Rust reflection: simplify dependencies, fix Android build compatibility (#8512)

* flatbuffers Rust reflection: replace num with num-traits

num crate is a wrapper over num-traits and a few other crates, that
reexports the APIs from all of them. We only need num-traits.

Signed-off-by: Marcin Radomski <dextero@google.com>

* Rust reflection: drop dependency on stdint crate

We only use it to get intmax_t for deriving alignment, which is an alias
for `core::ffi::c_long` [1]. We can use that directly instead.

[1] https://docs.rs/stdint/1.0.0/stdint/type.intmax_t.html

Signed-off-by: Marcin Radomski <dextero@google.com>

* Rust reflection: drop dependency on escape_string crate

It's used to format a string used for debugging only, so we might as
well use the builtin Debug representation of a string.

Signed-off-by: Marcin Radomski <dextero@google.com>

* Rust codegen: add derives on generated bitflags

Otherwise it limits the use of structs generated for reflection.fbs
in Rust reflection API.

Signed-off-by: Marcin Radomski <dextero@google.com>

* Rust flatbuffers: update bitflags dependency to 2.8

Signed-off-by: Marcin Radomski <dextero@google.com>

* Rust codegen: use bitflags v2 API for converting from bits

from_bits_unchecked was replaced with safe from_bits_retain.

Signed-off-by: Marcin Radomski <dextero@google.com>

* Regenerate Rust code after idl change

Signed-off-by: Marcin Radomski <dextero@google.com>

* Regenerate reflection_generated.rs

With flatc --rust ../../../reflection/reflection.fbs

Signed-off-by: Marcin Radomski <dextero@google.com>

* ts/BUILD.bazel: add missing import

Found by Buildifire presubmit:

  Function "sh_binary" is not global anymore and needs to be loaded from
  "@rules_shell//shell:sh_binary.bzl".

Signed-off-by: Marcin Radomski <dextero@google.com>

* Update expected value in generated_code_debug_prints_correctly test

In bitflags v2, the debug string representation of enum values is
different than it was in v1:
  Blue -> Color(Blue)
  (empty) -> LongEnum(0x0)

This change adjusts the expected test value.

Signed-off-by: Marcin Radomski <dextero@google.com>

* Fix tests build on Swift 5.8

grpc-swift 1.4.1 depends on swift-nio-ssl 2.14.0+ [1]. swift-nio-ssl 2.29.1
published on 2025-01-30, introduced some code [2] that uses a "switch
expression syntax" supported since Swift 5.9 [3]. Attempts to compile it with
Swift 5.8 cause build errors.

swift-nio-ssl project doesn't seem to support Swift 5.8. A commit from
2024-10-29 removes a "deprecated reference to a Swift 5.8 pipeline" [4].

swift-nio-ssl 2.29.0 is the last version that can be compiled with Swift
5.8. This commit pins it to that exact version.

[1] 66e27d7e84/Package.swift (L33)
[2] 3cb4d5ad12 (diff-bc1db1321ff689c2819245dcce1a3080554f0fc13f81b8d326c97e7d42717c8fR54)
[3] https://github.com/swiftlang/swift-evolution/blob/main/proposals/0380-if-switch-expressions.md
[4] 8a6b89d9a4

---------

Signed-off-by: Marcin Radomski <dextero@google.com>
Co-authored-by: Marcin Radomski <dextero@google.com>

rust/reflection/src/lib.rs

@@ -29,11 +29,9 @@ use flatbuffers::{
 use reflection_generated::reflection::{BaseType, Field, Object, Schema};
 
 use core::mem::size_of;
-use escape_string::escape;
-use num::traits::float::Float;
-use num::traits::int::PrimInt;
-use num::traits::FromPrimitive;
-use stdint::uintmax_t;
+use num_traits::float::Float;
+use num_traits::int::PrimInt;
+use num_traits::FromPrimitive;
 use thiserror::Error;
 
 #[derive(Error, Debug, PartialEq)]
@@ -541,7 +539,9 @@ pub unsafe fn set_string(
 
     if delta != 0 {
         // Rounds the delta up to the nearest multiple of the maximum int size to keep the types after the insersion point aligned.
-        let mask = (size_of::<uintmax_t>() - 1) as isize;
+        // stdint crate defines intmax_t as an alias for c_long; use it directly to avoid extra
+        // dependency.
+        let mask = (size_of::<core::ffi::c_long>() - 1) as isize;
         let offset = (delta + mask) & !mask;
         let mut visited_vec = vec![false; buf.len()];
 
@@ -715,7 +715,8 @@ unsafe fn get_any_value_string(
                     }
                     let mut field_value = get_any_field_string(&table, &field, schema);
                     if field.type_().base_type() == BaseType::String {
-                        field_value = escape(field_value.as_str()).to_string();
+                        // Escape the string
+                        field_value = format!("{:?}", field_value.as_str());
                     }
                     s += field.name();
                     s += ": ";

rust/reflection/src/safe_buffer.rs

@@ -25,9 +25,9 @@ use crate::{
     FlatbufferResult, ForwardsUOffset,
 };
 use flatbuffers::{Follow, Table, Vector, VerifierOptions};
-use num::traits::float::Float;
-use num::traits::int::PrimInt;
-use num::traits::FromPrimitive;
+use num_traits::float::Float;
+use num_traits::int::PrimInt;
+use num_traits::FromPrimitive;
 use std::collections::HashMap;
 
 #[derive(Debug)]