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Oct 10, 2025
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Add frontend options to write SIL and LLVM IR as additional compilation output #84392

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4 changes: 4 additions & 0 deletions include/swift/AST/IRGenRequests.h
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Original file line number Diff line number Diff line change
Expand Up @@ -151,6 +151,7 @@ struct IRGenDescriptor {
const PrimarySpecificPaths &PSPs;
StringRef PrivateDiscriminator;
ArrayRef<std::string> parallelOutputFilenames;
ArrayRef<std::string> parallelIROutputFilenames;
llvm::GlobalVariable **outModuleHash;
llvm::raw_pwrite_stream *out = nullptr;

Expand Down Expand Up @@ -188,6 +189,7 @@ struct IRGenDescriptor {
PSPs,
PrivateDiscriminator,
{},
{},
outModuleHash};
}

Expand All @@ -197,6 +199,7 @@ struct IRGenDescriptor {
std::unique_ptr<SILModule> &&SILMod, StringRef ModuleName,
const PrimarySpecificPaths &PSPs, SymsToEmit symsToEmit = std::nullopt,
ArrayRef<std::string> parallelOutputFilenames = {},
ArrayRef<std::string> parallelIROutputFilenames = {},
llvm::GlobalVariable **outModuleHash = nullptr) {
return IRGenDescriptor{M,
symsToEmit,
Expand All @@ -209,6 +212,7 @@ struct IRGenDescriptor {
PSPs,
"",
parallelOutputFilenames,
parallelIROutputFilenames,
outModuleHash};
}

Expand Down
6 changes: 6 additions & 0 deletions include/swift/Basic/SupplementaryOutputPaths.def
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Expand Up @@ -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)
3 changes: 2 additions & 1 deletion include/swift/FrontendTool/FrontendTool.h
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Expand Up @@ -79,7 +79,8 @@ int performFrontend(ArrayRef<const char *> args,
FrontendObserver *observer = nullptr);

bool performCompileStepsPostSema(CompilerInstance &Instance, int &ReturnValue,
FrontendObserver *observer);
FrontendObserver *observer,
ArrayRef<const char *> CommandLineArgs);

} // namespace swift

Expand Down
14 changes: 13 additions & 1 deletion include/swift/Option/FrontendOptions.td
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Expand Up @@ -63,6 +63,18 @@ 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>">,
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Since these are being modeled as additional supplementary outputs they also need a flag SupplementaryOutput:

swift/include/swift/Option/Options.td

Line 58 in 391a18d

def SupplementaryOutput : OptionFlag;

Flags<[FrontendOption, NoInteractiveOption, ArgumentIsPath,
SupplementaryOutput, CacheInvariant]>,
HelpText<"Output SIL to <path> as additional output during compilation">;

def ir_output_path
: Separate<["-"], "ir-output-path">, MetaVarName<"<path>">,
Flags<[FrontendOption, NoInteractiveOption, ArgumentIsPath,
SupplementaryOutput, CacheInvariant]>,
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">;
Expand Down Expand Up @@ -266,7 +278,7 @@ 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.">;

Expand Down
5 changes: 3 additions & 2 deletions include/swift/Subsystems.h
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Expand Up @@ -250,9 +250,10 @@ namespace swift {
GeneratedModule
performIRGeneration(ModuleDecl *M, const IRGenOptions &Opts,
const TBDGenOptions &TBDOpts,
std::unique_ptr<SILModule> SILMod,
StringRef ModuleName, const PrimarySpecificPaths &PSPs,
std::unique_ptr<SILModule> SILMod, StringRef ModuleName,
const PrimarySpecificPaths &PSPs,
ArrayRef<std::string> parallelOutputFilenames,
ArrayRef<std::string> parallelIROutputFilenames,
llvm::GlobalVariable **outModuleHash = nullptr);

/// Turn the given Swift file into LLVM IR and return the generated module.
Expand Down
12 changes: 12 additions & 0 deletions lib/Driver/ToolChains.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -953,6 +953,12 @@ 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
Expand Down Expand Up @@ -1237,6 +1243,12 @@ 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);
Expand Down
137 changes: 95 additions & 42 deletions lib/Frontend/ArgsToFrontendOutputsConverter.cpp
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Expand Up @@ -275,15 +275,15 @@ SupplementaryOutputPathsComputer::computeOutputPaths() const {

if (InputsAndOutputs.hasPrimaryInputs())
assert(OutputFiles.size() == pathsFromUser->size());
else if (InputsAndOutputs.isSingleThreadedWMO())
assert(OutputFiles.size() == pathsFromUser->size() &&
pathsFromUser->size() == 1);
else {
// Multi-threaded WMO is the exception
assert(OutputFiles.size() == InputsAndOutputs.inputCount() &&
pathsFromUser->size() == (InputsAndOutputs.hasInputs() ? 1 : 0));
if (!InputsAndOutputs.isSingleThreadedWMO()) {
assert(OutputFiles.size() == InputsAndOutputs.inputCount());
}
assert(pathsFromUser->size() == 1 ||
pathsFromUser->size() == InputsAndOutputs.inputCount());
}

