Add frontend options to write SIL and LLVM IR as additional compilation output.

This change introduces two new frontend options that enable writing
intermediate representations as additional outputs during compilation:

-sil-output-path <path>: Outputs SIL to the specified path
-ir-output-path <path>: Outputs LLVM IR to the specified path

These options can be useful for debugging and analysis tools
workflows that need access to intermediate compilation artifacts
without requiring separate compiler invocations.

rdar://160297898

Author: rjmansfield

include/swift/Basic/SupplementaryOutputPaths.def

@@ -166,3 +166,9 @@ OUTPUT(YAMLOptRecordPath, TY_YAMLOptRecord)
 
 /// The output path for bitstream optimization record file.
 OUTPUT(BitstreamOptRecordPath, TY_BitstreamOptRecord)
+
+/// The output path to which we should output SIL as extra compilation output.
+OUTPUT(SILOutputPath, TY_SIL)
+
+/// The output path to which we should output LLVM IR as extra compilation output.
+OUTPUT(LLVMIROutputPath, TY_LLVM_IR)

include/swift/Option/FrontendOptions.td

@@ -63,6 +63,14 @@ def emit_module_semantic_info_path
   : Separate<["-"], "emit-module-semantic-info-path">, MetaVarName<"<path>">,
     HelpText<"Output semantic info of current module to <path>">;
 
+def sil_output_path
+  : Separate<["-"], "sil-output-path">, MetaVarName<"<path>">,
+    HelpText<"Output SIL to <path> as additional output during compilation">;
+
+def ir_output_path
+  : Separate<["-"], "ir-output-path">, MetaVarName<"<path>">,
+    HelpText<"Output LLVM IR to <path> as additional output during compilation">;
+
 def diagnostic_documentation_path
   : Separate<["-"], "diagnostic-documentation-path">, MetaVarName<"<path>">,
   HelpText<"Path to diagnostic documentation resources">;
@@ -266,7 +274,7 @@ def serialize_dependency_scan_cache : Flag<["-"], "serialize-dependency-scan-cac
 
 def reuse_dependency_scan_cache : Flag<["-"], "load-dependency-scan-cache">,
    HelpText<"For performing a dependency scan, deserialize the scanner's internal state from a prior scan.">;
-   
+
 def validate_prior_dependency_scan_cache : Flag<["-"], "validate-prior-dependency-scan-cache">,
    HelpText<"For performing a dependency scan with a prior scanner state, validate module dependencies.">;
 

lib/Driver/ToolChains.cpp

@@ -943,6 +943,12 @@ void ToolChain::JobContext::addFrontendSupplementaryOutputArguments(
   addOutputsOfType(arguments, Output, Args,
                    file_types::TY_SwiftModuleSummaryFile,
                    "-emit-module-summary-path");
+
+  // Add extra output paths for SIL and LLVM IR
+  addOutputsOfType(arguments, Output, Args, file_types::TY_SIL,
+                   "-sil-output-path");
+  addOutputsOfType(arguments, Output, Args, file_types::TY_LLVM_IR,
+                   "-ir-output-path");
 }
 
 ToolChain::InvocationInfo
@@ -1226,6 +1232,12 @@ ToolChain::constructInvocation(const MergeModuleJobAction &job,
   addOutputsOfType(Arguments, context.Output, context.Args, file_types::TY_TBD,
                    "-emit-tbd-path");
 
+  // Add extra output paths for SIL and LLVM IR
+  addOutputsOfType(Arguments, context.Output, context.Args, file_types::TY_SIL,
+                   "-sil-output-path");
+  addOutputsOfType(Arguments, context.Output, context.Args, file_types::TY_LLVM_IR,
+                   "-ir-output-path");
+
   context.Args.AddLastArg(Arguments, options::OPT_emit_symbol_graph);
   context.Args.AddLastArg(Arguments, options::OPT_emit_symbol_graph_dir);
   context.Args.AddLastArg(Arguments, options::OPT_include_spi_symbols);

lib/Frontend/ArgsToFrontendOutputsConverter.cpp

@@ -380,12 +380,16 @@ SupplementaryOutputPathsComputer::getSupplementaryOutputPathsFromArguments()
       options::OPT_emit_module_semantic_info_path);
   auto optRecordOutput = getSupplementaryFilenamesFromArguments(
       options::OPT_save_optimization_record_path);
+  auto silOutput = getSupplementaryFilenamesFromArguments(
+      options::OPT_sil_output_path);
+  auto irOutput = getSupplementaryFilenamesFromArguments(
+      options::OPT_ir_output_path);
   if (!clangHeaderOutput || !moduleOutput || !moduleDocOutput ||
       !dependenciesFile || !referenceDependenciesFile ||
       !serializedDiagnostics || !loadedModuleTrace || !TBD ||
       !moduleInterfaceOutput || !privateModuleInterfaceOutput || !packageModuleInterfaceOutput ||
       !moduleSourceInfoOutput || !moduleSummaryOutput || !abiDescriptorOutput ||
-      !moduleSemanticInfoOutput || !optRecordOutput) {
+      !moduleSemanticInfoOutput || !optRecordOutput || !silOutput || !irOutput) {
     return std::nullopt;
   }
   std::vector<SupplementaryOutputPaths> result;
@@ -413,6 +417,8 @@ SupplementaryOutputPathsComputer::getSupplementaryOutputPathsFromArguments()
     sop.ModuleSemanticInfoOutputPath = (*moduleSemanticInfoOutput)[i];
     sop.YAMLOptRecordPath = (*optRecordOutput)[i];
     sop.BitstreamOptRecordPath = (*optRecordOutput)[i];
+    sop.SILOutputPath = (*silOutput)[i];
+    sop.LLVMIROutputPath = (*irOutput)[i];
     result.push_back(sop);
   }
   return result;
@@ -613,6 +619,9 @@ SupplementaryOutputPathsComputer::computeOutputPathsForOneInput(
       file_types::TY_BitstreamOptRecord, "",
       defaultSupplementaryOutputPathExcludingExtension);
 
