fix(build): don't export all symbols to dynamic symbol table (#16171)

Currently, we use `-rdynamic` for exporting Node API symbols to the
symbol table. `-rdynamic` will export *all* symbols, that means
previously unused functions will not be optimized away introducing a lot
of binary bloat. 

This patch uses `-exported_symbol` and `--export-dynamic-symbol` link
flags (not as universal as `-rdynamic`) to only mark Node API symbols to
be put in the dynamic symbol table.

.github/workflows/ci.yml

@@ -40,6 +40,7 @@ jobs:
           - os: ${{ github.repository == 'denoland/deno' && 'ubuntu-20.04-xl' || 'ubuntu-20.04' }}
             job: test
             profile: debug
+            use_sysroot: true
           - os: ${{ github.repository == 'denoland/deno' && 'ubuntu-20.04-xl' || 'ubuntu-20.04' }}
             job: lint
             profile: debug
@@ -412,7 +413,7 @@ jobs:
 
       # Verify that the binary actually works in the Ubuntu-16.04 sysroot.
       - name: Check deno binary (in sysroot)
-        if: matrix.use_sysroot
+        if: matrix.profile == 'release' && matrix.use_sysroot
         run: sudo chroot /sysroot "$(pwd)/target/release/deno" --version
 
       # TODO(ry): Because CI is so slow on for OSX and Windows, we currently

Cargo.lock

@@ -869,6 +869,7 @@ dependencies = [
  "rustyline-derive",
  "semver 1.0.14",
  "serde",
+ "serde_json",
  "serde_repr",
  "shell-escape",
  "tar",

cli/Cargo.toml

@@ -41,6 +41,7 @@ deno_websocket = { version = "0.76.0", path = "../ext/websocket" }
 deno_webstorage = { version = "0.66.0", path = "../ext/webstorage" }
 regex = "=1.6.0"
 serde = { version = "=1.0.144", features = ["derive"] }
+serde_json = "1.0.64"
 zstd = '=0.11.2'
 
 [target.'cfg(windows)'.build-dependencies]

cli/build.rs

@@ -344,7 +344,36 @@ fn main() {
   );
 
   #[cfg(not(target_os = "windows"))]
-  println!("cargo:rustc-link-arg-bin=deno=-rdynamic");
+  {
+    // Load the symbols file generated by the `napi_sym` macro.
+    #[derive(serde::Deserialize)]
+    struct Symbols {
+      symbols: Vec<String>,
+    }
+    let symbols_json =
+      std::fs::read_to_string("../tools/napi/symbol_exports.json").expect(
+        "Missing tools/napi/symbol_exports.json! This is a bug in napi_sym",
+      );
+    let symbols: Symbols = serde_json::from_str(&symbols_json)
+      .expect("tools/napi/symbol_exports.json is not valid JSON");
+
+    // Don't export all symbols into the dynamic symbol table. -rdynamic exports *all* symbols introducing binary bloat.
+    // We only need to export Node API symbols.
+    for symbol in symbols.symbols {
+      // TODO(@littledivy): We _might_ hit an argument size limit?
+      // Maybe use `--export-dynamic-symbol-list` / `--exported_symbols_list` instead? https://reviews.llvm.org/D107317
+      #[cfg(target_os = "macos")]
+      println!(
+        "cargo:rustc-link-arg-bin=deno=-Wl,-exported_symbol,_{}",
+        symbol
+      );
+      #[cfg(target_os = "linux")]
+      println!(
+        "cargo:rustc-link-arg-bin=deno=-Wl,--export-dynamic-symbol={}",
+        symbol
+      );
+    }
+  }
 
   // To debug snapshot issues uncomment:
   // op_fetch_asset::trace_serializer();