<div dir="ltr">the WinCodeViewLineTables::beginInstruction is called and the MI happens to have a DebugLoc.<div class="gmail_extra"><br></div><div class="gmail_extra">That's in fact exactly the scenario <span style="font-family:arial,sans-serif;font-size:13px">r204790 has fixed – processing of a function without a lexical scope but with at least one MI having DL.</span><br>
<br><div class="gmail_quote">2014-03-27 0:36 GMT+04:00 Eric Christopher <span dir="ltr"><<a href="mailto:echristo@gmail.com" target="_blank" class="cremed">echristo@gmail.com</a>></span>:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">But how do you know where/etc they are?<br>
<span><font color="#888888"><br>
-eric<br>
</font></span><div><div><br>
On Wed, Mar 26, 2014 at 1:33 PM, Timur Iskhodzhanov <<a href="mailto:timurrrr@google.com" target="_blank" class="cremed">timurrrr@google.com</a>> wrote:<br>
> 1 file/line number entry for a single jmp instruction.<br>
><br>
><br>
> 2014-03-27 0:22 GMT+04:00 Eric Christopher <<a href="mailto:echristo@gmail.com" target="_blank" class="cremed">echristo@gmail.com</a>>:<br>
><br>
>> On Wed, Mar 26, 2014 at 1:20 PM, Timur Iskhodzhanov <<a href="mailto:timurrrr@google.com" target="_blank" class="cremed">timurrrr@google.com</a>><br>
>> wrote:<br>
>> ><br>
>> ><br>
>> ><br>
>> > 2014-03-27 0:14 GMT+04:00 Eric Christopher <<a href="mailto:echristo@gmail.com" target="_blank" class="cremed">echristo@gmail.com</a>>:<br>
>> ><br>
>> >> On Wed, Mar 26, 2014 at 1:00 PM, Timur Iskhodzhanov<br>
>> >> <<a href="mailto:timurrrr@google.com" target="_blank" class="cremed">timurrrr@google.com</a>><br>
>> >> wrote:<br>
>> >> ><br>
>> >> ><br>
>> >> ><br>
>> >> > 2014-03-26 19:24 GMT+04:00 David Blaikie <<a href="mailto:dblaikie@gmail.com" target="_blank" class="cremed">dblaikie@gmail.com</a>>:<br>
>> >> ><br>
>> >> >> On Wed, Mar 26, 2014 at 4:24 AM, Timur Iskhodzhanov<br>
>> >> >> <<a href="mailto:timurrrr@google.com" target="_blank" class="cremed">timurrrr@google.com</a>><br>
>> >> >> wrote:<br>
>> >> >> > Author: timurrrr<br>
>> >> >> > Date: Wed Mar 26 06:24:36 2014<br>
>> >> >> > New Revision: 204795<br>
>> >> >> ><br>
>> >> >> > URL: <a href="http://llvm.org/viewvc/llvm-project?rev=204795&view=rev" target="_blank" class="cremed">http://llvm.org/viewvc/llvm-project?rev=204795&view=rev</a><br>
>> >> >> > Log:<br>
>> >> >> > Follow-up to r204790: don't try to emit line tables if there are<br>
>> >> >> > no<br>
>> >> >> > functions with DI in the TU<br>
>> >> >><br>
>> >> >> Hmm - is there any better way to do this? Should we only be building<br>
>> >> >> line tables for those functions with DI? Then we'd just emit line<br>
>> >> >> tables if we have any (non-empty) line tables to emit, right?<br>
>> >> ><br>
>> >> ><br>
>> >> > Is there a handy function available for that? :)<br>
>> >> ><br>
>> >><br>
>> >> From DwarfDebug::beginFunction:<br>
>> >><br>
>> >> // If there's no debug info for the function we're not going to do<br>
>> >> anything.<br>
>> >> if (!MMI->hasDebugInfo())<br>
>> >> return;<br>
>> >><br>
