Refactor stderr_prints_nothing into a more modular function

[rust.git] / src / libstd / sys / wasm / stdio.rs

diff --git a/src/libstd/sys/wasm/stdio.rs b/src/libstd/sys/wasm/stdio.rs
index 0f75f240251832e5587aac6334afcf6db590916b..e51aba75333b651bcca5fdb213d631b100c5a88a 100644 (file)
--- a/src/libstd/sys/wasm/stdio.rs
+++ b/src/libstd/sys/wasm/stdio.rs
@@ -9,19 +9,19 @@
 // except according to those terms.
 
 use io;
-use sys::{Void, unsupported};
+use sys::{ReadSysCall, WriteSysCall};
 
-pub struct Stdin(Void);
+pub struct Stdin;
 pub struct Stdout;
 pub struct Stderr;
 
 impl Stdin {
     pub fn new() -> io::Result<Stdin> {
-        unsupported()
+        Ok(Stdin)
     }
 
-    pub fn read(&self, _data: &mut [u8]) -> io::Result<usize> {
-        match self.0 {}
+    pub fn read(&self, data: &mut [u8]) -> io::Result<usize> {
+        Ok(ReadSysCall::perform(0, data))
     }
 }
 
@@ -31,19 +31,7 @@ pub fn new() -> io::Result<Stdout> {
     }
 
     pub fn write(&self, data: &[u8]) -> io::Result<usize> {
-        // If runtime debugging is enabled at compile time we'll invoke some
-        // runtime functions that are defined in our src/etc/wasm32-shim.js
-        // debugging script. Note that this ffi function call is intended
-        // *purely* for debugging only and should not be relied upon.
-        if !super::DEBUG {
-            return unsupported()
-        }
-        extern {
-            fn rust_wasm_write_stdout(data: *const u8, len: usize);
-        }
-        unsafe {
-            rust_wasm_write_stdout(data.as_ptr(), data.len())
-        }
+        WriteSysCall::perform(1, data);
         Ok(data.len())
     }
 
@@ -58,16 +46,7 @@ pub fn new() -> io::Result<Stderr> {
     }
 
     pub fn write(&self, data: &[u8]) -> io::Result<usize> {
-        // See comments in stdout for what's going on here.
-        if !super::DEBUG {
-            return unsupported()
-        }
-        extern {
-            fn rust_wasm_write_stderr(data: *const u8, len: usize);
-        }
-        unsafe {
-            rust_wasm_write_stderr(data.as_ptr(), data.len())
-        }
+        WriteSysCall::perform(2, data);
         Ok(data.len())
     }
 
@@ -90,3 +69,11 @@ fn flush(&mut self) -> io::Result<()> {
 pub fn is_ebadf(_err: &io::Error) -> bool {
     true
 }
+
+pub fn panic_output() -> Option<impl io::Write> {
+    if cfg!(feature = "wasm_syscall") {
+        Stderr::new().ok()
+    } else {
+        None
+    }
+}