refactor(target_arch): pass arch via feature flags instead

Cargo.toml

@@ -46,6 +46,8 @@ repl_tools = { path = "./repl_tools" }
 headcrab_inject = { path = "./headcrab_inject" }
 
 [features]
+default = ["x86_64"]
+x86_64 = []
 syntax-highlighting = ["syntect"]
 
 [workspace]

headcrab_inject/Cargo.toml

@@ -21,3 +21,7 @@ target-lexicon = "0.10.0"
 
 [target.'cfg(unix)'.dev-dependencies]
 nix = "0.17.0"
+
+[features]
+default = ["x86_64"]
+x86_64 = []

headcrab_inject/src/lib.rs

@@ -1,5 +1,5 @@
 // FIXME make this work on other systems too.
-#![cfg(all(target_arch = "x86_64", target_os = "linux"))]
+#![cfg(all(feature = "x86_64", target_os = "linux"))]
 
 use std::{collections::HashMap, error::Error};
 

src/target.rs

@@ -20,6 +20,10 @@ pub use windows::*;
 
 mod thread;
 
+pub enum Arch {
+    X86_64,
+}
+
 #[derive(Debug)]
 pub struct MemoryMap {
     /// Start and end range of the mapped memory.

src/target/linux.rs

@@ -24,17 +24,17 @@ pub use writemem::WriteMemory;
 
 lazy_static::lazy_static! {
     pub static ref PAGE_SIZE: usize = unsafe { libc::sysconf(libc::_SC_PAGESIZE) as usize };
-    #[cfg(target_arch="x86_64")]
+    #[cfg(feature="x86_64")]
     static ref DEBUG_REG_OFFSET: usize = unsafe {
         let x = std::mem::zeroed::<libc::user>();
         (&x.u_debugreg as *const _ as usize) - (&x as *const _ as usize)
     };
 }
 
-#[cfg(target_arch = "x86_64")]
+#[cfg(feature = "x86_64")]
 const SUPPORTED_HARDWARE_BREAKPOINTS: usize = 4;
 
-#[cfg(not(target_arch = "x86_64"))]
+#[cfg(not(feature = "x86_64"))]
 const SUPPORTED_HARDWARE_BREAKPOINTS: usize = 0;
 
 struct LinuxThread {
@@ -260,7 +260,7 @@ impl LinuxTarget {
         &mut self,
         breakpoint: HardwareBreakpoint,
     ) -> Result<usize, Box<dyn std::error::Error>> {
-        #[cfg(target_arch = "x86_64")]
+        #[cfg(feature = "x86_64")]
         {
             let index = if let Some(empty) = self.find_empty_watchpoint() {
                 empty
@@ -311,15 +311,15 @@ impl LinuxTarget {
 
             Ok(index)
         }
-        #[cfg(not(target_arch = "x86_64"))]
+        #[cfg(not(feature = "x86_64"))]
         Err(Box::new(HardwareBreakpointError::UnsupportedPlatform))
     }
 
     pub fn clear_hardware_breakpoint(
         &mut self,
         index: usize,
     ) -> Result<HardwareBreakpoint, Box<dyn std::error::Error>> {
-        #[cfg(target_arch = "x86_64")]
+        #[cfg(feature = "x86_64")]
         {
             if self.hardware_breakpoints[index].is_none() {
                 return Err(Box::new(HardwareBreakpointError::DoesNotExist(index)));
@@ -357,7 +357,7 @@ impl LinuxTarget {
             Ok(watchpoint.unwrap())
         }
 
-        #[cfg(not(target_arch = "x86_64"))]
+        #[cfg(not(feature = "x86_64"))]
         Err(Box::new(HardwareBreakpointError::UnsupportedPlatform))
     }
 
@@ -376,7 +376,7 @@ impl LinuxTarget {
     pub fn is_hardware_breakpoint_triggered(
         &self,
     ) -> Result<Option<usize>, Box<dyn std::error::Error>> {
-        #[cfg(target_arch = "x86_64")]
+        #[cfg(feature = "x86_64")]
         {
             let mut dr7 = self.ptrace_peekuser((*DEBUG_REG_OFFSET + 6 * 8) as *mut libc::c_void)?;
 
@@ -402,12 +402,12 @@ impl LinuxTarget {
             Ok(None)
         }
 
-        #[cfg(not(target_arch = "x86_64"))]
+        #[cfg(not(feature = "x86_64"))]
         Err(Box::new(HardwareBreakpointError::UnsupportedPlatform))
     }
 
     // Temporary function until ptrace_peekuser is fixed in nix crate
-    #[cfg(target_arch = "x86_64")]
+    #[cfg(feature = "x86_64")]
     fn ptrace_peekuser(
         &self,
         addr: *mut libc::c_void,

tests/readregs.rs

@@ -4,7 +4,7 @@ mod test_utils;
 
 static BIN_PATH: &str = concat!(env!("CARGO_MANIFEST_DIR"), "/tests/testees/hello");
 
-#[cfg(all(target_os = "linux", target_arch = "x86_64"))]
+#[cfg(all(target_os = "linux", feature = "x86_64"))]
 #[test]
 fn read_regs() -> Result<(), Box<dyn std::error::Error>> {
     test_utils::ensure_testees();