sys: syscalls: add a test syscall definition file

This exercises some subset of the preprocessor that would be nice to
still support.

Pull Request:	https://github.com/freebsd/freebsd-src/pull/1575

Makefile.inc1

@@ -1604,7 +1604,8 @@ _sysent_dirs+=	sys/compat/freebsd32
 _sysent_dirs+=	sys/amd64/linux		\
 		sys/amd64/linux32	\
 		sys/arm64/linux		\
-		sys/i386/linux
+		sys/i386/linux		\
+		sys/tools/syscalls/examples/cpp
 
 sysent: .PHONY
 .for _dir in ${_sysent_dirs}

sys/tools/syscalls/examples/cpp/Makefile

@@ -0,0 +1,3 @@
+GENERATED_PREFIX=	test_
+
+.include "../../../../conf/sysent.mk"

sys/tools/syscalls/examples/cpp/syscalls.conf

@@ -0,0 +1,10 @@
+sysnames="test_syscalls.c"
+sysproto="test_proto.h"
+sysproto_h=_TEST_SYSPROTO_H_
+syshdr="test_syscall.h"
+syssw="test_sysent.c"
+syscallprefix="TEST_SYS_"
+switchname="test_sysent"
+namesname="test_syscallnames"
+systrace="test_systrace_args.c"
+compat_set=""

sys/tools/syscalls/examples/cpp/syscalls.master

@@ -0,0 +1,26 @@
+#include <sys/param.h>
+#include <sys/sysent.h>
+#include <sys/sysproto.h>
+
+0	AUE_NULL		UNIMPL	unimpl_syscall0
+
+; Scenario #1: Vendor uses a reserved slot on just a single platform
+#ifdef PLATFORM_FOO
+1	AUE_NULL		STD {
+		int syscall1(
+		    int arg1
+		);
+	}
+#else
+1	AUE_NULL		RESERVED
+#endif
+
+; Scenario #2: The other way around; vendor obsoletes a syscall on newer
+; platforms
+#ifdef PLATFORM_FOO
+2	AUE_NULL		OBSOL	syscall2
+#else
+2	AUE_NULL		STD {
+		int syscall2(void);
+	}
+#endif

sys/tools/syscalls/examples/cpp/test_proto.h

@@ -0,0 +1,63 @@
+/*
+ * System call prototypes.
+ *
+ * DO NOT EDIT-- this file is automatically @generated.
+ */
+
+#ifndef _TEST_SYSPROTO_H_
+#define	_TEST_SYSPROTO_H_
+
+#include <sys/types.h>
+#include <sys/signal.h>
+#include <sys/cpuset.h>
+#include <sys/domainset.h>
+#include <sys/_ffcounter.h>
+#include <sys/_semaphore.h>
+#include <sys/ucontext.h>
+#include <sys/wait.h>
+
+#include <bsm/audit_kevents.h>
+
+struct proc;
+
+struct thread;
+
+#define	PAD_(t)	(sizeof(syscallarg_t) <= sizeof(t) ? \
+		0 : sizeof(syscallarg_t) - sizeof(t))
+
+#if BYTE_ORDER == LITTLE_ENDIAN
+#define	PADL_(t)	0
+#define	PADR_(t)	PAD_(t)
+#else
+#define	PADL_(t)	PAD_(t)
+#define	PADR_(t)	0
+#endif
+
+#ifdef PLATFORM_FOO
+struct syscall1_args {
+	char arg1_l_[PADL_(int)]; int arg1; char arg1_r_[PADR_(int)];
+};
+#else
+#endif
+#ifdef PLATFORM_FOO
+#else
+struct syscall2_args {
+	syscallarg_t dummy;
+};
+#endif
+#ifdef PLATFORM_FOO
+int	sys_syscall1(struct thread *, struct syscall1_args *);
+#else
+#endif
+#ifdef PLATFORM_FOO
+#else
+int	sys_syscall2(struct thread *, struct syscall2_args *);
+#endif
+#define	TEST_SYS_AUE_syscall1	AUE_NULL
+#define	TEST_SYS_AUE_syscall2	AUE_NULL
+
+#undef PAD_
+#undef PADL_
+#undef PADR_
+
+#endif /* !_TEST_SYSPROTO_H_ */

sys/tools/syscalls/examples/cpp/test_syscall.h

@@ -0,0 +1,10 @@
+/*
+ * System call numbers.
+ *
+ * DO NOT EDIT-- this file is automatically @generated.
+ */
+
+#define	TEST_SYS_syscall1	1
+				/* 2 is obsolete syscall2 */
+#define	TEST_SYS_syscall2	2
+#define	TEST_SYS_MAXSYSCALL	3

