extern variables and object-like macro consts

compiler/ast/ast.odin

@@ -134,6 +134,7 @@ Function :: struct {
 	params:     []Param,
 	result:     Type_Syntax,
 	body:       []Stmt_Id,
+	link_name:  string,
 	unsupported_reason: string,
 	diagnostic: source.Diagnostic_Id,
 }
@@ -141,10 +142,13 @@ Function :: struct {
 Global :: struct {
 	span:       source.Span,
 	name:       symbol.Id,
+	link_name:  string,
 	pkg:        Package_Id,
 	file:       File_Id,
 	type:       Type_Syntax,
 	immutable:  bool,
+	external:   bool,
+	writable:   bool,
 	expr:       Expr_Id,
 	diagnostic: source.Diagnostic_Id,
 }
@@ -184,6 +188,16 @@ Unsupported :: struct {
 	reason: string,
 }
 
+// Trampoline is a generated C wrapper source that must be compiled and linked
+// alongside the program so an internal-linkage (`static inline`) C function can
+// be called through an external symbol. `source` is the wrapper function only;
+// `header` is the absolute path it must `#include` (emitted once per header).
+Trampoline :: struct {
+	symbol: string,
+	source: string,
+	header: string,
+}
+
 Module :: struct {
 	exprs:      [dynamic]Expr,
 	statements: [dynamic]Stmt,
@@ -193,6 +207,7 @@ Module :: struct {
 	files:      [dynamic]File,
 	packages:   [dynamic]Package,
 	unsupported: [dynamic]Unsupported,
+	c_trampolines: [dynamic]Trampoline,
 	strings:    [dynamic]string,
 	type_store: types.Store,
 	allocator:  mem.Allocator,
@@ -210,6 +225,7 @@ init_module :: proc(allocator := context.allocator) -> Module {
 	module.files.allocator = allocator
 	module.packages.allocator = allocator
 	module.unsupported.allocator = allocator
+	module.c_trampolines.allocator = allocator
 	module.strings.allocator = allocator
 	return module
 }
@@ -221,17 +237,26 @@ destroy_module :: proc(module: ^Module) {
 	for function in module.functions {
 		delete(function.params, module.allocator)
 		delete(function.body, module.allocator)
+		delete(function.link_name, module.allocator)
 		delete(function.unsupported_reason, module.allocator)
 	}
 	for import_item in module.imports {
 		delete(import_item.path, module.allocator)
 	}
+	for global in module.globals {
+		delete(global.link_name, module.allocator)
+	}
 	for pkg in module.packages {
 		delete(pkg.path, module.allocator)
 	}
 	for item in module.unsupported {
 		delete(item.reason, module.allocator)
 	}
+	for trampoline in module.c_trampolines {
+		delete(trampoline.symbol, module.allocator)
+		delete(trampoline.source, module.allocator)
+		delete(trampoline.header, module.allocator)
+	}
 	for value in module.strings {
 		delete(value, module.allocator)
 	}
@@ -243,6 +268,7 @@ destroy_module :: proc(module: ^Module) {
 	delete(module.files)
 	delete(module.packages)
 	delete(module.unsupported)
+	delete(module.c_trampolines)
 	delete(module.strings)
 	types.destroy_store(&module.type_store)
 }