restricted c header imports

compiler/ast/ast.odin

@@ -128,10 +128,12 @@ Function :: struct {
 	pkg:        Package_Id,
 	file:       File_Id,
 	c_abi:      bool,
+	imported:   bool,
 	has_body:   bool,
 	params:     []Param,
 	result:     Type_Syntax,
 	body:       []Stmt_Id,
+	unsupported_reason: string,
 	diagnostic: source.Diagnostic_Id,
 }
 
@@ -167,6 +169,18 @@ Package :: struct {
 	path:      string,
 	name:      symbol.Id,
 	available: bool,
+	kind:      Package_Kind,
+}
+
+Package_Kind :: enum u8 {
+	Native,
+	C_Header,
+}
+
+Unsupported :: struct {
+	pkg:    Package_Id,
+	name:   symbol.Id,
+	reason: string,
 }
 
 Module :: struct {
@@ -177,6 +191,7 @@ Module :: struct {
 	imports:    [dynamic]Import,
 	files:      [dynamic]File,
 	packages:   [dynamic]Package,
+	unsupported: [dynamic]Unsupported,
 	strings:    [dynamic]string,
 	type_store: types.Store,
 	allocator:  mem.Allocator,
@@ -193,6 +208,7 @@ init_module :: proc(allocator := context.allocator) -> Module {
 	module.imports.allocator = allocator
 	module.files.allocator = allocator
 	module.packages.allocator = allocator
+	module.unsupported.allocator = allocator
 	module.strings.allocator = allocator
 	return module
 }
@@ -204,6 +220,7 @@ destroy_module :: proc(module: ^Module) {
 	for function in module.functions {
 		delete(function.params, module.allocator)
 		delete(function.body, module.allocator)
+		delete(function.unsupported_reason, module.allocator)
 	}
 	for import_item in module.imports {
 		delete(import_item.path, module.allocator)
@@ -211,6 +228,9 @@ destroy_module :: proc(module: ^Module) {
 	for pkg in module.packages {
 		delete(pkg.path, module.allocator)
 	}
+	for item in module.unsupported {
+		delete(item.reason, module.allocator)
+	}
 	for value in module.strings {
 		delete(value, module.allocator)
 	}
@@ -221,6 +241,7 @@ destroy_module :: proc(module: ^Module) {
 	delete(module.imports)
 	delete(module.files)
 	delete(module.packages)
+	delete(module.unsupported)
 	delete(module.strings)
 	types.destroy_store(&module.type_store)
 }