start

Author: kripken

src/passes/StringLowering.cpp

@@ -243,24 +243,27 @@ struct StringLowering : public StringGathering {
 
   Type nnExt = Type(HeapType::ext, NonNullable);
 
+  // Creates an imported string function, returning its name (which is equal to
+  // the true name of the import, if there is no conflict).
+  Name addImport(Module* module, Name trueName, Type params, Type results) {
+    auto name = Names::getValidFunctionName(*module, trueName);
+    auto sig = Signature(params, results);
+    Builder builder(*module);
+    auto* func = module->addFunction(builder.makeFunction(name, sig, {}));
+    func->module = "wasm:js-string";
+    func->base = trueName;
+    return name;
+  }
+
   void replaceInstructions(Module* module) {
     // Add all the possible imports up front, to avoid adding them during
     // parallel work. Optimizations can remove unneeded ones later.
-    Builder builder(*module);
-    auto array16 = Array(Field(Field::i16, Mutable));
+    auto nullArray16 = Type(Array(Field(Field::i16, Mutable)), Nullable);
 
-    {
-      fromCharCodeArrayImport = Names::getValidFunctionName(
-          *module, "string.fromCharCodeArray");
-      auto sig = Signature({Type(array16, Nullable), Type::i32, Type::i32}, nnExt);
-      module->addFunction(builder.makeFunction(fromCharCodeArrayImport, sig, {}));
-    }
-    {
-      fromCodePointImport = Names::getValidFunctionName(
-          *module, "string.fromCodePoint");
-      auto sig = Signature(Type::i32, nnExt);
-      module->addFunction(builder.makeFunction(fromCodePointImport, sig, {}));
-    }
+    // string.fromCharCodeArray: array, start, end -> ext
+    fromCharCodeArrayImport = addImport(module, "fromCharCodeArray", {nullArray16, Type::i32, Type::i32}, nnExt);
+    // string.fromCodePoint: codepoint -> ext
+    fromCodePointImport = addImport(module, "fromCodePoint", Type::i32, nnExt);
 
     // Replace the string instructions in parallel.
     struct Replacer : public WalkerPass<PostWalker<Replacer>> {

test/lit/passes/string-gathering.wast

@@ -27,12 +27,22 @@
   ;; CHECK:      (global $global2 stringref (global.get $string.const_bar))
   ;; LOWER:      (type $0 (func))
 
+  ;; LOWER:      (type $1 (array (mut i16)))
+
+  ;; LOWER:      (type $2 (func (param (ref null $1) i32 i32) (result (ref extern))))
+
+  ;; LOWER:      (type $3 (func (param i32) (result (ref extern))))
+
   ;; LOWER:      (import "string.const" "0" (global $string.const_bar (ref extern)))
 
   ;; LOWER:      (import "string.const" "1" (global $string.const_other (ref extern)))
 
   ;; LOWER:      (import "string.const" "2" (global $global (ref extern)))
 
+  ;; LOWER:      (import "wasm:js-string" "fromCharCodeArray" (func $fromCharCodeArray (type $2) (param (ref null $1) i32 i32) (result (ref extern))))
+
+  ;; LOWER:      (import "wasm:js-string" "fromCodePoint" (func $fromCodePoint (type $3) (param i32) (result (ref extern))))
+
   ;; LOWER:      (global $global2 externref (global.get $string.const_bar))
   (global $global2 (ref null string) (string.const "bar"))
 
@@ -111,6 +121,12 @@
 ;; Multiple possible reusable globals. Also test ignoring of imports.
 (module
   ;; CHECK:      (import "a" "b" (global $import (ref string)))
+  ;; LOWER:      (type $0 (array (mut i16)))
+
+  ;; LOWER:      (type $1 (func (param (ref null $0) i32 i32) (result (ref extern))))
+
+  ;; LOWER:      (type $2 (func (param i32) (result (ref extern))))
+
   ;; LOWER:      (import "a" "b" (global $import (ref extern)))
   (import "a" "b" (global $import (ref string)))
 
@@ -122,6 +138,10 @@
 
   ;; LOWER:      (import "string.const" "1" (global $global4 (ref extern)))
 
+  ;; LOWER:      (import "wasm:js-string" "fromCharCodeArray" (func $fromCharCodeArray (type $1) (param (ref null $0) i32 i32) (result (ref extern))))
+
+  ;; LOWER:      (import "wasm:js-string" "fromCodePoint" (func $fromCodePoint (type $2) (param i32) (result (ref extern))))
+
   ;; LOWER:      (global $global2 (ref extern) (global.get $global1))
   (global $global2 (ref string) (string.const "foo"))
 

test/lit/passes/string-lowering-instructions.wast

@@ -5,6 +5,16 @@
 (module
   ;; CHECK:      (type $0 (func (param externref externref externref externref)))
 
+  ;; CHECK:      (type $1 (array (mut i16)))
+
+  ;; CHECK:      (type $2 (func (param (ref null $1) i32 i32) (result (ref extern))))
+
+  ;; CHECK:      (type $3 (func (param i32) (result (ref extern))))
+
+  ;; CHECK:      (import "wasm:js-string" "fromCharCodeArray" (func $fromCharCodeArray (type $2) (param (ref null $1) i32 i32) (result (ref extern))))
+
+  ;; CHECK:      (import "wasm:js-string" "fromCodePoint" (func $fromCodePoint (type $3) (param i32) (result (ref extern))))
+
   ;; CHECK:      (func $string.as (type $0) (param $a externref) (param $b externref) (param $c externref) (param $d externref)
   ;; CHECK-NEXT:  (local.set $b
   ;; CHECK-NEXT:   (local.get $a)