[DebugInfo] Make children iterator bidirectional
Make the DIE iterator bidirectional so we can move to the previous
sibling of a DIE.
Differential revision: https://reviews.llvm.org/D49173
llvm-svn: 336823
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
index 6b7970d..7581575 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -584,6 +584,24 @@
return DWARFDie();
}
+DWARFDie DWARFUnit::getPreviousSibling(const DWARFDebugInfoEntry *Die) {
+ if (!Die)
+ return DWARFDie();
+ uint32_t Depth = Die->getDepth();
+ // Unit DIEs always have a depth of zero and never have siblings.
+ if (Depth == 0)
+ return DWARFDie();
+
+ // Find the previous DIE whose depth is the same as the Die's depth.
+ for (size_t I = getDIEIndex(Die) - 1; I >= 0; --I) {
+ if (DieArray[I].getDepth() == Depth - 1)
+ return DWARFDie();
+ if (DieArray[I].getDepth() == Depth)
+ return DWARFDie(this, &DieArray[I]);
+ }
+ return DWARFDie();
+}
+
DWARFDie DWARFUnit::getFirstChild(const DWARFDebugInfoEntry *Die) {
if (!Die->hasChildren())
return DWARFDie();
@@ -595,6 +613,21 @@
return DWARFDie(this, &DieArray[I]);
}
+DWARFDie DWARFUnit::getLastChild(const DWARFDebugInfoEntry *Die) {
+ if (!Die->hasChildren())
+ return DWARFDie();
+
+ uint32_t Depth = Die->getDepth();
+ for (size_t I = getDIEIndex(Die) + 1, EndIdx = DieArray.size(); I < EndIdx;
+ ++I) {
+ if (DieArray[I].getDepth() == Depth + 1 &&
+ DieArray[I].getTag() == dwarf::DW_TAG_null)
+ return DWARFDie(this, &DieArray[I]);
+ assert(DieArray[I].getDepth() > Depth && "Not processing children?");
+ }
+ return DWARFDie();
+}
+
const DWARFAbbreviationDeclarationSet *DWARFUnit::getAbbreviations() const {
if (!Abbrevs)
Abbrevs = Abbrev->getAbbreviationDeclarationSet(Header.getAbbrOffset());