DWARF: Generate the address lookup table from the DIE tree if .debug_aranges is not available.
Ported from LLDB.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139732 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/DebugInfo/DWARFCompileUnit.cpp b/lib/DebugInfo/DWARFCompileUnit.cpp
index 224ae92..d535df0 100644
--- a/lib/DebugInfo/DWARFCompileUnit.cpp
+++ b/lib/DebugInfo/DWARFCompileUnit.cpp
@@ -200,3 +200,40 @@
setDIERelations();
return DieArray.size();
}
+
+void DWARFCompileUnit::clearDIEs(bool keep_compile_unit_die) {
+ if (DieArray.size() > 1) {
+ // std::vectors never get any smaller when resized to a smaller size,
+ // or when clear() or erase() are called, the size will report that it
+ // is smaller, but the memory allocated remains intact (call capacity()
+ // to see this). So we need to create a temporary vector and swap the
+ // contents which will cause just the internal pointers to be swapped
+ // so that when "tmp_array" goes out of scope, it will destroy the
+ // contents.
+
+ // Save at least the compile unit DIE
+ std::vector<DWARFDebugInfoEntryMinimal> tmpArray;
+ DieArray.swap(tmpArray);
+ if (keep_compile_unit_die)
+ DieArray.push_back(tmpArray.front());
+ }
+}
+
+void
+DWARFCompileUnit::buildAddressRangeTable(DWARFDebugAranges *debug_aranges,
+ bool clear_dies_if_already_not_parsed){
+ // This function is usually called if there in no .debug_aranges section
+ // in order to produce a compile unit level set of address ranges that
+ // is accurate. If the DIEs weren't parsed, then we don't want all dies for
+ // all compile units to stay loaded when they weren't needed. So we can end
+ // up parsing the DWARF and then throwing them all away to keep memory usage
+ // down.
+ const bool clear_dies = extractDIEsIfNeeded(false) > 1;
+
+ DieArray[0].buildAddressRangeTable(this, debug_aranges);
+
+ // Keep memory down by clearing DIEs if this generate function
+ // caused them to be parsed.
+ if (clear_dies)
+ clearDIEs(true);
+}