2 files changed, 624 insertions, 0 deletions
diff --git a/intl/encoding_glue/Cargo.toml b/intl/encoding_glue/Cargo.toml
new file mode 100644
index 0000000000..114de5c3bd
--- /dev/null
+++ b/intl/encoding_glue/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "encoding_glue"
+description = "FFI functions for mozilla::Encoding that aren't appropriate to share on crates.io due to m-c dependencies"
+version = "0.1.0"
+authors = ["Henri Sivonen <hsivonen@hsivonen.fi>"]
+license = "MIT/Apache-2.0"
+
+[features]
+simd-accel = ["encoding_rs/simd-accel"]
+
+[dependencies]
+encoding_rs = "0.8.0"
+nsstring = { path = "../../xpcom/rust/nsstring" } 
+nserror = { path = "../../xpcom/rust/nserror" }
+xmldecl = "0.2.0"
diff --git a/intl/encoding_glue/src/lib.rs b/intl/encoding_glue/src/lib.rs
new file mode 100644
index 0000000000..277a7cde70
--- /dev/null
+++ b/intl/encoding_glue/src/lib.rs
@@ -0,0 +1,609 @@
+// Copyright 2015-2016 Mozilla Foundation. See the COPYRIGHT
+// file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Adapted from third_party/rust/encoding_rs/src/lib.rs, so the
+// "top-level directory" in the above notice refers to
+// third_party/rust/encoding_rs/.
+
+extern crate encoding_rs;
+extern crate nserror;
+extern crate nsstring;
+extern crate xmldecl;
+
+use encoding_rs::*;
+use nserror::*;
+use nsstring::*;
+use std::slice;
+
+/// Takes `Option<usize>`, the destination string and a value
+/// to return on failure and tries to start a bulk write of the
+/// destination string with the capacity given by the `usize`
+/// wrapped in the first argument. Returns the bulk write
+/// handle.
+macro_rules! try_start_bulk_write {
+    ($needed:expr,
+     $dst:ident,
+     $ret:expr) => {{
+        let needed = match $needed {
+            Some(needed) => needed,
+            None => {
+                return $ret;
+            }
+        };
+        match unsafe { $dst.bulk_write(needed, 0, false) } {
+            Err(_) => {
+                return $ret;
+            }
+            Ok(handle) => handle,
+        }
+    }};
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mozilla_encoding_decode_to_nsstring(
+    encoding: *mut *const Encoding,
+    src: *const u8,
+    src_len: usize,
+    dst: *mut nsAString,
+) -> nsresult {
+    let (rv, enc) = decode_to_nsstring(&**encoding, slice::from_raw_parts(src, src_len), &mut *dst);
+    *encoding = enc as *const Encoding;
+    rv
+}
+
+pub fn decode_to_nsstring(
+    encoding: &'static Encoding,
+    src: &[u8],
+    dst: &mut nsAString,
+) -> (nsresult, &'static Encoding) {
+    if let Some((enc, bom_length)) = Encoding::for_bom(src) {
+        return (
+            decode_to_nsstring_without_bom_handling(enc, &src[bom_length..], dst),
+            enc,
+        );
+    }
+    (
+        decode_to_nsstring_without_bom_handling(encoding, src, dst),
+        encoding,
+    )
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mozilla_encoding_decode_to_nsstring_with_bom_removal(
+    encoding: *const Encoding,
+    src: *const u8,
+    src_len: usize,
+    dst: *mut nsAString,
+) -> nsresult {
+    decode_to_nsstring_with_bom_removal(&*encoding, slice::from_raw_parts(src, src_len), &mut *dst)
+}
+
+pub fn decode_to_nsstring_with_bom_removal(
+    encoding: &'static Encoding,
+    src: &[u8],
+    dst: &mut nsAString,
+) -> nsresult {
+    let without_bom = if encoding == UTF_8 && src.starts_with(b"\xEF\xBB\xBF") {
+        &src[3..]
+    } else if (encoding == UTF_16LE && src.starts_with(b"\xFF\xFE"))
+        || (encoding == UTF_16BE && src.starts_with(b"\xFE\xFF"))
+    {
+        &src[2..]
