<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">+ Clément & Eric (not sure why Eric was dropped from the thread, sorry about that)<div class=""><div class=""><br class=""></div><div class="">The verifier failure is due to a combination of</div><div class="">1) The declaration of @memcmp being assigned a DISubprogram, and</div><div class="">2) The MergeICmps pass doesn't assign a debug location to the memcmps it generates</div><div class=""><br class=""></div><div class="">Hence, "inlinable function call" (memcmp) "in a function with debug info must have a !dbg location".</div><div class=""><br class=""></div><div class="">I think this could be addressed by either</div><div class="">1) Not assigning DISubprograms to builtin functions or</div><div class="">2) Having MergeICmps assigning some location to the memcmps it generates (probably a merged / line 0 location, but maybe the location of the first icmp if that'd be more helpful).</div><div class=""><br class=""></div><div class="">Or both. (1) would shrink debug info size a little, and seems simpler to implement, so I'll start there.</div><div class=""><br class=""></div><div class="">Anyone have thoughts on (2), or other suggestions?</div><div class=""><br class=""></div><div class="">thanks</div><div class="">vedant<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Nov 7, 2019, at 10:27 AM, Vedant Kumar via llvm-commits <<a href="mailto:llvm-commits@lists.llvm.org" class="">llvm-commits@lists.llvm.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html; charset=us-ascii" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Thanks for reverting. I'll dig into this today.<div class=""><br class=""></div><div class="">vedant<br class=""><div class=""><br class=""><blockquote type="cite" class=""><div class="">On Nov 7, 2019, at 9:09 AM, Eric Christopher via llvm-commits <<a href="mailto:llvm-commits@lists.llvm.org" class="">llvm-commits@lists.llvm.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="auto" class="">Thanks Hans!</div><br class=""><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Nov 7, 2019, 1:32 AM Hans Wennborg <<a href="mailto:hans@chromium.org" class="">hans@chromium.org</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">In Chromium it broke the build in a few configurations, so I've<br class="">
reverted in 5b9a072c39c.<br class="">
<br class="">
See <a href="https://bugs.chromium.org/p/chromium/issues/detail?id=1022296#c1" rel="noreferrer noreferrer" target="_blank" class="">https://bugs.chromium.org/p/chromium/issues/detail?id=1022296#c1</a><br class="">
for reproducer.<br class="">
<br class="">
On Thu, Nov 7, 2019 at 3:05 AM Eric Christopher via llvm-commits<br class="">
<<a href="mailto:llvm-commits@lists.llvm.org" target="_blank" rel="noreferrer" class="">llvm-commits@lists.llvm.org</a>> wrote:<br class="">
><br class="">
> As a heads up we're starting to see a problem around this commit with<br class="">
> backtraces for inline functions with msan where the line number has<br class="">
> gone away (replaced with 0).<br class="">
><br class="">
> Dave is looking at it, but I thought I'd send a message as early as I could.<br class="">
><br class="">
> -eric<br class="">
><br class="">
> On Mon, Nov 4, 2019 at 3:14 PM Vedant Kumar via llvm-commits<br class="">
> <<a href="mailto:llvm-commits@lists.llvm.org" target="_blank" rel="noreferrer" class="">llvm-commits@lists.llvm.org</a>> wrote:<br class="">
> ><br class="">
> ><br class="">
