vala: Don't require constant initializer in fast-vapi

Regression of 984c034

Extend --fast-vapi test by using --use-fast-vapi

See dino/dino#646
and https://gitlab.gnome.org/GNOME/vala/issues/461

codegen/valaccodebasemodule.vala

@@ -961,7 +961,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 			return;
 		}
 
-		if (!c.external) {
+		if (!c.external || (c.source_type == SourceFileType.FAST && c.value != null)) {
 			generate_type_declaration (c.type_reference, decl_space);
 
 			c.value.emit (this);

tests/fastvapi/Makefile.am

@@ -8,16 +8,24 @@ check-fastvapi: $(top_builddir)/compiler/valac
 		--basedir $(srcdir) \
 		$(srcdir)/fastvapitest.vala; \
 	tail -n +3 fastvapitest.vapi | diff -wu $(srcdir)/fastvapitest.vapi-expected - || exit 1; \
-	rm -f fastvapitest.vapi fastvapitest.c
+	G_DEBUG=fatal-warnings $(top_builddir)/compiler/valac \
+		-C \
+		--disable-version-header \
+		--use-fast-vapi fastvapitest.vapi \
+		--basedir $(srcdir) \
+		$(srcdir)/usefastvapitest.vala; \
+	rm -f fastvapitest.vapi fastvapitest.c usefastvapitest.c
 
 check: check-fastvapi
 
 EXTRA_DIST = \
 	fastvapitest.vala \
 	fastvapitest.vapi-expected \
+	usefastvapitest.vala \
 	$(NULL)
 
 CLEANFILES = \
 	fastvapitest.c \
 	fastvapitest.vapi \
+	usefastvapitest.c \
 	$(NULL)

tests/fastvapi/fastvapitest.vala

@@ -41,4 +41,11 @@ namespace FastVapi {
 	public struct TestSubStruct : TestStruct {
 		public static int static_field_name;
 	}
+
+	public const int CONSTANT_TWO = CONSTANT;
+
+	public enum EnumTestTwo {
+		VALUE = 3,
+		VALUE_TWO = VALUE,
+	}
 }

tests/fastvapi/fastvapitest.vapi-expected

@@ -41,6 +41,13 @@ namespace FastVapi {
 		[Source (filename = "fastvapitest.vala", line = 5, column = 3)]
 		VALUE
 	}
+	[Source (filename = "fastvapitest.vala", line = 47, column = 2)]
+	public enum EnumTestTwo {
+		[Source (filename = "fastvapitest.vala", line = 48, column = 3)]
+		VALUE = 3,
+		[Source (filename = "fastvapitest.vala", line = 49, column = 3)]
+		VALUE_TWO
+	}
 	[Source (filename = "fastvapitest.vala", line = 8, column = 2)]
 	public errordomain ErrorTest {
 		[Source (filename = "fastvapitest.vala", line = 9, column = 3)]
@@ -50,4 +57,6 @@ namespace FastVapi {
 	public delegate bool DelegateTest (int param);
 	[Source (filename = "fastvapitest.vala", line = 2, column = 2)]
 	public const int CONSTANT = 42;
+	[Source (filename = "fastvapitest.vala", line = 45, column = 2)]
+	public const int CONSTANT_TWO;
 }

tests/fastvapi/usefastvapitest.vala

@@ -0,0 +1,7 @@
+void main () {
+	assert (FastVapi.CONSTANT == 42);
+	assert (FastVapi.CONSTANT_TWO == 42);
+
+	assert (FastVapi.EnumTestTwo.VALUE == 3);
+	assert (FastVapi.EnumTestTwo.VALUE_TWO == 3);
+}

vala/valaconstant.vala

@@ -123,8 +123,11 @@ public class Vala.Constant : Symbol {
 
 		if (!external) {
 			if (value == null) {
-				error = true;
-				Report.error (source_reference, "A const field requires a value to be provided");
+				// constants from fast-vapi files are special
+				if (source_type != SourceFileType.FAST) {
+					error = true;
+					Report.error (source_reference, "A const field requires a value to be provided");
+				}
 			} else {
 				value.target_type = type_reference;