[PATCH] D148439: [clang-rename] Exit gracefully when no input provided

[Shivam Gupta via Phabricator via cfe-commits]

xgupta added inline comments.


================
Comment at: clang/tools/clang-rename/ClangRename.cpp:233
+      if (!Entry) {
+        errs() << "clang-rename: input file does not exist.\n";
+        return 1;
----------------
kbobyrev wrote:
> It is worth including the filename in the error message, otherwise it won't be possible to understand which one is missing (there can be multiple IIRC, right?).
> 
> Also, it's better to put this check to the top of main, where the `OP` if first declared, since this is a sanity check and we want to fail if the inputs are corrupted.
Thanks for the suggestion, I agree, I updated the error message regarding the filename. 

But I am not sure running a similar `for` loop again should be the correct way.
So just sharing the diff before committing, WDYT -

```
diff --git a/clang/tools/clang-rename/ClangRename.cpp b/clang/tools/clang-rename/ClangRename.cpp
index 24c9d8521..bc777cc01 100644
--- a/clang/tools/clang-rename/ClangRename.cpp
+++ b/clang/tools/clang-rename/ClangRename.cpp
@@ -106,6 +106,17 @@ int main(int argc, const char **argv) {
   }
   tooling::CommonOptionsParser &OP = ExpectedParser.get();
 
+  auto Files = OP.getSourcePathList();
+  tooling::RefactoringTool Tool(OP.getCompilations(), Files);
+    auto &FileMgr = Tool.getFiles();
+      for (const auto &File : Files) {
+      auto Entry = FileMgr.getFile(File);
+      if (!Entry) {
+        errs() << "clang-rename: " << File << " does not exist.\n";
+        return 1;
+      }
+    }
+
   if (!Input.empty()) {
     // Populate QualifiedNames and NewNames from a YAML file.
     ErrorOr<std::unique_ptr<MemoryBuffer>> Buffer =
@@ -162,8 +173,6 @@ int main(int argc, const char **argv) {
     return 1;
   }
 
-  auto Files = OP.getSourcePathList();
-  tooling::RefactoringTool Tool(OP.getCompilations(), Files);
   tooling::USRFindingAction FindingAction(SymbolOffsets, QualifiedNames, Force);
   Tool.run(tooling::newFrontendActionFactory(&FindingAction).get());
   const std::vector<std::vector<std::string>> &USRList =
@@ -222,7 +231,6 @@ int main(int argc, const char **argv) {
     DiagnosticsEngine Diagnostics(
         IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs()), &*DiagOpts,
         &DiagnosticPrinter, false);
-    auto &FileMgr = Tool.getFiles();
     SourceManager Sources(Diagnostics, FileMgr);
     Rewriter Rewrite(Sources, DefaultLangOptions);
 
```


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D148439/new/

https://reviews.llvm.org/D148439