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Revert "[clang][modules-driver] Add support for C++ named modules and import std" #193677

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Merged
naveen-seth merged 1 commit into from
Apr 23, 2026
Merged

Revert "[clang][modules-driver] Add support for C++ named modules and import std" #193677

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2 changes: 0 additions & 2 deletions clang/include/clang/Basic/DiagnosticDriverKinds.td
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Original file line number Diff line number Diff line change
Expand Up @@ -613,8 +613,6 @@ def err_drv_reduced_module_output_overrided : Warning<
"please consider use '-fmodule-output=' to specify the output file for reduced BMI explicitly">,
InGroup<DiagGroup<"reduced-bmi-output-overrided">>;

def err_drv_modules_driver_requires_reduced_bmi : Error<
"'-fmodules-driver' is currently incompatible with '-fno-modules-reduced-bmi'">;
def remark_performing_driver_managed_module_build : Remark<
"performing driver managed module build">, InGroup<ModulesDriver>;
def remark_modules_manifest_not_found : Remark<
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4 changes: 0 additions & 4 deletions clang/include/clang/Driver/ModulesDriver.h
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Expand Up @@ -32,10 +32,6 @@ class Compilation;

namespace clang::driver::modules {

/// Emits diagnostics for arguments incompatible with -fmodules-driver.
void diagnoseModulesDriverArgs(llvm::opt::DerivedArgList &DAL,
DiagnosticsEngine &Diags);

/// The parsed Standard library module manifest.
struct StdModuleManifest {
struct Module {
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2 changes: 0 additions & 2 deletions clang/lib/Driver/Driver.cpp
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Expand Up @@ -1832,8 +1832,6 @@ Compilation *Driver::BuildCompilation(ArrayRef<const char *> ArgList) {
if (UseModulesDriver) {
Diags.Report(diag::remark_performing_driver_managed_module_build);

modules::diagnoseModulesDriverArgs(C->getArgs(), Diags);

// Read the Standard library module manifest and, if available, add all
// discovered modules to this Compilation. Jobs for modules specified in
// the manifest that are not required by any command-line input are pruned
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100 changes: 11 additions & 89 deletions clang/lib/Driver/ModulesDriver.cpp
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Expand Up @@ -21,7 +21,6 @@
#include "clang/Driver/Job.h"
#include "clang/Driver/Tool.h"
#include "clang/Driver/ToolChain.h"
#include "clang/Driver/Types.h"
#include "clang/Frontend/StandaloneDiagnostic.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/DepthFirstIterator.h"
Expand All @@ -48,14 +47,6 @@ using namespace clang;
using namespace driver;
using namespace modules;

void driver::modules::diagnoseModulesDriverArgs(llvm::opt::DerivedArgList &DAL,
DiagnosticsEngine &Diags) {
if (!DAL.hasFlag(options::OPT_fmodules_reduced_bmi,
options::OPT_fno_modules_reduced_bmi, true)) {
Diags.Report(diag::err_drv_modules_driver_requires_reduced_bmi);
}
}

namespace clang::driver::modules {
static bool fromJSON(const llvm::json::Value &Params,
StdModuleManifest::Module::LocalArguments &LocalArgs,
Expand Down Expand Up @@ -1261,16 +1252,6 @@ static SmallVector<JobNode *> createNodesForUnusedStdlibModuleJobs(
return StdlibModuleNodesToPrune;
}

// Returns the derived argument list for the tool chain responsible
// for creating \p Job.
static const DerivedArgList &getToolChainArgs(Compilation &C,
const Command &Job) {
const auto &TC = Job.getCreator().getToolChain();
const auto &SourceAction = Job.getSource();
return C.getArgsForToolChain(&TC, SourceAction.getOffloadingArch(),
SourceAction.getOffloadingDeviceKind());
}

/// Creates a job for the Clang module described by \p MD.
static std::unique_ptr<Command>
createClangModulePrecompileJob(Compilation &C, const Command &ImportingJob,
Expand All @@ -1282,7 +1263,9 @@ createClangModulePrecompileJob(Compilation &C, const Command &ImportingJob,
Action *PA = C.MakeAction<PrecompileJobAction>(IA, types::ID::TY_ModuleFile);
PA->propagateOffloadInfo(&ImportingJob.getSource());

const auto &TCArgs = getToolChainArgs(C, ImportingJob);
const auto &TC = ImportingJob.getCreator().getToolChain();
const auto &TCArgs = C.getArgsForToolChain(&TC, PA->getOffloadingArch(),
PA->getOffloadingDeviceKind());

const auto &BuildArgs = MD.getBuildArguments();
ArgStringList JobArgs;
Expand Down Expand Up @@ -1336,7 +1319,12 @@ installScanCommandLines(Compilation &C,
ArgStringList JobArgs;
JobArgs.reserve(BuildArgs.size());

auto &TCArgs = getToolChainArgs(C, Job);
const auto &SourceAction = Job.getSource();
const auto &TC = Job.getCreator().getToolChain();
auto &TCArgs =
C.getArgsForToolChain(&TC, SourceAction.getOffloadingArch(),
SourceAction.getOffloadingDeviceKind());

for (const auto &Arg : BuildArgs)
JobArgs.push_back(TCArgs.MakeArgString(Arg));

