[DWARF] check whether the DIE is valid before querying for information

paulsemel · paulsemel · commit 0c27bc2e1fe3 · 2019-04-03T17:13:45.000Z
Differential Revision: https://reviews.llvm.org/D60147 llvm-svn: 357607
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -925,6 +925,9 @@ DWARFContext::DIEsForAddress DWARFContext::getDIEsForAddress(uint64_t Address) {
     DWARFDie DIE = Worklist.back();
     Worklist.pop_back();
 
+    if (!DIE.isValid())
+      continue;
+
     if (DIE.getTag() == DW_TAG_lexical_block &&
         DIE.addressRangeContainsAddress(Address)) {
       Result.BlockDIE = DIE;
diff --git a/llvm/test/DebugInfo/dwarfdump-bad-lookup-address.test b/llvm/test/DebugInfo/dwarfdump-bad-lookup-address.test
@@ -0,0 +1,11 @@
+#RUN: llvm-dwarfdump -lookup 1161 %p/Inputs/dwarfdump-test.macho-i386.o | FileCheck %s
+
+// When we pass an address to getDIEsFromAddress that doesn't belong to any DIE
+// (only to a CU), this function is triggering an assert, which is not the
+// intended behavior (as the address still belongs to a CU).
+
+#CHECK: DW_TAG_compile_unit
+#CHECK-NEXT:   DW_AT_producer{{.*}}"clang version 3.6.2 (tags/RELEASE_362/final)"
+#CHECK-NEXT:   DW_AT_language{{.*}}DW_LANG_C_plus_plus
+#CHECK-NEXT:   DW_AT_name{{.*}}"dwarfdump-test.cc"
+#CHECK-NOT:    DW_TAG
