Rework how Rust generated files are laid out (#6731)

* Refactored Rust Generated code into a module directory.

Each symbol will be generated into one file and then
imported into a module. This breaks the "out_dir"
pattern where some users would generate code in their
target/ directory. Also, these objects are best used
in their own module. It will be hard for users to share
their own module structure with flatbuffers namespaces.

There may be solutions to these drawbacks but that should
be discussed. I don't want to overengineer here.

* shadow error

* try fix .bat file

* fix .bat 2

* Restore accidentally deleted files

* Fixed some DONOTSUBMITs and made Rust outdir pattern use symlinks.

* fixed binary files

* git clang format

* make generated onefiles not public and fix .bat

* reduced diff with master in generate_code.sh

* fix shadowed variable

* add object api flags to .bat

* space

* Removed extern crate and extra &

* use statement

* more clippy lints

* format

* Undo extern crate -> use change, it actually matters to our tests

Co-authored-by: Casper Neo <cneo@google.com>

tests/include_test2/mod.rs

@@ -0,0 +1,15 @@
+// Automatically generated by the Flatbuffers compiler. Do not modify.
+pub mod my_game {
+    use super::*;
+    pub mod other_name_space {
+        use super::*;
+        mod from_include_generated;
+        pub use self::from_include_generated::*;
+        mod unused_generated;
+        pub use self::unused_generated::*;
+        mod table_b_generated;
+        pub use self::table_b_generated::*;
+    } // other_name_space
+} // my_game
+mod table_a_generated;
+pub use self::table_a_generated::*;

tests/include_test2/my_game/other_name_space/from_include_generated.rs

@@ -0,0 +1,89 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+extern crate flatbuffers;
+use std::mem;
+use std::cmp::Ordering;
+use self::flatbuffers::{EndianScalar, Follow};
+use super::*;
+#[deprecated(since = "2.0.0", note = "Use associated constants instead. This will no longer be generated in 2021.")]
+pub const ENUM_MIN_FROM_INCLUDE: i64 = 0;
+#[deprecated(since = "2.0.0", note = "Use associated constants instead. This will no longer be generated in 2021.")]
+pub const ENUM_MAX_FROM_INCLUDE: i64 = 0;
+#[deprecated(since = "2.0.0", note = "Use associated constants instead. This will no longer be generated in 2021.")]
+#[allow(non_camel_case_types)]
+pub const ENUM_VALUES_FROM_INCLUDE: [FromInclude; 1] = [
+  FromInclude::IncludeVal,
+];
+
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Default)]
+#[repr(transparent)]
+pub struct FromInclude(pub i64);
+#[allow(non_upper_case_globals)]
+impl FromInclude {
+  pub const IncludeVal: Self = Self(0);
+
+  pub const ENUM_MIN: i64 = 0;
+  pub const ENUM_MAX: i64 = 0;
+  pub const ENUM_VALUES: &'static [Self] = &[
+    Self::IncludeVal,
+  ];
+  /// Returns the variant's name or "" if unknown.
+  pub fn variant_name(self) -> Option<&'static str> {
+    match self {
+      Self::IncludeVal => Some("IncludeVal"),
+      _ => None,
+    }
+  }
+}
+impl std::fmt::Debug for FromInclude {
+  fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    if let Some(name) = self.variant_name() {
+      f.write_str(name)
+    } else {
+      f.write_fmt(format_args!("<UNKNOWN {:?}>", self.0))
+    }
+  }
+}
+impl<'a> flatbuffers::Follow<'a> for FromInclude {
+  type Inner = Self;
+  #[inline]
+  fn follow(buf: &'a [u8], loc: usize) -> Self::Inner {
+    let b = unsafe {
+      flatbuffers::read_scalar_at::<i64>(buf, loc)
+    };
+    Self(b)
+  }
+}
+
+impl flatbuffers::Push for FromInclude {
+    type Output = FromInclude;
+    #[inline]
+    fn push(&self, dst: &mut [u8], _rest: &[u8]) {
+        unsafe { flatbuffers::emplace_scalar::<i64>(dst, self.0); }
+    }
+}
+
+impl flatbuffers::EndianScalar for FromInclude {
+  #[inline]
+  fn to_little_endian(self) -> Self {
+    let b = i64::to_le(self.0);
+    Self(b)
+  }
+  #[inline]
+  #[allow(clippy::wrong_self_convention)]
+  fn from_little_endian(self) -> Self {
+    let b = i64::from_le(self.0);
+    Self(b)
+  }
+}
+
+impl<'a> flatbuffers::Verifiable for FromInclude {
+  #[inline]
+  fn run_verifier(
+    v: &mut flatbuffers::Verifier, pos: usize
+  ) -> Result<(), flatbuffers::InvalidFlatbuffer> {
+    use self::flatbuffers::Verifiable;
+    i64::run_verifier(v, pos)
+  }
+}
+
+impl flatbuffers::SimpleToVerifyInSlice for FromInclude {}