+    } else {
+        src
+    };
+    decode_to_nsstring_without_bom_handling(encoding, without_bom, dst)
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mozilla_encoding_decode_to_nsstring_without_bom_handling(
+    encoding: *const Encoding,
+    src: *const u8,
+    src_len: usize,
+    dst: *mut nsAString,
+) -> nsresult {
+    decode_to_nsstring_without_bom_handling(
+        &*encoding,
+        slice::from_raw_parts(src, src_len),
+        &mut *dst,
+    )
+}
+
+pub fn decode_to_nsstring_without_bom_handling(
+    encoding: &'static Encoding,
+    src: &[u8],
+    dst: &mut nsAString,
+) -> nsresult {
+    let mut decoder = encoding.new_decoder_without_bom_handling();
+    let mut handle = try_start_bulk_write!(
+        decoder.max_utf16_buffer_length(src.len()),
+        dst,
+        NS_ERROR_OUT_OF_MEMORY
+    );
+    let (result, read, written, had_errors) =
+        decoder.decode_to_utf16(src, handle.as_mut_slice(), true);
+    debug_assert_eq!(result, CoderResult::InputEmpty);
+    debug_assert_eq!(read, src.len());
+    debug_assert!(written <= handle.as_mut_slice().len());
+    let _ = handle.finish(written, true);
+    if had_errors {
+        return NS_OK_HAD_REPLACEMENTS;
+    }
+    NS_OK
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mozilla_encoding_decode_to_nsstring_without_bom_handling_and_without_replacement(
+    encoding: *const Encoding,
+    src: *const u8,
+    src_len: usize,
+    dst: *mut nsAString,
+) -> nsresult {
+    decode_to_nsstring_without_bom_handling_and_without_replacement(
+        &*encoding,
+        slice::from_raw_parts(src, src_len),
+        &mut *dst,
+    )
+}
+
+pub fn decode_to_nsstring_without_bom_handling_and_without_replacement(
+    encoding: &'static Encoding,
+    src: &[u8],
+    dst: &mut nsAString,
+) -> nsresult {
+    let mut decoder = encoding.new_decoder_without_bom_handling();
+    let mut handle = try_start_bulk_write!(
+        decoder.max_utf16_buffer_length(src.len()),
+        dst,
+        NS_ERROR_OUT_OF_MEMORY
+    );
+    let (result, read, written) =
+        decoder.decode_to_utf16_without_replacement(src, handle.as_mut_slice(), true);
+    match result {
+        DecoderResult::InputEmpty => {
+            debug_assert_eq!(read, src.len());
+            debug_assert!(written <= handle.as_mut_slice().len());
+            let _ = handle.finish(written, true);
+            NS_OK
+        }
+        DecoderResult::Malformed(_, _) => {
+            // Let handle's drop() run
+            NS_ERROR_UDEC_ILLEGALINPUT
+        }
+        DecoderResult::OutputFull => unreachable!(),
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mozilla_encoding_encode_from_utf16(
+    encoding: *mut *const Encoding,
+    src: *const u16,
+    src_len: usize,
+    dst: *mut nsACString,
+) -> nsresult {
+    let (rv, enc) = encode_from_utf16(&**encoding, slice::from_raw_parts(src, src_len), &mut *dst);
+    *encoding = enc as *const Encoding;
+    rv
+}
+
+pub fn encode_from_utf16(
+    encoding: &'static Encoding,
+    src: &[u16],
+    dst: &mut nsACString,
+) -> (nsresult, &'static Encoding) {
+    let output_encoding = encoding.output_encoding();
+    let mut encoder = output_encoding.new_encoder();
+    let mut handle = try_start_bulk_write!(
+        encoder.max_buffer_length_from_utf16_if_no_unmappables(src.len()),
+        dst,
+        (NS_ERROR_OUT_OF_MEMORY, output_encoding)
+    );
+
+    let mut total_read = 0;
+    let mut total_written = 0;
+    let mut total_had_errors = false;
+    loop {
+        let (result, read, written, had_errors) = encoder.encode_from_utf16(
+            &src[total_read..],
+            &mut (handle.as_mut_slice())[total_written..],
+            true,
+        );
+        total_read += read;
+        total_written += written;
+        total_had_errors |= had_errors;
+        match result {
+            CoderResult::InputEmpty => {
+                debug_assert_eq!(total_read, src.len());
+                debug_assert!(total_written <= handle.as_mut_slice().len());
+                let _ = handle.finish(total_written, true);
+                if total_had_errors {
+                    return (NS_OK_HAD_REPLACEMENTS, output_encoding);
+                }
+                return (NS_OK, output_encoding);
+            }
+            CoderResult::OutputFull => {
+                if let Some(needed) = checked_add(
+                    total_written,
+                    encoder.max_buffer_length_from_utf16_if_no_unmappables(src.len() - total_read),
+                ) {
+                    if unsafe {
+                        handle
+                            .restart_bulk_write(needed, total_written, false)
+                            .is_ok()
+                    } {
+                        continue;
+                    }
+                }
+                return (NS_ERROR_OUT_OF_MEMORY, output_encoding);
+            }
