Merge pull request #697 from ChrisDenton/cleanup-win

Cleanup Windows trace modules

Author: ChrisDenton

src/backtrace/mod.rs

@@ -189,15 +189,15 @@ cfg_if::cfg_if! {
     } else if #[cfg(all(windows, not(target_vendor = "uwp")))] {
         cfg_if::cfg_if! {
             if #[cfg(any(target_arch = "x86_64", target_arch = "aarch64", target_arch = "arm64ec"))] {
-                mod dbghelp64;
-                use dbghelp64 as dbghelp;
+                mod win64;
+                use self::win64::trace as trace_imp;
+                pub(crate) use self::win64::Frame as FrameImp;
             } else if #[cfg(any(target_arch = "x86", target_arch = "arm"))] {
-                mod dbghelp32;
-                use dbghelp32 as dbghelp;
+                mod win32;
+                use self::win32::trace as trace_imp;
+                pub(crate) use self::win32::Frame as FrameImp;
             }
         }
-        use self::dbghelp::trace as trace_imp;
-        pub(crate) use self::dbghelp::Frame as FrameImp;
     } else {
         mod noop;
         use self::noop::trace as trace_imp;

src/backtrace/dbghelp32.rs src/backtrace/win32.rs

@@ -9,8 +9,6 @@
 //! Note that all dbghelp support is loaded dynamically, see `src/dbghelp.rs`
 //! for more information about that.
 
-#![allow(bad_style)]
-
 use super::super::{dbghelp, windows_sys::*};
 use core::ffi::c_void;
 use core::mem;
@@ -111,14 +109,6 @@ pub unsafe fn trace(cb: &mut dyn FnMut(&super::Frame) -> bool) {
         Err(()) => return, // oh well...
     };
 
-    // On x86_64 and ARM64 we opt to not use the default `Sym*` functions from
-    // dbghelp for getting the function table and module base. Instead we use
-    // the `RtlLookupFunctionEntry` function in kernel32 which will account for
-    // JIT compiler frames as well. These should be equivalent, but using
-    // `Rtl*` allows us to backtrace through JIT frames.
-    //
-    // Note that `RtlLookupFunctionEntry` only works for in-process backtraces,
-    // but that's all we support anyway, so it all lines up well.
     let function_table_access = dbghelp.SymFunctionTableAccess64();
     let get_module_base = dbghelp.SymGetModuleBase64();
 
@@ -127,6 +117,7 @@ pub unsafe fn trace(cb: &mut dyn FnMut(&super::Frame) -> bool) {
     // Attempt to use `StackWalkEx` if we can, but fall back to `StackWalk64`
     // since it's in theory supported on more systems.
     match (*dbghelp.dbghelp()).StackWalkEx() {
+        #[allow(non_snake_case)]
         Some(StackWalkEx) => {
             let mut inner: STACKFRAME_EX = mem::zeroed();
             inner.StackFrameSize = mem::size_of::<STACKFRAME_EX>() as u32;

src/backtrace/dbghelp64.rs src/backtrace/win64.rs

@@ -6,8 +6,6 @@
 //! We still report inlined frames during symbolization by consulting the appropriate
 //! `dbghelp` functions.
 
-#![allow(bad_style)]
-
 use super::super::windows_sys::*;
 use core::ffi::c_void;
 
@@ -77,11 +75,6 @@ impl MyContext {
     }
 }
 
-#[cfg(any(
-    target_arch = "x86_64",
-    target_arch = "aarch64",
-    target_arch = "arm64ec"
-))]
 #[inline(always)]
 pub unsafe fn trace(cb: &mut dyn FnMut(&super::Frame) -> bool) {
     use core::ptr;
@@ -96,6 +89,10 @@ pub unsafe fn trace(cb: &mut dyn FnMut(&super::Frame) -> bool) {
         // The base address of the module containing the function will be stored here
         // when RtlLookupFunctionEntry returns successfully.
         let mut base = 0;
+        // We use the `RtlLookupFunctionEntry` function in kernel32 which allows
+        // us to backtrace through JIT frames.
+        // Note that `RtlLookupFunctionEntry` only works for in-process backtraces,
+        // but that's all we support anyway, so it all lines up well.
         let fn_entry = RtlLookupFunctionEntry(ip, &mut base, ptr::null_mut());
         if fn_entry.is_null() {
             // No function entry could be found - this may indicate a corrupt