[c standard] use WINPR_FALLTHROUGH

use the macro to silence intentional switch fallthrough locations

channels/urbdrc/client/libusb/libusb_udevice.c

@@ -22,6 +22,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <winpr/wtypes.h>
 #include <winpr/sysinfo.h>
 #include <winpr/collections.h>
 
@@ -286,10 +287,12 @@ static void LIBUSB_CALL func_iso_callback(struct libusb_transfer* transfer)
 			}
 		}
 			/* fallthrough */
-
+			WINPR_FALLTHROUGH
 		case LIBUSB_TRANSFER_CANCELLED:
+			/* fallthrough */
 			WINPR_FALLTHROUGH
 		case LIBUSB_TRANSFER_TIMED_OUT:
+			/* fallthrough */
 			WINPR_FALLTHROUGH
 		case LIBUSB_TRANSFER_ERROR:
 		{

client/X11/xf_input.c

@@ -38,6 +38,7 @@
 #include "xf_input.h"
 
 #include <winpr/assert.h>
+#include <winpr/wtypes.h>
 #include <freerdp/log.h>
 #define TAG CLIENT_TAG("x11")
 
@@ -855,15 +856,19 @@ static int xf_input_handle_event_remote(xfContext* xfc, const XEvent* event)
 		{
 			case XI_TouchBegin:
 				xf_input_pens_unhover(xfc);
+				/* fallthrough */
 				WINPR_FALLTHROUGH
 			case XI_TouchUpdate:
+				/* fallthrough */
 				WINPR_FALLTHROUGH
 			case XI_TouchEnd:
 				xf_input_touch_remote(xfc, cookie.cc->data, cookie.cc->evtype);
 				break;
 			case XI_ButtonPress:
+				/* fallthrough */
 				WINPR_FALLTHROUGH
 			case XI_Motion:
+				/* fallthrough */
 				WINPR_FALLTHROUGH
 			case XI_ButtonRelease:
 			{
@@ -877,6 +882,7 @@ static int xf_input_handle_event_remote(xfContext* xfc, const XEvent* event)
 					break;
 				}
 			}
+				/* fallthrough */
 				WINPR_FALLTHROUGH
 			default:
 				xf_input_pens_unhover(xfc);

libfreerdp/core/credssp_auth.c

@@ -27,6 +27,7 @@
 #include <freerdp/peer.h>
 
 #include <winpr/crt.h>
+#include <winpr/wtypes.h>
 #include <winpr/assert.h>
 #include <winpr/library.h>
 #include <winpr/registry.h>
@@ -706,7 +707,7 @@ void credssp_auth_free(rdpCredsspAuth* auth)
 			case AUTH_STATE_FINAL:
 				WINPR_ASSERT(auth->table->DeleteSecurityContext);
 				auth->table->DeleteSecurityContext(&auth->context);
-				/* FALLTHROUGH */
+				/* fallthrouth */
 				WINPR_FALLTHROUGH
 			case AUTH_STATE_CREDS:
 				WINPR_ASSERT(auth->table->FreeCredentialsHandle);

libfreerdp/core/gateway/rpc_client.c

@@ -22,6 +22,7 @@
 #include <freerdp/log.h>
 
 #include <winpr/crt.h>
+#include <winpr/wtypes.h>
 #include <winpr/assert.h>
 #include <winpr/print.h>
 #include <winpr/synch.h>
@@ -286,7 +287,7 @@ static int rpc_client_recv_pdu(rdpRpc* rpc, RPC_PDU* pdu)
 						WLog_ERR(TAG, "rpc_secure_bind: error sending rpc_auth_3 pdu!");
 						return -1;
 					}
-					/* FALLTHROUGH */
+					/* fallthrough */
 					WINPR_FALLTHROUGH
 				case RPC_BIND_STATE_COMPLETE:
 					rpc_client_transition_to_state(rpc, RPC_CLIENT_STATE_CONTEXT_NEGOTIATED);

winpr/include/config/wtypes.h.in

@@ -29,9 +29,13 @@
 #define WINPR_RESTRICT
 #endif
 
-// C17 related macros
-#if defined(__STDC__) && defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201710L)
-#define WINPR_FALLTHROUGH [[fallthrough]]
+// C23 related macros
+#if defined(__STDC__) && defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 202311L)
+#define WINPR_FALLTHROUGH [[fallthrough]];
+#elif defined(__clang__)
+#define WINPR_FALLTHROUGH __attribute__((fallthrough));
+#elif defined(__GNUC__) && (__GNUC__ >= 7)
+#define WINPR_FALLTHROUGH __attribute__((fallthrough));
 #else
 #define WINPR_FALLTHROUGH
 #endif

winpr/libwinpr/crt/unicode_builtin.c

@@ -38,6 +38,7 @@ See the header file "utf.h" for complete documentation.
 
