<div dir="ltr"><div dir="ltr"><div dir="ltr">Yes, I understand and really appreciate your help, Artem.<br><br>Last night I had the same insight, but splitting the VerDecls to different DeclStmts had no effect.<br><br>Bellow is the dump of the source-level CFG for the block in question. One thing I have noticed from the CFG is that all my calls were tagged "template". Any idea why? </div><div dir="ltr">Maybe that has something to do with why UninitializedVariables Analysis is sigseg-faulting.</div><div dir="ltr"><br></div><div dir="ltr"><div dir="ltr">[B181]</div><div dir="ltr"> 1: jmp_buf __setjmp_buf;</div><div dir="ltr"> 2: <b>template</b> setjmp</div><div dir="ltr"> 3: [B181.2] (ImplicitCastExpr, FunctionToPointerDecay, int (*)(struct __jmp_buf_tag *)) </div><div dir="ltr"> 4: __setjmp_buf</div><div dir="ltr"> 5: [B181.4] (ImplicitCastExpr, ArrayToPointerDecay, struct __jmp_buf_tag *)</div><div dir="ltr"> 6: [B181.3]([B181.5])</div><div dir="ltr"> 7: int __setjmp_ret = <b>template</b> setjmp(__setjmp_buf);</div><div dir="ltr"> 8: <b>template</b> __spec_begin</div><div dir="ltr"> 9: [B181.8] (ImplicitCastExpr, FunctionToPointerDecay, unsigned int (*)(jmp_buf *, int))</div><div dir="ltr"> 10: __setjmp_buf</div><div dir="ltr"> 11: &[B181.10]</div><div dir="ltr"> 12: __setjmp_ret</div><div dir="ltr"> 13: [B181.12] (ImplicitCastExpr, LValueToRValue, int)</div><div dir="ltr"> 14: [B181.9]([B181.11], [B181.13])</div><div dir="ltr"> 15: unsigned int __spec_mode = <b>template</b> __spec_begin(&__setjmp_buf, __setjmp_ret);</div><div dir="ltr"> 16: __spec_mode</div><div dir="ltr"> 17: [B181.16] (ImplicitCastExpr, LValueToRValue, unsigned int)</div><div dir="ltr"> 18: [B181.17] == 1</div><div dir="ltr"> 19: <b>template</b> __begin_spec_slow_path</div><div dir="ltr"> 20: [B181.19] (ImplicitCastExpr, FunctionToPointerDecay, void (*)(void))</div><div dir="ltr"> 21: [B181.20]()</div><div dir="ltr"> 22: global_maxNumVertices</div><div dir="ltr"> 23: [B181.22] (ImplicitCastExpr, LValueToRValue, ULONGINT_T)</div><div dir="ltr"> 24: (long)[B181.23] (CStyleCastExpr, IntegralCast, long)</div><div dir="ltr"> 25: long __tmp_maxNumVertices = (long)global_maxNumVertices;</div><div dir="ltr"> 26: __tmp_maxNumVertices</div><div dir="ltr"> 27: typeof (tmp_maxNumVertices) ___a = (__tmp_maxNumVertices);</div><div dir="ltr"> 28: maxNumVertices</div><div dir="ltr"> 29: [B181.28] (ImplicitCastExpr, LValueToRValue, ULONGINT_T)</div><div dir="ltr"> 30: 1 (ImplicitCastExpr, IntegralCast, unsigned long)</div><div dir="ltr"> 31: [B181.29] + [B181.30]</div><div dir="ltr"> 32: typeof (maxNumVertices + 1) ___b = (maxNumVertices + 1); </div><div dir="ltr"> 33: ___a</div><div dir="ltr"> 34: [B181.33] (ImplicitCastExpr, LValueToRValue, typeof (tmp_maxNumVertices))</div><div dir="ltr"> 35: [B181.34] (ImplicitCastExpr, IntegralCast, unsigned long)</div><div dir="ltr"> 36: ___b</div><div dir="ltr"> 37: [B181.36] (ImplicitCastExpr, LValueToRValue, typeof (maxNumVertices + 1)) </div><div dir="ltr"> 38: [B181.35] > [B181.37]</div><div dir="ltr"> T: ([B181.38]) ? ... : ... </div><div dir="ltr"> Preds (1): B185</div><div dir="ltr"> Succs (2): B179 B180</div><div><br></div><br></div></div></div><br><div class="gmail_quote"><div dir="ltr">On Tue, Sep 25, 2018 at 2:47 PM Artem Dergachev <<a href="mailto:noqnoqneo@gmail.com" target="_blank">noqnoqneo@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 text="#000000" bgcolor="#FFFFFF">
Remote debugging is hard, but here's something i notice: i don't
think you can declare multiple variables of different types in the
same DeclStmt. Eg., you can do `int x = 1, *y = 0;`, but you can't
do `int x = 1, unsigned y = 0;`. Could you try to produce a separate
DeclStmt for every VarDecl and see if it helps?<br>
<br>
If it doesn't, can i also have a look at the CFG? Just do
CFG.dump().<br>
<br>