>> >> // Grab the lexical scopes for the function, if we don't have any of<br>
>> >> those<br>
>> >> // then we're not going to be able to do anything.<br>
>> >> LScopes.initialize(*MF);<br>
>> >> if (LScopes.empty())<br>
>> >> return;<br>
>> >><br>
>> >> -eric<br>
>> ><br>
>> ><br>
>> > This is almost exactly the beginning of<br>
>> > WinCodeViewLineTables::beginFunction() as of yesterday :)<br>
>> > So yes, I'm aware of this and I do/did use it.<br>
>> ><br>
>> > However, IIUC it turns out that "if we don't have any [lexical scopes]<br>
>> > then<br>
>> > we're not going to be able to do anything" we still can emit minimal DI<br>
>> > for<br>
>> > a function. [see r204790 + r204791]<br>
>><br>
>> Without looking (my backlog is insane) what's the info you're emitting for<br>
>> it?<br>
>><br>
>> -eric<br>
>><br>
>> ><br>
>> >> >> I assume these COFF line tables don't actually get referenced from<br>
>> >> >> any<br>
>> >> >> other debug info (since the rest of our info is DWARF), but I've<br>
>> >> >> been<br>
>> >> >> thinking of cleaning up our other line table handling code a bit so<br>
>> >> >> that it's a bit more structured - letting the line table object<br>
>> >> >> itself<br>
>> >> >> decide whether it should be emitted (by virtue of being non-empty)<br>
>> >> >> and<br>
>> >> >> then having line table clients (CUs in DwarfDebug - no analogy for<br>
>> >> >> COFF which has no line table client) query the line table to see if<br>
>> >> >> it'll be there and attach the DW_AT_stmt_list if there will be a<br>
>> >> >> line<br>
>> >> >> table.<br>
>> >> >><br>
>> >> >> - David<br>
>> >> >><br>
>> >> >> ><br>
>> >> >> > Added:<br>
>> >> >> > llvm/trunk/test/DebugInfo/COFF/asan2.ll<br>
>> >> >> > Modified:<br>
>> >> >> > llvm/trunk/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp<br>
>> >> >> ><br>
>> >> >> > Modified:<br>
>> >> >> > llvm/trunk/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp<br>
>> >> >> > URL:<br>
>> >> >> ><br>
>> >> >> ><br>
>> >> >> > <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp?rev=204795&r1=204794&r2=204795&view=diff" target="_blank" class="cremed">http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp?rev=204795&r1=204794&r2=204795&view=diff</a><br>
>> >> >> ><br>
>> >> >> ><br>
>> >> >> ><br>
>> >> >> > ==============================================================================<br>
>> >> >> > --- llvm/trunk/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp<br>
>> >> >> > (original)<br>
>> >> >> > +++ llvm/trunk/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp<br>
>> >> >> > Wed<br>
>> >> >> > Mar<br>
>> >> >> > 26 06:24:36 2014<br>
>> >> >> > @@ -304,11 +304,18 @@ void WinCodeViewLineTables::beginFunctio<br>
>> >> >> > }<br>
>> >> >> > }<br>
>> >> >> ><br>
>> >> >> > -void WinCodeViewLineTables::endFunction(const MachineFunction *)<br>
>> >> >> > {<br>
>> >> >> > +void WinCodeViewLineTables::endFunction(const MachineFunction<br>
>> >> >> > *MF) {<br>
>> >> >> > if (!Asm || !CurFn) // We haven't created any debug info for<br>
>> >> >> > this<br>
>> >> >> > function.<br>
