DependencyScanningTool.cpp

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//===- DependencyScanningTool.cpp - clang-scan-deps service ---------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
 
#include "clang/Tooling/DependencyScanning/DependencyScanningTool.h"
#include "clang/Frontend/Utils.h"
 
namespace clang {
namespace tooling {
namespace dependencies {
 
std::vector<std::string> FullDependencies::getCommandLine(
    std::function<StringRef(ModuleID)> LookupPCMPath) const {
  std::vector<std::string> Ret = getCommandLineWithoutModulePaths();
 
  for (ModuleID MID : ClangModuleDeps)
    Ret.push_back(("-fmodule-file=" + LookupPCMPath(MID)).str());
 
  return Ret;
}
 
std::vector<std::string>
FullDependencies::getCommandLineWithoutModulePaths() const {
  std::vector<std::string> Args = OriginalCommandLine;
 
  Args.push_back("-fno-implicit-modules");
  Args.push_back("-fno-implicit-module-maps");
  for (const PrebuiltModuleDep &PMD : PrebuiltModuleDeps)
    Args.push_back("-fmodule-file=" + PMD.PCMFile);
 
  // This argument is unused in explicit compiles.
  llvm::erase_if(Args, [](const std::string &Arg) {
    return Arg.find("-fmodules-cache-path=") == 0;
  });
 
  // TODO: Filter out the remaining implicit modules leftovers
  // (e.g. "-fmodules-prune-interval=" or "-fmodules-prune-after=").
 
  return Args;
}
 
DependencyScanningTool::DependencyScanningTool(
    DependencyScanningService &Service)
    : Worker(Service) {}
 
llvm::Expected<std::string> DependencyScanningTool::getDependencyFile(
    const std::vector<std::string> &CommandLine, StringRef CWD,
    llvm::Optional<StringRef> ModuleName) {
  /// Prints out all of the gathered dependencies into a string.
  class MakeDependencyPrinterConsumer : public DependencyConsumer {
  public:
    void
    handleDependencyOutputOpts(const DependencyOutputOptions &Opts) override {
      this->Opts = std::make_unique<DependencyOutputOptions>(Opts);
    }
 
    void handleFileDependency(StringRef File) override {
      Dependencies.push_back(std::string(File));
    }
 
    void handlePrebuiltModuleDependency(PrebuiltModuleDep PMD) override {
      // Same as `handleModuleDependency`.
    }
 
    void handleModuleDependency(ModuleDeps MD) override {
      // These are ignored for the make format as it can't support the full
      // set of deps, and handleFileDependency handles enough for implicitly
      // built modules to work.
    }
 
    void handleContextHash(std::string Hash) override {}
 
    void printDependencies(std::string &S) {
      assert(Opts && "Handled dependency output options.");
 
      class DependencyPrinter : public DependencyFileGenerator {
      public:
        DependencyPrinter(DependencyOutputOptions &Opts,
                          ArrayRef<std::string> Dependencies)
            : DependencyFileGenerator(Opts) {
          for (const auto &Dep : Dependencies)
            addDependency(Dep);
        }
 
        void printDependencies(std::string &S) {
          llvm::raw_string_ostream OS(S);
          outputDependencyFile(OS);
        }
      };
 
      DependencyPrinter Generator(*Opts, Dependencies);
      Generator.printDependencies(S);
    }
 
  private:
    std::unique_ptr<DependencyOutputOptions> Opts;
    std::vector<std::string> Dependencies;
  };
 
  MakeDependencyPrinterConsumer Consumer;
  auto Result =
      Worker.computeDependencies(CWD, CommandLine, Consumer, ModuleName);
  if (Result)
    return std::move(Result);
  std::string Output;
  Consumer.printDependencies(Output);
  return Output;
}
 
llvm::Expected<FullDependenciesResult>
DependencyScanningTool::getFullDependencies(
    const std::vector<std::string> &CommandLine, StringRef CWD,
    const llvm::StringSet<> &AlreadySeen,
    llvm::Optional<StringRef> ModuleName) {
  class FullDependencyPrinterConsumer : public DependencyConsumer {
  public:
    FullDependencyPrinterConsumer(const llvm::StringSet<> &AlreadySeen)
        : AlreadySeen(AlreadySeen) {}
 
    void
    handleDependencyOutputOpts(const DependencyOutputOptions &Opts) override {}
 
    void handleFileDependency(StringRef File) override {
      Dependencies.push_back(std::string(File));
    }
 
    void handlePrebuiltModuleDependency(PrebuiltModuleDep PMD) override {
      PrebuiltModuleDeps.emplace_back(std::move(PMD));
    }
 
    void handleModuleDependency(ModuleDeps MD) override {
      ClangModuleDeps[MD.ID.ContextHash + MD.ID.ModuleName] = std::move(MD);
    }
 
    void handleContextHash(std::string Hash) override {
      ContextHash = std::move(Hash);
    }
 
    FullDependenciesResult getFullDependencies(
        const std::vector<std::string> &OriginalCommandLine) const {
      FullDependencies FD;
 
      FD.OriginalCommandLine =
          ArrayRef<std::string>(OriginalCommandLine).slice(1);
 
      FD.ID.ContextHash = std::move(ContextHash);
 
      FD.FileDeps.assign(Dependencies.begin(), Dependencies.end());
 
      for (auto &&M : ClangModuleDeps) {
        auto &MD = M.second;
        if (MD.ImportedByMainFile)
          FD.ClangModuleDeps.push_back(MD.ID);
      }
 
      FD.PrebuiltModuleDeps = std::move(PrebuiltModuleDeps);
 
      FullDependenciesResult FDR;
 
      for (auto &&M : ClangModuleDeps) {
        // TODO: Avoid handleModuleDependency even being called for modules
        //   we've already seen.
        if (AlreadySeen.count(M.first))
          continue;
        FDR.DiscoveredModules.push_back(std::move(M.second));
      }
 
      FDR.FullDeps = std::move(FD);
      return FDR;
    }
 
  private:
    std::vector<std::string> Dependencies;
    std::vector<PrebuiltModuleDep> PrebuiltModuleDeps;
    std::map<std::string, ModuleDeps> ClangModuleDeps;
    std::string ContextHash;
    std::vector<std::string> OutputPaths;
    const llvm::StringSet<> &AlreadySeen;
  };
 
  FullDependencyPrinterConsumer Consumer(AlreadySeen);
  llvm::Error Result =
      Worker.computeDependencies(CWD, CommandLine, Consumer, ModuleName);
  if (Result)
    return std::move(Result);
  return Consumer.getFullDependencies(CommandLine);
}
 
} // end namespace dependencies
} // end namespace tooling
} // end namespace clang