all: add stdcall attribute, unhandled exception handler, get_raw_stdin, v_realloc

vlib/builtin/builtin.v

@@ -158,7 +158,16 @@ TODO
 	print_backtrace()
 #endif
 */
+}
 
+[unsafe_fn]
+pub fn v_realloc(b byteptr, n int) byteptr {
+	ptr := C.realloc(b, n)
+	if ptr == 0 {
+		panic('realloc($n) failed')
+	}
+
+	return ptr
 }
 
 pub fn v_calloc(n int) byteptr {

vlib/builtin/builtin_windows.c.v

@@ -64,6 +64,7 @@ fn builtin_init() {
 		C.SetConsoleMode(C.GetStdHandle(C.STD_OUTPUT_HANDLE), C.ENABLE_PROCESSED_OUTPUT | 0x0004) // enable_virtual_terminal_processing
 		C.setbuf(C.stdout, 0)
 	}
+	add_unhandled_exception_handler()
 }
 
 fn print_backtrace_skipping_top_frames(skipframes int) bool {
@@ -139,3 +140,56 @@ fn print_backtrace_skipping_top_frames_mingw(skipframes int) bool {
 	eprintln('print_backtrace_skipping_top_frames_mingw is not implemented')
 	return false
 }
+
+
+//TODO copypaste from os
+// we want to be able to use this here without having to `import os`
+struct ExceptionRecord {
+pub:
+	// status_ constants
+	code u32
+	flags u32
+	
+	record &ExceptionRecord
+	address voidptr
+	param_count u32
+	// params []voidptr
+}
+
+ struct ContextRecord {
+	// TODO
+}
+
+struct ExceptionPointers {
+pub:
+	exception_record &ExceptionRecord
+	context_record &ContextRecord
+}
+
+type VectoredExceptionHandler fn(&ExceptionPointers)u32
+
+fn C.AddVectoredExceptionHandler(u32, VectoredExceptionHandler)
+fn add_vectored_exception_handler(handler VectoredExceptionHandler) {
+	C.AddVectoredExceptionHandler(1, handler)
+}
+
+[windows_stdcall]
+fn unhandled_exception_handler(e &ExceptionPointers) u32 {
+	match e.exception_record.code {
+		// These are 'used' by the backtrace printer 
+		// so we dont want to catch them...
+		0x4001000A, 0x40010006 {
+			return 0
+		}
+		else {
+			println('Unhandled Exception 0x${e.exception_record.code:X}')
+			print_backtrace_skipping_top_frames(5)
+		}
+	}
+
+	return 0
+}
+
+pub fn add_unhandled_exception_handler() {
+	add_vectored_exception_handler(unhandled_exception_handler)
+}

vlib/os/const_windows.c.v

@@ -102,3 +102,38 @@ const (
 	o_noctty	= 0			// make file non-controlling tty (ignored on Windows)
 	o_nonblock	= 0			// don't block on opening file (ignored on Windows)
 )
+
+const (
+	status_access_violation =          0xC0000005
+	status_in_page_error =             0xC0000006
+	status_invalid_handle =            0xC0000008
+	status_invalid_parameter =         0xC000000D
+	status_no_memory =                 0xC0000017
+	status_illegal_instruction =       0xC000001D
+	status_noncontinuable_exception =  0xC0000025
+	status_invalid_disposition =       0xC0000026
+	status_array_bounds_exceeded =     0xC000008C
+	status_float_denormal_operand =    0xC000008D
+	status_float_divide_by_zero =      0xC000008E
+	status_float_inexact_result =      0xC000008F
+	status_float_invalid_operation =   0xC0000090
+	status_float_overflow =            0xC0000091
+	status_float_stack_check =         0xC0000092
+	status_float_underflow =           0xC0000093
+	status_integer_divide_by_zero =    0xC0000094
+	status_integer_overflow =          0xC0000095
+	status_privileged_instruction =    0xC0000096
+	status_stack_overflow =            0xC00000FD
+	status_dll_not_found =             0xC0000135
+	status_ordinal_not_found =         0xC0000138
+	status_entrypoint_not_found =      0xC0000139
+	status_control_c_exit =            0xC000013A
+	status_dll_init_failed =           0xC0000142
+	status_float_multiple_faults =     0xC00002B4
+	status_float_multiple_traps =      0xC00002B5
+	status_reg_nat_consumption =       0xC00002C9
+	status_heap_corruption =           0xC0000374
+	status_stack_buffer_overrun =      0xC0000409
+	status_invalid_cruntime_parameter = 0xC0000417
+	status_assertion_failure =         0xC0000420
+)

