Add global initializers to wasm2asm (#1434)

Adds support for (constant i32/f32/f64) global variable initializers, which were previously ignored though get_global/set_global are supported.

1 files changed, 38 insertions, 0 deletions

diff --git a/src/wasm2asm.h b/src/wasm2asm.h
index 346c1c677..ca67b0aa8 100644
--- a/src/wasm2asm.h
+++ b/src/wasm2asm.h
@@ -211,6 +211,7 @@ private:
   void addImport(Ref ast, Import* import);
   void addTables(Ref ast, Module* wasm);
   void addExports(Ref ast, Module* wasm);
+  void addGlobal(Ref ast, Global* global);
   void addWasmCompatibilityFuncs(Module* wasm);
   void setNeedsAlmostASM(const char *reason);
   void addMemoryGrowthFuncs(Ref ast);
@@ -418,6 +419,10 @@ Ref Wasm2AsmBuilder::processWasm(Module* wasm) {
     pow2ed <<= 1;
   }
   tableSize = pow2ed;
+  // globals
+  for (auto& global : wasm->globals) {
+    addGlobal(asmFunc[3], global.get());
+  }
   // functions
   for (auto& func : wasm->functions) {
     asmFunc[3]->push_back(processFunction(func.get()));
@@ -578,6 +583,39 @@ void Wasm2AsmBuilder::addExports(Ref ast, Module* wasm) {
   ast->push_back(ValueBuilder::makeStatement(ValueBuilder::makeReturn(exports)));
 }
 
+void Wasm2AsmBuilder::addGlobal(Ref ast, Global* global) {
+  if (auto* const_ = global->init->dynCast<Const>()) {
+    Ref theValue;
+    switch (const_->type) {
+      case Type::i32: {
+        theValue = ValueBuilder::makeInt(const_->value.geti32());
+        break;
+      }
+      case Type::f32: {
+        theValue = ValueBuilder::makeCall(MATH_FROUND,
+          makeAsmCoercion(ValueBuilder::makeDouble(const_->value.getf32()), ASM_DOUBLE)
+        );
+        break;
+      }
+      case Type::f64: {
+        theValue = makeAsmCoercion(ValueBuilder::makeDouble(const_->value.getf64()), ASM_DOUBLE);
+        break;
+      }
+      default: {
+        assert(false && "Global const type not supported");
+      }
+    }
+    Ref theVar = ValueBuilder::makeVar();
+    ast->push_back(theVar);
+    ValueBuilder::appendToVar(theVar,
+      fromName(global->name),
+      theValue
+    );
+  } else {
+    assert(false && "Global init type not supported");
+  }
+}
+
 Ref Wasm2AsmBuilder::processFunction(Function* func) {
   if (flags.debug) {
     static int fns = 0;