more const in format detection

BaseImporter::SearchFileHeaderForToken() expected a pointer to a non-const token list. This was probably an oversight, as nobody would realistically expect the function to change the list. Furthermore, it prevented token lists from being compiled to read-only memory, in some cases even causing the compiler to generate thread-safe initialization.

The list is now const and all callers declare their token lists static const, thus compiling them to read-only memory.

code/AssetLib/AMF/AMFImporter.cpp

@@ -511,7 +511,7 @@ bool AMFImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool p
  }
 
  if (extension.empty() || pCheckSig) {
- const char *tokens[] = { "<amf" };
+ static const char * const tokens[] = { "<amf" };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);
  }
 

code/AssetLib/ASE/ASELoader.cpp

@@ -106,7 +106,7 @@ bool ASEImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool c
  }
 
  if ((!extension.length() || cs) && pIOHandler) {
- const char *tokens[] = { "*3dsmax_asciiexport" };
+ static const char * const tokens[] = { "*3dsmax_asciiexport" };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);
  }
  return false;

code/AssetLib/BVH/BVHLoader.cpp

@@ -100,7 +100,7 @@ bool BVHLoader::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool cs)
  return true;
 
  if ((!extension.length() || cs) && pIOHandler) {
- const char *tokens[] = { "HIERARCHY" };
+ static const char * const tokens[] = { "HIERARCHY" };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);
  }
  return false;

code/AssetLib/Blender/BlenderLoader.cpp

@@ -113,8 +113,8 @@ BlenderImporter::~BlenderImporter() {
  delete modifier_cache;
 }
 
-static const char *Tokens[] = { "BLENDER" };
-static const char *TokensForSearch[] = { "blender" };
+static const char * const Tokens[] = { "BLENDER" };
+static const char * const TokensForSearch[] = { "blender" };
 
 // ------------------------------------------------------------------------------------------------
 // Returns whether the class can handle the format of the given file.

code/AssetLib/COB/COBLoader.cpp

@@ -110,7 +110,7 @@ bool COBImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool c
  }
 
  else if ((!extension.length() || checkSig) && pIOHandler) {
- const char *tokens[] = { "Caligary" };
+ static const char * const tokens[] = { "Caligary" };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);
  }
  return false;

code/AssetLib/CSM/CSMLoader.cpp

@@ -99,7 +99,7 @@ bool CSMImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool
  return true;
 
  if ((checkSig || !extension.length()) && pIOHandler) {
- const char* tokens[] = {"$Filename"};
+ static const char * const tokens[] = {"$Filename"};
  return SearchFileHeaderForToken(pIOHandler,pFile,tokens,1);
  }
  return false;

code/AssetLib/Collada/ColladaLoader.cpp

@@ -141,7 +141,7 @@ bool ColladaLoader::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool
  if (nullptr == pIOHandler) {
  return true;
  }
- static const char* tokens[] = {
+ static const char * const tokens[] = {
  "<collada"
  };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);

code/AssetLib/DXF/DXFLoader.cpp

@@ -130,8 +130,8 @@ bool DXFImporter::CanRead( const std::string& filename, IOSystem* pIOHandler, bo
  }
 
  if ( extension.empty() || checkSig ) {
- const char *pTokens[] = { "SECTION", "HEADER", "ENDSEC", "BLOCKS" };
- return BaseImporter::SearchFileHeaderForToken(pIOHandler, filename, pTokens, 4, 32 );
+ static const char * const pTokens[] = { "SECTION", "HEADER", "ENDSEC", "BLOCKS" };
+ return SearchFileHeaderForToken(pIOHandler, filename, pTokens, 4, 32 );
  }
 
  return false;

code/AssetLib/FBX/FBXImporter.cpp

@@ -108,7 +108,7 @@ bool FBXImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool c
 
  else if ((!extension.length() || checkSig) && pIOHandler) {
  // at least ASCII-FBX files usually have a 'FBX' somewhere in their head
- const char *tokens[] = { "fbx" };
+ static const char * const tokens[] = { "fbx" };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);
  }
  return false;

code/AssetLib/IFC/IFCLoader.cpp

@@ -137,9 +137,8 @@ bool IFCImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool c
  // note: this is the common identification for STEP-encoded files, so
  // it is only unambiguous as long as we don't support any further
  // file formats with STEP as their encoding.
- const char *tokens[] = { "ISO-10303-21" };
- const bool found(SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1));
- return found;
+ static const char * const tokens[] = { "ISO-10303-21" };
+ return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);
  }
  return false;
 }

code/AssetLib/Irr/IRRLoader.cpp

@@ -106,7 +106,7 @@ bool IRRImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool c
  if (nullptr == pIOHandler) {
  return true;
  }
- const char *tokens[] = { "irr_scene" };
+ static const char * const tokens[] = { "irr_scene" };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);
  }
 

code/AssetLib/Irr/IRRMeshLoader.cpp

@@ -101,7 +101,7 @@ bool IRRMeshImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bo
  * must return true here.
  */
  if (!pIOHandler) return true;
- const char *tokens[] = { "irrmesh" };
+ static const char * const tokens[] = { "irrmesh" };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);
  }
  return false;

code/AssetLib/MD5/MD5Loader.cpp

@@ -109,7 +109,7 @@ bool MD5Importer::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool c
  if (!pIOHandler) {
  return true;
  }
- const char *tokens[] = { "MD5Version" };
+ static const char * const tokens[] = { "MD5Version" };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);
  }
 

