[llvm] r298518 - Fix PR32298 by adding an early exit to getFrameIndexExprs().

[Adrian Prantl via llvm-commits]

Author: adrian
Date: Wed Mar 22 11:50:16 2017
New Revision: 298518

URL: http://llvm.org/viewvc/llvm-project?rev=298518&view=rev
Log:
Fix PR32298 by adding an early exit to getFrameIndexExprs().

Also add an assertion for the case that there are multiple FI
expressions with a DW_OP_LLVM_fragment; which should violate internal
constraints in DbgVariable.

Added:
    llvm/trunk/test/DebugInfo/X86/single-fi.ll
Modified:
    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=298518&r1=298517&r2=298518&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Wed Mar 22 11:50:16 2017
@@ -199,6 +199,12 @@ const DIType *DbgVariable::getType() con
 }
 
 ArrayRef<DbgVariable::FrameIndexExpr> DbgVariable::getFrameIndexExprs() const {
+  if (FrameIndexExprs.size() == 1)
+    return FrameIndexExprs;
+
+  assert(all_of(FrameIndexExprs,
+                [](const FrameIndexExpr &A) { return A.Expr->isFragment(); }) &&
+         "multiple FI expressions without DW_OP_LLVM_fragment");
   std::sort(FrameIndexExprs.begin(), FrameIndexExprs.end(),
             [](const FrameIndexExpr &A, const FrameIndexExpr &B) -> bool {
               return A.Expr->getFragmentInfo()->OffsetInBits <

Added: llvm/trunk/test/DebugInfo/X86/single-fi.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/single-fi.ll?rev=298518&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/single-fi.ll (added)
+++ llvm/trunk/test/DebugInfo/X86/single-fi.ll Wed Mar 22 11:50:16 2017
@@ -0,0 +1,40 @@
+; RUN: %llc_dwarf -march=x86-64 -o - %s -filetype=obj \
+; RUN:   | llvm-dwarfdump -debug-dump=info - | FileCheck %s
+; A single FI location. This used to trigger an assertion in debug libstdc++.
+; CHECK: DW_TAG_formal_parameter
+;                                          fbreg -8
+; CHECK-NEXT: DW_AT_location {{.*}} (<0x2> 91 78 )
+; CHECK-NEXT: DW_AT_name {{.*}} "dipsy"
+define void @tinkywinky(i8* %dipsy) !dbg !6 {
+entry:
+  %dipsy.addr = alloca i8*
+  store i8* %dipsy, i8** %dipsy.addr
+  call void @llvm.dbg.declare(metadata i8** %dipsy.addr, metadata !12, metadata
+!13), !dbg !14
+  ret void, !dbg !15
+}
+
+declare void @llvm.dbg.declare(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4}
+!llvm.ident = !{!5}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 5.0.0 (trunk 297917) (llvm/trunk 297929)", isOptimized: false,
+runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "teletubbies.c", directory: "/home/davide/work/llvm/build-clang/bin")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{!"clang version 5.0.0 (trunk 297917) (llvm/trunk 297929)"}
+!6 = distinct !DISubprogram(name: "tinkywinky", scope: !1, file: !1, line: 1, type: !7, isLocal: false, isDefinition: true, scopeLine: 1, flags:
+DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
+!7 = !DISubroutineType(types: !8)
+!8 = !{null, !9}
+!9 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !10, size: 64)
+!10 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !11)
+!11 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!12 = !DILocalVariable(name: "dipsy", arg: 1, scope: !6, file: !1, line: 1, type: !9)
+!13 = !DIExpression()
+!14 = !DILocation(line: 1, column: 29, scope: !6)
+!15 = !DILocation(line: 1, column: 37, scope: !6)