sys/tools/syscalls/examples/cpp/test_syscalls.c

@@ -0,0 +1,19 @@
+/*
+ * System call names.
+ *
+ * DO NOT EDIT-- this file is automatically @generated.
+ */
+
+const char *test_syscallnames[] = {
+	"#0",			/* 0 = unimpl_syscall0 */
+#ifdef PLATFORM_FOO
+	"syscall1",			/* 1 = syscall1 */
+#else
+	"#1",			/* 1 = reserved for local use */
+#endif
+#ifdef PLATFORM_FOO
+	"obs_syscall2",			/* 2 = obsolete syscall2 */
+#else
+	"syscall2",			/* 2 = syscall2 */
+#endif
+};

sys/tools/syscalls/examples/cpp/test_sysent.c

@@ -0,0 +1,26 @@
+/*
+ * System call switch table.
+ *
+ * DO NOT EDIT-- this file is automatically @generated.
+ */
+
+#include <sys/param.h>
+#include <sys/sysent.h>
+#include <sys/sysproto.h>
+
+#define AS(name) (sizeof(struct name) / sizeof(syscallarg_t))
+
+/* The casts are bogus but will do for now. */
+struct sysent test_sysent[] = {
+	{ .sy_narg = 0, .sy_call = (sy_call_t *)nosys, .sy_auevent = AUE_NULL, .sy_flags = 0, .sy_thrcnt = SY_THR_ABSENT },	/* 0 = unimpl_syscall0 */
+#ifdef PLATFORM_FOO
+	{ .sy_narg = AS(syscall1_args), .sy_call = (sy_call_t *)sys_syscall1, .sy_auevent = AUE_NULL, .sy_flags = 0, .sy_thrcnt = SY_THR_STATIC },	/* 1 = syscall1 */
+#else
+	{ .sy_narg = 0, .sy_call = (sy_call_t *)nosys, .sy_auevent = AUE_NULL, .sy_flags = 0, .sy_thrcnt = SY_THR_ABSENT },	/* 1 = reserved for local use */
+#endif
+#ifdef PLATFORM_FOO
+	{ .sy_narg = 0, .sy_call = (sy_call_t *)nosys, .sy_auevent = AUE_NULL, .sy_flags = 0, .sy_thrcnt = SY_THR_ABSENT },	/* 2 = obsolete syscall2 */
+#else
+	{ .sy_narg = 0, .sy_call = (sy_call_t *)sys_syscall2, .sy_auevent = AUE_NULL, .sy_flags = 0, .sy_thrcnt = SY_THR_STATIC },	/* 2 = syscall2 */
+#endif
+};

sys/tools/syscalls/examples/cpp/test_systrace_args.c

@@ -0,0 +1,91 @@
+/*
+ * System call argument to DTrace register array conversion.
+ *
+ * This file is part of the DTrace syscall provider.
+ *
+ * DO NOT EDIT-- this file is automatically @generated.
+ */
+
+static void
+systrace_args(int sysnum, void *params, uint64_t *uarg, int *n_args)
+{
+	int64_t *iarg = (int64_t *)uarg;
+	int a = 0;
+	switch (sysnum) {
+#ifdef PLATFORM_FOO
+	/* syscall1 */
+	case 1: {
+		struct syscall1_args *p = params;
+		iarg[a++] = p->arg1; /* int */
+		*n_args = 1;
+		break;
+	}
+#else
+#endif
+#ifdef PLATFORM_FOO
+#else
+	/* syscall2 */
+	case 2: {
+		*n_args = 0;
+		break;
+	}
+#endif
+	default:
+		*n_args = 0;
+		break;
+	};
+}
+static void
+systrace_entry_setargdesc(int sysnum, int ndx, char *desc, size_t descsz)
+{
+	const char *p = NULL;
+	switch (sysnum) {
+#ifdef PLATFORM_FOO
+	/* syscall1 */
+	case 1:
+		switch (ndx) {
+		case 0:
+			p = "int";
+			break;
+		default:
+			break;
+		};
+		break;
+#else
+#endif
+#ifdef PLATFORM_FOO
+#else
+	/* syscall2 */
+	case 2:
+		break;
+#endif
+	default:
+		break;
+	};
+	if (p != NULL)
+		strlcpy(desc, p, descsz);
+}
+static void
+systrace_return_setargdesc(int sysnum, int ndx, char *desc, size_t descsz)
+{
+	const char *p = NULL;
+	switch (sysnum) {
+#ifdef PLATFORM_FOO
+	/* syscall1 */
+	case 1:
+		if (ndx == 0 || ndx == 1)
+			p = "int";
+		break;
+#else
+#endif
+#ifdef PLATFORM_FOO
+#else
+	/* syscall2 */
+	case 2:
+#endif
+	default:
+		break;
+	};
+	if (p != NULL)
+		strlcpy(desc, p, descsz);
+}