+        }
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mozilla_encoding_decode_to_nscstring(
+    encoding: *mut *const Encoding,
+    src: *const nsACString,
+    dst: *mut nsACString,
+) -> nsresult {
+    debug_assert_ne!(src as usize, dst as usize);
+    let (rv, enc) = decode_to_nscstring(&**encoding, &*src, &mut *dst);
+    *encoding = enc as *const Encoding;
+    rv
+}
+
+pub fn decode_to_nscstring(
+    encoding: &'static Encoding,
+    src: &nsACString,
+    dst: &mut nsACString,
+) -> (nsresult, &'static Encoding) {
+    if let Some((enc, bom_length)) = Encoding::for_bom(src) {
+        return (
+            decode_from_slice_to_nscstring_without_bom_handling(enc, &src[bom_length..], dst, 0),
+            enc,
+        );
+    }
+    (
+        decode_to_nscstring_without_bom_handling(encoding, src, dst),
+        encoding,
+    )
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mozilla_encoding_decode_to_nscstring_with_bom_removal(
+    encoding: *const Encoding,
+    src: *const nsACString,
+    dst: *mut nsACString,
+) -> nsresult {
+    debug_assert_ne!(src as usize, dst as usize);
+    decode_to_nscstring_with_bom_removal(&*encoding, &*src, &mut *dst)
+}
+
+pub fn decode_to_nscstring_with_bom_removal(
+    encoding: &'static Encoding,
+    src: &nsACString,
+    dst: &mut nsACString,
+) -> nsresult {
+    let without_bom = if encoding == UTF_8 && src.starts_with(b"\xEF\xBB\xBF") {
+        &src[3..]
+    } else if (encoding == UTF_16LE && src.starts_with(b"\xFF\xFE"))
+        || (encoding == UTF_16BE && src.starts_with(b"\xFE\xFF"))
+    {
+        &src[2..]
+    } else {
+        return decode_to_nscstring_without_bom_handling(encoding, src, dst);
+    };
+    decode_from_slice_to_nscstring_without_bom_handling(encoding, without_bom, dst, 0)
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mozilla_encoding_decode_to_nscstring_without_bom_handling(
+    encoding: *const Encoding,
+    src: *const nsACString,
+    dst: *mut nsACString,
+) -> nsresult {
+    debug_assert_ne!(src as usize, dst as usize);
+    decode_to_nscstring_without_bom_handling(&*encoding, &*src, &mut *dst)
+}
+
+pub fn decode_to_nscstring_without_bom_handling(
+    encoding: &'static Encoding,
+    src: &nsACString,
+    dst: &mut nsACString,
+) -> nsresult {
+    let bytes = &src[..];
+    let valid_up_to = if encoding == UTF_8 {
+        Encoding::utf8_valid_up_to(bytes)
+    } else if encoding.is_ascii_compatible() {
+        Encoding::ascii_valid_up_to(bytes)
+    } else if encoding == ISO_2022_JP {
+        Encoding::iso_2022_jp_ascii_valid_up_to(bytes)
+    } else {
+        return decode_from_slice_to_nscstring_without_bom_handling(encoding, src, dst, 0);
+    };
+    if valid_up_to == bytes.len() {
+        if dst.fallible_assign(src).is_err() {
+            return NS_ERROR_OUT_OF_MEMORY;
+        }
+        return NS_OK;
+    }
+    decode_from_slice_to_nscstring_without_bom_handling(encoding, src, dst, valid_up_to)
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mozilla_encoding_decode_from_slice_to_nscstring_without_bom_handling(
+    encoding: *const Encoding,
+    src: *const u8,
+    src_len: usize,
+    dst: *mut nsACString,
+    already_validated: usize,
+) -> nsresult {
+    decode_from_slice_to_nscstring_without_bom_handling(
+        &*encoding,
+        slice::from_raw_parts(src, src_len),
+        &mut *dst,
+        already_validated,
+    )
+}
+
+fn decode_from_slice_to_nscstring_without_bom_handling(
+    encoding: &'static Encoding,
+    src: &[u8],
+    dst: &mut nsACString,
+    already_validated: usize,
+) -> nsresult {
+    let bytes = src;
+    let mut decoder = encoding.new_decoder_without_bom_handling();
+    let mut handle = try_start_bulk_write!(Some(src.len()), dst, NS_ERROR_OUT_OF_MEMORY);
+
+    if already_validated != 0 {
+        (handle.as_mut_slice())[..already_validated].copy_from_slice(&bytes[..already_validated]);
+    }
+    let mut total_read = already_validated;
+    let mut total_written = already_validated;
+    let mut total_had_errors = false;
+    loop {
+        let (result, read, written, had_errors) = decoder.decode_to_utf8(
+            &bytes[total_read..],
+            &mut (handle.as_mut_slice())[total_written..],
+            true,
+        );
+        total_read += read;
+        total_written += written;
+        total_had_errors |= had_errors;
+        match result {
+            CoderResult::InputEmpty => {
+                debug_assert_eq!(total_read, bytes.len());
+                let _ = handle.finish(total_written, true);
+                if total_had_errors {
+                    return NS_OK_HAD_REPLACEMENTS;
+                }
+                return NS_OK;
+            }
+            CoderResult::OutputFull => {
+                // Allocate for the worst case. That is, we should come
+                // here at most once per invocation of this method.