<div class="m_-307315359463317007m_-7535279087831355520moz-cite-prefix">On 9/24/18 3:26 PM, João Paulo
Labegalini de Carvalho wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">Artem,
<div><br>
</div>
<div>First of all, thank you for your reply.<br>
<br>
Indeed, I am auto-generating AST made of regular nodes. More
specifically, my SpecStmt node has four sub-nodes. A DeclStmt
that I use to hang the variables a need, a Expr to compare
__spec_mode and decide which path to take (SlowPath or
FastPath) and two CompoundStmts. So SpecStmt looks like an
IfStmt with both then and else statements.<br>
<br>
Bellow is the part of the AST which triggers the sigsegv
(Please find the AST for the whole FunctionDecl attached):</div>
<div><br>
</div>
<div>
<div>| | |-<b>SpecStmt</b> 0x15c1ca8
<./spec.h:127:32></div>
<div>| | | |-DeclStmt 0x15c09e8 <col:32></div>
<div>| | | | |-VarDecl 0x15c0368 <col:32>
col:32 <b>__setjmp_buf</b> 'jmp_buf':'struct __jmp_buf_tag
[1]' auto</div>
<div>| | | | |-VarDecl 0x15c03c8 <col:32>
col:32 <b>__setjmp_ret</b> 'int' auto cinit</div>
<div>| | | | | `-CallExpr 0x15c0630 <col:32>
'int'</div>
<div>| | | | | |-ImplicitCastExpr 0x15c0618
<col:32> 'int (*)(jmp_buf *)'
<FunctionToPointerDecay></div>
<div>| | | | | | `-DeclRefExpr 0x15c05e0
<col:32> 'int (jmp_buf *)' Function 0x15c04d8 '<b>setjmp</b>'
'int (jmp_buf *)'</div>
<div>| | | | | `-ImplicitCastExpr 0x15c0450
<col:32> 'jmp_buf *' <ArrayToPointerDecay></div>
<div>| | | | | `-DeclRefExpr 0x15c0428
<col:32> 'jmp_buf':'struct __jmp_buf_tag [1]' Var
0x15c0368 '<b>__setjmp_buf</b>' 'jmp_buf':'struct
__jmp_buf_tag [1]'</div>
<div>| | | | `-VarDecl 0x15c0660 <col:32>
col:32 <b>__spec_mode</b> 'unsigned int' auto cinit</div>
<div>| | | | `-CallExpr 0x15c0990 <col:32>
'unsigned int'</div>
<div>| | | | |-ImplicitCastExpr 0x15c0978
<col:32> 'unsigned int (*)(jmp_buf *, int)'
<FunctionToPointerDecay></div>
<div>| | | | | `-DeclRefExpr 0x15c0940
<col:32> 'unsigned int (jmp_buf *, int)' Function
0x15c07d0 '<b>__spec_begin</b>' 'unsigned int (jmp_buf *,
int)'</div>
<div>| | | | |-ImplicitCastExpr 0x15c0730
<col:32> 'jmp_buf *' <LValueToRValue></div>
<div>| | | | | `-UnaryOperator 0x15c06e8
<col:32> 'jmp_buf *' prefix '&'</div>
<div>| | | | | `-DeclRefExpr 0x15c06c0
<col:32> 'jmp_buf':'struct __jmp_buf_tag [1]' Var
0x15c0368 '<b>__setjmp_buf'</b> 'jmp_buf':'struct
__jmp_buf_tag [1]'</div>
<div>| | | | `-ImplicitCastExpr 0x15c0748
<col:32> 'int' <LValueToRValue> </div>
<div>| | | | `-DeclRefExpr 0x15c0708
<col:32> 'int' Var 0x15c03c8 '<b>__setjmp_ret</b>'
'int'</div>
<div>| | | |-BinaryOperator 0x15c0a60 <col:32>
'bool' lvalue '=='</div>
<div>| | | | |-ImplicitCastExpr 0x15c0a28
<col:32> 'unsigned int' <LValueToRValue></div>
<div>| | | | | `-DeclRefExpr 0x15c0a00 <col:32>
'unsigned int' lvalue Var 0x15c0660 '<b>__spec_mode'</b> 'unsigned
int'</div>
<div>| | | | `-IntegerLiteral 0x15c0a40 <col:32>
'int' 1</div>
<div>| | | |-CompoundStmt 0x15c1c38 <col:32></div>
</div>
<div><br>
</div>
<div dir="ltr"><br>
</div>
<div>Thanks in advance for any help!<br>
<br>
</div>
<div>Respectfully,</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr">On Mon, Sep 24, 2018 at 4:36 PM Artem Dergachev
<<a href="mailto:noqnoqneo@gmail.com" target="_blank">noqnoqneo@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 text="#000000" bgcolor="#FFFFFF"> Is the DeclRefExpr for
__spec_mode pointing to a valid VarDecl? Would this VarDecl
be encountered previously during analysis in order to
populate TransferFunctions::vals()? Dunno if that makes
sense, i didn't really look at this analysis.<br>
<br>
I guess i want to look at your full -ast-dump. It seems that
you are not only adding a new Stmt kind, but also you're
getting into business of auto-generating AST made of some
regular nodes, probably as its children. This is often hard
because it's very easy to break invariants that the normal
AST obeys and there's no way to verify those invariants