// For other cases, process the paths normally
std::vector<SupplementaryOutputPaths> outputPaths;
unsigned i = 0;
bool hadError = InputsAndOutputs.forEachInputProducingSupplementaryOutput(
Expand Down Expand Up @@ -380,39 +380,78 @@ 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) {
!moduleInterfaceOutput || !privateModuleInterfaceOutput ||
!packageModuleInterfaceOutput || !moduleSourceInfoOutput ||
!moduleSummaryOutput || !abiDescriptorOutput ||
!moduleSemanticInfoOutput || !optRecordOutput || !silOutput ||
!irOutput) {
return std::nullopt;
}
std::vector<SupplementaryOutputPaths> result;

const unsigned N =
InputsAndOutputs.countOfFilesProducingSupplementaryOutput();
// In WMO mode with multiple IR output paths, we need to create one
// SupplementaryOutputPaths per input file, not just one for the module
unsigned N = InputsAndOutputs.countOfFilesProducingSupplementaryOutput();
if (!InputsAndOutputs.hasPrimaryInputs() && irOutput->size() > 1) {
// WMO mode with multiple IR outputs: use input count instead of 1
N = InputsAndOutputs.inputCount();
}

// Find the index of SIL output path matching module name
auto findSILIndexForModuleName = [&]() -> unsigned {
if (!InputsAndOutputs.hasPrimaryInputs() && silOutput->size() > 1) {
// In WMO mode with multiple SIL output paths, find the one whose matches
// module name
for (unsigned i = 0; i < silOutput->size(); ++i) {
StringRef silPath = (*silOutput)[i];
if (!silPath.empty()) {
StringRef basename = llvm::sys::path::stem(silPath);
if (basename == ModuleName) {
return i;
}
}
}
// If no match found, fall back to first
return 0;
}
return 0;
};

unsigned silOutputIndex = findSILIndexForModuleName();

for (unsigned i = 0; i < N; ++i) {
SupplementaryOutputPaths sop;
sop.ClangHeaderOutputPath = (*clangHeaderOutput)[i];
sop.ModuleOutputPath = (*moduleOutput)[i];
sop.ModuleDocOutputPath = (*moduleDocOutput)[i];
sop.DependenciesFilePath = (*dependenciesFile)[i];
sop.ReferenceDependenciesFilePath = (*referenceDependenciesFile)[i];
sop.SerializedDiagnosticsPath = (*serializedDiagnostics)[i];
sop.LoadedModuleTracePath = (*loadedModuleTrace)[i];
sop.TBDPath = (*TBD)[i];
sop.ModuleInterfaceOutputPath = (*moduleInterfaceOutput)[i];
sop.PrivateModuleInterfaceOutputPath = (*privateModuleInterfaceOutput)[i];
sop.PackageModuleInterfaceOutputPath = (*packageModuleInterfaceOutput)[i];
sop.ModuleSourceInfoOutputPath = (*moduleSourceInfoOutput)[i];
sop.ModuleSummaryOutputPath = (*moduleSummaryOutput)[i];
sop.ABIDescriptorOutputPath = (*abiDescriptorOutput)[i];
sop.APIDescriptorOutputPath = (*apiDescriptorOutput)[i];
sop.ConstValuesOutputPath = (*constValuesOutput)[i];
sop.ModuleSemanticInfoOutputPath = (*moduleSemanticInfoOutput)[i];
sop.YAMLOptRecordPath = (*optRecordOutput)[i];
sop.BitstreamOptRecordPath = (*optRecordOutput)[i];
// In multi-threaded WMO with multiple IR outputs, most supplementary outputs
// are per-module (size 1), only IR is per-file. Use index 0 for module outputs.
unsigned moduleIndex = (!InputsAndOutputs.hasPrimaryInputs() && irOutput->size() > 1) ? 0 : i;
sop.ClangHeaderOutputPath = (*clangHeaderOutput)[moduleIndex];
sop.ModuleOutputPath = (*moduleOutput)[moduleIndex];
sop.ModuleDocOutputPath = (*moduleDocOutput)[moduleIndex];
sop.DependenciesFilePath = (*dependenciesFile)[moduleIndex];
sop.ReferenceDependenciesFilePath = (*referenceDependenciesFile)[moduleIndex];
sop.SerializedDiagnosticsPath = (*serializedDiagnostics)[moduleIndex];
sop.LoadedModuleTracePath = (*loadedModuleTrace)[moduleIndex];
sop.TBDPath = (*TBD)[moduleIndex];
sop.ModuleInterfaceOutputPath = (*moduleInterfaceOutput)[moduleIndex];
sop.PrivateModuleInterfaceOutputPath = (*privateModuleInterfaceOutput)[moduleIndex];
sop.PackageModuleInterfaceOutputPath = (*packageModuleInterfaceOutput)[moduleIndex];
sop.ModuleSourceInfoOutputPath = (*moduleSourceInfoOutput)[moduleIndex];
sop.ModuleSummaryOutputPath = (*moduleSummaryOutput)[moduleIndex];
sop.ABIDescriptorOutputPath = (*abiDescriptorOutput)[moduleIndex];
sop.APIDescriptorOutputPath = (*apiDescriptorOutput)[moduleIndex];
sop.ConstValuesOutputPath = (*constValuesOutput)[moduleIndex];
sop.ModuleSemanticInfoOutputPath = (*moduleSemanticInfoOutput)[moduleIndex];
sop.YAMLOptRecordPath = (*optRecordOutput)[moduleIndex];
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Hmm, not sure this is right for optimization record (...OptRecordPath) files.There should be one per source file/.o/llvm module.