+                if let Some(needed) = checked_add(
+                    total_written,
+                    decoder.max_utf8_buffer_length(bytes.len() - total_read),
+                ) {
+                    if unsafe {
+                        handle
+                            .restart_bulk_write(needed, total_written, false)
+                            .is_ok()
+                    } {
+                        continue;
+                    }
+                }
+                return NS_ERROR_OUT_OF_MEMORY;
+            }
+        }
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mozilla_encoding_decode_to_nscstring_without_bom_handling_and_without_replacement(
+    encoding: *const Encoding,
+    src: *const nsACString,
+    dst: *mut nsACString,
+) -> nsresult {
+    decode_to_nscstring_without_bom_handling_and_without_replacement(&*encoding, &*src, &mut *dst)
+}
+
+pub fn decode_to_nscstring_without_bom_handling_and_without_replacement(
+    encoding: &'static Encoding,
+    src: &nsACString,
+    dst: &mut nsACString,
+) -> nsresult {
+    let bytes = &src[..];
+    if encoding == UTF_8 {
+        let valid_up_to = Encoding::utf8_valid_up_to(bytes);
+        if valid_up_to == bytes.len() {
+            if dst.fallible_assign(src).is_err() {
+                return NS_ERROR_OUT_OF_MEMORY;
+            }
+            return NS_OK;
+        }
+        return NS_ERROR_UDEC_ILLEGALINPUT;
+    }
+    let valid_up_to = if encoding.is_ascii_compatible() {
+        Encoding::ascii_valid_up_to(bytes)
+    } else if encoding == ISO_2022_JP {
+        Encoding::iso_2022_jp_ascii_valid_up_to(bytes)
+    } else {
+        0
+    };
+    if valid_up_to == bytes.len() {
+        if dst.fallible_assign(src).is_err() {
+            return NS_ERROR_OUT_OF_MEMORY;
+        }
+        return NS_OK;
+    }
+    let mut decoder = encoding.new_decoder_without_bom_handling();
+    let mut handle = try_start_bulk_write!(
+        checked_add(
+            valid_up_to,
+            decoder.max_utf8_buffer_length_without_replacement(bytes.len() - valid_up_to)
+        ),
+        dst,
+        NS_ERROR_OUT_OF_MEMORY
+    );
+    let (result, read, written) = {
+        let dest = handle.as_mut_slice();
+        dest[..valid_up_to].copy_from_slice(&bytes[..valid_up_to]);
+        decoder.decode_to_utf8_without_replacement(
+            &src[valid_up_to..],
+            &mut dest[valid_up_to..],
+            true,
+        )
+    };
+    match result {
+        DecoderResult::InputEmpty => {
+            debug_assert_eq!(valid_up_to + read, src.len());
+            debug_assert!(valid_up_to + written <= handle.as_mut_slice().len());
+            let _ = handle.finish(valid_up_to + written, true);
+            NS_OK
+        }
+        DecoderResult::Malformed(_, _) => {
+            // let handle's drop() run
+            NS_ERROR_UDEC_ILLEGALINPUT
+        }
+        DecoderResult::OutputFull => unreachable!(),
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn mozilla_encoding_encode_from_nscstring(
+    encoding: *mut *const Encoding,
+    src: *const nsACString,
+    dst: *mut nsACString,
+) -> nsresult {
+    let (rv, enc) = encode_from_nscstring(&**encoding, &*src, &mut *dst);
+    *encoding = enc as *const Encoding;
+    rv
+}
+
+pub fn encode_from_nscstring(
+    encoding: &'static Encoding,
+    src: &nsACString,
+    dst: &mut nsACString,
+) -> (nsresult, &'static Encoding) {
+    let output_encoding = encoding.output_encoding();
+    let bytes = &src[..];
+    if output_encoding == UTF_8 {
+        let valid_up_to = Encoding::utf8_valid_up_to(bytes);
+        if valid_up_to == bytes.len() {
+            if dst.fallible_assign(src).is_err() {
