[clang-tools-extra] [clang-doc] Refactor error handling to use ExitOnError (PR #141699)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-tools-extra

Author: Samarth Narang (snarang181)

<details>
<summary>Changes</summary>

This patch refactors the clang-doc tool to replace manual error handling (e.g., checking error codes and calling exit()) with llvm::ExitOnError.

Addresses:
- https://github.com/llvm/llvm-project/issues/140085

Benefits:
- Improves maintainability by reducing boilerplate error checks
- Provides consistent error handling behavior across the tool
- Aligns clang-doc error handling with modern LLVM patterns

No functional or user-facing behavior changes are expected.

- Ran `ninja check-clang-tools` to ensure no regressions

Please let me know if additional reviewers or tests are needed!


---
Full diff: https://github.com/llvm/llvm-project/pull/141699.diff


1 Files Affected:

- (modified) clang-tools-extra/clang-doc/tool/ClangDocMain.cpp (+10-22) 


``````````diff
diff --git a/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp b/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp
index 8e8f7053a8f87..e7efa4b15d80f 100644
--- a/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp
+++ b/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp
@@ -49,6 +49,7 @@
 using namespace clang::ast_matchers;
 using namespace clang::tooling;
 using namespace clang;
+static llvm::ExitOnError ExitOnErr;
 
 static llvm::cl::extrahelp CommonHelp(CommonOptionsParser::HelpMessage);
 static llvm::cl::OptionCategory ClangDocCategory("clang-doc options");
@@ -236,6 +237,8 @@ int main(int argc, const char **argv) {
   llvm::sys::PrintStackTraceOnErrorSignal(argv[0]);
   std::error_code OK;
 
+  ExitOnErr.setBanner("clang-doc error: ");
+
   const char *Overview =
       R"(Generates documentation from source code and comments.
 
@@ -259,11 +262,7 @@ Example usage for a project using a compile commands database:
   // Fail early if an invalid format was provided.
   std::string Format = getFormatString();
   llvm::outs() << "Emiting docs in " << Format << " format.\n";
-  auto G = doc::findGeneratorByName(Format);
-  if (!G) {
-    llvm::errs() << toString(G.takeError()) << "\n";
-    return 1;
-  }
+  auto G = ExitOnErr(doc::findGeneratorByName(Format));
 
   ArgumentsAdjuster ArgAdjuster;
   if (!DoxygenOnly)
@@ -284,10 +283,7 @@ Example usage for a project using a compile commands database:
       {UserStylesheets.begin(), UserStylesheets.end()}};
 
   if (Format == "html") {
-    if (auto Err = getHtmlAssetFiles(argv[0], CDCtx)) {
-      llvm::errs() << toString(std::move(Err)) << "\n";
-      return 1;
-    }
+    ExitOnErr(getHtmlAssetFiles(argv[0], CDCtx));
   }
 
   // Mapping phase
@@ -300,7 +296,7 @@ Example usage for a project using a compile commands database:
                       "these files and continue:\n"
                    << toString(std::move(Err)) << "\n";
     else {
-      llvm::errs() << toString(std::move(Err)) << "\n";
+      ExitOnErr(std::move(Err));
       return 1;
     }
   }
@@ -371,22 +367,14 @@ Example usage for a project using a compile commands database:
   sortUsrToInfo(USRToInfo);
 
   // Ensure the root output directory exists.
-  if (std::error_code Err = llvm::sys::fs::create_directories(OutDirectory);
-      Err != std::error_code()) {
-    llvm::errs() << "Failed to create directory '" << OutDirectory << "'\n";
-    return 1;
-  }
+  ExitOnErr(
+      llvm::errorCodeToError(llvm::sys::fs::create_directories(OutDirectory)));
 
   // Run the generator.
   llvm::outs() << "Generating docs...\n";
-  if (auto Err =
-          G->get()->generateDocs(OutDirectory, std::move(USRToInfo), CDCtx)) {
-    llvm::errs() << toString(std::move(Err)) << "\n";
-    return 1;
-  }
-
+  ExitOnErr(G->generateDocs(OutDirectory, std::move(USRToInfo), CDCtx));
   llvm::outs() << "Generating assets for docs...\n";
-  Err = G->get()->createResources(CDCtx);
+  Err = G->createResources(CDCtx);
   if (Err) {
     llvm::outs() << "warning: " << toString(std::move(Err)) << "\n";
   }

``````````

</details>


https://github.com/llvm/llvm-project/pull/141699