Can you check that there will be two .yaml or two .bitstream files produced after this patch for the following test case:

% cat > test-save-bitstream/A.swift
public func A() -> Int {
  print(5)
  return 6
}
 % cat > test-save-bitstream/B.swift
public func B() -> Int {
  print("In B: \(7)")
  return 8
}
% cd test-save-bitstream
% ..../swift-macosx-arm64/bin/swiftc -wmo -num-threads 1 -v -c A.swift B.swift -save-optimization-record=bitstream
% ls -ltr
 main.opt.bitstream
 B.opt.bitstream
 % .../swift-macosx-arm64/bin/swiftc -wmo -num-threads 1 -v -c A.swift B.swift -save-optimization-record=yaml
 % ls -ltr
 main.opt.yaml
 B.opt.yaml

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Yes, it generates two separate files.

% ~/swift/build/Ninja-RelWithDebInfoAssert/swift-macosx-arm64/bin/swiftc -wmo -num-threads 1 -v -c A.swift B.swift -save-optimization-record=bitstream
Swift version 6.3-dev (LLVM 2673c29efb030de, Swift 5e4b1f6c2fc517b)
Target: arm64-apple-macosx26.0
/Users/ryan_mansfield/swift/build/Ninja-RelWithDebInfoAssert/swift-macosx-arm64/bin/swift-frontend -frontend -c A.swift B.swift -save-optimization-record=bitstream -save-optimization-record-path main.opt.bitstream -target arm64-apple-macosx26.0 -Xllvm -aarch64-use-tbi -enable-objc-interop -color-diagnostics -Xcc -fcolor-diagnostics -empty-abi-descriptor -no-auto-bridging-header-chaining -module-name main -in-process-plugin-server-path /Users/ryan_mansfield/swift/build/Ninja-RelWithDebInfoAssert/swift-macosx-arm64/lib/swift/host/libSwiftInProcPluginServer.dylib -plugin-path /Users/ryan_mansfield/swift/build/Ninja-RelWithDebInfoAssert/swift-macosx-arm64/lib/swift/host/plugins -plugin-path /Users/ryan_mansfield/swift/build/Ninja-RelWithDebInfoAssert/swift-macosx-arm64/local/lib/swift/host/plugins -num-threads 1 -o A.o -o B.o
ryan_mansfield@MacBook-Pro-2 swift % ls -1 *.bitstream                                                                                                                                   
B.opt.bitstream
main.opt.bitstream

