Release 0.20.0 (#1203)

Following as much from
[c2rust/wiki/Release-Process](https://github.com/immunant/c2rust/wiki/Release-Process)
as still works/applies, plus some extra additions, I ...
* [ ] `cargo outdated -R`: doesn't work due to unknown print request
`split-debuginfo`
* [ ] `cargo update`: doesn't work because of old nightly
* [ ] `cargo clippy`:
  * [x] `cargo clippy --fix`
  * [x] Other trivial `cargo clippy` fixes
* [x] `cargo fmt --check`
* [x] Updated versions from `0.19.0` to `0.20.0`.
* [x] Specified missing versions for relative dependencies.
* [x] `cargo build`
* [x] `cargo +stable build -p c2rust`
* [x] Set `publish = false` in crates that are unstable due to
`#![feature(rustc_private)]`.

Then I will publish the crates in this order with `cargo +stable -p
$package`:
* `c2rust-asm-casts`
* `c2rust-ast-builder`
* `c2rust-ast-printer`
* `c2rust-build-paths`
* `c2rust-ast-exporter`
* `c2rust-bitfields-derive`
* `c2rust-bitfields`
* `c2rust-transpile`
* `c2rust`

or if this works, then I'll use this:

```
cargo +nightly publish --workspace --dry-run -Z package-workspace --exclude c2rust-analysis-rt --exclude c2rust-instrument --exclude c2rust-pdg --exclude c2rust-analyze
```

I need to use `cargo +stable` for this because the pinned nightly does
not correctly resolve the `Cargo.lock` for a workspace, and thus tries
to incompatibly update it.

Author: kkysen

Cargo.lock

@@ -24,7 +24,7 @@ exclude = [
 ]
 
 [workspace.package]
-version = "0.19.0"
+version = "0.20.0"
 authors = ["The C2Rust Project Developers <[email protected]>"]
 edition = "2021"
 rust-version = "1.65"

Cargo.toml

@@ -10,6 +10,7 @@ repository.workspace = true
 license.workspace = true
 keywords.workspace = true
 categories.workspace = true
+publish = false
 
 [dependencies]
 serde = { version = "1.0", features = ["derive"] }

analysis/runtime/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 libc = "0.2"
-c2rust-analysis-rt = { path = "../../runtime", optional = true, version = "0.19.0" }
+c2rust-analysis-rt = { path = "../../runtime", optional = true, version = "0.20.0" }
 
 [features]
 miri = []

analysis/tests/lighttpd-minimal/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 libc = "0.2"
-c2rust-analysis-rt = { path = "../../runtime", optional = true, version = "0.19.0" }
+c2rust-analysis-rt = { path = "../../runtime", optional = true, version = "0.20.0" }
 
 [features]
 miri = []

analysis/tests/lighttpd/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2021"
 
 [dependencies]
 libc = "0.2"
-c2rust-analysis-rt = { path = "../../runtime", optional = true, version = "0.19.0" }
+c2rust-analysis-rt = { path = "../../runtime", optional = true, version = "0.20.0" }
 
 [features]
 miri = []

analysis/tests/minimal/Cargo.toml

@@ -7,7 +7,7 @@ edition = "2021"
 
 [dependencies]
 libc = "0.2"
-c2rust-analysis-rt = { path = "../../runtime", optional = true, version = "0.19.0" }
+c2rust-analysis-rt = { path = "../../runtime", optional = true, version = "0.20.0" }
 
 [features]
 miri = []

analysis/tests/misc/Cargo.toml

@@ -10,12 +10,13 @@ repository.workspace = true
 license.workspace = true
 keywords.workspace = true
 categories.workspace = true
+publish = false
 
 [dependencies]
 polonius-engine = "0.13.0"
 rustc-hash = "1.1.0"
 bitflags = "1.3.2"
-c2rust-pdg = { path = "../pdg" }
+c2rust-pdg = { path = "../pdg", version = "0.20.0"}
 bincode = "1.0"
 serde = "1.0"
 assert_matches = "1.5.0"
@@ -32,11 +33,11 @@ toml_edit = "0.19.8"
 sha2 = "0.10.8"
 
 [build-dependencies]
-c2rust-build-paths = { path = "../c2rust-build-paths", version = "0.19.0" }
+c2rust-build-paths = { path = "../c2rust-build-paths", version = "0.20.0" }
 print_bytes = "1.1"
 
 [dev-dependencies]
-c2rust-build-paths = { path = "../c2rust-build-paths", version = "0.19.0" }
+c2rust-build-paths = { path = "../c2rust-build-paths", version = "0.20.0" }
 clap = { version = "4.1.9", features = ["derive"] }
 shlex = "1.3.0"
 

c2rust-analyze/Cargo.toml

@@ -426,7 +426,7 @@ fn parse_def_id(s: &str) -> Result<DefId, String> {
     };
 
     let rendered = format!("{:?}", def_id);
-    if &rendered != orig_s {
+    if rendered != orig_s {
         return Err(format!(
             "path mismatch: after parsing input {}, obtained a different path {:?}",
             orig_s, def_id
@@ -915,7 +915,7 @@ fn run(tcx: TyCtxt) {
                     borrowck::borrowck_mir(
                         &acx,
                         &info.dataflow,
-                        &mut asn.perms_mut(),
+                        asn.perms_mut(),
                         &updates_forbidden,
                         name.as_str(),
                         &mir,
@@ -964,7 +964,7 @@ fn run(tcx: TyCtxt) {
             loop_count, num_changed
         );
 
-        if &asn.perms.as_slice()[..gacx.num_global_pointers()] == &old_gasn {
+        if asn.perms.as_slice()[..gacx.num_global_pointers()] == old_gasn {
             break;
         }
     }
@@ -1117,13 +1117,13 @@ fn run(tcx: TyCtxt) {
                     continue;
                 }
                 ann.emit(span, format_args!("typeof({:?}) = {}", local, ty_str));
-                if static_non_null_ptrs.len() > 0 {
+                if !static_non_null_ptrs.is_empty() {
                     ann.emit(
                         span,
                         format_args!("  static NON_NULL: {:?}", static_non_null_ptrs),
                     );
                 }
-                if dynamic_non_null_ptrs.len() > 0 {
+                if !dynamic_non_null_ptrs.is_empty() {
                     ann.emit(
                         span,
                         format_args!("  dynamic NON_NULL: {:?}", dynamic_non_null_ptrs),

c2rust-analyze/src/analyze.rs

@@ -126,17 +126,17 @@ impl<'tcx> TypeChecker<'tcx, '_> {
                         {
                             let field_lifetime_param = OriginParam::try_from(field_lifetime_arg).ok();
 
-                            field_lifetime_param.and_then(|field_lifetime_param| {
+                            if let Some((base_lifetime_param, og)) = field_lifetime_param.and_then(|field_lifetime_param| {
                                 base_origin_param_map.get_key_value(&field_lifetime_param)
-                            }).map(|(base_lifetime_param, og)| {
+                            }) {
                                 debug!(
                                     "mapping {base_adt_def:?} lifetime parameter {base_lifetime_param:?} to \
                                     {base_adt_def:?}.{:} struct definition lifetime parameter {field_struct_lifetime_param:?}, \
                                     corresponding to its lifetime parameter {field_lifetime_param:?} within {base_adt_def:?}",
                                     field_def.name
                                 );
-                            field_origin_param_map.push((*field_struct_lifetime_param, *og));
-                            });
+                                field_origin_param_map.push((*field_struct_lifetime_param, *og));
+                            }
                         }
 
                         let origin_params= self.ltcx.arena().alloc_from_iter(field_origin_param_map.into_iter());