>> >> >> > return;<br>
>> >> >> ><br>
>> >> >> > - if (!CurFn->Instrs.empty()) {<br>
>> >> >> > + const Function *GV = MF->getFunction();<br>
>> >> >> > + assert(FnDebugInfo.count(GV) == true);<br>
>> >> >><br>
>> >> >> "count == true" seems a bit confusing for a few reasons. Should that<br>
>> >> >> be either just "assert(x.count(y))" or "assert(x.count(y) != 0)" (or<br>
>> >> >> greater than zero or 1 or whatever). "== true" always reads as<br>
>> >> >> weird/redundant to me.<br>
>> >> >><br>
>> >> >> > + assert(CurFn == &FnDebugInfo[GV]);<br>
>> >> >> > +<br>
>> >> >> > + if (CurFn->Instrs.empty()) {<br>
>> >> >> > + FnDebugInfo.erase(GV);<br>
>> >> >> > + VisitedFunctions.pop_back();<br>
>> >> >> > + } else {<br>
>> >> >> > // Define end label for subprogram.<br>
>> >> >> > MCSymbol *FunctionEndSym =<br>
>> >> >> > Asm->OutStreamer.getContext().CreateTempSymbol();<br>
>> >> >> > Asm->OutStreamer.EmitLabel(FunctionEndSym);<br>
>> >> >> ><br>
>> >> >> > Added: llvm/trunk/test/DebugInfo/COFF/asan2.ll<br>
>> >> >> > URL:<br>
>> >> >> ><br>
>> >> >> ><br>
>> >> >> > <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/COFF/asan2.ll?rev=204795&view=auto" target="_blank" class="cremed">http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/COFF/asan2.ll?rev=204795&view=auto</a><br>
>> >> >> ><br>
>> >> >> ><br>
>> >> >> ><br>
>> >> >> > ==============================================================================<br>
>> >> >> > --- llvm/trunk/test/DebugInfo/COFF/asan2.ll (added)<br>
>> >> >> > +++ llvm/trunk/test/DebugInfo/COFF/asan2.ll Wed Mar 26 06:24:36<br>
>> >> >> > 2014<br>
>> >> >> > @@ -0,0 +1,52 @@<br>
>> >> >> > +; RUN: llc -mcpu=core2 -mtriple=i686-pc-win32 -O0 < %s |<br>
>> >> >> > FileCheck<br>
>> >> >> > --check-prefix=X86 %s<br>
>> >> >> > +<br>
>> >> >> > +; This LL file was generated by running clang on the following<br>
>> >> >> > code<br>
>> >> >> > with<br>
>> >> >> > +; -fsanitize=address<br>
>> >> >> > +; D:\asan.c:<br>
>> >> >> > +; 1 unsigned char c = 42;<br>
>> >> >> > +<br>
>> >> >> > +; Just make sure we don't try to emit the line table.<br>
>> >> >> > +; X86-NOT: .section .debug$S,"rn"<br>
>> >> >> > +<br>
>> >> >> > +; ModuleID = 'asan.c'<br>
>> >> >> > +target datalayout = "e-m:w-p:32:32-i64:64-f80:32-n8:16:32-S32"<br>
>> >> >> > +target triple = "i686-pc-win32"<br>
>> >> >> > +<br>
>> >> >> > +@c = global { i8, [63 x i8] } { i8 42, [63 x i8] zeroinitializer<br>
>> >> >> > },<br>
>> >> >> > align 32<br>
>> >> >> > +@llvm.global_ctors = appending global [1 x { i32, void ()* }] [{<br>
>> >> >> > i32,<br>
>> >> >> > void ()* } { i32 1, void ()* @asan.module_ctor }]<br>
>> >> >> > +@__asan_gen_ = private constant [7 x i8] c"asan.c\00", align 1<br>
>> >> >> > +@__asan_gen_1 = private unnamed_addr constant [2 x i8] c"c\00",<br>
>> >> >> > align 1<br>
>> >> >> > +@0 = internal global [1 x { i32, i32, i32, i32, i32, i32 }] [{<br>
>> >> >> > i32,<br>
>> >> >> > i32, i32, i32, i32, i32 } { i32 ptrtoint ({ i8, [63 x i8] }* @c to<br>
>> >> >> > i32), i32<br>