% ~/swift/build/Ninja-RelWithDebInfoAssert/swift-macosx-arm64/bin/swiftc -wmo -num-threads 1 -v -c A.swift B.swift -save-optimization-record=yaml     
Swift version 6.3-dev (LLVM 2673c29efb030de, Swift 5e4b1f6c2fc517b)
Target: arm64-apple-macosx26.0
/Users/ryan_mansfield/swift/build/Ninja-RelWithDebInfoAssert/swift-macosx-arm64/bin/swift-frontend -frontend -c A.swift B.swift -save-optimization-record=yaml -save-optimization-record-path main.opt.yaml -target arm64-apple-macosx26.0 -Xllvm -aarch64-use-tbi -enable-objc-interop -color-diagnostics -Xcc -fcolor-diagnostics -empty-abi-descriptor -no-auto-bridging-header-chaining -module-name main -in-process-plugin-server-path /Users/ryan_mansfield/swift/build/Ninja-RelWithDebInfoAssert/swift-macosx-arm64/lib/swift/host/libSwiftInProcPluginServer.dylib -plugin-path /Users/ryan_mansfield/swift/build/Ninja-RelWithDebInfoAssert/swift-macosx-arm64/lib/swift/host/plugins -plugin-path /Users/ryan_mansfield/swift/build/Ninja-RelWithDebInfoAssert/swift-macosx-arm64/local/lib/swift/host/plugins -num-threads 1 -o A.o -o B.o
 % ls -1 *.yaml                                                                                                                                   
B.opt.yaml
main.opt.yaml

Interestingly the swiftc 6.2 I have installed generates only main.opt.bitstream or main.opt.yaml

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Yes, it generates two separate files.

👍

Interestingly the swiftc 6.2 I have installed generates only main.opt.bitstream or main.opt.yaml

Yes, I fixed this behavior recently.

sop.BitstreamOptRecordPath = (*optRecordOutput)[moduleIndex];
sop.SILOutputPath = (*silOutput)[silOutputIndex];
sop.LLVMIROutputPath = (*irOutput)[i];
result.push_back(sop);
}
return result;
Expand All @@ -439,6 +478,15 @@ SupplementaryOutputPathsComputer::getSupplementaryFilenamesFromArguments(
paths.emplace_back();
return paths;
}
// Special handling for SIL and IR output paths: allow multiple paths per file
// type
else if ((pathID == options::OPT_sil_output_path ||
pathID == options::OPT_ir_output_path) &&
paths.size() > N) {
// For parallel compilation, we can have multiple SIL/IR output paths
// so return all the paths.
return paths;
}

if (paths.empty())
return std::vector<std::string>(N, std::string());
Expand Down Expand Up @@ -613,6 +661,9 @@ SupplementaryOutputPathsComputer::computeOutputPathsForOneInput(
file_types::TY_BitstreamOptRecord, "",
defaultSupplementaryOutputPathExcludingExtension);

auto SILOutputPath = pathsFromArguments.SILOutputPath;
auto LLVMIROutputPath = pathsFromArguments.LLVMIROutputPath;

SupplementaryOutputPaths sop;
sop.ClangHeaderOutputPath = clangHeaderOutputPath;
sop.ModuleOutputPath = moduleOutputPath;
Expand All @@ -635,6 +686,8 @@ SupplementaryOutputPathsComputer::computeOutputPathsForOneInput(
sop.ModuleSemanticInfoOutputPath = ModuleSemanticInfoOutputPath;
sop.YAMLOptRecordPath = YAMLOptRecordPath;
sop.BitstreamOptRecordPath = bitstreamOptRecordPath;
sop.SILOutputPath = SILOutputPath;
sop.LLVMIROutputPath = LLVMIROutputPath;
return sop;
}

Expand Down Expand Up @@ -741,18 +794,18 @@ createFromTypeToPathMap(const TypeToPathMap *map) {

std::optional<std::vector<SupplementaryOutputPaths>>
SupplementaryOutputPathsComputer::readSupplementaryOutputFileMap() const {
if (Arg *A = Args.getLastArg(options::OPT_emit_objc_header_path,
options::OPT_emit_module_path,
options::OPT_emit_module_doc_path,
options::OPT_emit_dependencies_path,
options::OPT_emit_reference_dependencies_path,
options::OPT_serialize_diagnostics_path,
options::OPT_emit_loaded_module_trace_path,
options::OPT_emit_module_interface_path,
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)) {
if (Arg *A = Args.getLastArg(
options::OPT_emit_objc_header_path, options::OPT_emit_module_path,
options::OPT_emit_module_doc_path,
options::OPT_emit_dependencies_path,
options::OPT_emit_reference_dependencies_path,
options::OPT_serialize_diagnostics_path,
options::OPT_emit_loaded_module_trace_path,
options::OPT_emit_module_interface_path,
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_sil_output_path, options::OPT_ir_output_path)) {
Diags.diagnose(SourceLoc(),
diag::error_cannot_have_supplementary_outputs,
A->getSpelling(), "-supplementary-output-file-map");
Expand Down
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