<div dir="ltr">Hi Alexey,<div><br></div><div>make sense. My confusion comes from the fact that GCC could compile and run the code. But your explanation is compatible </div><div>with OpenMP specification. Thanks very much! </div><div><br></div><div>Sincerely</div><div>Xiaohui</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Mar 18, 2015 at 11:56 PM, Bataev, Alexey <span dir="ltr"><<a href="mailto:a.bataev@hotmail.com" target="_blank">a.bataev@hotmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>Hi,<br>
I don't think your code is correct, because actually there are 2
structured blocks where you think there is only one.<br>
According to OpenMP standard structured block "For C/C++, an
executable statement, ...", i.e. single statement, not several
statements. So, the detection is correct.<br>
You have to enclose two first stmts into braces to make it
compatible with OpenMP standard.<span class="HOEnZb"><font color="#888888"><br>
<br>
<pre cols="72">--
Best regards,
Alexey Bataev
=============
Software Engineer
Intel Compiler Team</pre>
<br>
18.03.2015 21:08, xiaohui chen пишет:<br>
</font></span></div><div><div class="h5">
<blockquote type="cite">
<div dir="ltr"><br>
<div class="gmail_extra">just correct a typo, please read the
below message. </div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Wed, Mar 18, 2015 at 1:01 PM,
xiaohui chen <span dir="ltr"><<a href="mailto:xchen198812@gmail.com" target="_blank">xchen198812@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">Hi,
<div>I am using clang version 3.6.0 (trunk 224915).</div>
<div><br>
</div>
<div>Clang can not parse the following valid OpenMP
code:</div>
<div><br>
</div>
<div>
<div> 1 #include<omp.h></div>
<div> 2 void main()</div>
<div> 3 {</div>
<div> 4 int i;</div>
<div> 5 #pragma omp parallel</div>
<div> 6 #pragma omp sections</div>
<div> 7 {</div>
<div> 8 i++;</div>
<div> 9 i++;</div>
<div> 10 #pragma omp section</div>
<div> 11 i++;</div>
<div> 12 }</div>
<div> 13 }</div>
</div>
<div><br>
</div>
<div>The bug comes from line 8 and 9.</div>
<div><br>
</div>
<div>In OpenMP documentation (<a href="http://www.openmp.org/mp-documents/OpenMP4.0.0.pdf" target="_blank">http://www.openmp.org/mp-documents/OpenMP4.0.0.pdf</a>)
page 62,</div>
<div>it says"Each structured block in the sections
construct is preceded by a section directive </div>
<div>except possibly the first block, for which a
preceding section directive is optional." .</div>
<div><br>
</div>
<div>it means that the section directive is optional for
the first block, but not the first statement.</div>
<div><br>
</div>
<div>in function StmtResult
Sema::ActOnOpenMPSectionsDirective, </div>
<div><br>
</div>
<div>
<div>3021 StmtResult
Sema::ActOnOpenMPSectionsDirective(ArrayRef<OMPClause
*> Clauses,</div>
<div>3022
Stmt *AStmt,</div>
<div>3023
SourceLocation StartLoc,</div>
<div>3024
SourceLocation EndLoc) {</div>
<div>3025 assert(AStmt &&
isa<CapturedStmt>(AStmt) && "Captured
statement expected");</div>
<div>3026 auto BaseStmt = AStmt;</div>
<div>3027 while (CapturedStmt *CS =
dyn_cast_or_null<CapturedStmt>(BaseStmt))</div>
<div>3028 BaseStmt = CS->getCapturedStmt();</div>
<div>3029 if (auto C =
dyn_cast_or_null<CompoundStmt>(BaseStmt)) {</div>
<div>3030 auto S = C->children();</div>
<div>3031 if (!S)</div>
<div>3032 return StmtError();</div>
<div>3033 // All associated statements must be
'#pragma omp section' except for</div>
<div>3034 // the first one.</div>
<div>3035 for (++S; S; ++S) {</div>
<div>3036 auto SectionStmt = *S;</div>
<div>3037 if (!SectionStmt ||
!isa<OMPSectionDirective>(SectionStmt)) {</div>
<div>3038 if (SectionStmt)</div>
<div>3039
Diag(SectionStmt->getLocStart(),</div>
<div>3040
diag::err_omp_sections_substmt_not_section);</div>
<div>3041 return StmtError();</div>
<div>3042 }</div>
<div>3043 }</div>
<div>3044 } else {</div>
<div>3045 Diag(AStmt->getLocStart(),
diag::err_omp_sections_not_compound_stmt);</div>
<div>3046 return StmtError();</div>
<div>3047 }</div>
<div>3048 </div>
<div>3049
getCurFunction()->setHasBranchProtectedScope();</div>
<div>3050 </div>
<div>3051 return
OMPSectionsDirective::Create(Context, StartLoc,
EndLoc, Clauses,</div>
<div>3052
AStmt);</div>
<div>3053 }</div>
</div>
<div><br>
</div>
<div>Notice from line 3035 to line 3042, it just checks
the first statement not the first block.</div>
<div><br>
</div>
<div><br>
</div>
</div>
<br>
</blockquote>
</div>
<br>
</div>
</div>
<br>
<br>
<br>
<br>
</blockquote>
<br>
<br>
</div></div></div>
</blockquote></div><br></div>