Fix link error with containers defined in same slice as element

Adds forward declaration of classes with public visibility before
slice2cpp's default forward declaration is included.

5 files changed, 38 insertions, 2 deletions

diff --git a/slicer/test/classtype.ice b/slicer/test/classtype.ice
index 98ec34a..54f4d45 100644
--- a/slicer/test/classtype.ice
+++ b/slicer/test/classtype.ice
@@ -8,6 +8,7 @@ module TestModule {
 		int a;
 		int b;
 	};
+	sequence<ClassType> Classes;
 };
 
 #endif
diff --git a/slicer/test/collections.ice b/slicer/test/collections.ice
index c9845e0..60798cd 100644
--- a/slicer/test/collections.ice
+++ b/slicer/test/collections.ice
@@ -7,7 +7,6 @@
 module TestModule {
 	sequence<string> SimpleSeq;
 	sequence<BuiltIns> BuiltInSeq;
-	sequence<ClassType> Classes;
 	local sequence<StructType> Structs;
 	dictionary<int, ClassType> ClassMap;
 	local dictionary<int, StructType> StructMap;
diff --git a/slicer/test/preprocessor.cpp b/slicer/test/preprocessor.cpp
index 4f474ee..eddeb31 100644
--- a/slicer/test/preprocessor.cpp
+++ b/slicer/test/preprocessor.cpp
@@ -10,7 +10,7 @@
 #include <tool/parser.h>
 
 using ComponentsCount = std::map<std::string, unsigned int>;
-ComponentsCount COMPONENTS_IN_TEST_ICE = {{"classtype.ice", 1}, {"classes.ice", 3}, {"collections.ice", 6},
+ComponentsCount COMPONENTS_IN_TEST_ICE = {{"classtype.ice", 2}, {"classes.ice", 3}, {"collections.ice", 5},
 		{"enums.ice", 2}, {"inheritance.ice", 12}, {"interfaces.ice", 0}, {"json.ice", 2}, {"locals.ice", 7},
 		{"optionals.ice", 2}, {"structs.ice", 4}, {"types.ice", 3}, {"xml.ice", 5}};
 
diff --git a/slicer/test/serializers.cpp b/slicer/test/serializers.cpp
index 3ab54e5..c8f8390 100644
--- a/slicer/test/serializers.cpp
+++ b/slicer/test/serializers.cpp
@@ -690,3 +690,9 @@ BOOST_AUTO_TEST_CASE(enum_lookups)
 	BOOST_CHECK_EQUAL("One", Slicer::ModelPartForEnum<TestModule::SomeNumbers>::lookup(TestModule::SomeNumbers::One));
 	BOOST_CHECK_EQUAL(TestModule::SomeNumbers::One, Slicer::ModelPartForEnum<TestModule::SomeNumbers>::lookup("One"));
 }
+
+BOOST_AUTO_TEST_CASE(sequence_element_in_same_slice_link_bug)
+{
+	// Link error when sequence element type defined in same slice.
+	Slicer::ModelPartForSequence<TestModule::Classes> mp(nullptr);
+}
diff --git a/slicer/tool/parser.cpp b/slicer/tool/parser.cpp
index 81bb10e..d2288ae 100644
--- a/slicer/tool/parser.cpp
+++ b/slicer/tool/parser.cpp
@@ -14,6 +14,32 @@
 namespace fs = std::filesystem;
 
 namespace Slicer {
+	class ForwardDeclare : public Slice::ParserVisitor {
+	public:
+		ForwardDeclare(FILE * c) : cpp(c) { }
+		bool
+		visitModuleStart(const Slice::ModulePtr & m) override
+		{
+			fprintbf(cpp, "namespace %s {\n", m->name());
+			return true;
+		}
+
+		bool
+		visitClassDefStart(const Slice::ClassDefPtr & c) override
+		{
+			fprintbf(cpp, "class ICE_CLASS(JAM_DLL_PUBLIC) %s;\n", c->name());
+			return false;
+		};
+
+		void
+		visitModuleEnd(const Slice::ModulePtr & m) override
+		{
+			fprintbf(cpp, "} // %s\n\n", m->name());
+		}
+
+		FILE * cpp;
+	};
+
 	template<typename TPtr>
 	bool
 	ignoreType(const TPtr & t)
@@ -102,6 +128,10 @@ namespace Slicer {
 
 		fprintbf(cpp, "// Begin Slicer code\n\n");
 		fprintbf(cpp, "#include <%s>\n\n", (headerPrefix / "modelPartsTypes.impl.h").string());
+
+		ForwardDeclare fd {cpp};
+		u->visit(&fd, true);
+
 		fprintbf(cpp, "#include <%s>\n", fs::path(topLevelFile.filename()).replace_extension(".h").string());
 		for (const auto & m : u->modules()) {
 			for (const auto & i : metaDataValues("slicer:include:", m->getMetaData())) {