From: Rico Tzschichholz <ricotz@ubuntu.com>
Date: Tue, 18 Jun 2019 21:34:09 +0000 (+0200)
Subject: codegen: Don't write declaration of extern symbols with given header
X-Git-Tag: 0.45.3~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=70c4b16d83c90959e806cc055fb0dd65bef0cab3;p=thirdparty%2Fvala.git

codegen: Don't write declaration of extern symbols with given header

The corresponding header will provide the declaration and therefore fix
build with -Werror=redundant-decls.

Set cheader_filename for implicit to_string() method of enums which is
transformed into symbol calls from glib-object.h. This avoids the leak of
an superfluous prototype of that method into the generated c code.

Fixes https://gitlab.gnome.org/GNOME/vala/issues/745
---

diff --git a/codegen/valaccodeattribute.vala b/codegen/valaccodeattribute.vala
index 5728fb469..87d5142e8 100644
--- a/codegen/valaccodeattribute.vala
+++ b/codegen/valaccodeattribute.vala
@@ -837,13 +837,13 @@ public class Vala.CCodeAttribute : AttributeCache {
 		if (sym is DynamicProperty || sym is DynamicMethod) {
 			return "";
 		}
-		if (sym.parent_symbol != null) {
+		if (sym.parent_symbol != null && !sym.is_extern) {
 			var parent_headers = get_ccode_header_filenames (sym.parent_symbol);
 			if (parent_headers.length > 0) {
 				return parent_headers;
 			}
 		}
-		if (sym.source_reference != null && !sym.external_package) {
+		if (sym.source_reference != null && !sym.external_package && !sym.is_extern) {
 			// don't add default include directives for VAPI files
 			return sym.source_reference.file.get_cinclude_filename ();
 		}
diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index e3d8d3b55..af1b761ca 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -657,16 +657,16 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 		if (sym is Constant && ((Constant) sym).value is InitializerList) {
 			return false;
 		}
-		if (sym.external_package || (!decl_space.is_header && CodeContext.get ().use_header && !sym.is_internal_symbol ())) {
+		if (sym.external_package || (!decl_space.is_header && CodeContext.get ().use_header && !sym.is_internal_symbol ())
+		    || (sym.is_extern && get_ccode_header_filenames (sym).length > 0)) {
 			// add feature test macros
 			foreach (unowned string feature_test_macro in get_ccode_feature_test_macros (sym).split (",")) {
 				decl_space.add_feature_test_macro (feature_test_macro);
 			}
 			// add appropriate include file
 			foreach (unowned string header_filename in get_ccode_header_filenames (sym).split (",")) {
-				decl_space.add_include (header_filename, !sym.external_package ||
-				                                         (sym.external_package &&
-				                                          sym.from_commandline));
+				decl_space.add_include (header_filename,
+					!sym.is_extern && (!sym.external_package || (sym.external_package && sym.from_commandline)));
 			}
 			// declaration complete
 			return true;
diff --git a/tests/Makefile.am b/tests/Makefile.am
index b67d91c5b..3439c786f 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -98,6 +98,7 @@ TESTS = \
 	methods/lambda.vala \
 	methods/closures.vala \
 	methods/contains.vala \
+	methods/extern.vala \
 	methods/iterator.vala \
 	methods/prepostconditions.vala \
 	methods/same-name.vala \
diff --git a/tests/methods/extern.vala b/tests/methods/extern.vala
new file mode 100644
index 000000000..45ee4b3f7
--- /dev/null
+++ b/tests/methods/extern.vala
@@ -0,0 +1,31 @@
+[CCode (cname = "g_strdup", cheader_filename = "glib.h")]
+extern string strdup (string s);
+
+[CCode (cname = "vala_some_thing")]
+extern void some_thing ();
+
+namespace Foo {
+	[CCode (cname = "g_strdup", cheader_filename = "glib.h")]
+	extern string strdup (string s);
+
+	[CCode (cname = "vala_some_thing")]
+	extern void some_thing ();
+}
+
+public class Bar {
+	[CCode (cname = "g_strdup", cheader_filename = "glib.h")]
+	public static extern string strdup (string s);
+
+	[CCode (cname = "vala_some_thing")]
+	public static extern void some_thing ();
+}
+
+void main () {
+	assert ("foo" == strdup ("foo"));
+	assert ("foo" == Foo.strdup ("foo"));
+	assert ("foo" == Bar.strdup ("foo"));
+
+	assert (some_thing != null);
+	assert (Foo.some_thing != null);
+	assert (Bar.some_thing != null);
+}
diff --git a/vala/valaenumvaluetype.vala b/vala/valaenumvaluetype.vala
index 896371323..be8ac15d0 100644
--- a/vala/valaenumvaluetype.vala
+++ b/vala/valaenumvaluetype.vala
@@ -48,6 +48,7 @@ public class Vala.EnumValueType : ValueType {
 			to_string_method = new Method ("to_string", string_type);
 			to_string_method.access = SymbolAccessibility.PUBLIC;
 			to_string_method.is_extern = true;
+			to_string_method.set_attribute_string ("CCode", "cheader_filename", "glib-object.h");
 			to_string_method.owner = type_symbol.scope;
 			to_string_method.this_parameter = new Parameter ("this", this);
 			to_string_method.scope.add (to_string_method.this_parameter.name, to_string_method.this_parameter);