> > Author: Vedant Kumar<br class="">
> > Date: 2019-11-04T15:14:24-08:00<br class="">
> > New Revision: a5c8ec4baa2c00d8dbca36ffd236a40f9e0c07ed<br class="">
> ><br class="">
> > URL: <a href="https://github.com/llvm/llvm-project/commit/a5c8ec4baa2c00d8dbca36ffd236a40f9e0c07ed" rel="noreferrer noreferrer" target="_blank" class="">https://github.com/llvm/llvm-project/commit/a5c8ec4baa2c00d8dbca36ffd236a40f9e0c07ed</a><br class="">
> > DIFF: <a href="https://github.com/llvm/llvm-project/commit/a5c8ec4baa2c00d8dbca36ffd236a40f9e0c07ed.diff" rel="noreferrer noreferrer" target="_blank" class="">https://github.com/llvm/llvm-project/commit/a5c8ec4baa2c00d8dbca36ffd236a40f9e0c07ed.diff</a><br class="">
> ><br class="">
> > LOG: [CGDebugInfo] Emit subprograms for decls when AT_tail_call is understood<br class="">
> ><br class="">
> > Currently, clang emits subprograms for declared functions when the<br class="">
> > target debugger or DWARF standard is known to support entry values<br class="">
> > (DW_OP_entry_value & the GNU equivalent).<br class="">
> ><br class="">
> > Treat DW_AT_tail_call the same way to allow debuggers to follow cross-TU<br class="">
> > tail calls.<br class="">
> ><br class="">
> > Pre-patch debug session with a cross-TU tail call:<br class="">
> ><br class="">
> > ```<br class="">
> > * frame #0: 0x0000000100000fa4 main`target at b.c:4:3 [opt]<br class="">
> > frame #1: 0x0000000100000f99 main`main at a.c:8:10 [opt]<br class="">
> > ```<br class="">
> ><br class="">
> > Post-patch (note that the tail-calling frame, "helper", is visible):<br class="">
> ><br class="">
> > ```<br class="">
> > * frame #0: 0x0000000100000fa4 main`target at b.c:4:3 [opt]<br class="">
> > frame #1: 0x0000000100000f80 main`helper [opt] [artificial]<br class="">
> > frame #2: 0x0000000100000f99 main`main at a.c:8:10 [opt]<br class="">
> > ```<br class="">
> ><br class="">
> > <a href="rdar://46577651" class="">rdar://46577651</a><br class="">
> ><br class="">
> > Differential Revision: <a href="https://reviews.llvm.org/D69743" rel="noreferrer noreferrer" target="_blank" class="">https://reviews.llvm.org/D69743</a><br class="">
> ><br class="">
> > Added:<br class="">
> ><br class="">
> ><br class="">
> > Modified:<br class="">
> > clang/lib/CodeGen/CGDebugInfo.cpp<br class="">
> > clang/test/CodeGen/debug-info-extern-call.c<br class="">
> > clang/test/CodeGenCXX/dbg-info-all-calls-described.cpp<br class="">
> > llvm/test/DebugInfo/X86/dwarf-callsite-related-attrs.ll<br class="">
> ><br class="">
> > Removed:<br class="">
> ><br class="">
> ><br class="">
> ><br class="">
> > ################################################################################<br class="">
> > diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp<br class="">
> > index e0bb3fda7acf..c0c8fd3c8f16 100644<br class="">
> > --- a/clang/lib/CodeGen/CGDebugInfo.cpp<br class="">
> > +++ b/clang/lib/CodeGen/CGDebugInfo.cpp<br class="">
> > @@ -3748,9 +3748,7 @@ void CGDebugInfo::EmitFunctionDecl(GlobalDecl GD, SourceLocation Loc,<br class="">
> > void CGDebugInfo::EmitFuncDeclForCallSite(llvm::CallBase *CallOrInvoke,<br class="">
> > QualType CalleeType,<br class="">
> > const FunctionDecl *CalleeDecl) {<br class="">
> > - auto &CGOpts = CGM.getCodeGenOpts();<br class="">
> > - if (!CGOpts.EnableDebugEntryValues || !CGM.getLangOpts().Optimize ||<br class="">
> > - !CallOrInvoke)<br class="">
> > + if (!CallOrInvoke || getCallSiteRelatedAttrs() == llvm::DINode::FlagZero)<br class="">
