[llvm] Add option to dump IR to files instead of stderr (PR #66412)

[Arthur Eubanks via llvm-commits]

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@@ -733,21 +822,31 @@ void PrintIRInstrumentation::printAfterPass(StringRef PassID, Any IR) {
       !shouldPrintAtPassNumber())
     return;
 
-  const Module *M;
-  std::string IRName;
-  StringRef StoredPassID;
-  std::tie(M, IRName, StoredPassID) = popModuleDesc(PassID);
+  auto [M, DumpIRFilename, IRName, StoredPassID] = popPassRunDescriptor(PassID);
   assert(StoredPassID == PassID && "mismatched PassID");
 
   if (!shouldPrintIR(IR) || !shouldPrintAfterPass(PassID))
     return;
 
-  dbgs() << "*** IR Dump "
-         << (shouldPrintAtPassNumber()
-                 ? StringRef(formatv("At {0}-{1}", CurrentPassNumber, PassID))
-                 : StringRef(formatv("After {0}", PassID)))
-         << " on " << IRName << " ***\n";
-  unwrapAndPrint(dbgs(), IR);
+  auto WriteIRToStream = [&](raw_ostream &Stream, const StringRef IRName) {
+    Stream << "; *** IR Dump "
+           << (shouldPrintAtPassNumber()
+                   ? StringRef(formatv("At {0}-{1}", CurrentPassNumber, PassID))
+                   : StringRef(formatv("After {0}", PassID)))
+           << " on " << IRName << " ***\n";
+    unwrapAndPrint(Stream, IR);
+  };
+
+  if (!irDumpDirectory().empty()) {
+    assert(!DumpIRFilename.empty() && "DumpIRFilename must not be empty and "
+                                      "should be set in printBeforePass");
+    DumpIRFilename += getFileSuffix(SuffixType::After);
+    llvm::raw_fd_ostream DumpIRFileStream{
+        prepareDumpIRFileDescriptor(DumpIRFilename), /* shouldClose */ true};
+    WriteIRToStream(DumpIRFileStream, IRName);
+  } else {
+    WriteIRToStream(dbgs(), IRName);
+  }
 }
 
 void PrintIRInstrumentation::printAfterPassInvalidated(StringRef PassID) {
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aeubanks wrote:

we should have some tests for invalidated IR

https://github.com/llvm/llvm-project/pull/66412