.github/workflows/check-binary-size.yml

@@ -0,0 +1,83 @@
+# This workflow checks if a PR commit has changed the size of a hello world Rust program.
+# It downloads Rustc and compiles two versions of a stage0 compiler - one using the base commit
+# of the PR, and one using the latest commit in the PR.
+# If the size of the hello world program has changed, it posts a comment to the PR.
+name: Check binary size
+
+on:
+  pull_request_target:
+    branches:
+      - master
+
+jobs:
+  test:
+    name: Check binary size
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+    steps:
+      - name: Print info
+        run: |
+          echo "Current SHA: ${{ github.event.pull_request.head.sha }}"
+          echo "Base SHA: ${{ github.event.pull_request.base.sha }}"
+      - name: Clone Rustc
+        uses: actions/checkout@v3
+        with:
+          repository: rust-lang/rust
+          fetch-depth: 1
+      - name: Fetch backtrace
+        run: git submodule update --init library/backtrace
+      - name: Create hello world program that uses backtrace
+        run: printf "fn main() { panic!(); }" > foo.rs
+      - name: Build binary with base version of backtrace
+        run: |
+          printf "[llvm]\ndownload-ci-llvm = true\n\n[rust]\nincremental = false\n" > config.toml
+          cd library/backtrace
+          git remote add head-pr https://github.com/${{ github.event.pull_request.head.repo.full_name }}
+          git fetch --all
+          git checkout ${{ github.event.pull_request.base.sha }}
+          cd ../..
+          git add library/backtrace
+          python3 x.py build library --stage 0
+          ./build/x86_64-unknown-linux-gnu/stage0-sysroot/bin/rustc -O foo.rs -o binary-reference
+      - name: Build binary with PR version of backtrace
+        run: |
+          cd library/backtrace
+          git checkout ${{ github.event.pull_request.head.sha }}
+          cd ../..
+          git add library/backtrace
+          rm -rf build/x86_64-unknown-linux-gnu/stage0-std
+          python3 x.py build library --stage 0
+          ./build/x86_64-unknown-linux-gnu/stage0-sysroot/bin/rustc -O foo.rs -o binary-updated
+      - name: Display binary size
+        run: |
+          ls -la binary-*
+          echo "SIZE_REFERENCE=$(stat -c '%s' binary-reference)" >> "$GITHUB_ENV"
+          echo "SIZE_UPDATED=$(stat -c '%s' binary-updated)" >> "$GITHUB_ENV"
+      - name: Post a PR comment if the size has changed
+        uses: actions/github-script@v6
+        with:
+          script: |
+            const reference = process.env.SIZE_REFERENCE;
+            const updated = process.env.SIZE_UPDATED;
+            const diff = updated - reference;
+            const plus = diff > 0 ? "+" : "";
+            const diff_str = `${plus}${diff}B`;
+
+            if (diff !== 0) {
+              const percent = (((updated / reference) - 1) * 100).toFixed(2);
+              // The body is created here and wrapped so "weirdly" to avoid whitespace at the start of the lines,
+              // which is interpreted as a code block by Markdown.
+              const body = `Below is the size of a hello-world Rust program linked with libstd with backtrace.
+
+            Original binary size: **${reference}B**
+            Updated binary size: **${updated}B**
+            Difference: **${diff_str}** (${percent}%)`;
+
+              github.rest.issues.createComment({
+                issue_number: context.issue.number,
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                body
+              })
+            }

.github/workflows/main.yml

@@ -229,7 +229,7 @@ jobs:
       with:
         submodules: true
     - name: Install Rust
-      run: rustup update 1.55.0 && rustup default 1.55.0
+      run: rustup update 1.65.0 && rustup default 1.65.0
     - run: cargo build
 
   miri:

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "backtrace"
-version = "0.3.68"
+version = "0.3.69"
 authors = ["The Rust Project Developers"]
 build = "build.rs"
 license = "MIT OR Apache-2.0"
@@ -14,6 +14,7 @@ A library to acquire a stack trace (backtrace) at runtime in a Rust program.
 autoexamples = true
 autotests = true
 edition = "2018"
+exclude = ["/ci/"]
 
 [workspace]
 members = ['crates/cpp_smoke_test', 'crates/as-if-std']
@@ -27,7 +28,6 @@ exclude = [
 [dependencies]
 cfg-if = "1.0"
 rustc-demangle = "0.1.4"
-libc = { version = "0.2.146", default-features = false }
 
 # Optionally enable the ability to serialize a `Backtrace`, controlled through
 # the `serialize-*` features below.
@@ -37,11 +37,13 @@ rustc-serialize = { version = "0.3", optional = true }
 # Optionally demangle C++ frames' symbols in backtraces.
 cpp_demangle = { default-features = false, version = "0.4.0", optional = true, features = ["alloc"] }
 
