Update toolchain to 2024-08-05

* Remove `gen_function_local_variable` and `initializer_fn_name`, the
  last uses of both of which were removed in model-checking#3305.
* Remove `arg_count`, which was introduced in model-checking#3363, but not actually
  used.
* Remove `insert_bb`, which was introduced in model-checking#3382, but not actually
  used.

The toolchain upgrade to 2024-08-04 includes several bugfixes to
dead-code analysis in rustc, explaining why we the recent PRs as listed
above weren't flagged before for introducing dead code.

Resolves: model-checking#3411

kani-compiler/src/codegen_cprover_gotoc/context/goto_ctx.rs

@@ -139,17 +139,6 @@ impl<'tcx> GotocCtx<'tcx> {
         sym
     }
 
-    // Generate a Symbol Expression representing a function variable from the MIR
-    pub fn gen_function_local_variable(
-        &mut self,
-        c: u64,
-        fname: &str,
-        t: Type,
-        loc: Location,
-    ) -> Symbol {
-        self.gen_stack_variable(c, fname, "var", t, loc)
-    }
-
     /// Given a counter `c` a function name `fname, and a prefix `prefix`, generates a new function local variable
     /// It is an error to reuse an existing `c`, `fname` `prefix` tuple.
     fn gen_stack_variable(

kani-compiler/src/codegen_cprover_gotoc/utils/names.rs

@@ -45,10 +45,6 @@ impl<'tcx> GotocCtx<'tcx> {
         (name, base_name)
     }
 
-    pub fn initializer_fn_name(var_name: &str) -> String {
-        format!("{var_name}_init")
-    }
-
     /// The name for a tuple field
     pub fn tuple_fld_name(n: usize) -> String {
         format!("{n}")

kani-compiler/src/kani_middle/transform/body.rs

@@ -17,14 +17,10 @@ pub struct MutableBody {
 
     /// Declarations of locals within the function.
     ///
-    /// The first local is the return value pointer, followed by `arg_count`
-    /// locals for the function arguments, followed by any user-declared
-    /// variables and temporaries.
+    /// The first local is the return value pointer, followed by locals for the function arguments,
+    /// followed by any user-declared variables and temporaries.
     locals: Vec<LocalDecl>,
 
-    /// The number of arguments this function takes.
-    arg_count: usize,
-
     /// Debug information pertaining to user variables, including captures.
     var_debug_info: Vec<VarDebugInfo>,
 
@@ -54,15 +50,10 @@ impl MutableBody {
         &self.locals
     }
 
-    pub fn arg_count(&self) -> usize {
-        self.arg_count
-    }
-
     /// Create a mutable body from the original MIR body.
     pub fn from(body: Body) -> Self {
         MutableBody {
             locals: body.locals().to_vec(),
-            arg_count: body.arg_locals().len(),
             spread_arg: body.spread_arg(),
             blocks: body.blocks,
             var_debug_info: body.var_debug_info,
@@ -72,14 +63,7 @@ impl MutableBody {
 
     /// Create the new body consuming this mutable body.
     pub fn into(self) -> Body {
-        Body::new(
-            self.blocks,
-            self.locals,
-            self.arg_count,
-            self.var_debug_info,
-            self.spread_arg,
-            self.span,
-        )
+        Body::new(self.blocks, self.locals, self.var_debug_info, self.spread_arg, self.span)
     }
 
     /// Add a new local to the body with the given attributes.

rust-toolchain.toml

@@ -2,5 +2,5 @@
 # SPDX-License-Identifier: Apache-2.0 OR MIT
 
 [toolchain]
-channel = "nightly-2024-08-03"
+channel = "nightly-2024-08-05"
 components = ["llvm-tools", "rustc-dev", "rust-src", "rustfmt"]