Automatically generate user space syscall prototypes

Any instances of userptr<T> in the kernel syscall prototypes are translated to regular pointers for the user space prototypes. Also, this requires marking sys_exit's magic syscall comment with a new flag to indicate it does not return.

Automatically generate user space syscall prototypes
5ca8b8e0 · Austin Clements · 203de796 · 5ca8b8e0 · 5ca8b8e0 · 5ca8b8e0
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,7 @@ NM = $(TOOLPREFIX)nm
 OBJCOPY = $(TOOLPREFIX)objcopy
 STRIP = $(TOOLPREFIX)strip

-INCLUDES  = -iquote include -Istdinc -I$(QEMUSRC) -include param.h -include include/compiler.h
+INCLUDES  = -iquote include -iquote$(O)/include -Istdinc -I$(QEMUSRC) -include param.h -include include/compiler.h
 COMFLAGS  = -static -g -MD -m64 -O3 -Wall -Werror -DHW_$(HW) -DXV6 \
 	    -fno-builtin -fno-strict-aliasing -fno-omit-frame-pointer -fms-extensions \
 	    -mno-sse -mcx16 -mno-red-zone $(INCLUDES)

--- a/bin/Makefrag
+++ b/bin/Makefrag
@@ -57,5 +57,7 @@ $(O)/bin/%: $(O)/bin/%.unstripped
 	$(Q)mkdir -p $(@D)
 	$(Q)$(STRIP) -o $@ $<

+$(addsuffix .o,$(UPROGS)): $(O)/include/sysstubs.h
+
 .PRECIOUS: $(O)/bin/%.o $(O)/bin/%.unstripped
 -include $(O)/bin/*.d
--- a/include/user.h
+++ b/include/user.h
@@ -2,40 +2,9 @@

 BEGIN_DECLS
 struct stat;
-struct ipcmsg;
+struct sockaddr;

-// system calls
-int fork(int);
-int exit(void) __attribute__((noreturn));
-int wait(void);
-int pipe(int*);
-ssize_t write(int, const void*, size_t);
-ssize_t read(int, void*, size_t);
-int close(int);
-int kill(int);
-int exec(const char*, const char**);
-int openat(int dirfd, const char *pathname, int omode);
-int mknod(const char*, int, int);
-int unlink(const char*);
-int fstat(int fd, struct stat*);
-int link(const char*, const char*);
-int mkdir(const char*);
-int mkdirat(int dirfd, const char *pathname);
-int chdir(const char*);
-int dup(int);
-int getpid(void);
-char* sbrk(int);
-int nsleep(u64);
-u64 uptime(void);
-int map(void *addr, size_t len);
-int unmap(void *addr, size_t len);
-int halt(void);
-ssize_t pread(int, void*, size_t, off_t);
-int async(int, size_t, off_t, int, int);
-int script(void *addr, u64 len, u64 chunk);
-int setfs(u64 base);
-int setaffinity(int cpu);
-long futex(const u64* addr, int op, u64 val, u64 timer);
+#include "sysstubs.h"

 // ulib.c
 int stat(char*, struct stat*);
@@ -48,6 +17,7 @@ char* strchr(const char*, char c);
 int strcmp(const char*, const char*);
 int strncmp(const char *p, const char *q, size_t n);
 int open(const char*, int);
+int mkdir(const char*);

 char* gets(char*, int max);
 unsigned int strlen(const char*);

--- a/kernel/sysproc.cc
+++ b/kernel/sysproc.cc
@@ -20,7 +20,7 @@ sys_fork(int flags)
  return fork(flags);
 }

-//SYSCALL
+//SYSCALL NORET
 int
 sys_exit(void)
 {

--- a/lib/Makefrag
+++ b/lib/Makefrag
@@ -10,5 +10,10 @@ $(O)/lib/sysstubs.S: tools/syscalls.py kernel/*.cc
 	$(Q)mkdir -p $(@D)
 	$(Q)python $^ --ustubs > $@

+$(O)/include/sysstubs.h: tools/syscalls.py kernel/*.cc
+	@echo "  GEN    $@"
+	$(Q)mkdir -p $(@D)
+	$(Q)python $^ --udecls > $@
+
 .PRECIOUS: $(O)/lib/%.o
 -include $(O)/lib/*.d
--- a/lib/wquser.cc
+++ b/lib/wquser.cc
@@ -14,8 +14,6 @@ static std::atomic<int> nextid;

 static wq *wq_;

-extern "C" long wqwait(void);
-
 static void __attribute__((used))
 initworker(void)
 {

--- a/tools/syscalls.py
+++ b/tools/syscalls.py
@@ -7,6 +7,8 @@ def main():
                      help="output kernel syscall vectors")
    parser.add_option("--ustubs", action="store_true",
                      help="output user syscall stubs")
+    parser.add_option("--udecls", action="store_true",
+                      help="output user syscall declarations")
    (options, args) = parser.parse_args()

    if len(args) < 1:
@@ -59,6 +61,14 @@ def main():
            print "  ret"
            print

+    if options.udecls:
+        for syscall in syscalls:
+            extra = ""
+            if "NORET" in syscall.flags:
+                extra = " __attribute__((noreturn))"
+            print "%s %s(%s)%s;" % (syscall.rettype, syscall.uname,
+                                    ", ".join(syscall.uargs), extra)
+
 class Syscall(object):
    def __init__(self, kname, rettype, kargs, flags, num=None):
        self.kname, self.rettype, self.kargs, self.flags, self.num = \
@@ -68,6 +78,17 @@ class Syscall(object):

        # Construct user space prototype
        self.uname = self.basename
+        uargs = []
+        for karg in kargs:
+            m = re.match("(.*?) *[a-z_]+$", karg)
+            atype = m.group(1)
+            while True:
+                atype2 = re.sub("userptr<(.*)>", r"\1*", atype)
+                if atype2 == atype:
+                    break
+                atype = atype2
+            uargs.append(atype)
+        self.uargs = uargs

    def __repr__(self):
        return "Syscall(%r,%r,%r,%r,%r)" % (