Restrict validation output to just validation errors in the API (#1253)

Do not print the entire and possibly very large module when validation fails. Leave printing to tools using the validator, instead of always doing it in the validator where it can't be overridden.

Author: dcodeIO

src/passes/pass.cpp

@@ -232,6 +232,7 @@ void PassRunner::run() {
       // validate, ignoring the time
       std::cerr << "[PassRunner]   (validating)\n";
       if (!WasmValidator().validate(*wasm, options.features, validationFlags)) {
+        WasmPrinter::printModule(wasm);
         if (passDebug >= 2) {
           std::cerr << "Last pass (" << pass->name << ") broke validation. Here is the module before: \n" << moduleBefore.str() << "\n";
         } else {
@@ -247,6 +248,7 @@ void PassRunner::run() {
     // validate
     std::cerr << "[PassRunner] (final validation)\n";
     if (!WasmValidator().validate(*wasm, options.features, validationFlags)) {
+      WasmPrinter::printModule(wasm);
       std::cerr << "final module does not validate\n";
       abort();
     }

src/tools/asm2wasm.cpp

@@ -207,6 +207,7 @@ int main(int argc, const char *argv[]) {
   }
 
   if (!WasmValidator().validate(wasm, options.passOptions.features)) {
+    WasmPrinter::printModule(&wasm);
     Fatal() << "error in validating output";
   }
 

src/tools/s2wasm.cpp

@@ -194,8 +194,10 @@ int main(int argc, const char *argv[]) {
 
   if (options.extra["validate"] != "none") {
     if (options.debug) std::cerr << "Validating..." << std::endl;
-    if (!wasm::WasmValidator().validate(linker.getOutput().wasm,
+    Module* output = &linker.getOutput().wasm;
+    if (!wasm::WasmValidator().validate(*output,
          WasmValidator::Globally | (options.extra["validate"] == "web" ? WasmValidator::Web : 0))) {
+      WasmPrinter::printModule(output);
       Fatal() << "Error: linked module is not valid.\n";
     }
   }

src/tools/wasm-as.cpp

@@ -94,6 +94,7 @@ int main(int argc, const char *argv[]) {
     if (options.debug) std::cerr << "Validating..." << std::endl;
     if (!wasm::WasmValidator().validate(wasm, Feature::All,
          WasmValidator::Globally | (options.extra["validate"] == "web" ? WasmValidator::Web : 0))) {
+      WasmPrinter::printModule(&wasm);
       Fatal() << "Error: input module is not valid.\n";
     }
   }

src/tools/wasm-merge.cpp

@@ -627,6 +627,7 @@ int main(int argc, const char* argv[]) {
   }
 
   if (!WasmValidator().validate(output)) {
+    WasmPrinter::printModule(&output);
     Fatal() << "error in validating output";
   }
 

src/tools/wasm-opt.cpp

@@ -129,13 +129,15 @@ int main(int argc, const char* argv[]) {
     }
 
     if (!WasmValidator().validate(wasm, features)) {
+      WasmPrinter::printModule(&wasm);
       Fatal() << "error in validating input";
     }
   } else {
     // translate-to-fuzz
     TranslateToFuzzReader reader(wasm);
     reader.read(options.extra["infile"]);
     if (!WasmValidator().validate(wasm, features)) {
+      WasmPrinter::printModule(&wasm);
       std::cerr << "translate-to-fuzz must always generate a valid module";
       abort();
     }
@@ -176,7 +178,11 @@ int main(int argc, const char* argv[]) {
   if (options.runningPasses()) {
     if (options.debug) std::cerr << "running passes...\n";
     options.runPasses(wasm);
-    assert(WasmValidator().validate(wasm, features));
+    bool valid = WasmValidator().validate(wasm, features);
+    if (!valid) {
+      WasmPrinter::printModule(&wasm);
+    }
+    assert(valid);
   }
 
   if (fuzzExec) {
@@ -192,7 +198,11 @@ int main(int argc, const char* argv[]) {
       auto input = buffer.getAsChars();
       WasmBinaryBuilder parser(second, input, false);
       parser.read();
-      assert(WasmValidator().validate(second, features));
+      bool valid = WasmValidator().validate(second, features);
+      if (!valid) {
+        WasmPrinter::printModule(&second);
+      }
+      assert(valid);
     }
     results.check(*compare);
   }

src/tools/wasm-shell.cpp

@@ -287,7 +287,11 @@ int main(int argc, const char* argv[]) {
         builders[moduleName].swap(builder);
         modules[moduleName].swap(module);
         i++;
-        assert(WasmValidator().validate(*modules[moduleName]));
+        bool valid = WasmValidator().validate(*modules[moduleName]);
+        if (!valid) {
+          WasmPrinter::printModule(modules[moduleName].get());
+        }
+        assert(valid);
         run_asserts(moduleName, &i, &checked, modules[moduleName].get(), &root, builders[moduleName].get(), entry);
       } else {
         run_asserts(Name(), &i, &checked, nullptr, &root, nullptr, entry);

src/wasm/wasm-validator.cpp

@@ -1036,8 +1036,6 @@ bool WasmValidator::validate(Module& module, FeatureSet features, Flags flags) {
       std::cerr << info.getStream(func.get()).str();
     }
     std::cerr << info.getStream(nullptr).str();
-    // also print the module
-    WasmPrinter::printModule(&module, std::cerr);
   }
   return info.valid.load();
 }