-addr2line = { version = "0.20.0", default-features = false }
+[target.'cfg(not(all(windows, target_env = "msvc", not(target_vendor = "uwp"))))'.dependencies]
 miniz_oxide = { version = "0.7.0", default-features = false }
+addr2line = { version = "0.21.0", default-features = false }
+libc = { version = "0.2.146", default-features = false }
 
-[dependencies.object]
-version = "0.31.1"
+[target.'cfg(not(all(windows, target_env = "msvc", not(target_vendor = "uwp"))))'.dependencies.object]
+version = "0.32.0"
 default-features = false
 features = ['read_core', 'elf', 'macho', 'pe', 'unaligned', 'archive']
 

build.rs

@@ -1,16 +1,24 @@
 extern crate cc;
 
 use std::env;
+use std::path::Path;
 
-fn main() {
+// Must be public so the build script of `std` can call it.
+pub fn main() {
     match env::var("CARGO_CFG_TARGET_OS").unwrap_or_default().as_str() {
         "android" => build_android(),
         _ => {}
     }
 }
 
 fn build_android() {
-    let expansion = match cc::Build::new().file("src/android-api.c").try_expand() {
+    // Resolve `src/android-api.c` relative to this file.
+    // Required to support calling this from the `std` build script.
+    let android_api_c = Path::new(file!())
+        .parent()
+        .unwrap()
+        .join("src/android-api.c");
+    let expansion = match cc::Build::new().file(android_api_c).try_expand() {
         Ok(result) => result,
         Err(e) => {
             println!("failed to run C compiler: {}", e);

crates/as-if-std/Cargo.toml

@@ -15,15 +15,21 @@ bench = false
 cfg-if = "1.0"
 rustc-demangle = "0.1.21"
 libc = { version = "0.2.146", default-features = false }
-addr2line = { version = "0.20.0", default-features = false, optional = true }
-miniz_oxide = { version = "0.7", default-features = false }
 
-[dependencies.object]
-version = "0.31.1"
+[target.'cfg(not(all(windows, target_env = "msvc", not(target_vendor = "uwp"))))'.dependencies]
+miniz_oxide = { version = "0.7.0", optional = true, default-features = false }
+addr2line = { version = "0.21.0", optional = true, default-features = false }
+
+[target.'cfg(not(all(windows, target_env = "msvc", not(target_vendor = "uwp"))))'.dependencies.object]
+version = "0.32.0"
 default-features = false
 optional = true
 features = ['read_core', 'elf', 'macho', 'pe', 'unaligned', 'archive']
 
+[build-dependencies]
+# Dependency of the `backtrace` crate
+cc = "1.0.67"
+
 [features]
 default = ['backtrace']
-backtrace = ['addr2line', 'object']
+backtrace = ['addr2line', 'miniz_oxide', 'object']

crates/as-if-std/build.rs

@@ -1,3 +1,11 @@
+// backtrace-rs requires a feature check on Android targets, so
+// we need to run its build.rs as well.
+#[allow(unused_extern_crates)]
+#[path = "../../build.rs"]
+mod backtrace_build_rs;
+
 fn main() {
     println!("cargo:rustc-cfg=backtrace_in_libstd");
+
+    backtrace_build_rs::main();
 }

src/print.rs

@@ -83,7 +83,8 @@ impl<'a, 'b> BacktraceFmt<'a, 'b> {
     /// This is currently a no-op but is added for future compatibility with
     /// backtrace formats.
     pub fn finish(&mut self) -> fmt::Result {
-        // Currently a no-op-- including this hook to allow for future additions.
+        #[cfg(target_os = "fuchsia")]
+        fuchsia::finish_context(self.fmt)?;
         Ok(())
     }
 

src/print/fuchsia.rs

@@ -425,7 +425,7 @@ impl DsoPrinter<'_, '_> {
 
 /// This function prints the Fuchsia symbolizer markup for all information contained in a DSO.
 pub fn print_dso_context(out: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-    out.write_str("{{{reset}}}\n")?;
+    out.write_str("{{{reset:begin}}}\n")?;
     let mut visitor = DsoPrinter {
         writer: out,
         module_count: 0,
@@ -434,3 +434,8 @@ pub fn print_dso_context(out: &mut core::fmt::Formatter<'_>) -> core::fmt::Resul
     for_each_dso(&mut visitor);
     visitor.error
 }
+
+/// This function prints the Fuchsia symbolizer markup to end the backtrace.
+pub fn finish_context(out: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+    out.write_str("{{{reset:end}}}\n")
+}

