Replace backtrace crate with stabilized std::backtrace implementation (#186)

* Replace `backtrace` crate with stabilized `std::backtrace` implementation

Rust 1.65 [stabilized `std::backtrace::Backtrace`], which we can use in
place of the `backtrace` crate to reduce our dependency stack.

Normally `Backtrace::capture()` would listen to the `RUST_BACKTRACE`
and `RUST_LIB_BACKTRACE` environment variables, but this is unsuitable
for us as capturing backtraces is configured via boolean debug
feature flags in the `AllocatorDebugSettings` struct.  Fortunately
`Backtrace::force_capture()` exists which circumvents these env var
checks and always returns a backtrace, and is hence used in the codebase
here.

Unfortuantely the type no longer implements `Clone` like
`backtrace::Backtrace`, requiring us to wrap it in an `Arc` (because
most of our types are thread-safe) to clone the `Backtrace` around
various (sub)allocations and statistics reports.

[stabilized `std::backtrace::Backtrace`]: https://blog.rust-lang.org/2022/11/03/Rust-1.65.0.html#stabilized-apis

* Test MSRV in CI

* Bump edition to 2021 to match MSRV 1.65

Author: MarijnS95

.cargo/config.toml

@@ -78,7 +78,6 @@ rustflags = [
     # END - Embark standard lints v6 for Rust 1.55+
 
     # Our additional lints
-    "-Wclippy::clone_on_ref_ptr",
     "-Wclippy::cognitive_complexity",
     "-Wclippy::needless_pass_by_value",
     "-Wclippy::option_if_let_else",

.github/workflows/ci.yml

@@ -18,6 +18,21 @@ jobs:
       - name: Cargo check
         run: cargo check --workspace --all-targets --features ${{ matrix.features }} --no-default-features
 
+  check_msrv:
+    name: Check MSRV (1.65.0)
+    strategy:
+      matrix:
+        include:
+        - os: ubuntu-latest
+          features: vulkan
+        - os: windows-latest
+          features: vulkan,d3d12
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@1.65.0
+      - run: cargo check --workspace --all-targets --features ${{ matrix.features }} --no-default-features
+
   test:
     name: Test Suite
     strategy:

Cargo.toml

@@ -2,14 +2,15 @@
 name = "gpu-allocator"
 version = "0.24.0"
 authors = ["Traverse Research <opensource@traverseresearch.nl>"]
-edition = "2018"
+edition = "2021"
 license = "MIT OR Apache-2.0"
 description = "Memory allocator for GPU memory in Vulkan and DirectX 12"
 categories = ["rendering", "rendering::graphics-api"]
 homepage = "https://github.com/Traverse-Research/gpu-allocator"
 repository = "https://github.com/Traverse-Research/gpu-allocator"
 keywords = ["vulkan", "memory", "allocator"]
 documentation = "https://docs.rs/gpu-allocator/"
+rust-version = "1.65"
 
 include = [
     "/README.md",
@@ -19,7 +20,6 @@ include = [
 ]
 
 [dependencies]
-backtrace = "0.3"
 log = "0.4"
 thiserror = "1.0"
 presser = { version = "0.3" }

README.md

@@ -6,6 +6,7 @@
 [![LICENSE](https://img.shields.io/badge/license-MIT-blue.svg)](LICENSE-MIT)
 [![LICENSE](https://img.shields.io/badge/license-apache-blue.svg?logo=apache)](LICENSE-APACHE)
 [![Contributor Covenant](https://img.shields.io/badge/contributor%20covenant-v1.4%20adopted-ff69b4.svg)](../main/CODE_OF_CONDUCT.md)
+[![MSRV](https://img.shields.io/badge/rustc-1.65.0+-ab6000.svg)](https://blog.rust-lang.org/2022/11/03/Rust-1.65.0.html)
 
 [![Banner](banner.png)](https://traverseresearch.nl)
 