> > return;<br class="">
> ><br class="">
> > auto *Func = CallOrInvoke->getCalledFunction();<br class="">
> > @@ -4824,10 +4822,10 @@ llvm::DINode::DIFlags CGDebugInfo::getCallSiteRelatedAttrs() const {<br class="">
> > bool SupportsDWARFv4Ext =<br class="">
> > CGM.getCodeGenOpts().DwarfVersion == 4 &&<br class="">
> > (CGM.getCodeGenOpts().getDebuggerTuning() == llvm::DebuggerKind::LLDB ||<br class="">
> > - (CGM.getCodeGenOpts().EnableDebugEntryValues &&<br class="">
> > - CGM.getCodeGenOpts().getDebuggerTuning() == llvm::DebuggerKind::GDB));<br class="">
> > + CGM.getCodeGenOpts().getDebuggerTuning() == llvm::DebuggerKind::GDB);<br class="">
> ><br class="">
> > - if (!SupportsDWARFv4Ext && CGM.getCodeGenOpts().DwarfVersion < 5)<br class="">
> > + if (!SupportsDWARFv4Ext && CGM.getCodeGenOpts().DwarfVersion < 5 &&<br class="">
> > + !CGM.getCodeGenOpts().EnableDebugEntryValues)<br class="">
> > return llvm::DINode::FlagZero;<br class="">
> ><br class="">
> > return llvm::DINode::FlagAllCallsDescribed;<br class="">
> ><br class="">
> > diff --git a/clang/test/CodeGen/debug-info-extern-call.c b/clang/test/CodeGen/debug-info-extern-call.c<br class="">
> > index e35669b78f93..7f58fe59a635 100644<br class="">
> > --- a/clang/test/CodeGen/debug-info-extern-call.c<br class="">
> > +++ b/clang/test/CodeGen/debug-info-extern-call.c<br class="">
> > @@ -1,8 +1,21 @@<br class="">
> > -// RUN: %clang -Xclang -femit-debug-entry-values -g -O2 -target x86_64-none-linux-gnu -S -emit-llvm %s -o - | FileCheck %s -check-prefix=CHECK-EXT<br class="">
> > -// CHECK-EXT: !DISubprogram(name: "fn1"<br class="">
> > +// When entry values are emitted, expect a subprogram for extern decls so that<br class="">
> > +// the dwarf generator can describe call site parameters at extern call sites.<br class="">
> > +//<br class="">
> > +// RUN: %clang -Xclang -femit-debug-entry-values -g -O2 -target x86_64-none-linux-gnu -S -emit-llvm %s -o - | FileCheck %s -check-prefix=ENTRY-VAL<br class="">
> > +// ENTRY-VAL: !DISubprogram(name: "fn1"<br class="">
> ><br class="">
> > -// RUN: %clang -g -O2 -target x86_64-none-linux-gnu -S -emit-llvm %s -o - | FileCheck %s<br class="">
> > -// CHECK-NOT: !DISubprogram(name: "fn1"<br class="">
> > +// Similarly, when the debugger tuning is gdb, expect a subprogram for extern<br class="">
> > +// decls so that the dwarf generator can describe information needed for tail<br class="">
> > +// call frame reconstrution.<br class="">
> > +//<br class="">
> > +// RUN: %clang -g -O2 -target x86_64-none-linux-gnu -ggdb -S -emit-llvm %s -o - | FileCheck %s -check-prefix=GDB<br class="">
> > +// GDB: !DISubprogram(name: "fn1"<br class="">
> > +//<br class="">
> > +// Do not emit a subprogram for extern decls when entry values are disabled and<br class="">
> > +// the tuning is not set to gdb.<br class="">
> > +//<br class="">
> > +// RUN: %clang -g -O2 -target x86_64-none-linux-gnu -gsce -S -emit-llvm %s -o - | FileCheck %s -check-prefix=SCE<br class="">
> > +// SCE-NOT: !DISubprogram(name: "fn1"<br class="">
> ><br class="">
> > extern int fn1(int a, int b);<br class="">
> ><br class="">
> ><br class="">
> > diff --git a/clang/test/CodeGenCXX/dbg-info-all-calls-described.cpp b/clang/test/CodeGenCXX/dbg-info-all-calls-described.cpp<br class="">
> > index 1cb2b6c609f3..667c2469b55e 100644<br class="">
> > --- a/clang/test/CodeGenCXX/dbg-info-all-calls-described.cpp<br class="">
> > +++ b/clang/test/CodeGenCXX/dbg-info-all-calls-described.cpp<br class="">
