StandAlone/DirStackFileIncluder.h

   1 //
   2 // Copyright (C) 2002-2005  3Dlabs Inc. Ltd.
   3 // Copyright (C) 2017 Google, Inc.
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  36
  37 #pragma once
  38
  39 #include <vector>
  40 #include <string>
  41 #include <fstream>
  42 #include <algorithm>
  43 #include <set>
  44
  45 #include "./../glslang/Public/ShaderLang.h"
  46
  47 // Default include class for normal include convention of search backward
  48 // through the stack of active include paths (for nested includes).
  49 // Can be overridden to customize.
  50 class DirStackFileIncluder : public glslang::TShader::Includer {
  51 public:
  52     DirStackFileIncluder() : externalLocalDirectoryCount(0) { }
  53
  54     virtual IncludeResult* includeLocal(const char* headerName,
  55                                         const char* includerName,
  56                                         size_t inclusionDepth) override
  57     {
  58         return readLocalPath(headerName, includerName, (int)inclusionDepth);
  59     }
  60
  61     virtual IncludeResult* includeSystem(const char* headerName,
  62                                          const char* /*includerName*/,
  63                                          size_t /*inclusionDepth*/) override
  64     {
  65         return readSystemPath(headerName);
  66     }
  67
  68     // Externally set directories. E.g., from a command-line -I<dir>.
  69     //  - Most-recently pushed are checked first.
  70     //  - All these are checked after the parse-time stack of local directories
  71     //    is checked.
  72     //  - This only applies to the "local" form of #include.
  73     //  - Makes its own copy of the path.
  74     virtual void pushExternalLocalDirectory(const std::string& dir)
  75     {
  76         directoryStack.push_back(dir);
  77         externalLocalDirectoryCount = (int)directoryStack.size();
  78     }
  79
  80     virtual void releaseInclude(IncludeResult* result) override
  81     {
  82         if (result != nullptr) {
  83             delete [] static_cast<tUserDataElement*>(result->userData);
  84             delete result;
  85         }
  86     }
  87
  88     virtual std::set<std::string> getIncludedFiles()
  89     {
  90         return includedFiles;
  91     }
  92
  93     virtual ~DirStackFileIncluder() override { }
  94
  95 protected:
  96     typedef char tUserDataElement;
  97     std::vector<std::string> directoryStack;
  98     int externalLocalDirectoryCount;
  99     std::set<std::string> includedFiles;
 100
 101     // Search for a valid "local" path based on combining the stack of include
 102     // directories and the nominal name of the header.
 103     virtual IncludeResult* readLocalPath(const char* headerName, const char* includerName, int depth)
 104     {
 105         // Discard popped include directories, and
 106         // initialize when at parse-time first level.
 107         directoryStack.resize(depth + externalLocalDirectoryCount);
 108         if (depth == 1)
 109             directoryStack.back() = getDirectory(includerName);
 110
 111         // Find a directory that works, using a reverse search of the include stack.
 112         for (auto it = directoryStack.rbegin(); it != directoryStack.rend(); ++it) {
 113             std::string path = *it + '/' + headerName;
 114             std::replace(path.begin(), path.end(), '\\', '/');
 115             std::ifstream file(path, std::ios_base::binary | std::ios_base::ate);
 116             if (file) {
 117                 directoryStack.push_back(getDirectory(path));
 118                 includedFiles.insert(path);
 119                 return newIncludeResult(path, file, (int)file.tellg());
 120             }
 121         }
 122
 123         return nullptr;
 124     }
 125
 126     // Search for a valid <system> path.
 127     // Not implemented yet; returning nullptr signals failure to find.
 128     virtual IncludeResult* readSystemPath(const char* /*headerName*/) const
 129     {
 130         return nullptr;
 131     }
 132
 133     // Do actual reading of the file, filling in a new include result.
 134     virtual IncludeResult* newIncludeResult(const std::string& path, std::ifstream& file, int length) const
 135     {
 136         char* content = new tUserDataElement [length];
 137         file.seekg(0, file.beg);
 138         file.read(content, length);
 139         return new IncludeResult(path, content, length, content);
 140     }
 141
 142     // If no path markers, return current working directory.
 143     // Otherwise, strip file name and return path leading up to it.
 144     virtual std::string getDirectory(const std::string path) const
 145     {
 146         size_t last = path.find_last_of("/\\");
 147         return last == std::string::npos ? "." : path.substr(0, last);
 148     }
 149 };