From 69535280c6ac2d19e03ecb11034b36c806df2f5d Mon Sep 17 00:00:00 2001
From: "Victor M. Alvarez" <plusvic@gmail.com>
Date: Thu, 29 Aug 2024 16:35:42 +0200
Subject: [PATCH] fix: issue while creating statically linked binary that
 depends on `musl` instead of `glibc`.

Closes #181
---
 .cargo/config.toml  | 20 ++++++++++++++++++++
 lib/src/wasm/mod.rs | 12 ++++++++++++
 2 files changed, 32 insertions(+)
 create mode 100644 .cargo/config.toml

diff --git a/.cargo/config.toml b/.cargo/config.toml
new file mode 100644
index 00000000..35f09c87
--- /dev/null
+++ b/.cargo/config.toml
@@ -0,0 +1,20 @@
+# Special configuration for linking with musl instead of glibc.
+# See: https://github.com/VirusTotal/yara-x/issues/181
+#
+[target.x86_64-unknown-linux-musl]
+# Relocation model is "pic" by default (i.e: position independent code),
+# Here we force the "static" (i.e: non-relocatable code) model. Without this
+# the produced binaries crash with SIGSEGV as described in:
+# https://github.com/rust-lang/rust/issues/74757
+# https://github.com/rust-lang/rust/issues/81987
+rustflags = ["-C", "relocation-model=static"]
+# This is not necessary when building from a host where gcc already links
+# against musl by default, and it can be commented out (e.g: when building 
+# from a Alpine Linux host). But in most cases what we want is cross-compiling 
+# a host with a standard gcc that links against glibc. In such cases from we 
+# must link using musl-gcc.
+#
+# In Debian/Ubuntu you need to install the musl-tools package in order to
+# build YARA-X with musl. This package contains musl-gcc, which is a gcc
+# wrapper that creates binaries that depends on musl instead of glibc.
+linker = "musl-gcc"
diff --git a/lib/src/wasm/mod.rs b/lib/src/wasm/mod.rs
index 83ed643b..45eb3f41 100644
--- a/lib/src/wasm/mod.rs
+++ b/lib/src/wasm/mod.rs
@@ -707,8 +707,20 @@ pub(crate) struct WasmSymbols {
 lazy_static! {
     pub(crate) static ref CONFIG: Config = {
         let mut config = Config::default();
+        // Wasmtime produces a nasty warning when linked against musl. The
+        // warning can be fixed by disabling native unwind information.
+        //
+        // More details:
+        //
+        // https://github.com/bytecodealliance/wasmtime/issues/8897
+        // https://github.com/VirusTotal/yara-x/issues/181
+        //
+        #[cfg(target_env = "musl")]
+        config.native_unwind_info(false);
+
         config.cranelift_opt_level(wasmtime::OptLevel::SpeedAndSize);
         config.epoch_interruption(true);
+
         config
     };
     pub(crate) static ref ENGINE: Engine = Engine::new(&CONFIG).unwrap();