[llvm] [PDB] Fix and simplify module index lookup (PR #179869)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-debuginfo

@llvm/pr-subscribers-platform-windows

Author: Haohai Wen (HaohaiWen)

<details>
<summary>Changes</summary>

The range returned by IntervalMap::find is only guranteed to end after
address queried. We have to check whether queried address is inside this
range.

---
Full diff: https://github.com/llvm/llvm-project/pull/179869.diff


1 Files Affected:

- (modified) llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp (+6-10) 


``````````diff
diff --git a/llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp b/llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp
index 49674b4c32de0..cfa3328f5f2d6 100644
--- a/llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp
@@ -410,20 +410,16 @@ uint64_t NativeSession::getVAFromSectOffset(uint32_t Section,
 bool NativeSession::moduleIndexForVA(uint64_t VA, uint16_t &ModuleIndex) const {
   ModuleIndex = 0;
   auto Iter = AddrToModuleIndex.find(VA);
-  if (Iter == AddrToModuleIndex.end())
-    return false;
-  ModuleIndex = Iter.value();
-  return true;
+  if (Iter.valid() && !IMap::KeyTraits::startLess(VA, Iter.start())) {
+    ModuleIndex = Iter.value();
+    return true;
+  }
+  return false;
 }
 
 bool NativeSession::moduleIndexForSectOffset(uint32_t Sect, uint32_t Offset,
                                              uint16_t &ModuleIndex) const {
-  ModuleIndex = 0;
-  auto Iter = AddrToModuleIndex.find(getVAFromSectOffset(Sect, Offset));
-  if (Iter == AddrToModuleIndex.end())
-    return false;
-  ModuleIndex = Iter.value();
-  return true;
+  return moduleIndexForVA(getVAFromSectOffset(Sect, Offset), ModuleIndex);
 }
 
 void NativeSession::parseSectionContribs() {

``````````

</details>


https://github.com/llvm/llvm-project/pull/179869