[wasm] Fix unicode names occuring in error messages

If a String object contains unicode, the returned {ToCString()} may
actually longer than the {length()} of the String.
But it's always null-terminated, so we can just print it without
explicitly passing a length.

R=ahaas@chromium.org

Change-Id: I3398f151d70ed459ecd8093ea18409670a7374c7
Reviewed-on: https://chromium-review.googlesource.com/548058
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46225}

src/wasm/module-compiler.h

@@ -193,17 +193,15 @@ class InstanceBuilder {
 #define ERROR_THROWER_WITH_MESSAGE(TYPE)                                      \
   void Report##TYPE(const char* error, uint32_t index,                        \
                     Handle<String> module_name, Handle<String> import_name) { \
-    thrower_->TYPE("Import #%d module=\"%.*s\" function=\"%.*s\" error: %s",  \
-                   index, module_name->length(),                              \
-                   module_name->ToCString().get(), import_name->length(),     \
+    thrower_->TYPE("Import #%d module=\"%s\" function=\"%s\" error: %s",      \
+                   index, module_name->ToCString().get(),                     \
                    import_name->ToCString().get(), error);                    \
   }                                                                           \
                                                                               \
   MaybeHandle<Object> Report##TYPE(const char* error, uint32_t index,         \
                                    Handle<String> module_name) {              \
-    thrower_->TYPE("Import #%d module=\"%.*s\" error: %s", index,             \
-                   module_name->length(), module_name->ToCString().get(),     \
-                   error);                                                    \
+    thrower_->TYPE("Import #%d module=\"%s\" error: %s", index,               \
+                   module_name->ToCString().get(), error);                    \
     return MaybeHandle<Object>();                                             \
   }
 

test/mjsunit/wasm/unicode.js

@@ -54,3 +54,32 @@ checkExports('☺☺mul☺☺', '☺☺mul☺☺', '☺☺add☺☺', '☺☺add
       () => builder.instantiate(), WebAssembly.CompileError,
       /Compiling wasm function #0:three snowmen: ☃☃☃ failed: /);
 })();
+
+(function errorMessageUnicodeInImportModuleName() {
+  var builder = new WasmModuleBuilder();
+  builder.addImport('three snowmen: ☃☃☃', 'foo', kSig_i_v);
+  assertThrows(
+      () => builder.instantiate({}), TypeError,
+      /WebAssembly Instantiation: Import #0 module="three snowmen: ☃☃☃" error: /);
+})();
+
+(function errorMessageUnicodeInImportElemName() {
+  var builder = new WasmModuleBuilder();
+  builder.addImport('mod', 'three snowmen: ☃☃☃', kSig_i_v);
+  assertThrows(
+      () => builder.instantiate({mod: {}}), WebAssembly.LinkError,
+      'WebAssembly Instantiation: Import #0 module="mod" function="three ' +
+          'snowmen: ☃☃☃" error: function import requires a callable');
+})();
+
+(function errorMessageUnicodeInImportModAndElemName() {
+  var builder = new WasmModuleBuilder();
+  let mod_name = '☮▁▂▃▄☾ ♛ ◡ ♛ ☽▄▃▂▁☮';
+  let func_name = '☾˙❀‿❀˙☽';
+  builder.addImport(mod_name, func_name, kSig_i_v);
+  assertThrows(
+      () => builder.instantiate({[mod_name]: {}}), WebAssembly.LinkError,
+      'WebAssembly Instantiation: Import #0 module="' + mod_name +
+          '" function="' + func_name +
+          '" error: function import requires a callable');
+})();