 ------------------------------------------------------------------------ */
 
+#include <winpr/wtypes.h>
 #include <winpr/string.h>
 #include <winpr/assert.h>
 
@@ -242,14 +243,19 @@ static ConversionResult winpr_ConvertUTF16toUTF8_Internal(const uint16_t** sourc
 				case 4:
 					*--target = (uint8_t)((ch | byteMark) & byteMask);
 					ch >>= 6;
-
+					/* fallthrough */
+					WINPR_FALLTHROUGH
 				case 3:
 					*--target = (uint8_t)((ch | byteMark) & byteMask);
 					ch >>= 6;
+					/* fallthrough */
+					WINPR_FALLTHROUGH
 
 				case 2:
 					*--target = (uint8_t)((ch | byteMark) & byteMask);
 					ch >>= 6;
+					/* fallthrough */
+					WINPR_FALLTHROUGH
 
 				case 1:
 					*--target = (uint8_t)(ch | firstByteMark[bytesToWrite]);
@@ -262,12 +268,18 @@ static ConversionResult winpr_ConvertUTF16toUTF8_Internal(const uint16_t** sourc
 					/* note: everything falls through. */
 				case 4:
 					--target;
+					/* fallthrough */
+					WINPR_FALLTHROUGH
 
 				case 3:
 					--target;
+					/* fallthrough */
+					WINPR_FALLTHROUGH
 
 				case 2:
 					--target;
+					/* fallthrough */
+					WINPR_FALLTHROUGH
 
 				case 1:
 					--target;
@@ -309,10 +321,14 @@ static bool isLegalUTF8(const uint8_t* source, int length)
 		case 4:
 			if ((a = (*--srcptr)) < 0x80 || a > 0xBF)
 				return false;
+			/* fallthrough */
+			WINPR_FALLTHROUGH
 
 		case 3:
 			if ((a = (*--srcptr)) < 0x80 || a > 0xBF)
 				return false;
+			/* fallthrough */
+			WINPR_FALLTHROUGH
 
 		case 2:
 			if ((a = (*--srcptr)) > 0xBF)
@@ -348,7 +364,10 @@ static bool isLegalUTF8(const uint8_t* source, int length)
 				default:
 					if (a < 0x80)
 						return false;
+					break;
 			}
+			/* fallthrough */
+			WINPR_FALLTHROUGH
 
 		case 1:
 			if (*source >= 0x80 && *source < 0xC2)
@@ -404,22 +423,32 @@ static ConversionResult winpr_ConvertUTF8toUTF16_Internal(const uint8_t** source
 			case 5:
 				ch += *source++;
 				ch <<= 6; /* remember, illegal UTF-8 */
+				          /* fallthrough */
+				WINPR_FALLTHROUGH
 
 			case 4:
 				ch += *source++;
 				ch <<= 6; /* remember, illegal UTF-8 */
+				          /* fallthrough */
+				WINPR_FALLTHROUGH
 
 			case 3:
 				ch += *source++;
 				ch <<= 6;
+				/* fallthrough */
+				WINPR_FALLTHROUGH
 
 			case 2:
 				ch += *source++;
 				ch <<= 6;
+				/* fallthrough */
+				WINPR_FALLTHROUGH
 
 			case 1:
 				ch += *source++;
 				ch <<= 6;
+				/* fallthrough */
+				WINPR_FALLTHROUGH
 
 			case 0:
 				ch += *source++;

winpr/libwinpr/ncrypt/ncrypt_pkcs11.c

@@ -208,9 +208,12 @@ static CK_RV object_load_attributes(NCryptP11ProviderHandle* provider, CK_SESSIO
 				return rv;
 			/* fallthrough */
 			WINPR_FALLTHROUGH
-
 		case CKR_ATTRIBUTE_SENSITIVE:
+			/* fallthrough */
+			WINPR_FALLTHROUGH
 		case CKR_ATTRIBUTE_TYPE_INVALID:
+			/* fallthrough */
+			WINPR_FALLTHROUGH
 		case CKR_BUFFER_TOO_SMALL:
 			/* attributes need some buffers for the result value */
 			if (!attributes_allocate_buffers(attributes, count))

winpr/libwinpr/sspi/Kerberos/kerberos.c

@@ -818,6 +818,7 @@ static SECURITY_STATUS SEC_ENTRY kerberos_InitializeSecurityContextA(
 				goto bad_token;
 
 			/* Continue to AP-REQ */
+			/* fall through */
 			WINPR_FALLTHROUGH
 
 		case KERBEROS_STATE_AP_REQ:

winpr/libwinpr/sspi/Negotiate/negotiate.c

@@ -21,6 +21,7 @@
 #include <winpr/config.h>
 
 #include <winpr/crt.h>
+#include <winpr/wtypes.h>
 #include <winpr/assert.h>
 #include <winpr/sspi.h>
 #include <winpr/tchar.h>
@@ -798,7 +799,9 @@ static SECURITY_STATUS SEC_ENTRY negotiate_InitializeSecurityContextW(
 				case REJECT:
 					return SEC_E_LOGON_DENIED;
 				case REQUEST_MIC:
-					context->mic = TRUE; /* fallthrough */
+					context->mic = TRUE;
+					/* fallthrough */
+					WINPR_FALLTHROUGH
 				case ACCEPT_INCOMPLETE:
 					context->state = NEGOTIATE_STATE_NEGORESP;
 					break;