@@ -129,6 +130,10 @@ drop(resource);
 allocator.free(allocation).unwrap();
 ```
 
+## Minimum Supported Rust Version
+
+The MSRV for this crate and the `vulkan` and `d3d12` features is Rust 1.65.  Any other features such as the `visualizer` (with all the `egui` dependencies) may have a higher requirement and are not tested in our CI.
+
 ## License
 
 Licensed under either of

README.tpl

@@ -6,6 +6,7 @@
 [![LICENSE](https://img.shields.io/badge/license-MIT-blue.svg)](LICENSE-MIT)
 [![LICENSE](https://img.shields.io/badge/license-apache-blue.svg?logo=apache)](LICENSE-APACHE)
 [![Contributor Covenant](https://img.shields.io/badge/contributor%20covenant-v1.4%20adopted-ff69b4.svg)](../main/CODE_OF_CONDUCT.md)
+[![MSRV](https://img.shields.io/badge/rustc-1.65.0+-ab6000.svg)](https://blog.rust-lang.org/2022/11/03/Rust-1.65.0.html)
 
 [![Banner](banner.png)](https://traverseresearch.nl)
 
@@ -18,6 +19,10 @@ gpu-allocator = "0.24.0"
 
 {{readme}}
 
+## Minimum Supported Rust Version
+
+The MSRV for this crate and the `vulkan` and `d3d12` features is Rust 1.65.  Any other features such as the `visualizer` (with all the `egui` dependencies) may have a higher requirement and are not tested in our CI.
+
 ## License
 
 Licensed under either of

src/allocator/dedicated_block_allocator/mod.rs

@@ -3,16 +3,20 @@
 #[cfg(feature = "visualizer")]
 pub(crate) mod visualizer;
 
-use super::{resolve_backtrace, AllocationReport, AllocationType, SubAllocator, SubAllocatorBase};
-use crate::{AllocationError, Result};
+use std::{backtrace::Backtrace, sync::Arc};
+
 use log::{log, Level};
 
+use super::{AllocationReport, AllocationType, SubAllocator, SubAllocatorBase};
+use crate::{AllocationError, Result};
+
 #[derive(Debug)]
 pub(crate) struct DedicatedBlockAllocator {
     size: u64,
     allocated: u64,
+    /// Only used if [`crate::AllocatorDebugSettings::store_stack_traces`] is [`true`]
     name: Option<String>,
-    backtrace: Option<backtrace::Backtrace>,
+    backtrace: Arc<Backtrace>,
 }
 
 impl DedicatedBlockAllocator {
@@ -21,7 +25,7 @@ impl DedicatedBlockAllocator {
             size,
             allocated: 0,
             name: None,
-            backtrace: None,
+            backtrace: Arc::new(Backtrace::disabled()),
         }
     }
 }
@@ -35,7 +39,7 @@ impl SubAllocator for DedicatedBlockAllocator {
         _allocation_type: AllocationType,
         _granularity: u64,
         name: &str,
-        backtrace: Option<backtrace::Backtrace>,
+        backtrace: Arc<Backtrace>,
     ) -> Result<(u64, std::num::NonZeroU64)> {
         if self.allocated != 0 {
             return Err(AllocationError::OutOfMemory);
@@ -86,7 +90,6 @@ impl SubAllocator for DedicatedBlockAllocator {
     ) {
         let empty = "".to_string();
         let name = self.name.as_ref().unwrap_or(&empty);
-        let backtrace = resolve_backtrace(&self.backtrace);
 
         log!(
             log_level,
@@ -103,7 +106,7 @@ impl SubAllocator for DedicatedBlockAllocator {
             memory_block_index,
             self.size,
             name,
-            backtrace
+            self.backtrace
         )
     }
 

src/allocator/free_list_allocator/mod.rs

@@ -3,11 +3,16 @@
 #[cfg(feature = "visualizer")]
 pub(crate) mod visualizer;
 
-use super::{resolve_backtrace, AllocationReport, AllocationType, SubAllocator, SubAllocatorBase};
-use crate::{AllocationError, Result};
+use std::{
+    backtrace::Backtrace,
+    collections::{HashMap, HashSet},
+    sync::Arc,
+};
 
 use log::{log, Level};
-use std::collections::{HashMap, HashSet};
+
+use super::{AllocationReport, AllocationType, SubAllocator, SubAllocatorBase};
+use crate::{AllocationError, Result};
 
 const USE_BEST_FIT: bool = true;
 
@@ -26,7 +31,8 @@ pub(crate) struct MemoryChunk {
     pub(crate) offset: u64,
     pub(crate) allocation_type: AllocationType,
     pub(crate) name: Option<String>,
-    pub(crate) backtrace: Option<backtrace::Backtrace>, // Only used if STORE_STACK_TRACES is true
+    /// Only used if [`crate::AllocatorDebugSettings::store_stack_traces`] is [`true`]
+    pub(crate) backtrace: Arc<Backtrace>,
     next: Option<std::num::NonZeroU64>,
     prev: Option<std::num::NonZeroU64>,
 }
@@ -73,7 +79,7 @@ impl FreeListAllocator {
                 offset: 0,
                 allocation_type: AllocationType::Free,
                 name: None,
-                backtrace: None,
+                backtrace: Arc::new(Backtrace::disabled()),
                 prev: None,
                 next: None,
             },
@@ -156,7 +162,7 @@ impl SubAllocator for FreeListAllocator {
         allocation_type: AllocationType,
         granularity: u64,
         name: &str,
-        backtrace: Option<backtrace::Backtrace>,
+        backtrace: Arc<Backtrace>,
     ) -> Result<(u64, std::num::NonZeroU64)> {
         let free_size = self.size - self.allocated;
         if size > free_size {
@@ -296,7 +302,7 @@ impl SubAllocator for FreeListAllocator {
             })?;
             chunk.allocation_type = AllocationType::Free;
             chunk.name = None;