>> >> >> > 1, i32 64, i32 ptrtoint ([2 x i8]* @__asan_gen_1 to i32), i32<br>
>> >> >> > ptrtoint ([7 x<br>
>> >> >> > i8]* @__asan_gen_ to i32), i32 0 }]<br>
>> >> >> > +@llvm.global_dtors = appending global [1 x { i32, void ()* }] [{<br>
>> >> >> > i32,<br>
>> >> >> > void ()* } { i32 1, void ()* @asan.module_dtor }]<br>
>> >> >> > +<br>
>> >> >> > +define internal void @asan.module_ctor() {<br>
>> >> >> > + call void @__asan_init_v3()<br>
>> >> >> > + call void @__asan_register_globals(i32 ptrtoint ([1 x { i32,<br>
>> >> >> > i32,<br>
>> >> >> > i32, i32, i32, i32 }]* @0 to i32), i32 1)<br>
>> >> >> > + ret void<br>
>> >> >> > +}<br>
>> >> >> > +<br>
>> >> >> > +declare void @__asan_init_v3()<br>
>> >> >> > +<br>
>> >> >> > +declare void @__asan_before_dynamic_init(i32)<br>
>> >> >> > +<br>
>> >> >> > +declare void @__asan_after_dynamic_init()<br>
>> >> >> > +<br>
>> >> >> > +declare void @__asan_register_globals(i32, i32)<br>
>> >> >> > +<br>
>> >> >> > +declare void @__asan_unregister_globals(i32, i32)<br>
>> >> >> > +<br>
>> >> >> > +define internal void @asan.module_dtor() {<br>
>> >> >> > + call void @__asan_unregister_globals(i32 ptrtoint ([1 x { i32,<br>
>> >> >> > i32,<br>
>> >> >> > i32, i32, i32, i32 }]* @0 to i32), i32 1)<br>
>> >> >> > + ret void<br>
>> >> >> > +}<br>
>> >> >> > +<br>
>> >> >> > +!<a href="http://llvm.dbg.cu" target="_blank" class="cremed">llvm.dbg.cu</a> = !{!0}<br>
>> >> >> > +!llvm.module.flags = !{!3, !4}<br>
>> >> >> > +!llvm.ident = !{!5}<br>
>> >> >> > +<br>
>> >> >> > +!0 = metadata !{i32 786449, metadata !1, i32 12, metadata !"clang<br>
>> >> >> > version 3.5.0 ", i1 false, metadata !"", i32 0, metadata !2,<br>
>> >> >> > metadata<br>
>> >> >> > !2,<br>
>> >> >> > metadata !2, metadata !2, metadata !2, metadata !"", i32 2} ; [<br>
>> >> >> > DW_TAG_compile_unit ] [D:\/asan.c] [DW_LANG_C99]<br>
>> >> >> > +!1 = metadata !{metadata !"asan.c", metadata !"D:\5C"}<br>
>> >> >> > +!2 = metadata !{}<br>
>> >> >> > +!3 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}<br>
>> >> >> > +!4 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}<br>
>> >> >> > +!5 = metadata !{metadata !"clang version 3.5.0 "}<br>
>> >> >> ><br>
>> >> >> ><br>
>> >> >> > _______________________________________________<br>
>> >> >> > llvm-commits mailing list<br>
>> >> >> > <a href="mailto:llvm-commits@cs.uiuc.edu" target="_blank" class="cremed">llvm-commits@cs.uiuc.edu</a><br>
>> >> >> > <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits" target="_blank" class="cremed">http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits</a><br>
>> >> ><br>
>> >> ><br>
>> >> ><br>
>> >> > _______________________________________________<br>
>> >> > llvm-commits mailing list<br>
>> >> > <a href="mailto:llvm-commits@cs.uiuc.edu" target="_blank" class="cremed">llvm-commits@cs.uiuc.edu</a><br>
>> >> > <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits" target="_blank" class="cremed">http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits</a><br>
>> >> ><br>
>> ><br>
>> ><br>
><br>
><br>
</div></div></blockquote></div><br></div></div>