+  auto SILOutputPath = pathsFromArguments.SILOutputPath;
+  auto LLVMIROutputPath = pathsFromArguments.LLVMIROutputPath;
+
   SupplementaryOutputPaths sop;
   sop.ClangHeaderOutputPath = clangHeaderOutputPath;
   sop.ModuleOutputPath = moduleOutputPath;
@@ -635,6 +644,8 @@ SupplementaryOutputPathsComputer::computeOutputPathsForOneInput(
   sop.ModuleSemanticInfoOutputPath = ModuleSemanticInfoOutputPath;
   sop.YAMLOptRecordPath = YAMLOptRecordPath;
   sop.BitstreamOptRecordPath = bitstreamOptRecordPath;
+  sop.SILOutputPath = SILOutputPath;
+  sop.LLVMIROutputPath = LLVMIROutputPath;
   return sop;
 }
 
@@ -752,7 +763,9 @@ SupplementaryOutputPathsComputer::readSupplementaryOutputFileMap() const {
                                options::OPT_emit_private_module_interface_path,
                                options::OPT_emit_package_module_interface_path,
                                options::OPT_emit_module_source_info_path,
-                               options::OPT_emit_tbd_path)) {
+                               options::OPT_emit_tbd_path,
+                               options::OPT_sil_output_path,
+                               options::OPT_ir_output_path)) {
     Diags.diagnose(SourceLoc(),
                    diag::error_cannot_have_supplementary_outputs,
                    A->getSpelling(), "-supplementary-output-file-map");

lib/FrontendTool/FrontendTool.cpp

@@ -2100,6 +2100,13 @@ static bool performCompileStepsPostSILGen(CompilerInstance &Instance,
   if (Action == FrontendOptions::ActionType::EmitSIL)
     return writeSIL(*SM, PSPs, Instance, Invocation.getSILOptions());
 
+  // Write extra SIL output if requested
+  if (!PSPs.SupplementaryOutputs.SILOutputPath.empty()) {
+    if (writeSIL(*SM, Instance.getMainModule(), Invocation.getSILOptions(),
+                 PSPs.SupplementaryOutputs.SILOutputPath, Instance.getOutputBackend()))
+      return true;
+  }
+
   assert(Action >= FrontendOptions::ActionType::Immediate &&
          "All actions not requiring IRGen must have been handled!");
   assert(Action != FrontendOptions::ActionType::REPL &&
@@ -2144,6 +2151,17 @@ static bool performCompileStepsPostSILGen(CompilerInstance &Instance,
       generateIR(IRGenOpts, Invocation.getTBDGenOptions(), std::move(SM), PSPs,
                  OutputFilename, MSF, HashGlobal, ParallelOutputFilenames);
 
+  // Write extra LLVM IR output if requested
+  if (IRModule && !PSPs.SupplementaryOutputs.LLVMIROutputPath.empty()) {
+    if (withOutputPath(Instance.getDiags(), Instance.getOutputBackend(),
+                       PSPs.SupplementaryOutputs.LLVMIROutputPath,
+                       [&](raw_ostream &out) -> bool {
+                         IRModule.getModule()->print(out, nullptr);
+                         return false;
+                       }))
+      return true;
+  }
+
   // Cancellation check after IRGen.
   if (Instance.isCancellationRequested())
     return true;

test/Driver/ir-output-path.swift

@@ -0,0 +1,14 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -emit-object -ir-output-path %t/test.ll %s -o %t/test.o
+// RUN: %FileCheck -input-file %t/test.ll %s --check-prefix=IR-CHECK
+// RUN: test -f %t/test.o
+
+// Test that -ir-output-path produces LLVM IR output alongside normal compilation
+
+func testFunction() -> Int {
+    return 42
+}
+
+let _ = testFunction()
+
+// IR-CHECK: @"$s4test0A8FunctionSiyF"

test/Driver/output-file-map-sil-ir.swift

@@ -0,0 +1,17 @@
+// RUN: %empty-directory(%t)
+// RUN: echo '"%s": { "sil": "%t/test.sil", "llvm-ir": "%t/test.ll" }' > %t/output-file-map.json
+// RUN: %target-swift-frontend -emit-object -supplementary-output-file-map %t/output-file-map.json %s -o %t/test.o -module-name test
+// RUN: %FileCheck -input-file %t/test.sil %s --check-prefix=SIL-CHECK
+// RUN: %FileCheck -input-file %t/test.ll %s --check-prefix=IR-CHECK
+// RUN: test -f %t/test.o
+
+// Test that SIL and IR files can be requested via output file map
+
+func testFunction() -> Int {
+    return 42
+}
+
+let _ = testFunction()
+
+// SIL-CHECK: sil hidden @$s4test0A8FunctionSiyF : $@convention(thin) () -> Int
+// IR-CHECK: @"$s4test0A8FunctionSiyF"

test/Driver/sil-output-path.swift

@@ -0,0 +1,12 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -emit-object -sil-output-path %t/test.sil %s -o %t/test.o
+// RUN: %FileCheck -input-file %t/test.sil %s --check-prefix=SIL-CHECK
+// RUN: test -f %t/test.o
+
+// Test that -sil-output-path produces SIL output alongside normal compilation
+
+func testFunction() -> Int {
+    return 42
+}
+
+// SIL-CHECK: sil hidden @$s4test0A8FunctionSiyF : $@convention(thin) () -> Int