[llvm] [llvm-pdbutil] Avoid reading EC names from non-EC modules (PR #223253)

[via llvm-commits]

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@@ -503,15 +503,21 @@ Error DumpOutputStyle::dumpModules() {
                      Desc.getModuleStreamIndex(), Desc.getNumberOfFiles(),
                      Desc.hasECInfo());
 
-        auto PdbPathOrErr = Stream.getECName(Desc.getPdbFilePathNameIndex());
-        if (!PdbPathOrErr)
-          return PdbPathOrErr.takeError();
-        StringRef PdbFilePath = *PdbPathOrErr;
-
-        auto SrcPathOrErr = Stream.getECName(Desc.getSourceFileNameIndex());
-        if (!SrcPathOrErr)
-          return SrcPathOrErr.takeError();
-        StringRef SrcFilePath = *SrcPathOrErr;
+        StringRef PdbFilePath;
+        if (Desc.getPdbFilePathNameIndex() != 0) {
+          auto PdbPathOrErr = Stream.getECName(Desc.getPdbFilePathNameIndex());
+          if (!PdbPathOrErr)
+            return PdbPathOrErr.takeError();
+          PdbFilePath = *PdbPathOrErr;
+        }
+
+        StringRef SrcFilePath;
+        if (Desc.getSourceFileNameIndex()) {
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Nerixyz wrote:

You can merge this `if` with the one above.

https://github.com/llvm/llvm-project/pull/223253