llvm/tools/llvm-libtool-darwin/DependencyInfo.h

   1 //===-- DependencyInfo.h --------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/ADT/StringRef.h"
  10 #include "llvm/Support/FileSystem.h"
  11 #include "llvm/Support/WithColor.h"
  12 #include "llvm/Support/raw_ostream.h"
  13
  14 #include <set>
  15
  16 class DependencyInfo {
  17 public:
  18   explicit DependencyInfo(std::string DependencyInfoPath)
  19       : DependencyInfoPath(DependencyInfoPath) {}
  20
  21   virtual ~DependencyInfo(){};
  22
  23   virtual void addMissingInput(llvm::StringRef Path) {
  24     NotFounds.insert(Path.str());
  25   }
  26
  27   // Writes the dependencies to specified path. The content is first sorted by
  28   // OpCode and then by the filename (in alphabetical order).
  29   virtual void write(llvm::Twine Version,
  30                      const std::vector<std::string> &Inputs,
  31                      std::string Output) {
  32     std::error_code EC;
  33     llvm::raw_fd_ostream OS(DependencyInfoPath, EC, llvm::sys::fs::OF_None);
  34     if (EC) {
  35       llvm::WithColor::defaultErrorHandler(llvm::createStringError(
  36           EC,
  37           "failed to write to " + DependencyInfoPath + ": " + EC.message()));
  38       return;
  39     }
  40
  41     auto AddDep = [&OS](DependencyInfoOpcode Opcode,
  42                         const llvm::StringRef &Path) {
  43       OS << static_cast<uint8_t>(Opcode);
  44       OS << Path;
  45       OS << '\0';
  46     };
  47
  48     AddDep(DependencyInfoOpcode::Tool, Version.str());
  49
  50     // Sort the input by its names.
  51     std::vector<llvm::StringRef> InputNames;
  52     InputNames.reserve(Inputs.size());
  53     for (const auto &F : Inputs)
  54       InputNames.push_back(F);
  55     llvm::sort(InputNames);
  56
  57     for (const auto &In : InputNames)
  58       AddDep(DependencyInfoOpcode::InputFound, In);
  59
  60     for (const std::string &F : NotFounds)
  61       AddDep(DependencyInfoOpcode::InputMissing, F);
  62
  63     AddDep(DependencyInfoOpcode::Output, Output);
  64   }
  65
  66 private:
  67   enum DependencyInfoOpcode : uint8_t {
  68     Tool = 0x00,
  69     InputFound = 0x10,
  70     InputMissing = 0x11,
  71     Output = 0x40,
  72   };
  73
  74   const std::string DependencyInfoPath;
  75   std::set<std::string> NotFounds;
  76 };
  77
  78 // Subclass to avoid any overhead when not using this feature
  79 class DummyDependencyInfo : public DependencyInfo {
  80 public:
  81   DummyDependencyInfo() : DependencyInfo("") {}
  82   void addMissingInput(llvm::StringRef Path) override {}
  83   void write(llvm::Twine Version, const std::vector<std::string> &Inputs,
  84              std::string Output) override {}
  85 };