other than seeing how everything crashes and debugging.<br>
<br>
<div class="m_-307315359463317007m_-7535279087831355520m_-6700653932672170602moz-cite-prefix">On
9/24/18 4:43 AM, João Paulo Labegalini de Carvalho via
cfe-dev wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div dir="ltr">You are right, I should have been more
specific. In my case crashing means segmentation fault
inside runOnBlock function
(lib/Analysis/UninitializedValues.cpp).<br>
<br>
Please find the stack trace attached.</div>
<br>
<div class="gmail_quote">
<div dir="ltr">On Mon, Sep 24, 2018 at 4:09 AM Csaba
Raduly <<a href="mailto:rcsaba@gmail.com" target="_blank">rcsaba@gmail.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi
João Paulo,<br>
<br>
<br>
On Sun, Sep 23, 2018 at 11:39 PM, João Paulo
Labegalini de Carvalho<br>
via cfe-dev <<a href="mailto:cfe-dev@lists.llvm.org" target="_blank">cfe-dev@lists.llvm.org</a>>
wrote:<br>
> Hi,<br>
><br>
> I have implemented a new Stmt in clang which
given<br>
><br>
> __speculate {<br>
> // user code<br>
> }<br>
><br>
> generates LLVM IR equivalent to as if the
following code was given:<br>
><br>
...<br>
><br>
> However, if UninitializedVariablesAnalysis is
enabled, clang crashes at<br>
> runOnBlock function
(lib/Analysis/UninitializedValues.cpp). If I disable
it<br>
> via -Wno-uninitialized, the code generated runs
flawlessly and works as<br>
> expected.<br>
<br>
"crash" is a meaningless term. Does it generate an
access violation,<br>
an assertion failure, or something else?<br>
What was the error message? Is there a stack trace?<br>
<br>
<br>
Csaba<br>
<br>
-- <br>
You can get very substantial performance
improvements<br>
by not doing the right thing. - Scott Meyers, An
Effective C++11/14 Sampler<br>
So if you're looking for a completely portable, 100%
standards-conformat way<br>
to get the wrong information: this is what you want.
- Scott Meyers (C++TDaWYK)<br>
</blockquote>
</div>
<br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr" class="m_-307315359463317007m_-7535279087831355520m_-6700653932672170602gmail_signature" data-smartmail="gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>João Paulo L. de Carvalho<br>
Computer Science | IC-UNICAMP | Campinas , SP
- Brazil</div>
<div><a href="mailto:jaopaulolc@gmail.com" target="_blank">jaopaulolc@gmail.com</a></div>
<div><a href="mailto:joao.carvalho@ic.unicamp.br" target="_blank">joao.carvalho@ic.unicamp.br</a><br>
<a href="mailto:j160924@dac.unicamp.br" target="_blank">j160924@dac.unicamp.br</a></div>
</div>
</div>
</div>
</div>
</div>
<br>
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<br>
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</blockquote>
</div>
<br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr" class="m_-307315359463317007m_-7535279087831355520gmail_signature" data-smartmail="gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>João Paulo L. de Carvalho<br>
Computer Science | IC-UNICAMP | Campinas , SP - Brazil</div>
<div><a href="mailto:jaopaulolc@gmail.com" target="_blank">jaopaulolc@gmail.com</a></div>
<div><a href="mailto:joao.carvalho@ic.unicamp.br" target="_blank">joao.carvalho@ic.unicamp.br</a><br>
<a href="mailto:j160924@dac.unicamp.br" target="_blank">j160924@dac.unicamp.br</a></div>
</div>
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</div>
</blockquote>
<br>
</div>
</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="m_-307315359463317007gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div>João Paulo L. de Carvalho<br>Computer Science | IC-UNICAMP | Campinas , SP - Brazil</div><div><a href="mailto:jaopaulolc@gmail.com" target="_blank">jaopaulolc@gmail.com</a></div><div><a href="mailto:joao.carvalho@ic.unicamp.br" target="_blank">joao.carvalho@ic.unicamp.br</a><br><a href="mailto:j160924@dac.unicamp.br" target="_blank">j160924@dac.unicamp.br</a></div></div></div></div></div>