Properly fix and test _Unwind_Resume issues.

Author: rkistner

.cargo/config

@@ -0,0 +1,19 @@
+# On Linux, if we don't link to gcc_eh, we get can get this error when loading the loadable extension:
+# undefined symbol: _Unwind_Resume
+# This adds around 29KB to the loadable extension.
+# It may also be an option to just define _Unwind_Resume, but it causes crashes on errors on e.g. iOS, so rather avoid it.
+
+[target.x86_64-unknown-linux-gnu]
+rustflags = [
+    "-C", "link-arg=-lgcc_eh",
+]
+
+[target.i686-linux-unknown-linux-gnu]
+rustflags = [
+    "-C", "link-arg=-lgcc_eh",
+]
+
+[target.aarch64-linux-unknown-linux-gnu]
+rustflags = [
+    "-C", "link-arg=-lgcc_eh",
+]

.github/workflows/tests.yml

@@ -33,6 +33,5 @@ jobs:
           ./target/release/powersync_sqlite ":memory:" "select powersync_rs_version()"
 
       - name: Check loadable extension
-        # This should actually be using a plain sqlite build, but this does seem to expose typical build issues at least.
         run: |
-          ./target/release/powersync_sqlite ":memory:" ".load ./target/release/libpowersync" "select powersync_rs_version()"
+          ./target/release/sqlite3 ":memory:" ".load ./target/release/libpowersync" "select powersync_rs_version()"

Cargo.lock

@@ -5,7 +5,7 @@ members = [
 ]
 resolver = "2"
 # We cannot build shell and lodable and the same time
-default-members = ["crates/shell"]
+default-members = ["crates/shell", "crates/sqlite"]
 
 [profile.dev]
 panic = "abort"

Cargo.toml

@@ -3,9 +3,9 @@ fn main() {
     let mut cfg = cc::Build::new();
 
     // Compile the SQLite source
-    cfg.file("./sqlite/sqlite3.c");
-    cfg.file("./sqlite/shell.c");
-    cfg.include("./sqlite");
+    cfg.file("../sqlite/sqlite/sqlite3.c");
+    cfg.file("../sqlite/sqlite/shell.c");
+    cfg.include("../sqlite/sqlite");
 
     // General SQLite options
     cfg.define("SQLITE_THREADSAFE", Some("0"));

crates/shell/build.rs

@@ -28,19 +28,6 @@ fn panic(_info: &core::panic::PanicInfo) -> ! {
 #[lang = "eh_personality"]
 extern "C" fn eh_personality() {}
 
-#[cfg(target_family = "wasm")]
-#[no_mangle]
-pub fn __rust_alloc_error_handler(_: core::alloc::Layout) -> ! {
-    core::intrinsics::abort()
-}
-
-
-// Not used, but must be defined in some cases. Most notably when using native sqlite3 and loading
-// the extension.
-#[allow(non_upper_case_globals)]
-#[no_mangle]
-pub static mut _Unwind_Resume: *mut core::ffi::c_void = core::ptr::null_mut();
-
 
 #[no_mangle]
 pub extern "C" fn core_init(_dummy: *mut c_char) -> c_int {

crates/shell/src/main.rs

@@ -0,0 +1,16 @@
+[package]
+name = "sqlite3"
+edition.workspace = true
+version.workspace = true
+homepage.workspace = true
+repository.workspace = true
+license.workspace = true
+authors.workspace = true
+keywords.workspace = true
+
+[dependencies]
+
+[features]
+
+[build-dependencies]
+cc = "1.0.46"

crates/sqlite/Cargo.toml

@@ -0,0 +1,5 @@
+# sqlite
+
+This builds a plain sqlite3 shell.
+
+We could build this with plain gcc/clang, or download a pre-built binary, but it's simple enough with Rust tooling.

crates/sqlite/README.md

@@ -0,0 +1,25 @@
+
+fn main() {
+    let mut cfg = cc::Build::new();
+
+    // Compile the SQLite source
+    cfg.file("./sqlite/sqlite3.c");
+    cfg.file("./sqlite/shell.c");
+    cfg.include("./sqlite");
+
+    // General SQLite options
+    cfg.define("SQLITE_THREADSAFE", Some("0"));
+    cfg.define("SQLITE_ENABLE_BYTECODE_VTAB", Some("1"));
+
+    // Compile with readline support (also requires -lreadline / cargo:rustc-link-lib=readline below)
+    cfg.define("HAVE_READLINE", Some("1"));
+
+    // Silence warnings generated for SQLite
+    cfg.flag("-Wno-implicit-fallthrough");
+    cfg.flag("-Wno-unused-parameter");
+    cfg.flag("-Wno-null-pointer-subtraction");
+
+    cfg.compile("sqlite");
+
+    println!("cargo:rustc-link-lib=readline");
+}