-            chunk.backtrace = None;
+            chunk.backtrace = Arc::new(Backtrace::disabled());
 
             self.allocated -= chunk.size;
 
@@ -356,7 +362,6 @@ impl SubAllocator for FreeListAllocator {
             }
             let empty = "".to_string();
             let name = chunk.name.as_ref().unwrap_or(&empty);
-            let backtrace = resolve_backtrace(&chunk.backtrace);
 
             log!(
                 log_level,
@@ -379,7 +384,7 @@ impl SubAllocator for FreeListAllocator {
                 chunk.offset,
                 chunk.allocation_type,
                 name,
-                backtrace
+                chunk.backtrace
             );
         }
     }

src/allocator/mod.rs

@@ -1,3 +1,7 @@
+use std::{backtrace::Backtrace, sync::Arc};
+
+use log::*;
+
 use crate::result::*;
 
 pub(crate) mod dedicated_block_allocator;
@@ -6,8 +10,6 @@ pub(crate) use dedicated_block_allocator::DedicatedBlockAllocator;
 pub(crate) mod free_list_allocator;
 pub(crate) use free_list_allocator::FreeListAllocator;
 
-use log::*;
-
 #[derive(PartialEq, Copy, Clone, Debug)]
 #[repr(u8)]
 pub(crate) enum AllocationType {
@@ -32,18 +34,7 @@ pub(crate) struct AllocationReport {
     pub(crate) name: String,
     pub(crate) size: u64,
     #[cfg(feature = "visualizer")]
-    pub(crate) backtrace: Option<backtrace::Backtrace>,
-}
-
-pub(crate) fn resolve_backtrace(backtrace: &Option<backtrace::Backtrace>) -> String {
-    backtrace.as_ref().map_or_else(
-        || "".to_owned(),
-        |bt| {
-            let mut bt = bt.clone();
-            bt.resolve();
-            format!("{:?}", bt)
-        },
-    )
+    pub(crate) backtrace: Arc<Backtrace>,
 }
 
 #[cfg(feature = "visualizer")]
@@ -59,7 +50,7 @@ pub(crate) trait SubAllocator: SubAllocatorBase + std::fmt::Debug + Sync + Send
         allocation_type: AllocationType,
         granularity: u64,
         name: &str,
-        backtrace: Option<backtrace::Backtrace>,
+        backtrace: Arc<Backtrace>,
     ) -> Result<(u64, std::num::NonZeroU64)>;
 
     fn free(&mut self, chunk_id: Option<std::num::NonZeroU64>) -> Result<()>;

src/d3d12/mod.rs

@@ -1,6 +1,6 @@
 #![deny(clippy::unimplemented, clippy::unwrap_used, clippy::ok_expect)]
 
-use std::fmt;
+use std::{backtrace::Backtrace, fmt, sync::Arc};
 
 use log::{debug, warn, Level};
 
@@ -421,7 +421,7 @@ impl MemoryType {
         &mut self,
         device: &ID3D12DeviceVersion,
         desc: &AllocationCreateDesc<'_>,
-        backtrace: Option<backtrace::Backtrace>,
+        backtrace: Arc<Backtrace>,
         allocation_sizes: &AllocationSizes,
     ) -> Result<Allocation> {
         let allocation_type = AllocationType::Linear;
@@ -717,20 +717,20 @@ impl Allocator {
         let size = desc.size;
         let alignment = desc.alignment;
 
-        let backtrace = if self.debug_settings.store_stack_traces {
-            Some(backtrace::Backtrace::new_unresolved())
+        let backtrace = Arc::new(if self.debug_settings.store_stack_traces {
+            Backtrace::force_capture()
         } else {
-            None
-        };
+            Backtrace::disabled()
+        });
 
         if self.debug_settings.log_allocations {
             debug!(
                 "Allocating `{}` of {} bytes with an alignment of {}.",
                 &desc.name, size, alignment
             );
             if self.debug_settings.log_stack_traces {
-                let backtrace = backtrace::Backtrace::new();
-                debug!("Allocation stack trace: {:?}", &backtrace);
+                let backtrace = Backtrace::force_capture();
+                debug!("Allocation stack trace: {}", backtrace);
             }
         }
 
@@ -761,8 +761,8 @@ impl Allocator {
             let name = allocation.name.as_deref().unwrap_or("<null>");
             debug!("Freeing `{}`.", name);
             if self.debug_settings.log_stack_traces {
-                let backtrace = backtrace::Backtrace::new();
-                debug!("Free stack trace: {:?}", backtrace);
+                let backtrace = Backtrace::force_capture();
+                debug!("Free stack trace: {}", backtrace);
             }
         }
 

src/visualizer/allocation_reports.rs

@@ -1,7 +1,9 @@
+use std::backtrace::BacktraceStatus;
+
 use egui::{Label, Response, Sense, Ui, WidgetText};
 use egui_extras::{Column, TableBuilder};
 
-use crate::allocator::{fmt_bytes, resolve_backtrace, AllocationReport};
+use crate::allocator::{fmt_bytes, AllocationReport};
 
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
 pub(crate) enum AllocationReportVisualizeSorting {
@@ -121,9 +123,9 @@ pub(crate) fn render_allocation_reports_ui(
                     ui.label(name);
                 });
 
-                if backtrace.is_some() {
+                if backtrace.status() == BacktraceStatus::Captured {
                     resp.1.on_hover_ui(|ui| {
-                        ui.label(resolve_backtrace(&backtrace));
+                        ui.label(backtrace.to_string());
                     });
                 }