Expand Down Expand Up @@ -1539,73 +1527,6 @@ static void createAndConnectRoot(CompilationGraph &Graph) {
}
}

/// Creates a temporary output path for \p ModuleName.
static std::string createModuleOutputPath(const Compilation &C,
StringRef ModuleName) {
// Sanitize the ':' included in parition names. It is illegal for filenames on
// Windows.
SmallString<32> SanitizedModuleName(ModuleName);
llvm::replace(SanitizedModuleName, ':', '-');
auto ModuleOutputPath = C.getDriver().GetTemporaryPath(
SanitizedModuleName, types::getTypeTempSuffix(types::TY_ModuleFile));
return ModuleOutputPath;
}

/// Adds the '-fmodule-output=' argument for the module produced by \p Node.
static void configureNamedModuleOutputArg(Compilation &C,
NamedModuleJobNode &Node,
StringRef ModuleOutputPath) {
auto &Job = *Node.Job;
const auto &TCArgs = getToolChainArgs(C, Job);
auto JobArgs = Job.getArguments();
JobArgs.push_back(
TCArgs.MakeArgString("-fmodule-output=" + ModuleOutputPath));
Job.replaceArguments(std::move(JobArgs));
}

/// Propagates the '-fmodule-file=' mapping for the named module described by
/// \p Node to each dependent job.
static void propagateModuleFileMappingArg(Compilation &C,
NamedModuleJobNode &Node,
StringRef ModuleOutputPath) {
const StringRef ModuleName = Node.InputDeps.ModuleName;

auto DependentNodes = llvm::drop_begin(llvm::depth_first<CGNode *>(&Node));
auto DependentScannedNodes = llvm::map_range(
llvm::make_filter_range(DependentNodes, llvm::IsaPred<ScannedJobNode>),
llvm::CastTo<ScannedJobNode>);

for (ScannedJobNode *DependentNode : DependentScannedNodes) {
auto &DependentJob = *DependentNode->Job;
const auto &TCArgs = getToolChainArgs(C, DependentJob);
auto JobArgs = DependentJob.getArguments();
JobArgs.push_back(TCArgs.MakeArgString("-fmodule-file=" + ModuleName + "=" +
ModuleOutputPath));
DependentJob.replaceArguments(std::move(JobArgs));
}
}

/// Finalizes command lines for C++20 named module dependencies.
///
/// The command lines produced by dependency scanning are only adjusted to
/// handle discovered Clang modules. For C++20 named modules, we update the
/// command-lines here.
static void fixupNamedModuleCommandLines(Compilation &C,
CompilationGraph &Graph) {
const auto NamedModuleNodes = llvm::map_range(
llvm::make_filter_range(Graph, llvm::IsaPred<NamedModuleJobNode>),
llvm::CastTo<NamedModuleJobNode>);

for (NamedModuleJobNode *Node : NamedModuleNodes) {
const StringRef ModuleName = Node->InputDeps.ModuleName;
const auto ModuleOutputPath = createModuleOutputPath(C, ModuleName);
C.addTempFile(C.getArgs().MakeArgString(ModuleOutputPath));

configureNamedModuleOutputArg(C, *Node, ModuleOutputPath);
propagateModuleFileMappingArg(C, *Node, ModuleOutputPath);
}
}

/// Moves jobs from \p Graph into \p C in the graph's topological order.
static void feedJobsBackIntoCompilation(Compilation &C,
CompilationGraph &&Graph) {
Expand Down Expand Up @@ -1679,6 +1600,7 @@ void driver::modules::runModulesDriver(
if (!Diags.isLastDiagnosticIgnored())
llvm::WriteGraph<const CompilationGraph *>(llvm::errs(), &Graph);

fixupNamedModuleCommandLines(C, Graph);
// TODO: Fix-up command-lines for named module imports.

feedJobsBackIntoCompilation(C, std::move(Graph));
}
111 changes: 0 additions & 111 deletions clang/test/Driver/modules-driver-both-modules-types.cpp
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88 changes: 0 additions & 88 deletions clang/test/Driver/modules-driver-cxx-modules-only.cpp
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