Index: src/ResolvExpr/CurrentObject.cc
===================================================================
--- src/ResolvExpr/CurrentObject.cc	(revision 92c0f814eb9a7a9fdc68157a5d60b40b700525c2)
+++ src/ResolvExpr/CurrentObject.cc	(revision 56e49b0f2a7f4c543915bdf9e4bd2fa65be2d947)
@@ -36,5 +36,5 @@
 				return constExpr->get_constant()->get_ival();
 			} else {
-				assertf( false, "Non-integer constant expression in getConstValue", toString( constExpr ).c_str() ); // xxx - might be semantic error
+				assertf( false, "Non-integer constant expression in getConstValue %s", toString( constExpr ).c_str() ); // xxx - might be semantic error
 			}
 		} else if ( dynamic_cast< OneType * >( constExpr->get_result() ) ) {
@@ -176,5 +176,5 @@
 				setPosition( castExpr->get_arg() );
 			} else if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( expr ) ) {
-				assertf( dynamic_cast<EnumInstType *> ( varExpr->get_result() ), "ArrayIterator given variable that isn't an enum constant", toString( expr ).c_str() );
+				assertf( dynamic_cast<EnumInstType *> ( varExpr->get_result() ), "ArrayIterator given variable that isn't an enum constant : %s", toString( expr ).c_str() );
 				index = 0; // xxx - get actual value of enum constant
 			} else if ( dynamic_cast< SizeofExpr * >( expr ) || dynamic_cast< AlignofExpr * >( expr ) ) {
@@ -518,5 +518,5 @@
 			curTypes = newTypes;
 			newTypes.clear();
-			assertf( desigAlts.size() == curTypes.size(), "Designator alternatives (%d) and current types (%d) out of sync", desigAlts.size(), curTypes.size() );
+			assertf( desigAlts.size() == curTypes.size(), "Designator alternatives (%zu) and current types (%zu) out of sync", desigAlts.size(), curTypes.size() );
 		} // for
 		if ( desigAlts.size() > 1 ) {
Index: src/SymTab/Validate.cc
===================================================================
--- src/SymTab/Validate.cc	(revision 92c0f814eb9a7a9fdc68157a5d60b40b700525c2)
+++ src/SymTab/Validate.cc	(revision 56e49b0f2a7f4c543915bdf9e4bd2fa65be2d947)
@@ -903,5 +903,5 @@
 		FunctionType * ftype = functionDecl->get_functionType();
 		std::list< DeclarationWithType * > & retVals = ftype->get_returnVals();
-		assertf( retVals.size() == 0 || retVals.size() == 1, "Function %s has too many return values: %d", functionDecl->get_name().c_str(), retVals.size() );
+		assertf( retVals.size() == 0 || retVals.size() == 1, "Function %s has too many return values: %zu", functionDecl->get_name().c_str(), retVals.size() );
 		if ( retVals.size() == 1 ) {
 			// ensure all function return values have a name - use the name of the function to disambiguate (this also provides a nice bit of help for debugging).