tests/include_test2/my_game/other_name_space/table_b_generated.rs

@@ -0,0 +1,134 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+extern crate flatbuffers;
+use std::mem;
+use std::cmp::Ordering;
+use self::flatbuffers::{EndianScalar, Follow};
+use super::*;
+pub enum TableBOffset {}
+#[derive(Copy, Clone, PartialEq)]
+
+pub struct TableB<'a> {
+  pub _tab: flatbuffers::Table<'a>,
+}
+
+impl<'a> flatbuffers::Follow<'a> for TableB<'a> {
+    type Inner = TableB<'a>;
+    #[inline]
+    fn follow(buf: &'a [u8], loc: usize) -> Self::Inner {
+        Self { _tab: flatbuffers::Table { buf, loc } }
+    }
+}
+
+impl<'a> TableB<'a> {
+    pub const fn get_fully_qualified_name() -> &'static str {
+        "MyGame.OtherNameSpace.TableB"
+    }
+
+    #[inline]
+    pub fn init_from_table(table: flatbuffers::Table<'a>) -> Self {
+        TableB { _tab: table }
+    }
+    #[allow(unused_mut)]
+    pub fn create<'bldr: 'args, 'args: 'mut_bldr, 'mut_bldr>(
+        _fbb: &'mut_bldr mut flatbuffers::FlatBufferBuilder<'bldr>,
+        args: &'args TableBArgs<'args>) -> flatbuffers::WIPOffset<TableB<'bldr>> {
+      let mut builder = TableBBuilder::new(_fbb);
+      if let Some(x) = args.a { builder.add_a(x); }
+      builder.finish()
+    }
+
+    pub fn unpack(&self) -> TableBT {
+      let a = self.a().map(|x| {
+        Box::new(x.unpack())
+      });
+      TableBT {
+        a,
+      }
+    }
+    pub const VT_A: flatbuffers::VOffsetT = 4;
+
+  #[inline]
+  pub fn a(&self) -> Option<super::super::TableA<'a>> {
+    self._tab.get::<flatbuffers::ForwardsUOffset<super::super::TableA>>(TableB::VT_A, None)
+  }
+}
+
+impl flatbuffers::Verifiable for TableB<'_> {
+  #[inline]
+  fn run_verifier(
+    v: &mut flatbuffers::Verifier, pos: usize
+  ) -> Result<(), flatbuffers::InvalidFlatbuffer> {
+    use self::flatbuffers::Verifiable;
+    v.visit_table(pos)?
+     .visit_field::<flatbuffers::ForwardsUOffset<super::super::TableA>>("a", Self::VT_A, false)?
+     .finish();
+    Ok(())
+  }
+}
+pub struct TableBArgs<'a> {
+    pub a: Option<flatbuffers::WIPOffset<super::super::TableA<'a>>>,
+}
+impl<'a> Default for TableBArgs<'a> {
+    #[inline]
+    fn default() -> Self {
+        TableBArgs {
+            a: None,
+        }
+    }
+}
+pub struct TableBBuilder<'a: 'b, 'b> {
+  fbb_: &'b mut flatbuffers::FlatBufferBuilder<'a>,
+  start_: flatbuffers::WIPOffset<flatbuffers::TableUnfinishedWIPOffset>,
+}
+impl<'a: 'b, 'b> TableBBuilder<'a, 'b> {
+  #[inline]
+  pub fn add_a(&mut self, a: flatbuffers::WIPOffset<super::super::TableA<'b >>) {
+    self.fbb_.push_slot_always::<flatbuffers::WIPOffset<super::super::TableA>>(TableB::VT_A, a);
+  }
+  #[inline]
+  pub fn new(_fbb: &'b mut flatbuffers::FlatBufferBuilder<'a>) -> TableBBuilder<'a, 'b> {
+    let start = _fbb.start_table();
+    TableBBuilder {
+      fbb_: _fbb,
+      start_: start,
+    }
+  }
+  #[inline]
+  pub fn finish(self) -> flatbuffers::WIPOffset<TableB<'a>> {
+    let o = self.fbb_.end_table(self.start_);
+    flatbuffers::WIPOffset::new(o.value())
+  }
+}
+
+impl std::fmt::Debug for TableB<'_> {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    let mut ds = f.debug_struct("TableB");
+      ds.field("a", &self.a());
+      ds.finish()
+  }
+}
+#[non_exhaustive]
+#[derive(Debug, Clone, PartialEq)]
+pub struct TableBT {
+  pub a: Option<Box<super::super::TableAT>>,
+}
+impl Default for TableBT {
+  fn default() -> Self {
+    Self {
+      a: None,
+    }
+  }
+}
+impl TableBT {
+  pub fn pack<'b>(
+    &self,
+    _fbb: &mut flatbuffers::FlatBufferBuilder<'b>
+  ) -> flatbuffers::WIPOffset<TableB<'b>> {
+    let a = self.a.as_ref().map(|x|{
+      x.pack(_fbb)
+    });
+    TableB::create(_fbb, &TableBArgs{
+      a,
+    })
+  }
+}

