Add support for pipe2 API. NFC (#26480)

Becuase we support `pipe` already we already support the `flags=0`
version of `pipe2`.

Simply deleting the definition of `SYS_pipe` musl will use
`__syscall_pipe2` for both `pipe` and `pipe2`.

See #14824 (this doesn't fix the issue but works around the specific
instance of it).

Author: sbc100

src/lib/libsigs.js

@@ -261,7 +261,7 @@ sigs = {
   __syscall_mknodat__sig: 'iipii',
   __syscall_newfstatat__sig: 'iippi',
   __syscall_openat__sig: 'iipip',
-  __syscall_pipe__sig: 'ip',
+  __syscall_pipe2__sig: 'ipi',
   __syscall_poll__sig: 'ipii',
   __syscall_readlinkat__sig: 'iippp',
   __syscall_recvfrom__sig: 'iippipp',

src/lib/libsyscall.js

@@ -194,11 +194,14 @@ var SyscallsLibrary = {
     var old = SYSCALLS.getStreamFromFD(fd);
     return FS.dupStream(old).fd;
   },
-  __syscall_pipe__deps: ['$PIPEFS'],
-  __syscall_pipe: (fdPtr) => {
+  __syscall_pipe2__deps: ['$PIPEFS'],
+  __syscall_pipe2: (fdPtr, flags) => {
     if (fdPtr == 0) {
       throw new FS.ErrnoError({{{ cDefs.EFAULT }}});
     }
+    if (flags && flags != {{{ cDefs.O_CLOEXEC }}}) {
+      throw new FS.ErrnoError({{{ cDefs.ENOTSUP }}});
+    }
 
     var res = PIPEFS.createPipe();
 

src/struct_info.json

@@ -102,6 +102,7 @@
             "F_SETLKW",
             "F_GETLK",
             "S_ISVTX",
+            "O_CLOEXEC",
             "O_RDONLY",
             "O_ACCMODE",
             "F_DUPFD",

system/lib/libc/emscripten_syscall_stubs.c

@@ -262,7 +262,6 @@ weak int __syscall_setsockopt(int sockfd, int level, int optname, intptr_t optva
 
 UNIMPLEMENTED(acct, (intptr_t filename))
 UNIMPLEMENTED(mincore, (intptr_t addr, size_t length, intptr_t vec))
-UNIMPLEMENTED(pipe2, (intptr_t fds, int flags))
 UNIMPLEMENTED(pselect6, (int nfds, intptr_t readfds, intptr_t writefds, intptr_t exceptfds, intptr_t timeout, intptr_t sigmaks))
 UNIMPLEMENTED(ppoll, (intptr_t fds, int nfds, intptr_t timeout, intptr_t sigmask, int size))
 UNIMPLEMENTED(recvmmsg, (int sockfd, intptr_t msgvec, size_t vlen, int flags, ...))

system/lib/libc/musl/arch/emscripten/bits/syscall.h

@@ -5,7 +5,6 @@
 #define SYS_sync		 __syscall_sync
 #define SYS_rmdir		 __syscall_rmdir
 #define SYS_dup		 __syscall_dup
-#define SYS_pipe		 __syscall_pipe
 #define SYS_acct		 __syscall_acct
 #define SYS_ioctl		 __syscall_ioctl
 #define SYS_setpgid		 __syscall_setpgid

system/lib/libc/musl/arch/emscripten/syscall_arch.h

@@ -21,7 +21,6 @@ int __syscall_access(intptr_t path, int amode);
 int __syscall_sync(void);
 int __syscall_rmdir(intptr_t path);
 int __syscall_dup(int fd);
-int __syscall_pipe(intptr_t fd);
 int __syscall_acct(intptr_t filename);
 int __syscall_ioctl(int fd, int request, ...);
 int __syscall_setpgid(int pid, int gpid);

system/lib/wasmfs/syscalls.cpp

@@ -1331,8 +1331,11 @@ int __syscall_ioctl(int fd, int request, ...) {
   }
 }
 
-int __syscall_pipe(intptr_t fd) {
+int __syscall_pipe2(intptr_t fd, int flags) {
   auto* fds = (__wasi_fd_t*)fd;
+  if (flags && flags != O_CLOEXEC) {
+    return -ENOTSUP;
+  }
 
   // Make a pipe: Two PipeFiles that share a single data source between them, so
   // that writing to one can be read in the other.

test/codesize/test_codesize_hello_dylink_all.json

@@ -1,7 +1,7 @@
 {
-  "a.out.js": 244330,
-  "a.out.nodebug.wasm": 577696,
-  "total": 822026,
+  "a.out.js": 244367,
+  "a.out.nodebug.wasm": 577720,
+  "total": 822087,
   "sent": [
     "IMG_Init",
     "IMG_Load",
@@ -247,7 +247,7 @@
     "__syscall_mknodat",
     "__syscall_newfstatat",
     "__syscall_openat",
-    "__syscall_pipe",
+    "__syscall_pipe2",
     "__syscall_poll",
     "__syscall_readlinkat",
     "__syscall_recvfrom",
@@ -1436,7 +1436,7 @@
     "env.__syscall_mknodat",
     "env.__syscall_newfstatat",
     "env.__syscall_openat",
-    "env.__syscall_pipe",
+    "env.__syscall_pipe2",
     "env.__syscall_poll",
     "env.__syscall_readlinkat",
     "env.__syscall_recvfrom",
@@ -1889,7 +1889,6 @@
     "__syscall_munlockall",
     "__syscall_munmap",
     "__syscall_pause",
-    "__syscall_pipe2",
     "__syscall_ppoll",
     "__syscall_prlimit64",
     "__syscall_pselect6",
@@ -3752,7 +3751,6 @@
     "$__syscall_msync",
     "$__syscall_munmap",
     "$__syscall_pause",
-    "$__syscall_pipe2",
     "$__syscall_ppoll",
     "$__syscall_prlimit64",
     "$__syscall_pselect6",

test/unistd/misc.c

@@ -80,6 +80,13 @@ int main() {
   printf(", errno: %d\n", errno);
   errno = 0;
 
+  printf("pipe2(good): %d", pipe2(pipe_arg, 0));
+  printf(", errno: %d\n", errno);
+  errno = 0;
+  printf("pipe2(bad): %d", pipe2(0, 0));
+  printf(", errno: %d\n", errno);
+  errno = 0;
+
   char* exec_argv[] = {"arg", 0};
   char* exec_env[] = {"a=b", 0};
   printf("execl: %d", execl("working/program", "arg", 0));

test/unistd/misc.out

@@ -13,6 +13,8 @@ nice: -1, errno: 63
 pause: -1, errno: 27
 pipe(good): 0, errno: 0
 pipe(bad): -1, errno: 21
+pipe2(good): 0, errno: 0
+pipe2(bad): -1, errno: 21
 execl: -1, errno: 45
 execle: -1, errno: 45
 execlp: -1, errno: 45