From 2ab751892691170d86c0c09e585a9534a9c90b28 Mon Sep 17 00:00:00 2001
From: clover caruso <git@paperclover.net>
Date: Thu, 1 Oct 2026 16:21:57 -0700
Subject: [PATCH] feat: release builds keep their symbol tables and frame
 pointers

- Release executables keep their symbol tables, so backtraces, crash logs, perf, gdb and Instruments name functions
- Every target builds with frame pointers

The Linux linker shim strips debug info itself after linking, since zig's
linker drops the symbol table along with it.

Assisted-by: claude-opus-5.5
---
 .cargo/config.toml                |  4 ++++
 crates/snowbound/linux/package.sh |  2 +-
 platform/linux/cc.sh              | 17 ++++++++++++++---
 tools/RELEASE.md                  | 16 ++++++++++++++++
 tools/release.py                  |  3 +--
 5 files changed, 36 insertions(+), 6 deletions(-)
 create mode 100644 .cargo/config.toml

diff --git a/.cargo/config.toml b/.cargo/config.toml
new file mode 100644
index 0000000000000000000000000000000000000000..aa6d5b2e6d5d57a2c4430226a230a668e4b11515
--- /dev/null
+++ b/.cargo/config.toml
@@ -0,0 +1,4 @@
+# Frame pointers let perf, Instruments and other sampling profilers walk the stack.
+# A cfg table, unlike build.rustflags, joins the flags the platform scripts give each target.
+[target.'cfg(all())']
+rustflags = ["-C", "force-frame-pointers=yes"]
diff --git a/crates/snowbound/linux/package.sh b/crates/snowbound/linux/package.sh
index 5148246208f612efa89e62f3c4d3cd895cb1b78c..bef78477ae8b222b1f31aa24fc72bbd6d86376ff 100755
--- a/crates/snowbound/linux/package.sh
+++ b/crates/snowbound/linux/package.sh
@@ -10,7 +10,7 @@ mkdir -p "$target/dist"
 [ $# -gt 0 ] || set -- x86_64 aarch64
 for arch do
     triple=$arch-unknown-linux-gnu
-    CARGO_PROFILE_RELEASE_STRIP=symbols sh "$root/platform/linux/cargo.sh" "$arch" build \
+    sh "$root/platform/linux/cargo.sh" "$arch" build \
         --manifest-path "$root/Cargo.toml" --release -p snowbound
     # PT_INTERP becomes PT_NULL, so the kernel starts the executable at `loader`'s entry, which
     # finds the system's dynamic loader, NixOS's too. zig rejects --no-dynamic-linker.
diff --git a/platform/linux/cc.sh b/platform/linux/cc.sh
index e0ab47ba4099c1fe5b9a9334fffec0eb62fd5200..6c24c8eefff93f4ab6dc7ad2a3f9538b5bad290b 100755
--- a/platform/linux/cc.sh
+++ b/platform/linux/cc.sh
@@ -1,8 +1,19 @@
 #!/bin/sh
 # zig cc for $ZIG_TARGET, as `cargo.sh` sets it: the C compiler and linker. zig rejects
-# rustc's --target, --no-undefined-version and -O1.
+# rustc's --target, --no-undefined-version and -O1, and strips the symbol table with the debug
+# info, so the debug info goes after linking.
+strip= output= previous=
 for arg do
     shift
-    case $arg in --target=* | -Wl,--no-undefined-version | -Wl,-O1) ;; *) set -- "$@" "$arg" ;; esac
+    [ "$previous" = -o ] && output=$arg
+    previous=$arg
+    case $arg in
+    --target=* | -Wl,--no-undefined-version | -Wl,-O1) ;;
+    -Wl,--strip-debug) strip=1 ;;
+    *) set -- "$@" "$arg" ;;
+    esac
 done
-exec zig cc -target "$ZIG_TARGET" "$@"
+zig cc -target "$ZIG_TARGET" "$@" || exit
+[ -z "$strip" ] ||
+    "$(rustc --print sysroot)/lib/rustlib/$(rustc -vV | sed -n 's/^host: //p')/bin/rust-objcopy" \
+        --strip-debug "$output"
diff --git a/tools/RELEASE.md b/tools/RELEASE.md
index db4fb11faaebc1f1c5b4c858a0d97e5fadb86243..9932ebe78b20620f7cf3ce25ef6252c8f41f2d02 100644
--- a/tools/RELEASE.md
+++ b/tools/RELEASE.md
@@ -146,6 +146,22 @@ version above 2.17. The Linux executable links only libc, libm, libpthread and
 libdl; Wayland, X11, xkbcommon, EGL, Vulkan, fontconfig, GStreamer and Enchant
 are loaded at run time.
 
+## Symbols and frame pointers
+
+Every executable keeps its symbol table, so backtraces, crash logs, `perf`, gdb
+and Instruments name functions; Cargo's release profile strips only debug info
+(`platform/linux/cc.sh` does that itself, as zig's linker would strip both).
+`.cargo/config.toml` builds every target with frame pointers, and Rust's
+standard library ships with them. The symbols cost about a fifth: Linux x86_64
+grows from 53 to 62 MB, Windows x86_64 from 55 to 72 MB, and the macOS app
+already carried them. Line tables would take an executable to some 250 MB, and
+a dSYM adds 34 MB zipped per Mac architecture, so neither ships; build with
+`CARGO_PROFILE_RELEASE_DEBUG=line-tables-only` for files and lines. Windows
+tools that read only PDBs see no names: the Rust targets here emit DWARF, from
+which lld's PDB keeps only global symbols. Linux's crash log gives a signal's
+frames as `snowbound(+0x1a2b3c)`, since glibc's `backtrace_symbols_fd` reads only
+dynamic symbols; `addr2line -f -e snowbound 0x1a2b3c` names them.
+
 ## In the app
 
 `update.rs` runs one thread. With automatic checks on (Options, General) and a
diff --git a/tools/release.py b/tools/release.py
index 613c355cda313fc689194130fa70cbe8cd4390db..4d07a236a93c0e5b46ed9f0a15959039cb1c224b 100755
--- a/tools/release.py
+++ b/tools/release.py
@@ -188,8 +188,7 @@ def build_windows(architectures):
     Windows it supports."""
     built = {}
     for arch in architectures:
-        run(['sh', ROOT / 'platform/windows/cargo.sh', arch, 'build', '--release', '-p', 'snowbound'],
-            env={**os.environ, 'CARGO_PROFILE_RELEASE_STRIP': 'symbols'})
+        run(['sh', ROOT / 'platform/windows/cargo.sh', arch, 'build', '--release', '-p', 'snowbound'])
         built[f'windows-{arch}'] = ROOT / f'target/windows/{WINDOWS[arch]}/release/snowbound.exe'
     return built
 
-- 
2.54.0