+                return (NS_ERROR_OUT_OF_MEMORY, output_encoding);
+            }
+            return (NS_OK, output_encoding);
+        }
+        return (NS_ERROR_UDEC_ILLEGALINPUT, output_encoding);
+    }
+    let valid_up_to = if output_encoding == ISO_2022_JP {
+        Encoding::iso_2022_jp_ascii_valid_up_to(bytes)
+    } else {
+        debug_assert!(output_encoding.is_ascii_compatible());
+        Encoding::ascii_valid_up_to(bytes)
+    };
+    if valid_up_to == bytes.len() {
+        if dst.fallible_assign(src).is_err() {
+            return (NS_ERROR_OUT_OF_MEMORY, output_encoding);
+        }
+        return (NS_OK, output_encoding);
+    }
+
+    // Encoder requires valid UTF-8. Using std instead of encoding_rs
+    // to avoid unsafe blocks.
+    let trail = if let Ok(trail) = ::std::str::from_utf8(&bytes[valid_up_to..]) {
+        trail
+    } else {
+        return (NS_ERROR_UDEC_ILLEGALINPUT, output_encoding);
+    };
+
+    let mut encoder = output_encoding.new_encoder();
+    let mut handle = try_start_bulk_write!(
+        checked_add(
+            valid_up_to,
+            encoder.max_buffer_length_from_utf8_if_no_unmappables(trail.len())
+        ),
+        dst,
+        (NS_ERROR_OUT_OF_MEMORY, output_encoding)
+    );
+
+    if valid_up_to != 0 {
+        // to_mut() shouldn't fail right after setting length.
+        (handle.as_mut_slice())[..valid_up_to].copy_from_slice(&bytes[..valid_up_to]);
+    }
+
+    // `total_read` tracks `trail` only but `total_written` tracks the overall situation!
+    // This asymmetry is here, because trail is materialized as `str` without resorting
+    // to unsafe code here.
+    let mut total_read = 0;
+    let mut total_written = valid_up_to;
+    let mut total_had_errors = false;
+    loop {
+        let (result, read, written, had_errors) = encoder.encode_from_utf8(
+            &trail[total_read..],
+            &mut (handle.as_mut_slice())[total_written..],
+            true,
+        );
+        total_read += read;
+        total_written += written;
+        total_had_errors |= had_errors;
+        match result {
+            CoderResult::InputEmpty => {
+                debug_assert_eq!(valid_up_to + total_read, src.len());
+                debug_assert!(total_written <= handle.as_mut_slice().len());
+                let _ = handle.finish(total_written, true);
+                if total_had_errors {
+                    return (NS_OK_HAD_REPLACEMENTS, output_encoding);
+                }
+                return (NS_OK, output_encoding);
+            }
+            CoderResult::OutputFull => {
+                if let Some(needed) = checked_add(
+                    total_written,
+                    encoder.max_buffer_length_from_utf8_if_no_unmappables(trail.len() - total_read),
+                ) {
+                    if unsafe {
+                        handle
+                            .restart_bulk_write(needed, total_written, false)
+                            .is_ok()
+                    } {
+                        continue;
+                    }
+                }
+                return (NS_ERROR_OUT_OF_MEMORY, output_encoding);
+            }
+        }
+    }
+}
+
+#[inline(always)]
+fn checked_add(num: usize, opt: Option<usize>) -> Option<usize> {
+    if let Some(n) = opt {
+        n.checked_add(num)
+    } else {
+        None
+    }
+}
+
+// Declared in nsHtml5StreamParser.cpp
+#[no_mangle]
+pub unsafe extern "C" fn xmldecl_parse(
+    buf: *const u8,
+    buf_len: usize,
+) -> *const encoding_rs::Encoding {
+    if let Some(encoding) = xmldecl::parse(std::slice::from_raw_parts(buf, buf_len)) {
+        encoding
+    } else {
+        std::ptr::null()
+    }
+}