Commit 437311756d

@@ -223,6 +223,9 @@ pub const Value = opaque {
     pub const setInitializer = LLVMSetInitializer;
     extern fn LLVMSetInitializer(GlobalVar: *const Value, ConstantVal: *const Value) void;
 
+    pub const setDLLStorageClass = LLVMSetDLLStorageClass;
+    extern fn LLVMSetDLLStorageClass(Global: *const Value, Class: DLLStorageClass) void;
+
     pub const addCase = LLVMAddCase;
     extern fn LLVMAddCase(Switch: *const Value, OnVal: *const Value, Dest: *const BasicBlock) void;
 
@@ -1482,6 +1485,12 @@ pub const CallAttr = enum(c_int) {
     AlwaysInline,
 };
 
+pub const DLLStorageClass = enum(c_uint) {
+    Default,
+    DLLImport,
+    DLLExport,
+};
+
 pub const address_space = struct {
     pub const default: c_uint = 0;
 

@@ -1103,6 +1103,7 @@ pub const Object = struct {
             }
             llvm_global.setUnnamedAddr(.False);
             llvm_global.setLinkage(.External);
+            if (module.wantDllExports()) llvm_global.setDLLStorageClass(.Default);
             if (self.di_map.get(decl)) |di_node| {
                 if (try decl.isFunction()) {
                     const di_func = @ptrCast(*llvm.DISubprogram, di_node);
@@ -1128,6 +1129,7 @@ pub const Object = struct {
             const exp_name = exports[0].options.name;
             llvm_global.setValueName2(exp_name.ptr, exp_name.len);
             llvm_global.setUnnamedAddr(.False);
+            if (module.wantDllExports()) llvm_global.setDLLStorageClass(.DLLExport);
             if (self.di_map.get(decl)) |di_node| {
                 if (try decl.isFunction()) {
                     const di_func = @ptrCast(*llvm.DISubprogram, di_node);
@@ -1187,6 +1189,7 @@ pub const Object = struct {
             defer module.gpa.free(fqn);
             llvm_global.setValueName2(fqn.ptr, fqn.len);
             llvm_global.setLinkage(.Internal);
+            if (module.wantDllExports()) llvm_global.setDLLStorageClass(.Default);
             llvm_global.setUnnamedAddr(.True);
             if (decl.val.castTag(.variable)) |variable| {
                 const single_threaded = module.comp.bin_file.options.single_threaded;

@@ -1231,7 +1231,7 @@ pub fn create(gpa: Allocator, options: InitOptions) !*Compilation {
             break :blk lm;
         } else default_link_mode;
 
-        const dll_export_fns = if (options.dll_export_fns) |explicit| explicit else is_dyn_lib or options.rdynamic;
+        const dll_export_fns = options.dll_export_fns orelse (is_dyn_lib or options.rdynamic);
 
         const libc_dirs = try detectLibCIncludeDirs(
             arena,

@@ -6529,3 +6529,7 @@ pub fn addGlobalAssembly(mod: *Module, decl_index: Decl.Index, source: []const u
 
     mod.global_assembly.putAssumeCapacityNoClobber(decl_index, duped_source);
 }
+
+pub fn wantDllExports(mod: Module) bool {
+    return mod.comp.bin_file.options.dll_export_fns and mod.getTarget().os.tag == .windows;
+}