fix(benches): add cfg guards for configurator features

The benches modules were unconditionally importing from the configurator
module, which is only available when at least one of the elf, pe, or
bzimage features is enabled. This caused compilation failures when
building with --no-default-features or other feature combinations that
don't enable any loader features.

Added appropriate #[cfg(any(feature = "..."))] guards to all benchmark
modules and a no-op fallback benchmark function for when no configurator
features are enabled.

Fixes #215

Signed-off-by: pizzacat83 <17941141+pizzacat83@users.noreply.github.com>

Author: pizzacat83

benches/fdt.rs

@@ -4,6 +4,9 @@
 // found in the LICENSE-BSD-3-Clause file.
 //
 // SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+
+#![cfg(any(feature = "elf", feature = "pe", feature = "bzimage"))]
+
 extern crate criterion;
 extern crate linux_loader;
 extern crate vm_memory;

benches/main.rs

@@ -11,16 +11,32 @@ extern crate vm_memory;
 
 use criterion::{criterion_group, criterion_main, Criterion};
 
-#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+#[cfg(all(
+    any(target_arch = "x86", target_arch = "x86_64"),
+    any(feature = "elf", feature = "pe", feature = "bzimage")
+))]
 mod x86_64;
-#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+#[cfg(all(
+    any(target_arch = "x86", target_arch = "x86_64"),
+    any(feature = "elf", feature = "pe", feature = "bzimage")
+))]
 use x86_64::*;
 
-#[cfg(any(target_arch = "aarch64", target_arch = "riscv64"))]
+#[cfg(all(
+    any(target_arch = "aarch64", target_arch = "riscv64"),
+    any(feature = "elf", feature = "pe", feature = "bzimage")
+))]
 mod fdt;
-#[cfg(any(target_arch = "aarch64", target_arch = "riscv64"))]
+#[cfg(all(
+    any(target_arch = "aarch64", target_arch = "riscv64"),
+    any(feature = "elf", feature = "pe", feature = "bzimage")
+))]
 pub use fdt::*;
 
+// No-op benchmark when configurator module is not available
+#[cfg(not(any(feature = "elf", feature = "pe", feature = "bzimage")))]
+fn criterion_benchmark(_c: &mut Criterion) {}
+
 criterion_group! {
     name = benches;
     config = Criterion::default().sample_size(500);

benches/x86_64/mod.rs

@@ -6,6 +6,7 @@
 // SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
 
 #![cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+#![cfg(any(feature = "elf", feature = "pe", feature = "bzimage"))]
 
 extern crate linux_loader;
 extern crate vm_memory;