code/AssetLib/MMD/MMDImporter.cpp

@@ -94,8 +94,8 @@ bool MMDImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler,
  return SimpleExtensionCheck(pFile, "pmx");
  } else {
  // Check file Header
- static const char *pTokens[] = { "PMX " };
- return BaseImporter::SearchFileHeaderForToken(pIOHandler, pFile, pTokens, 1);
+ static const char * const pTokens[] = { "PMX " };
+ return SearchFileHeaderForToken(pIOHandler, pFile, pTokens, 1);
  }
 }
 

code/AssetLib/MS3D/MS3DLoader.cpp

@@ -104,7 +104,7 @@ bool MS3DImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool
  if (!pIOHandler) {
  return true;
  }
- const char* tokens[] = {"MS3D000000"};
+ static const char * const tokens[] = {"MS3D000000"};
  return SearchFileHeaderForToken(pIOHandler,pFile,tokens,1);
  }
  return false;

code/AssetLib/NDO/NDOLoader.cpp

@@ -91,7 +91,7 @@ bool NDOImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool
  return true;
 
  if ((checkSig || !extension.length()) && pIOHandler) {
- const char* tokens[] = {"nendo"};
+ static const char * const tokens[] = {"nendo"};
  return SearchFileHeaderForToken(pIOHandler,pFile,tokens,1,5);
  }
  return false;

code/AssetLib/OFF/OFFLoader.cpp

@@ -94,7 +94,7 @@ bool OFFImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool
  else if (!extension.length() || checkSig)
  {
  if (!pIOHandler)return true;
- const char* tokens[] = {"off"};
+ static const char * const tokens[] = {"off"};
  return SearchFileHeaderForToken(pIOHandler,pFile,tokens,1,3);
  }
  return false;

code/AssetLib/Ogre/OgreImporter.cpp

@@ -79,7 +79,7 @@ bool OgreImporter::CanRead(const std::string &pFile, Assimp::IOSystem *pIOHandle
  }
 
  if (EndsWith(pFile, ".mesh.xml", false)) {
- const char *tokens[] = { "<mesh>" };
+ static const char * const tokens[] = { "<mesh>" };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);
  } else {
  /// @todo Read and validate first header chunk?

code/AssetLib/OpenGEX/OpenGEXImporter.cpp

@@ -299,8 +299,8 @@ bool OpenGEXImporter::CanRead(const std::string &file, IOSystem *pIOHandler, boo
  if (!checkSig) {
  canRead = SimpleExtensionCheck(file, "ogex");
  } else {
- static const char *token[] = { "Metric", "GeometryNode", "VertexArray (attrib", "IndexArray" };
- canRead = BaseImporter::SearchFileHeaderForToken(pIOHandler, file, token, 4);
+ static const char * const token[] = { "Metric", "GeometryNode", "VertexArray (attrib", "IndexArray" };
+ canRead = SearchFileHeaderForToken(pIOHandler, file, token, 4);
  }
 
  return canRead;

code/AssetLib/Ply/PlyLoader.cpp

@@ -111,7 +111,7 @@ bool PLYImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool c
  if (!pIOHandler) {
  return true;
  }
- static const char *tokens[] = {
+ static const char * const tokens[] = {
  "ply"
  };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);

code/AssetLib/Q3D/Q3DLoader.cpp

@@ -92,7 +92,7 @@ bool Q3DImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool c
  else if (!extension.length() || checkSig) {
  if (!pIOHandler)
  return true;
- const char *tokens[] = { "quick3Do", "quick3Ds" };
+ static const char * const tokens[] = { "quick3Do", "quick3Ds" };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 2);
  }
  return false;

code/AssetLib/STL/STLLoader.cpp

@@ -150,7 +150,7 @@ bool STLImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool c
  if (!pIOHandler) {
  return true;
  }
- const char *tokens[] = { "STL", "solid" };
+ static const char * const tokens[] = { "STL", "solid" };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 2);
  }
 

code/AssetLib/Terragen/TerragenLoader.cpp

@@ -93,7 +93,7 @@ bool TerragenImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, b
  return true;
  }
 
- const char *tokens[] = { "terragen" };
+ static const char * const tokens[] = { "terragen" };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 1);
  }
 

code/AssetLib/XGL/XGLLoader.cpp

@@ -118,7 +118,7 @@ bool XGLImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler, bool c
  } else if (extension == "xml" || checkSig) {
  ai_assert(pIOHandler != NULL);
 
- const char *tokens[] = { "<world>", "<World>", "<WORLD>" };
+ static const char * const tokens[] = { "<world>", "<World>", "<WORLD>" };
  return SearchFileHeaderForToken(pIOHandler, pFile, tokens, 3);
  }
  return false;

code/Common/BaseImporter.cpp

@@ -155,7 +155,7 @@ void BaseImporter::GetExtensionList(std::set<std::string> &extensions) {
 // ------------------------------------------------------------------------------------------------
 /*static*/ bool BaseImporter::SearchFileHeaderForToken(IOSystem *pIOHandler,
  const std::string &pFile,
- const char **tokens,
+ const char * const *tokens,
  unsigned int numTokens,
  unsigned int searchBytes /* = 200 */,
  bool tokensSol /* false */,

include/assimp/BaseImporter.h

@@ -259,7 +259,7 @@ class ASSIMP_API BaseImporter {
  static bool SearchFileHeaderForToken(
  IOSystem *pIOSystem,
  const std::string &file,
- const char **tokens,
+ const char * const *tokens,
  unsigned int numTokens,
  unsigned int searchBytes = 200,
  bool tokensSol = false,