tests/include_test2/my_game/other_name_space/unused_generated.rs

@@ -0,0 +1,126 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+extern crate flatbuffers;
+use std::mem;
+use std::cmp::Ordering;
+use self::flatbuffers::{EndianScalar, Follow};
+use super::*;
+// struct Unused, aligned to 4
+#[repr(transparent)]
+#[derive(Clone, Copy, PartialEq)]
+pub struct Unused(pub [u8; 4]);
+impl Default for Unused { 
+  fn default() -> Self { 
+    Self([0; 4])
+  }
+}
+impl std::fmt::Debug for Unused {
+  fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    f.debug_struct("Unused")
+      .field("a", &self.a())
+      .finish()
+  }
+}
+
+impl flatbuffers::SimpleToVerifyInSlice for Unused {}
+impl flatbuffers::SafeSliceAccess for Unused {}
+impl<'a> flatbuffers::Follow<'a> for Unused {
+  type Inner = &'a Unused;
+  #[inline]
+  fn follow(buf: &'a [u8], loc: usize) -> Self::Inner {
+    <&'a Unused>::follow(buf, loc)
+  }
+}
+impl<'a> flatbuffers::Follow<'a> for &'a Unused {
+  type Inner = &'a Unused;
+  #[inline]
+  fn follow(buf: &'a [u8], loc: usize) -> Self::Inner {
+    flatbuffers::follow_cast_ref::<Unused>(buf, loc)
+  }
+}
+impl<'b> flatbuffers::Push for Unused {
+    type Output = Unused;
+    #[inline]
+    fn push(&self, dst: &mut [u8], _rest: &[u8]) {
+        let src = unsafe {
+            ::std::slice::from_raw_parts(self as *const Unused as *const u8, Self::size())
+        };
+        dst.copy_from_slice(src);
+    }
+}
+impl<'b> flatbuffers::Push for &'b Unused {
+    type Output = Unused;
+
+    #[inline]
+    fn push(&self, dst: &mut [u8], _rest: &[u8]) {
+        let src = unsafe {
+            ::std::slice::from_raw_parts(*self as *const Unused as *const u8, Self::size())
+        };
+        dst.copy_from_slice(src);
+    }
+}
+
+impl<'a> flatbuffers::Verifiable for Unused {
+  #[inline]
+  fn run_verifier(
+    v: &mut flatbuffers::Verifier, pos: usize
+  ) -> Result<(), flatbuffers::InvalidFlatbuffer> {
+    use self::flatbuffers::Verifiable;
+    v.in_buffer::<Self>(pos)
+  }
+}
+impl<'a> Unused {
+  #[allow(clippy::too_many_arguments)]
+  pub fn new(
+    a: i32,
+  ) -> Self {
+    let mut s = Self([0; 4]);
+    s.set_a(a);
+    s
+  }
+
+    pub const fn get_fully_qualified_name() -> &'static str {
+        "MyGame.OtherNameSpace.Unused"
+    }
+
+  pub fn a(&self) -> i32 {
+    let mut mem = core::mem::MaybeUninit::<i32>::uninit();
+    unsafe {
+      core::ptr::copy_nonoverlapping(
+        self.0[0..].as_ptr(),
+        mem.as_mut_ptr() as *mut u8,
+        core::mem::size_of::<i32>(),
+      );
+      mem.assume_init()
+    }.from_little_endian()
+  }
+
+  pub fn set_a(&mut self, x: i32) {
+    let x_le = x.to_little_endian();
+    unsafe {
+      core::ptr::copy_nonoverlapping(
+        &x_le as *const i32 as *const u8,
+        self.0[0..].as_mut_ptr(),
+        core::mem::size_of::<i32>(),
+      );
+    }
+  }
+
+  pub fn unpack(&self) -> UnusedT {
+    UnusedT {
+      a: self.a(),
+    }
+  }
+}
+
+#[derive(Debug, Clone, PartialEq, Default)]
+pub struct UnusedT {
+  pub a: i32,
+}
+impl UnusedT {
+  pub fn pack(&self) -> Unused {
+    Unused::new(
+      self.a,
+    )
+  }
+}
+

