[NFC] Dump DEBUG_VERIFY_GENERATED_CODE

rdar://54708850

Author: CodaFi

lib/IRGen/IRGen.cpp

@@ -480,22 +480,6 @@ bool swift::performLLVM(const IRGenOptions &Opts,
                         const version::Version &effectiveLanguageVersion,
                         StringRef OutputFilename,
                         UnifiedStatsReporter *Stats) {
-#ifndef NDEBUG
-// FIXME: Some bots are failing. See: rdar://54708850
-//#define DEBUG_VERIFY_GENERATED_CODE
-#endif
-
-#ifdef DEBUG_VERIFY_GENERATED_CODE
-  // To check that we only skip generating code when it would have no effect, in
-  // assertion builds we still generate the code, but write it into a temporary
-  // file that we compare to the original file.
-
-  /// The OutputFilename originally passed to us, if we are generating code for
-  /// an assertion. Empty if not.
-  StringRef OriginalOutputFilename = "";
-  /// Scratch buffer for temporary file's name.
-  SmallString<64> AssertScratch;
-#endif
 
   if (Opts.UseIncrementalLLVMCodeGen && HashGlobal) {
     // Check if we can skip the llvm part of the compilation if we have an
@@ -518,24 +502,7 @@ bool swift::performLLVM(const IRGenOptions &Opts,
         !Opts.PrintInlineTree &&
         !needsRecompile(OutputFilename, HashData, HashGlobal, DiagMutex)) {
       // The llvm IR did not change. We don't need to re-create the object file.
-#ifndef DEBUG_VERIFY_GENERATED_CODE
       return false;
-#else
-      // ...but we're in an asserts build, so we want to check that assumption.
-      auto AssertSuffix = llvm::sys::path::filename(OutputFilename);
-
-      auto EC = llvm::sys::fs::createTemporaryFile("assert", AssertSuffix,
-                                                   AssertScratch);
-      if (EC) {
-        diagnoseSync(Diags, DiagMutex,
-                     SourceLoc(), diag::error_opening_output,
-                     AssertScratch, EC.message());
-        return true;
-      }
-
-      OriginalOutputFilename = OutputFilename;
-      OutputFilename = AssertScratch;
-#endif
     }
 
     // Store the hash in the global variable so that it is written into the
@@ -622,42 +589,6 @@ bool swift::performLLVM(const IRGenOptions &Opts,
     if (DiagMutex)
       DiagMutex->unlock();
   }
-#ifdef DEBUG_VERIFY_GENERATED_CODE
-  if (!OriginalOutputFilename.empty()) {
-    // We're done changing the file; make sure it's saved before we compare.
-    RawOS->close();
-
-    auto result =
-        swift::areFilesDifferent(OutputFilename, OriginalOutputFilename,
-                                 /*allowDestinationErrors=*/false);
-
-    if (!result)
-      // File system error.
-      llvm::report_fatal_error(
-          Twine("Error comparing files: ") + result.getError().message()
-      );
-
-    switch (*result) {
-    case FileDifference::DifferentContents:
-      llvm::report_fatal_error(
-          "Swift skipped an LLVM compile that would have changed output; pass "
-          "-Xfrontend -disable-incremental-llvm-codegen to work around this bug"
-      );
-      // Note for future debuggers: If you see this error, either you changed
-      // LLVM and need to clean your build folder to rebuild everything with it,
-      // or IRGenOptions::writeLLVMCodeGenOptionsTo() doesn't account for a flag
-      // that changed LLVM's output between this compile and the previous one.
-
-    case FileDifference::SameContents:
-      // Removing the file is best-effort.
-      (void)llvm::sys::fs::remove(OutputFilename);
-      break;
-
-    case FileDifference::IdenticalFile:
-      llvm_unreachable("one of these should be a temporary file");
-    }
-  }
-#endif
 
   return false;
 }