From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 25 Jul 2011 14:28:18 +0000 (+0300)
Subject: Exception rework for loader components
X-Git-Url: http://git.tdb.fi/?p=libs%2Fdatafile.git;a=commitdiff_plain;h=302f73123da1194dd91b43138cd880cae9318a14

Exception rework for loader components
---

diff --git a/source/loader.cpp b/source/loader.cpp
index 51cdabe..2bf90ee 100644
--- a/source/loader.cpp
+++ b/source/loader.cpp
@@ -1,4 +1,5 @@
 #include <msp/strings/format.h>
+#include "dataerror.h"
 #include "loader.h"
 #include "type.h"
 
@@ -6,6 +7,16 @@ using namespace std;
 
 namespace {
 
+template<typename T>
+struct Set
+{
+	T &ref;
+	T orig;
+
+	Set(T &r, const T &v): ref(r), orig(r) { r = v; }
+	~Set() { ref = orig; }
+};
+
 bool signature_match(char s, char a)
 {
 	if(s==a)
@@ -41,9 +52,32 @@ bool signature_match(const string &st_sig, const string &act_sig)
 
 }
 
+
 namespace Msp {
 namespace DataFile {
 
+class unknown_keyword: public runtime_error
+{
+public:
+	unknown_keyword(const std::string &k):
+		runtime_error(k)
+	{ }
+
+	virtual ~unknown_keyword() throw() { }
+};
+
+
+class invalid_signature: public runtime_error
+{
+public:
+	invalid_signature(const std::string &k, const std::string & s):
+		runtime_error(format("%s %s", k, s))
+	{ }
+
+	virtual ~invalid_signature() throw() { }
+};
+
+
 Loader::Loader():
 	cur_st(0),
 	check_sub_loads(false)
@@ -75,7 +109,7 @@ void Loader::load(const Statement &st)
 
 void Loader::load_statement(const Statement &st)
 {
-	cur_st = &st;
+	Set<const Statement *> set_cst(cur_st, &st);
 
 	try
 	{
@@ -85,25 +119,23 @@ void Loader::load_statement(const Statement &st)
 			sub_loaded = false;
 			act->execute(*this, st);
 			if(check_sub_loads && !st.sub.empty() && !sub_loaded)
-				throw Exception("Substatements were not loaded");
+				throw logic_error("substatements ignored");
 		}
 	}
-	catch(Exception &e)
+	catch(const data_error &)
 	{
-		cur_st = 0;
-		if(!e.where()[0])
-			e.at(st.get_location());
-
 		throw;
 	}
-
-	cur_st = 0;
+	catch(const exception &e)
+	{
+		throw data_error(st.source, st.line, e);
+	}
 }
 
 void Loader::load_sub_with(Loader &ldr)
 {
 	if(!cur_st)
-		throw InvalidState("load_sub called without current statement");
+		throw logic_error("no current statement");
 
 	ldr.load(*cur_st);
 	sub_loaded = true;
@@ -128,13 +160,20 @@ LoaderAction *Loader::find_action(const ActionKey &key) const
 	ActionMap::const_iterator end = actions.upper_bound(ActionKey(key.keyword, "~"));
 
 	if(begin==end)
-		throw KeyError("Unknown keyword", key.keyword);
+		throw unknown_keyword(key.keyword);
 
 	for(ActionMap::const_iterator i=begin; i!=end; ++i)
 		if(signature_match(key.signature, i->first.signature))
 			return i->second;
 
-	throw KeyError(format("Keyword '%s' does not accept signature '%s'", key.keyword, key.signature));
+	throw invalid_signature(key.keyword, key.signature);
+}
+
+const string &Loader::get_source() const
+{
+	if(!cur_st)
+		throw logic_error("no current statement");
+	return cur_st->source;
 }
 
 
diff --git a/source/loader.h b/source/loader.h
index 4ea7994..6048861 100644
--- a/source/loader.h
+++ b/source/loader.h
@@ -3,7 +3,6 @@
 
 #include <map>
 #include <msp/io/file.h>
-#include "except.h"
 #include "loaderaction.h"
 #include "parser.h"
 #include "statement.h"
@@ -138,12 +137,7 @@ protected:
 	/** Returns the source of the statement being processed.  This can be used
 	to implement relative paths in include-like statements.  Note that the
 	source may not necessarily be a file. */
-	const std::string &get_source() const
-	{
-		if(!cur_st)
-			throw InvalidState("get_source called without current statement");
-		return cur_st->source;
-	}
+	const std::string &get_source() const;
 
 	virtual void finish() { }
 };
diff --git a/source/loaderaction.h b/source/loaderaction.h
index a6eb552..5b2f0b0 100644
--- a/source/loaderaction.h
+++ b/source/loaderaction.h
@@ -1,7 +1,6 @@
 #ifndef MSP_DATAFILE_LOADERACTION_H_
 #define MSP_DATAFILE_LOADERACTION_H_
 
-#include "except.h"
 #include "statement.h"
 
 namespace Msp {
diff --git a/source/objectloader.cpp b/source/objectloader.cpp
new file mode 100644
index 0000000..6d59812
--- /dev/null
+++ b/source/objectloader.cpp
@@ -0,0 +1,14 @@
+#include <msp/debug/demangle.h>
+#include "objectloader.h"
+
+using namespace std;
+
+namespace Msp {
+namespace DataFile {
+
+no_collection::no_collection(const type_info &t):
+	runtime_error(Debug::demangle(t.name()))
+{ }
+
+} // namespace DataFile
+} // namespace Msp
diff --git a/source/objectloader.h b/source/objectloader.h
index bab1ce5..f1cb6ff 100644
--- a/source/objectloader.h
+++ b/source/objectloader.h
@@ -1,11 +1,18 @@
 #ifndef MSP_DATAFILE_OBJECTLOADER_H_
 #define MSP_DATAFILE_OBJECTLOADER_H_
 
+#include <typeinfo>
 #include "loader.h"
 
 namespace Msp {
 namespace DataFile {
 
+class no_collection: public std::runtime_error
+{
+public:
+	no_collection(const std::type_info &);
+};
+
 class Collection;
 
 /**
@@ -47,7 +54,7 @@ public:
 	C &get_collection() const
 	{
 		if(!coll)
-			throw InvalidState("No collection");
+			throw no_collection(typeid(O));
 		return *coll;
 	}
 };