Use std::runtime_error instead of our own StringError as

a) it does the same job and
b) its type and what() survive the boundary between the libdcp .so
and the main DCP-o-matic executable.

Before this StringError-derived exceptions caught by DCP-o-matic
were only recognised as std::exceptions (without the what()) message.

I don't know why this happens, but this works around it.

3 files changed, 25 insertions, 64 deletions

diff --git a/src/certificate_chain.cc b/src/certificate_chain.cc
index c0bfd52f..b37c07bf 100644
--- a/src/certificate_chain.cc
+++ b/src/certificate_chain.cc
@@ -46,6 +46,7 @@
 using std::string;
 using std::ofstream;
 using std::ifstream;
+using std::runtime_error;
 using std::stringstream;
 using namespace dcp;
 
@@ -535,7 +536,7 @@ CertificateChain::add_signature_value (xmlpp::Node* parent, string ns) const
 		);
 
 	if (signature_context->signKey == 0) {
-		throw StringError ("could not read private key");
+		throw runtime_error ("could not read private key");
 	}
 
 	/* XXX: set key name to the PEM string: this can't be right! */
diff --git a/src/exceptions.cc b/src/exceptions.cc
index e1eaa52e..c588696e 100644
--- a/src/exceptions.cc
+++ b/src/exceptions.cc
@@ -25,10 +25,11 @@
 #include "compose.hpp"
 
 using std::string;
+using std::runtime_error;
 using namespace dcp;
 
 FileError::FileError (string message, boost::filesystem::path filename, int number)
-	: StringError (String::compose ("%1 (%2) (error %3)", message, filename.string(), number))
+	: runtime_error (String::compose ("%1 (%2) (error %3)", message, filename.string(), number))
 	, _filename (filename)
 	, _number (number)
 {
@@ -36,48 +37,36 @@ FileError::FileError (string message, boost::filesystem::path filename, int numb
 }
 
 UnresolvedRefError::UnresolvedRefError (string id)
-	: StringError (String::compose ("Unresolved reference to asset id %1", id))
+	: runtime_error (String::compose ("Unresolved reference to asset id %1", id))
 {
 
 }
 
 TimeFormatError::TimeFormatError (string bad_time)
-	: StringError (String::compose ("Bad time string %1", bad_time))
+	: runtime_error (String::compose ("Bad time string %1", bad_time))
 {
 
 }
 
 MissingAssetError::MissingAssetError (boost::filesystem::path path, AssetType type)
-	: _path (path)
-	, _type (type)
+	: DCPReadError (
+		type == MAIN_PICTURE    ? String::compose ("missing asset %1 for main picture", path.string()) :
+		(type == MAIN_SOUND     ? String::compose ("missing asset %1 for main sound", path.string()) :
+		 (type == MAIN_SUBTITLE ? String::compose ("missing asset %1 for main subtitle", path.string()) :
+		  String::compose ("missing asset %1", path.string()))))
 {
-	string type_name;
-	switch (_type) {
-	case MAIN_PICTURE:
-		type_name = " for main picture";
-		break;
-	case MAIN_SOUND:
-		type_name = " for main sound";
-		break;
-	case MAIN_SUBTITLE:
-		type_name = " for main subtitle";
-		break;
-	case UNKNOWN:
-		break;
-	}
-
-	_message = String::compose ("Missing asset %1%2", path.string(), type_name);
+
 }
 
 NotEncryptedError::NotEncryptedError (string const & what)
-	: StringError (String::compose ("%1 is not encrypted", what))
+	: runtime_error (String::compose ("%1 is not encrypted", what))
 {
 
 }
 
 
 ProgrammingError::ProgrammingError (string file, int line)
-	: StringError (String::compose ("Programming error at %1:%2", file, line))
+	: runtime_error (String::compose ("Programming error at %1:%2", file, line))
 {
 
 }
diff --git a/src/exceptions.h b/src/exceptions.h
index 01ac9ccc..801bfb01 100644
--- a/src/exceptions.h
+++ b/src/exceptions.h
@@ -29,32 +29,10 @@
 namespace dcp
 {
 
-/** @class StringError
- *  @brief An exception that uses a std::string to store its error message.
- */
-class StringError : public std::exception
-{
-public:
-	StringError () {}
-	StringError (std::string message)
-		: _message (message)
-	{}
-
-	~StringError () throw () {}
-
-	/** @return error message */
-	char const * what () const throw () {
-		return _message.c_str ();
-	}
-
-protected:
-	std::string _message;
-};
-
 /** @class FileError
  *  @brief An exception related to a file
  */
-class FileError : public StringError
+class FileError : public std::runtime_error
 {
 public:
 	FileError (std::string message, boost::filesystem::path filename, int number);
@@ -90,26 +68,23 @@ public:
 /** @class MiscError
  *  @brief A miscellaneous exception
  */
-class MiscError : public StringError
+class MiscError : public std::runtime_error
 {
 public:
 	MiscError (std::string message)
-		: StringError (message)
+		: std::runtime_error (message)
 	{}
 };
 
 /** @class DCPReadError
  *  @brief A DCP read exception
  */
-class DCPReadError : public StringError
+class DCPReadError : public std::runtime_error
 {
 public:
 	DCPReadError (std::string message)
-		: StringError (message)
+		: std::runtime_error (message)
 	{}
-
-protected:
-	DCPReadError () {}
 };
 
 /** @class MissingAssetError
@@ -127,27 +102,23 @@ public:
 
 	MissingAssetError (boost::filesystem::path, AssetType = UNKNOWN);
 	~MissingAssetError () throw () {}
-
-private:
-	boost::filesystem::path _path;
-	AssetType _type;
 };
 
 /** @class XMLError
  *  @brief An XML error
  */
-class XMLError : public StringError
+class XMLError : public std::runtime_error
 {
 public:
 	XMLError (std::string message)
-		: StringError (message)
+		: std::runtime_error (message)
 	{}
 };
 
 /** @class UnresolvedRefError
  *  @brief An exception caused by a reference (by UUID) to something which is not known
  */
-class UnresolvedRefError : public StringError
+class UnresolvedRefError : public std::runtime_error
 {
 public:
 	UnresolvedRefError (std::string id);
@@ -156,7 +127,7 @@ public:
 /** @class TimeFormatError
  *  @brief A an error with a string passed to LocalTime.
  */
-class TimeFormatError : public StringError
+class TimeFormatError : public std::runtime_error
 {
 public:
 	TimeFormatError (std::string bad_time);
@@ -166,7 +137,7 @@ public:
  *  @brief An error raised when creating a DecryptedKDM object for assets that are not
  *  encrypted.
  */
-class NotEncryptedError : public StringError
+class NotEncryptedError : public std::runtime_error
 {
 public:
 	NotEncryptedError (std::string const & what);
@@ -176,7 +147,7 @@ public:
 /** @class ProgrammingError
  *  @brief An exception thrown when a DCP_ASSERT fails; something that should not happen.
  */
-class ProgrammingError : public StringError
+class ProgrammingError : public std::runtime_error
 {
 public:
 	ProgrammingError (std::string file, int line);