vlib/os/os.v

@@ -787,6 +787,30 @@ pub fn get_raw_line() string {
 	}
 }
 
+pub fn get_raw_stdin() []byte {
+	$if windows {
+		unsafe {
+			block_bytes := 512
+			mut buf := malloc(block_bytes)
+			h_input := C.GetStdHandle(std_input_handle)
+			mut bytes_read := 0
+			mut offset := 0
+			for {
+				pos := buf + offset
+				res := C.ReadFile(h_input, pos, block_bytes, &bytes_read, 0)
+				if !res {
+					break
+				}
+				offset += bytes_read
+				buf = v_realloc(buf, offset + block_bytes + (block_bytes-bytes_read))
+			}
+			return array{element_size: 1 data: voidptr(buf) len: offset cap: offset }
+		}
+	} $else {
+		panic('get_raw_stdin not implemented on this platform...')
+	}
+}
+
 pub fn get_lines() []string {
 	mut line := ''
 	mut inputstr := []string{}

vlib/os/os_windows.c.v

@@ -311,3 +311,38 @@ pub fn (mut f File) close() {
 	C.fflush(f.cfile)
 	C.fclose(f.cfile)
 }
+
+pub struct ExceptionRecord {
+pub:
+	// status_ constants
+	code u32
+	flags u32
+	
+	record &ExceptionRecord
+	address voidptr
+	param_count u32
+	// params []voidptr
+}
+
+pub struct ContextRecord {
+	// TODO
+}
+
+pub struct ExceptionPointers {
+pub:
+	exception_record &ExceptionRecord
+	context_record &ContextRecord
+}
+
+pub type VectoredExceptionHandler fn(&ExceptionPointers)u32
+
+// This is defined in builtin because we use vectored exception handling
+// for our unhandled exception handler on windows
+
+// As a result this definition is commented out to prevent
+// duplicate definitions from displeasing the compiler
+// fn C.AddVectoredExceptionHandler(u32, VectoredExceptionHandler)
+
+pub fn add_vectored_exception_handler(first bool, handler VectoredExceptionHandler) {
+	C.AddVectoredExceptionHandler(u32(first), handler)
+}

vlib/v/gen/fn.v

@@ -37,6 +37,8 @@ fn (mut g Gen) gen_fn_decl(it ast.FnDecl) {
 	}
 	//
 	fn_start_pos := g.out.len
+
+	mut msvc_attrs := ''
 	match g.attr {
 		'inline' {
 			g.write('inline ')
@@ -95,6 +97,14 @@ fn (mut g Gen) gen_fn_decl(it ast.FnDecl) {
 		'_pure' {
 			g.write('__attribute__((const)) ')
 		}
+
+		// windows attributes (msvc/mingw)
+		// prefixed by windows to indicate they're for advanced users only and not really supported by V.
+
+		'windows_stdcall' {
+			msvc_attrs += '__stdcall '
+		}
+
 		else {
 			// nothing but keep V happy
 		}
@@ -174,8 +184,8 @@ fn (mut g Gen) gen_fn_decl(it ast.FnDecl) {
 				g.write('static ')
 				g.definitions.write('static ')
 			}
-			g.definitions.write('$type_name ${name}(')
+			g.definitions.write('$type_name $msvc_attrs ${name}(')
-			g.write('$type_name ${name}(')
+			g.write('$type_name $msvc_attrs ${name}(')
 		}
 		fargs, fargtypes := g.fn_args(it.args, it.is_variadic)
 		if it.no_body || (g.pref.use_cache && it.is_builtin) {