src/symbolize/gimli/parse_running_mmaps_unix.rs

@@ -85,16 +85,37 @@ impl FromStr for MapsEntry {
     // e.g.: "ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0                  [vsyscall]"
     // e.g.: "7f5985f46000-7f5985f48000 rw-p 00039000 103:06 76021795                  /usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2"
     // e.g.: "35b1a21000-35b1a22000 rw-p 00000000 00:00 0"
+    //
+    // Note that paths may contain spaces, so we can't use `str::split` for parsing (until
+    // Split::remainder is stabilized #77998).
     fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let mut parts = s
-            .split(' ') // space-separated fields
-            .filter(|s| s.len() > 0); // multiple spaces implies empty strings that need to be skipped.
-        let range_str = parts.next().ok_or("Couldn't find address")?;
-        let perms_str = parts.next().ok_or("Couldn't find permissions")?;
-        let offset_str = parts.next().ok_or("Couldn't find offset")?;
-        let dev_str = parts.next().ok_or("Couldn't find dev")?;
-        let inode_str = parts.next().ok_or("Couldn't find inode")?;
-        let pathname_str = parts.next().unwrap_or(""); // pathname may be omitted.
+        let (range_str, s) = s.trim_start().split_once(' ').unwrap_or((s, ""));
+        if range_str.is_empty() {
+            return Err("Couldn't find address");
+        }
+
+        let (perms_str, s) = s.trim_start().split_once(' ').unwrap_or((s, ""));
+        if perms_str.is_empty() {
+            return Err("Couldn't find permissions");
+        }
+
+        let (offset_str, s) = s.trim_start().split_once(' ').unwrap_or((s, ""));
+        if offset_str.is_empty() {
+            return Err("Couldn't find offset");
+        }
+
+        let (dev_str, s) = s.trim_start().split_once(' ').unwrap_or((s, ""));
+        if dev_str.is_empty() {
+            return Err("Couldn't find dev");
+        }
+
+        let (inode_str, s) = s.trim_start().split_once(' ').unwrap_or((s, ""));
+        if inode_str.is_empty() {
+            return Err("Couldn't find inode");
+        }
+
+        // Pathname may be omitted in which case it will be empty
+        let pathname_str = s.trim_start();
 
         let hex = |s| usize::from_str_radix(s, 16).map_err(|_| "Couldn't parse hex number");
         let address = if let Some((start, limit)) = range_str.split_once('-') {
@@ -229,4 +250,46 @@ fn check_maps_entry_parsing_32bit() {
             pathname: Default::default(),
         }
     );
+    assert_eq!(
+        "b7c79000-b7e02000 r--p 00000000 08:01 60662705   \
+                /executable/path/with some spaces"
+            .parse::<MapsEntry>()
+            .unwrap(),
+        MapsEntry {
+            address: (0xb7c79000, 0xb7e02000),
+            perms: ['r', '-', '-', 'p'],
+            offset: 0x00000000,
+            dev: (0x08, 0x01),
+            inode: 0x60662705,
+            pathname: "/executable/path/with some spaces".into(),
+        }
+    );
+    assert_eq!(
+        "b7c79000-b7e02000 r--p 00000000 08:01 60662705   \
+                /executable/path/with  multiple-continuous    spaces  "
+            .parse::<MapsEntry>()
+            .unwrap(),
+        MapsEntry {
+            address: (0xb7c79000, 0xb7e02000),
+            perms: ['r', '-', '-', 'p'],
+            offset: 0x00000000,
+            dev: (0x08, 0x01),
+            inode: 0x60662705,
+            pathname: "/executable/path/with  multiple-continuous    spaces  ".into(),
+        }
+    );
+    assert_eq!(
+        "  b7c79000-b7e02000  r--p  00000000  08:01  60662705   \
+                /executable/path/starts-with-spaces"
+            .parse::<MapsEntry>()
+            .unwrap(),
+        MapsEntry {
+            address: (0xb7c79000, 0xb7e02000),
+            perms: ['r', '-', '-', 'p'],
+            offset: 0x00000000,
+            dev: (0x08, 0x01),
+            inode: 0x60662705,
+            pathname: "/executable/path/starts-with-spaces".into(),
+        }
+    );
 }

src/symbolize/mod.rs

@@ -471,7 +471,7 @@ cfg_if::cfg_if! {
         mod dbghelp;
         use dbghelp as imp;
     } else if #[cfg(all(
-        any(unix, windows),
+        any(unix, all(windows, target_env = "gnu")),
         not(target_vendor = "uwp"),
         not(target_os = "emscripten"),
         any(not(backtrace_in_libstd), feature = "backtrace"),

src/windows.rs

@@ -177,9 +177,9 @@ macro_rules! ffi {
                     assert_eq!($name as usize, winapi::$name as usize);
                     let mut x: unsafe extern "system" fn($($args)*) -> $ret;
                     x = $name;
-                    drop(x);
+                    let _ = x;
                     x = winapi::$name;
-                    drop(x);
+                    let _ = x;
                 }
             }
         )*