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp?rev=296253&r1=296252&r2=296253&view=diff</a><br
class="gmail_msg">
==============================================================================<br
class="gmail_msg">
---
llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp
(original)<br
class="gmail_msg">
+++
llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp
Sat Feb 25 07:15:57 2017<br
class="gmail_msg">
@@ -329,6 +329,12 @@ void
DWARFDie::dump(raw_ostream
&OS, uns<br
class="gmail_msg">
<br class="gmail_msg">
// Dump all data in
the DIE for the attributes.<br
class="gmail_msg">
for (const auto
&AttrSpec :
AbbrevDecl->attributes())
{<br class="gmail_msg">
+ if (AttrSpec.Form
== DW_FORM_implicit_const) {<br
class="gmail_msg">
+ // We are
dumping .debug_info section
,<br class="gmail_msg">
+ //
implicit_const attribute
values are not really stored
here,<br class="gmail_msg">
+ // but in
.debug_abbrev section. So we
just skip such attrs.<br
class="gmail_msg">
+ continue;<br
class="gmail_msg">
+ }<br
class="gmail_msg">
dumpAttribute(OS,
*this, &offset,
AttrSpec.Attr,
AttrSpec.Form,<br
class="gmail_msg">
Indent);<br
class="gmail_msg">
}<br
class="gmail_msg">
<br class="gmail_msg">
<br class="gmail_msg">
_______________________________________________<br class="gmail_msg">
llvm-commits mailing list<br
class="gmail_msg">
<a moz-do-not-send="true"
href="mailto:llvm-commits@lists.llvm.org"
class="gmail_msg"
target="_blank">llvm-commits@lists.llvm.org</a><br
class="gmail_msg">
<a moz-do-not-send="true"
href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits"
rel="noreferrer"
class="gmail_msg"
target="_blank">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits</a><br
class="gmail_msg">
</blockquote>
</div>
</blockquote>
<br class="gmail_msg">
</div>
<div bgcolor="#FFFFFF"
text="#000000" class="gmail_msg">
<pre class="m_3395721182541375228m_-1917743091071114938m_-7804286437102967308m_-7636712434836838175moz-signature gmail_msg" cols="72">--
Best Regards,
Victor</pre>
</div>
</blockquote>
</div>
</div>
</blockquote>
<br class="gmail_msg">
</div>
<div bgcolor="#FFFFFF" text="#000000"
class="gmail_msg">
<pre class="m_3395721182541375228m_-1917743091071114938m_-7804286437102967308moz-signature gmail_msg" cols="72">--
Best Regards,
Victor</pre>
</div>
</blockquote>
</div>
</div>
</blockquote>
<br class="gmail_msg">
</div>
<div bgcolor="#FFFFFF" text="#000000" class="gmail_msg">
<pre class="m_3395721182541375228m_-1917743091071114938moz-signature gmail_msg" cols="72">--
Best Regards,
Victor</pre>
</div>
</blockquote>
</div>
</div>
</blockquote>
</div>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Best Regards,
Victor</pre>
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