Add per-platform file-open flags to std.os. Open buffers as desired in std._io.

Author: froystig

src/lib/_io.rs

@@ -43,7 +43,11 @@ fn new_buf_reader(str path) -> buf_reader {
     }
   }
 
-  auto fd = os.libc.open(_str.buf(path), 0);
+  auto fd = os.libc.open(_str.buf(path),
+                         os.libc_constants.O_RDONLY() |
+                         os.libc_constants.O_BINARY(),
+                         0u);
+
   if (fd < 0) {
     log "error opening file for reading";
     log sys.rustrt.last_os_error();
@@ -52,7 +56,9 @@ fn new_buf_reader(str path) -> buf_reader {
   ret fd_buf_reader(fd, new_buf());
 }
 
-fn new_buf_writer(str path) -> buf_writer {
+type fileflag = tag(append(), create(), truncate());
+
+fn new_buf_writer(str path, vec[fileflag] flags) -> buf_writer {
 
   unsafe obj fd_buf_writer(int fd) {
 
@@ -77,7 +83,23 @@ fn new_buf_writer(str path) -> buf_writer {
     }
   }
 
-  auto fd = os.libc.open(_str.buf(path), 0);
+  let int fflags =
+    os.libc_constants.O_WRONLY() |
+    os.libc_constants.O_BINARY();
+
+  for (fileflag f in flags) {
+    alt (f) {
+      case (append())   { fflags |= os.libc_constants.O_APPEND(); }
+      case (create())   { fflags |= os.libc_constants.O_CREAT(); }
+      case (truncate()) { fflags |= os.libc_constants.O_TRUNC(); }
+    }
+  }
+
+  auto fd = os.libc.open(_str.buf(path),
+                         fflags,
+                         os.libc_constants.S_IRUSR() |
+                         os.libc_constants.S_IWUSR());
+
   if (fd < 0) {
     log "error opening file for writing";
     log sys.rustrt.last_os_error();

src/lib/linux_os.rs

@@ -3,7 +3,7 @@ import _vec.vbuf;
 
 native mod libc = "libc.so.6" {
 
-  fn open(sbuf s, int flags) -> int;
+  fn open(sbuf s, int flags, uint mode) -> int;
   fn read(int fd, vbuf buf, uint count) -> int;
   fn write(int fd, vbuf buf, uint count) -> int;
   fn close(int fd) -> int;
@@ -17,3 +17,18 @@ native mod libc = "libc.so.6" {
   fn setenv(sbuf n, sbuf v, int overwrite) -> int;
   fn unsetenv(sbuf n) -> int;
 }
+
+mod libc_constants {
+  fn O_RDONLY() -> int { ret 0x0000; }
+  fn O_WRONLY() -> int { ret 0x0001; }
+  fn O_RDWR()   -> int { ret 0x0002; }
+  fn O_APPEND() -> int { ret 0x0400; }
+  fn O_CREAT()  -> int { ret 0x0040; }
+  fn O_EXCL()   -> int { ret 0x0080; }
+  fn O_TRUNC()  -> int { ret 0x0200; }
+  fn O_TEXT()   -> int { ret 0x0000; } // nonexistent in linux libc
+  fn O_BINARY() -> int { ret 0x0000; } // nonexistent in linux libc
+
+  fn S_IRUSR() -> uint { ret 0x0100u; }
+  fn S_IWUSR() -> uint { ret 0x0080u; }
+}

src/lib/macos_os.rs

@@ -3,7 +3,7 @@ import _vec.vbuf;
 
 native mod libc = "libc.dylib" {
 
-  fn open(sbuf s, int flags) -> int;
+  fn open(sbuf s, int flags, uint mode) -> int;
   fn read(int fd, vbuf buf, uint count) -> int;
   fn write(int fd, vbuf buf, uint count) -> int;
   fn close(int fd) -> int;
@@ -17,3 +17,18 @@ native mod libc = "libc.dylib" {
   fn setenv(sbuf n, sbuf v, int overwrite) -> int;
   fn unsetenv(sbuf n) -> int;
 }
+
+mod libc_constants {
+  fn O_RDONLY() -> int { ret 0x0000; }
+  fn O_WRONLY() -> int { ret 0x0001; }
+  fn O_RDWR()   -> int { ret 0x0002; }
+  fn O_APPEND() -> int { ret 0x0008; }
+  fn O_CREAT()  -> int { ret 0x0200; }
+  fn O_EXCL()   -> int { ret 0x0800; }
+  fn O_TRUNC()  -> int { ret 0x0400; }
+  fn O_TEXT()   -> int { ret 0x0000; } // nonexistent in darwin libc
+  fn O_BINARY() -> int { ret 0x0000; } // nonexistent in darwin libc
+
+  fn S_IRUSR() -> uint { ret 0x0400u; }
+  fn S_IWUSR() -> uint { ret 0x0200u; }
+}

src/lib/win32_os.rs

@@ -2,8 +2,23 @@ import _str.sbuf;
 import _vec.vbuf;
 
 native mod libc = "msvcrt.dll" {
-  fn open(sbuf s, int flags) -> int = "_open";
+  fn open(sbuf s, int flags, uint mode) -> int = "_open";
   fn read(int fd, vbuf buf, uint count) -> int = "_read";
   fn write(int fd, vbuf buf, uint count) -> int = "_write";
   fn close(int fd) -> int = "_close";
 }
+
+mod libc_constants {
+  fn O_RDONLY() -> int { ret 0x0000; }
+  fn O_WRONLY() -> int { ret 0x0001; }
+  fn O_RDWR()   -> int { ret 0x0002; }
+  fn O_APPEND() -> int { ret 0x0400; }
+  fn O_CREAT()  -> int { ret 0x0040; }
+  fn O_EXCL()   -> int { ret 0x0080; }
+  fn O_TRUNC()  -> int { ret 0x0200; }
+  fn O_TEXT()   -> int { ret 0x4000; }
+  fn O_BINARY() -> int { ret 0x8000; }
+
+  fn S_IRUSR() -> uint { ret 0x0100u; } // really _S_IREAD  in win32
+  fn S_IWUSR() -> uint { ret 0x0080u; } // really _S_IWRITE in win32
+}