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

[via llvm-commits]

llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-debuginfo

Author: oltolm (oltolm)

<details>
<summary>Changes</summary>

The module dumper resolves the PDB and source file name indices for every module, even when the module does not contain Edit and Continue information. If the DBI stream has no EC names table, `dump --modules` fails with:

  Unexpected error processing modules: Stream Error: The stream is too short
  to perform the requested operation.

Only resolve and print the EC names when the module's EC flag is set.

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


1 Files Affected:

- (modified) llvm/tools/llvm-pdbutil/DumpOutputStyle.cpp (+15-13) 


``````````diff
diff --git a/llvm/tools/llvm-pdbutil/DumpOutputStyle.cpp b/llvm/tools/llvm-pdbutil/DumpOutputStyle.cpp
index feb23ca2083d5..c1d82d0810daf 100644
--- a/llvm/tools/llvm-pdbutil/DumpOutputStyle.cpp
+++ b/llvm/tools/llvm-pdbutil/DumpOutputStyle.cpp
@@ -503,19 +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;
-
-        P.formatLine("pdb file ni: {0} `{1}`, src file ni: {2} `{3}`",
-                     Desc.getPdbFilePathNameIndex(), PdbFilePath,
-                     Desc.getSourceFileNameIndex(), SrcFilePath);
+        if (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;
+
+          P.formatLine("pdb file ni: {0} `{1}`, src file ni: {2} `{3}`",
+                       Desc.getPdbFilePathNameIndex(), PdbFilePath,
+                       Desc.getSourceFileNameIndex(), SrcFilePath);
+        }
         return Error::success();
       });
 }

``````````

</details>


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