> > @@ -56,6 +56,7 @@<br class="">
> ><br class="">
> > // NO-ATTR-NOT: FlagAllCallsDescribed<br class="">
> ><br class="">
> > +// HAS-ATTR-DAG: DISubprogram(name: "declaration1", {{.*}}, flags: DIFlagPrototyped<br class="">
> > // HAS-ATTR-DAG: DISubprogram(name: "declaration2", {{.*}}, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition<br class="">
> > // HAS-ATTR-DAG: DISubprogram(name: "struct1", {{.*}}, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)<br class="">
> > // HAS-ATTR-DAG: DISubprogram(name: "struct1", {{.*}}, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition<br class="">
> ><br class="">
> > diff --git a/llvm/test/DebugInfo/X86/dwarf-callsite-related-attrs.ll b/llvm/test/DebugInfo/X86/dwarf-callsite-related-attrs.ll<br class="">
> > index c37ce1eb7fbe..33e06faba57b 100644<br class="">
> > --- a/llvm/test/DebugInfo/X86/dwarf-callsite-related-attrs.ll<br class="">
> > +++ b/llvm/test/DebugInfo/X86/dwarf-callsite-related-attrs.ll<br class="">
> > @@ -25,6 +25,14 @@<br class="">
> ><br class="">
> > @sink = global i32 0, align 4, !dbg !0<br class="">
> ><br class="">
> > +define void @__has_no_subprogram() {<br class="">
> > +entry:<br class="">
> > + %0 = load volatile i32, i32* @sink, align 4<br class="">
> > + %inc = add nsw i32 %0, 1<br class="">
> > + store volatile i32 %inc, i32* @sink, align 4<br class="">
> > + ret void<br class="">
> > +}<br class="">
> > +<br class="">
> > ; ASM: DW_TAG_subprogram<br class="">
> > ; ASM: DW_AT_call_all_calls<br class="">
> > ; OBJ: [[bat_sp:.*]]: DW_TAG_subprogram<br class="">
> > @@ -70,6 +78,7 @@ entry:<br class="">
> > ; OBJ: DW_AT_call_tail_call<br class="">
> > define void @_Z3foov() !dbg !25 {<br class="">
> > entry:<br class="">
> > + tail call void @__has_no_subprogram()<br class="">
> > tail call void @_Z3barv(), !dbg !26<br class="">
> > tail call void @_Z3batv(), !dbg !27<br class="">
> > tail call void @_Z3barv(), !dbg !26<br class="">
> ><br class="">
> ><br class="">
> ><br class="">
> > _______________________________________________<br class="">
> > llvm-commits mailing list<br class="">
> > <a href="mailto:llvm-commits@lists.llvm.org" target="_blank" rel="noreferrer" class="">llvm-commits@lists.llvm.org</a><br class="">
> > <a href="https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits" rel="noreferrer noreferrer" target="_blank" class="">https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits</a><br class="">
> _______________________________________________<br class="">
> llvm-commits mailing list<br class="">
> <a href="mailto:llvm-commits@lists.llvm.org" target="_blank" rel="noreferrer" class="">llvm-commits@lists.llvm.org</a><br class="">
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</blockquote></div>
_______________________________________________<br class="">llvm-commits mailing list<br class=""><a href="mailto:llvm-commits@lists.llvm.org" class="">llvm-commits@lists.llvm.org</a><br class=""><a href="https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits" class="">https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits</a><br class=""></div></blockquote></div><br class=""></div></div>_______________________________________________<br class="">llvm-commits mailing list<br class=""><a href="mailto:llvm-commits@lists.llvm.org" class="">llvm-commits@lists.llvm.org</a><br class="">https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits<br class=""></div></blockquote></div><br class=""></div></div></body></html>