Let hermesc output a more helpful message by default

Summary: Before this diff, running `hermesc` reads stdin and then fails saying execution is unsupported. With this diff, it instead says to choose output and gives an example. Reviewed By: avp Differential Revision: D20967165 fbshipit-source-id: c6349cbaffe1deaa43d7a5344e89f7e07e945c81
Aliucord · Apr 10, 2020 · 181f6c6 · 181f6c6
1 parent a3e5639
commit 181f6c6
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Showing 11 changed files with 27 additions and 8 deletions.
diff --git a/include/hermes/CompilerDriver/CompilerDriver.h b/include/hermes/CompilerDriver/CompilerDriver.h
@@ -72,6 +72,9 @@ struct CompileResult {
   /* implicit */ CompileResult(CompileStatus status) : status(status) {}
 };
 
+/// Return the type of operation we're about to perform.
+OutputFormatKind outputFormatFromCommandLineOptions();
+
 /// Drive the Hermes compiler according to the command line options.
 /// \return an exit status.
 CompileResult compileFromCommandLineOptions();

diff --git a/lib/CompilerDriver/CompilerDriver.cpp b/lib/CompilerDriver/CompilerDriver.cpp
@@ -1858,6 +1858,9 @@ void printHermesCompilerVersion(llvm::raw_ostream &s) {
 void printHermesREPLVersion(llvm::raw_ostream &s) {
   printHermesVersion(s, " REPL", false);
 }
+OutputFormatKind outputFormatFromCommandLineOptions() {
+  return cl::DumpTarget;
+}
 
 CompileResult compileFromCommandLineOptions() {
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_STATS)

diff --git a/test/Parser/await-error.js b/test/Parser/await-error.js
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// RUN: (! %hermesc %s 2>&1 ) | %FileCheck --match-full-lines %s
+// RUN: (! %hermesc -dump-ast %s 2>&1 ) | %FileCheck --match-full-lines %s
 
 (async await => 3);
 // CHECK: {{.*}}:10:8: error: Unexpected usage of 'await' as an identifier

diff --git a/test/Parser/es6/binding-error-strict.js b/test/Parser/es6/binding-error-strict.js
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// RUN: (! %hermesc %s 2>&1 ) | %FileCheck --match-full-lines %s
+// RUN: (! %hermesc -dump-ast %s 2>&1 ) | %FileCheck --match-full-lines %s
 'use strict';
 
 class let {}

diff --git a/test/Parser/es6/const-error.js b/test/Parser/es6/const-error.js
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// RUN: (! %hermesc %s 2>&1 ) | %FileCheck --match-full-lines %s
+// RUN: (! %hermesc -dump-ast %s 2>&1 ) | %FileCheck --match-full-lines %s
 
 const abc;
 // CHECK: {{.*}}:10:7: error: missing initializer in const declaration

diff --git a/test/Parser/es6/export-error.js b/test/Parser/es6/export-error.js
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// RUN: (! %hermesc -commonjs -pretty-json %s 2>&1 ) | %FileCheck --match-full-lines %s
+// RUN: (! %hermesc -dump-ast -commonjs -pretty-json %s 2>&1 ) | %FileCheck --match-full-lines %s
 
 export { implements as x };
 // CHECK: {{.*}}/export-error.js:10:10: error: Invalid exported name

diff --git a/test/Parser/es6/for-of-error.js b/test/Parser/es6/for-of-error.js
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// RUN: (! %hermesc %s 2>&1 ) | %FileCheck --match-full-lines %s
+// RUN: (! %hermesc -dump-ast %s 2>&1 ) | %FileCheck --match-full-lines %s
 
 function *foo() { for (yield of x) print(1) }
 // CHECK: {{.*}}:10:24: error: invalid assignment left-hand side

diff --git a/test/Parser/es6/import-error.js b/test/Parser/es6/import-error.js
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// RUN: (! %hermesc -commonjs -pretty-json %s 2>&1 ) | %FileCheck --match-full-lines %s
+// RUN: (! %hermesc -dump-ast -commonjs -pretty-json %s 2>&1 ) | %FileCheck --match-full-lines %s
 'use strict';
 import { foo , foo } from 'foo.js';
 // CHECK: {{.*}}/import-error.js:10:16: error: Duplicate entry in import declaration list

diff --git a/test/Parser/es6/let-error.js b/test/Parser/es6/let-error.js
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// RUN: (! %hermesc %s 2>&1 ) | %FileCheck --match-full-lines %s
+// RUN: (! %hermesc -dump-ast %s 2>&1 ) | %FileCheck --match-full-lines %s
 
 let let = 3;
 // CHECK: {{.*}}:10:5: error: 'let' is disallowed as a lexically bound name

diff --git a/test/Parser/nullish-coalescing-error.js b/test/Parser/nullish-coalescing-error.js
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// RUN: (! %hermesc %s 2>&1) | %FileCheck %s --match-full-lines
+// RUN: (! %hermesc -dump-ast %s 2>&1) | %FileCheck %s --match-full-lines
 
 a ?? b && c;
 // CHECK: {{.*}}:10:1: error: Mixing '??' with '&&' or '||' requires parentheses

diff --git a/tools/hermesc/hermesc.cpp b/tools/hermesc/hermesc.cpp
@@ -26,9 +26,22 @@ int main(int argc, char **argv) {
   llvm::llvm_shutdown_obj Y;
   llvm::cl::AddExtraVersionPrinter(driver::printHermesCompilerVersion);
   llvm::cl::ParseCommandLineOptions(argc, argv, "Hermes driver\n");
+
+  if (driver::outputFormatFromCommandLineOptions() ==
+      OutputFormatKind::Execute) {
+    // --help says "Choose output:" so mimic the wording here
+    llvm::errs()
+        << "Please choose output, e.g. -emit-binary. hermesc does not support -exec.\n";
+    llvm::errs() << "Example: hermesc -emit-binary -out myfile.hbc myfile.js\n";
+    return EXIT_FAILURE;
+  }
+
   driver::CompileResult res = driver::compileFromCommandLineOptions();
   if (res.bytecodeProvider) {
     llvm::errs() << "Execution not supported with hermesc\n";
+    assert(
+        false &&
+        "Execution mode was not checked prior to compileFromCommandLineOptions");
     return EXIT_FAILURE;
   }
   return res.status;