codegen: Introduce VALA_EXPORT for public symbols to improve portability

Use it as replacement for "extern" and attribute every public symbol.

We want to ensure that public symbols are exported, which isn't the
default when generating a shared library in MSVC, for example.

1 files changed, 50 insertions, 0 deletions

diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index 3b1163b94..a1897e575 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -366,6 +366,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 	public bool requires_array_n_elements;
 	public bool requires_clear_mutex;
 	public bool requires_memdup2;
+	public bool requires_vala_extern;
 
 	public Set<string> wrappers;
 	Set<Symbol> generated_external_symbols;
@@ -799,6 +800,24 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 		cfile.add_function (fun);
 	}
 
+	/**
+	 * Define a macro hint for exporting a symbol in a portable way.
+	 */
+	void append_vala_extern_define (CCodeFile decl_space) {
+		var extern_define = new CCodeIfSection ("!defined(VALA_EXTERN)");
+
+		CCodeIfSection if_section;
+		if_section = new CCodeIfSection ("defined(_MSC_VER)");
+		extern_define.append (if_section);
+		if_section.append (new CCodeDefine ("VALA_EXTERN", "__declspec(dllexport) extern"));
+		if_section = if_section.append_else ("__GNUC__ >= 4");
+		if_section.append (new CCodeDefine ("VALA_EXTERN", "__attribute__((visibility(\"default\"))) extern"));
+		if_section = if_section.append_else ();
+		if_section.append (new CCodeDefine ("VALA_EXTERN", "extern"));
+
+		decl_space.add_define (extern_define);
+	}
+
 	public override void visit_source_file (SourceFile source_file) {
 		cfile = new CCodeFile (CCodeFileType.SOURCE, source_file);
 
@@ -812,6 +831,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 		requires_array_length = false;
 		requires_array_n_elements = false;
 		requires_clear_mutex = false;
+		requires_vala_extern = false;
 
 		wrappers = new HashSet<string> (str_hash, str_equal);
 		generated_external_symbols = new HashSet<Symbol> ();
@@ -857,6 +877,20 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 		if (requires_memdup2) {
 			append_vala_memdup2 ();
 		}
+		if (requires_vala_extern) {
+			if (context.header_filename != null) {
+				if (!header_file.add_declaration ("VALA_EXTERN")) {
+					append_vala_extern_define (header_file);
+				}
+				cfile.add_include (source_file.get_cinclude_filename (), true);
+				internal_header_file.add_include (source_file.get_cinclude_filename (), true);
+			} else {
+				if (!cfile.add_declaration ("VALA_EXTERN")) {
+					append_vala_extern_define (cfile);
+					append_vala_extern_define (internal_header_file);
+				}
+			}
+		}
 
 		var comments = source_file.get_comments();
 		if (comments != null) {
@@ -932,6 +966,9 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 			regfun.modifiers |= CCodeModifiers.STATIC | CCodeModifiers.UNUSED;
 		} else if (context.hide_internal && en.is_internal_symbol ()) {
 			regfun.modifiers |= CCodeModifiers.INTERNAL;
+		} else {
+			regfun.modifiers |= CCodeModifiers.EXTERN;
+			requires_vala_extern = true;
 		}
 
 		decl_space.add_function_declaration (regfun);
@@ -1054,6 +1091,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 					cdecl.modifiers = CCodeModifiers.STATIC;
 				} else {
 					cdecl.modifiers = CCodeModifiers.EXTERN;
+					requires_vala_extern = true;
 				}
 
 				decl_space.add_constant_declaration (cdecl);
@@ -1148,6 +1186,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 			cdecl.modifiers = CCodeModifiers.STATIC;
 		} else {
 			cdecl.modifiers = CCodeModifiers.EXTERN;
+			requires_vala_extern = true;
 		}
 		if (f.version.deprecated) {
 			cdecl.modifiers |= CCodeModifiers.DEPRECATED;
@@ -1167,6 +1206,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 				flock.modifiers = CCodeModifiers.STATIC;
 			} else {
 				flock.modifiers = CCodeModifiers.EXTERN;
+				requires_vala_extern = true;
 			}
 			decl_space.add_type_member_declaration (flock);
 		}
@@ -1184,6 +1224,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 						cdecl.modifiers = CCodeModifiers.STATIC;
 					} else {
 						cdecl.modifiers = CCodeModifiers.EXTERN;
+						requires_vala_extern = true;
 					}
 					decl_space.add_type_member_declaration (cdecl);
 				}
@@ -1199,6 +1240,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 					cdecl.modifiers = CCodeModifiers.STATIC;
 				} else {
 					cdecl.modifiers = CCodeModifiers.EXTERN;
+					requires_vala_extern = true;
 				}
 				decl_space.add_type_member_declaration (cdecl);
 
@@ -1209,6 +1251,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 						cdecl.modifiers = CCodeModifiers.STATIC;
 					} else {
 						cdecl.modifiers = CCodeModifiers.EXTERN;
+						requires_vala_extern = true;
 					}
 					decl_space.add_type_member_declaration (cdecl);
 				}
@@ -1358,6 +1401,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 				var_def.add_declarator (var_decl);
 				if (!f.is_private_symbol ()) {
 					var_def.modifiers = CCodeModifiers.EXTERN;
+					requires_vala_extern = true;
 				} else {
 					var_def.modifiers = CCodeModifiers.STATIC;
 				}
@@ -1381,6 +1425,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 							len_def.add_declarator (new CCodeVariableDeclarator (get_variable_array_length_cname (f, dim), new CCodeConstant ("0")));
 							if (!f.is_private_symbol ()) {
 								len_def.modifiers = CCodeModifiers.EXTERN;
+								requires_vala_extern = true;
 							} else {
 								len_def.modifiers = CCodeModifiers.STATIC;
 							}
@@ -1403,6 +1448,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 						target_def.add_declarator (new CCodeVariableDeclarator (get_ccode_delegate_target_name (f), new CCodeConstant ("NULL")));
 						if (!f.is_private_symbol ()) {
 							target_def.modifiers = CCodeModifiers.EXTERN;
+							requires_vala_extern = true;
 						} else {
 							target_def.modifiers = CCodeModifiers.STATIC;
 						}
@@ -1413,6 +1459,7 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 							target_destroy_notify_def.add_declarator (new CCodeVariableDeclarator (get_ccode_delegate_target_destroy_notify_name (f), new CCodeConstant ("NULL")));
 							if (!f.is_private_symbol ()) {
 								target_destroy_notify_def.modifiers = CCodeModifiers.EXTERN;
+								requires_vala_extern = true;
 							} else {
 								target_destroy_notify_def.modifiers = CCodeModifiers.STATIC;
 							}
@@ -1709,6 +1756,9 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 			function.modifiers |= CCodeModifiers.STATIC;
 		} else if (context.hide_internal && (prop.is_internal_symbol () || acc.access == SymbolAccessibility.INTERNAL)) {
 			function.modifiers |= CCodeModifiers.INTERNAL;
+		} else {
+			function.modifiers |= CCodeModifiers.EXTERN;
+			requires_vala_extern = true;
 		}
 		decl_space.add_function_declaration (function);
 	}