Require - for stdin input to hermes cli

Summary: Update tests and hermes.cpp so that '-' input is required to take stdin input.

Reviewed By: avp

Differential Revision: D20978967

fbshipit-source-id: 99eaf7341ba437287e6aa36e013686df51dda310

test/BCGen/HBC/long_string_table.js

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// RUN: %hermes -target=HBC -gc-sanitize-handles=0 -O %s | %hermes -target=HBC -gc-sanitize-handles=0 -O | %FileCheck --match-full-lines %s
+// RUN: %hermes -target=HBC -gc-sanitize-handles=0 -O %s | %hermes - -target=HBC -gc-sanitize-handles=0 -O | %FileCheck --match-full-lines %s
 
 // This test is meant to make sure that Hermes generates long instructions for
 // indexing into objects when it is necessary.

test/IRGen/source_loc.js

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// RUN: %hermes -O0 -dump-source-location -dump-ir < %s | %FileCheck --match-full-lines %s
+// RUN: %hermes - -O0 -dump-source-location -dump-ir < %s | %FileCheck --match-full-lines %s
 
 function foo(a,b) {
     if (a > b) {

test/SourceMap/cjs-map/symbolicator-modules-test.sh

@@ -27,7 +27,7 @@ SYM_TRACE="$TMPDIR/symbolicated_trace.txt"
 ( python3 "$SRCDIR/../stringize.py" SOURCEMAP < "$HBC_FILE.map" ;
   python3 "$SRCDIR/../stringize.py" STACKTRACE < "$RAW_TRACE" ;
   cat "$SRCDIR/../symbolicator.js.in"
-) | "$HERMES" -gc-sanitize-handles=0 > "$SYM_TRACE"
+) | "$HERMES" - -gc-sanitize-handles=0 > "$SYM_TRACE"
 
 cat "$SYM_TRACE"
 # CHECK: Error: ERROR_FOR_TESTING

test/SourceMap/symbolicator-test.sh

@@ -58,7 +58,7 @@ run_1_test() {
   ( python3 $SRCDIR/stringize.py SOURCEMAP < "$HBC_FILE.map" ;
     python3 $SRCDIR/stringize.py STACKTRACE < "$RAW_TRACE" ;
     cat $SRCDIR/symbolicator.js.in
-  ) | "$HERMES" -target=HBC -gc-sanitize-handles=0 > "$SYM_TRACE"
+  ) | "$HERMES" - -target=HBC -gc-sanitize-handles=0 > "$SYM_TRACE"
 
   # Ensure that the original and symbolicated stack trace are the same!
   if ! diff "$ORIG_TRACE" "$SYM_TRACE" ; then

test/hermes/large_literal_obj.js

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// RUN: echo "var obj ={0" ":0,"{1..65535} ":0};" | %hermes -target=HBC -O -gc-sanitize-handles=0
+// RUN: echo "var obj ={0" ":0,"{1..65535} ":0};" | %hermes - -target=HBC -O -gc-sanitize-handles=0
 // REQUIRES: !slow_debug
 
 // The above echo generates JavaScript code like this:

test/hermes/regress-exp-overflow.js

@@ -5,6 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-// RUN: echo "1" "**"{1..5000} | (! %hermes 2>&1 ) | %FileCheck --match-full-lines %s
+// RUN: echo "1" "**"{1..5000} | (! %hermes - 2>&1 ) | %FileCheck --match-full-lines %s
 
 // CHECK: <stdin>:1:{{.*}}: error: Too many nested expressions/statements/declarations

tools/hermes/hermes.cpp

@@ -178,6 +178,12 @@ int main(int argc, char **argv) {
   llvm::cl::AddExtraVersionPrinter(driver::printHermesCompilerVMVersion);
   llvm::cl::ParseCommandLineOptions(argc, argv, "Hermes driver\n");
 
+  if (cl::InputFilenames.size() == 0) {
+    llvm::errs()
+        << "Please provide a filename or '-' to take input from stdin\n";
+    return 0;
+  }
+
   // Tell compiler to emit async break check if time-limit feature is enabled
   // so that user can turn on this feature with single ExecutionTimeLimit
   // option.