Add in_gecko feature to libsqlite3-sys to bypass linking.

Cargo.toml

@@ -57,6 +57,7 @@ series = ["vtab"]
 extra_check = []
 modern_sqlite = ["libsqlite3-sys/bundled_bindings"]
 unstable = []
+in_gecko = ["modern_sqlite", "libsqlite3-sys/in_gecko"]
 
 [dependencies]
 time = "0.1.0"

libsqlite3-sys/Cargo.toml

@@ -30,6 +30,7 @@ unlock_notify = []
 preupdate_hook = []
 # 3.13.0
 session = ["preupdate_hook"]
+in_gecko = []
 
 [build-dependencies]
 bindgen = { version = "0.53", optional = true, default-features = false, features = ["runtime"] }

libsqlite3-sys/build.rs

@@ -4,6 +4,13 @@ use std::path::Path;
 fn main() {
     let out_dir = env::var("OUT_DIR").unwrap();
     let out_path = Path::new(&out_dir).join("bindgen.rs");
+    if cfg!(feature = "in_gecko") {
+        // When inside mozilla-central, we are included into the build with
+        // sqlite3.o directly, so we don't want to provide any linker arguments.
+        std::fs::copy("sqlite3/bindgen_bundled_version.rs", out_path)
+            .expect("Could not copy bindings to output directory");
+        return;
+    }
     if cfg!(feature = "sqlcipher") {
         if cfg!(any(
             feature = "bundled",