Add --strip-debug option to wasm-split (WebAssembly#8432)

wasm-split needs `-g` to use the name section (for `--keep-funcs`,
`--split-funcs`, and `--manifest` options), but it leaves the name
section (and any debug section if any) in the output, which you need to
strip in a separate step.

This option strips the debug section at the end.

Author: aheejin

src/tools/wasm-split/split-options.cpp

@@ -359,6 +359,13 @@ WasmSplitOptions::WasmSplitOptions()
          [&](Options* o, const std::string& arguments) {
            passOptions.debugInfo = true;
          })
+    .add("--strip-debug",
+         "",
+         "Strip debug info (including the names section)",
+         WasmSplitOption,
+         {Mode::Split, Mode::MultiSplit, Mode::Instrument},
+         Options::Arguments::Zero,
+         [&](Options* o, const std::string& arguments) { stripDebug = true; })
     .add("--output",
          "-o",
          "Output file.",

src/tools/wasm-split/split-options.h

@@ -51,6 +51,7 @@ struct WasmSplitOptions : ToolOptions {
   bool symbolMap = false;
   bool placeholderMap = false;
   bool jspi = false;
+  bool stripDebug = false;
 
   // TODO: Remove this. See the comment in wasm-binary.h.
   bool emitModuleNames = false;

src/tools/wasm-split/wasm-split.cpp

@@ -95,9 +95,14 @@ void adjustTableSize(Module& wasm, int initialSize, bool secondary = false) {
 void writeModule(Module& wasm,
                  std::string filename,
                  const WasmSplitOptions& options) {
+  if (options.stripDebug) {
+    PassRunner runner(&wasm, options.passOptions);
+    runner.add("strip-debug");
+    runner.run();
+  }
   ModuleWriter writer(options.passOptions);
   writer.setBinary(options.emitBinary);
-  writer.setDebugInfo(options.passOptions.debugInfo);
+  writer.setDebugInfo(options.passOptions.debugInfo && !options.stripDebug);
   if (options.emitModuleNames) {
     writer.setEmitModuleName(true);
   }

test/lit/help/wasm-split.test

@@ -153,6 +153,9 @@
 ;; CHECK-NEXT:                                        names section in wasm binary (or full
 ;; CHECK-NEXT:                                        debuginfo in wast)
 ;; CHECK-NEXT:
+;; CHECK-NEXT:   --strip-debug                        [split, multi-split, instrument] Strip
+;; CHECK-NEXT:                                        debug info (including the names section)
+;; CHECK-NEXT:
 ;; CHECK-NEXT:   --output,-o                          [instrument, merge-profiles, multi-split]
 ;; CHECK-NEXT:                                        Output file.
 ;; CHECK-NEXT:

test/lit/wasm-split/strip-debug.wast

@@ -0,0 +1,38 @@
+;; RUN: wasm-split %s --keep-funcs=foo -o1 %t.1.wasm -o2 %t.2.wasm -g --strip-debug
+;; RUN: wasm-dis %t.1.wasm | filecheck %s --check-prefix=PRIMARY
+;; RUN: wasm-dis %t.2.wasm | filecheck %s --check-prefix=SECONDARY
+
+;; Check that names are stripped from the output.
+;; PRIMARY-NOT: $foo
+;; SECONDARY-NOT: $bar
+
+;; PRIMARY:      (module
+;; PRIMARY-NEXT:  (type $0 (func))
+;; PRIMARY-NEXT:  (import "placeholder.deferred" "0" (func $fimport$0))
+;; PRIMARY-NEXT:  (table $0 1 funcref)
+;; PRIMARY-NEXT:  (elem $0 (i32.const 0) $fimport$0)
+;; PRIMARY-NEXT:  (export "table" (table $0))
+;; PRIMARY-NEXT:  (func $0
+;; PRIMARY-NEXT:   (call_indirect (type $0)
+;; PRIMARY-NEXT:    (i32.const 0)
+;; PRIMARY-NEXT:   )
+;; PRIMARY-NEXT:  )
+;; PRIMARY-NEXT: )
+
+;; SECONDARY:      (module
+;; SECONDARY-NEXT:  (type $0 (func))
+;; SECONDARY-NEXT:  (import "primary" "table" (table $timport$0 1 funcref))
+;; SECONDARY-NEXT:  (elem $0 (i32.const 0) $0)
+;; SECONDARY-NEXT:  (func $0
+;; SECONDARY-NEXT:   (nop)
+;; SECONDARY-NEXT:  )
+;; SECONDARY-NEXT: )
+
+(module
+  (func $foo
+    (call $bar)
+  )
+  (func $bar
+    (nop)
+  )
+)