Print wasm2asm parsing errors (#1251)

Author: kripken

CMakeLists.txt

@@ -244,7 +244,7 @@ SET_PROPERTY(TARGET asm2wasm PROPERTY CXX_STANDARD_REQUIRED ON)
 INSTALL(TARGETS asm2wasm DESTINATION ${CMAKE_INSTALL_BINDIR})
 
 SET(wasm2asm_SOURCES
-  src/wasm2asm-main.cpp
+  src/tools/wasm2asm.cpp
 )
 ADD_EXECUTABLE(wasm2asm
                ${wasm2asm_SOURCES})

README.md

@@ -35,7 +35,7 @@ Binaryen's internal IR is designed to be
 There are a few differences between Binaryen IR and the WebAssembly language:
 
  * Tree structure
-   * Binaryen IR [is an tree](https://github.com/WebAssembly/binaryen/issues/663), i.e., it has hierarchical structure, for convenience of optimization. This differs from the WebAssembly binary format which is a stack machine.
+   * Binaryen IR [is a tree](https://github.com/WebAssembly/binaryen/issues/663), i.e., it has hierarchical structure, for convenience of optimization. This differs from the WebAssembly binary format which is a stack machine.
    * Consequently Binaryen's text format allows only s-expressions. WebAssembly's official text format is primarily a linear instruction list (with s-expression extensions). Binaryen can't read the linear style, but it can read a wasm text file if it contains only s-expressions.
  * Types and unreachable code
    * WebAssembly limits block/if/loop types to none and the concrete value types (i32, i64, f32, f64). Binaryen IR has an unreachable type, and it allows block/if/loop to take it, allowing [local transforms that don't need to know the global context](https://github.com/WebAssembly/binaryen/issues/903).

src/wasm2asm-main.cpp src/tools/wasm2asm.cppsrc/wasm2asm-main.cpp renamed to src/tools/wasm2asm.cpp

@@ -57,21 +57,31 @@ int main(int argc, const char *argv[]) {
   auto input(
       read_file<std::vector<char>>(options.extra["infile"], Flags::Text, options.debug ? Flags::Debug : Flags::Release));
 
-  if (options.debug) std::cerr << "s-parsing..." << std::endl;
-  SExpressionParser parser(input.data());
-  Element &root = *parser.root;
-
-  if (options.debug) std::cerr << "w-parsing..." << std::endl;
+  Element* root;
   Module wasm;
-  SExpressionWasmBuilder builder(wasm, *root[0]);
+  Ref asmjs;
+
+  try {
+    if (options.debug) std::cerr << "s-parsing..." << std::endl;
+    SExpressionParser parser(input.data());
+    root = parser.root;
+
+    if (options.debug) std::cerr << "w-parsing..." << std::endl;
+    SExpressionWasmBuilder builder(wasm, *(*root)[0]);
 
-  if (options.debug) std::cerr << "asming..." << std::endl;
-  Wasm2AsmBuilder wasm2asm(builderFlags);
-  Ref asmjs = wasm2asm.processWasm(&wasm);
+    if (options.debug) std::cerr << "asming..." << std::endl;
+    Wasm2AsmBuilder wasm2asm(builderFlags);
+    asmjs = wasm2asm.processWasm(&wasm);
 
-  if (options.extra["asserts"] == "1") {
-    if (options.debug) std::cerr << "asserting..." << std::endl;
-    flattenAppend(asmjs, wasm2asm.processAsserts(root, builder));
+    if (options.extra["asserts"] == "1") {
+      if (options.debug) std::cerr << "asserting..." << std::endl;
+      flattenAppend(asmjs, wasm2asm.processAsserts(*root, builder));
+    }
+  } catch (ParseException& p) {
+    p.dump(std::cerr);
+    Fatal() << "error in parsing input";
+  } catch (std::bad_alloc& b) {
+    Fatal() << "error in building module, std::bad_alloc (possibly invalid request for silly amounts of memory)";
   }
 
   if (options.debug) {