tests/include_test2/table_a_generated.rs

@@ -0,0 +1,134 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+extern crate flatbuffers;
+use std::mem;
+use std::cmp::Ordering;
+use self::flatbuffers::{EndianScalar, Follow};
+use super::*;
+pub enum TableAOffset {}
+#[derive(Copy, Clone, PartialEq)]
+
+pub struct TableA<'a> {
+  pub _tab: flatbuffers::Table<'a>,
+}
+
+impl<'a> flatbuffers::Follow<'a> for TableA<'a> {
+    type Inner = TableA<'a>;
+    #[inline]
+    fn follow(buf: &'a [u8], loc: usize) -> Self::Inner {
+        Self { _tab: flatbuffers::Table { buf, loc } }
+    }
+}
+
+impl<'a> TableA<'a> {
+    pub const fn get_fully_qualified_name() -> &'static str {
+        "TableA"
+    }
+
+    #[inline]
+    pub fn init_from_table(table: flatbuffers::Table<'a>) -> Self {
+        TableA { _tab: table }
+    }
+    #[allow(unused_mut)]
+    pub fn create<'bldr: 'args, 'args: 'mut_bldr, 'mut_bldr>(
+        _fbb: &'mut_bldr mut flatbuffers::FlatBufferBuilder<'bldr>,
+        args: &'args TableAArgs<'args>) -> flatbuffers::WIPOffset<TableA<'bldr>> {
+      let mut builder = TableABuilder::new(_fbb);
+      if let Some(x) = args.b { builder.add_b(x); }
+      builder.finish()
+    }
+
+    pub fn unpack(&self) -> TableAT {
+      let b = self.b().map(|x| {
+        Box::new(x.unpack())
+      });
+      TableAT {
+        b,
+      }
+    }
+    pub const VT_B: flatbuffers::VOffsetT = 4;
+
+  #[inline]
+  pub fn b(&self) -> Option<my_game::other_name_space::TableB<'a>> {
+    self._tab.get::<flatbuffers::ForwardsUOffset<my_game::other_name_space::TableB>>(TableA::VT_B, None)
+  }
+}
+
+impl flatbuffers::Verifiable for TableA<'_> {
+  #[inline]
+  fn run_verifier(
+    v: &mut flatbuffers::Verifier, pos: usize
+  ) -> Result<(), flatbuffers::InvalidFlatbuffer> {
+    use self::flatbuffers::Verifiable;
+    v.visit_table(pos)?
+     .visit_field::<flatbuffers::ForwardsUOffset<my_game::other_name_space::TableB>>("b", Self::VT_B, false)?
+     .finish();
+    Ok(())
+  }
+}
+pub struct TableAArgs<'a> {
+    pub b: Option<flatbuffers::WIPOffset<my_game::other_name_space::TableB<'a>>>,
+}
+impl<'a> Default for TableAArgs<'a> {
+    #[inline]
+    fn default() -> Self {
+        TableAArgs {
+            b: None,
+        }
+    }
+}
+pub struct TableABuilder<'a: 'b, 'b> {
+  fbb_: &'b mut flatbuffers::FlatBufferBuilder<'a>,
+  start_: flatbuffers::WIPOffset<flatbuffers::TableUnfinishedWIPOffset>,
+}
+impl<'a: 'b, 'b> TableABuilder<'a, 'b> {
+  #[inline]
+  pub fn add_b(&mut self, b: flatbuffers::WIPOffset<my_game::other_name_space::TableB<'b >>) {
+    self.fbb_.push_slot_always::<flatbuffers::WIPOffset<my_game::other_name_space::TableB>>(TableA::VT_B, b);
+  }
+  #[inline]
+  pub fn new(_fbb: &'b mut flatbuffers::FlatBufferBuilder<'a>) -> TableABuilder<'a, 'b> {
+    let start = _fbb.start_table();
+    TableABuilder {
+      fbb_: _fbb,
+      start_: start,
+    }
+  }
+  #[inline]
+  pub fn finish(self) -> flatbuffers::WIPOffset<TableA<'a>> {
+    let o = self.fbb_.end_table(self.start_);
+    flatbuffers::WIPOffset::new(o.value())
+  }
+}
+
+impl std::fmt::Debug for TableA<'_> {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    let mut ds = f.debug_struct("TableA");
+      ds.field("b", &self.b());
+      ds.finish()
+  }
+}
+#[non_exhaustive]
+#[derive(Debug, Clone, PartialEq)]
+pub struct TableAT {
+  pub b: Option<Box<my_game::other_name_space::TableBT>>,
+}
+impl Default for TableAT {
+  fn default() -> Self {
+    Self {
+      b: None,
+    }
+  }
+}
+impl TableAT {
+  pub fn pack<'b>(
+    &self,
+    _fbb: &mut flatbuffers::FlatBufferBuilder<'b>
+  ) -> flatbuffers::WIPOffset<TableA<'b>> {
+    let b = self.b.as_ref().map(|x|{
+      x.pack(_fbb)
+    });
+    TableA::create(_fbb, &TableAArgs{
+      b,
+    })
+  }
+}