Merge pull request #2311 from fadams/fix-64bit-long-return-issue

Fix 64bit long return issue

5 files changed, 51 insertions, 0 deletions

diff --git a/tests/return64bit/test.c b/tests/return64bit/test.c
new file mode 100644
index 00000000..e75ee5c1
--- /dev/null
+++ b/tests/return64bit/test.c
@@ -0,0 +1,6 @@
+
+// This is just a trivial test function, the key bit of interest is that it returns a 64 bit long.
+long long test() {
+    long long x = ((long long)1234 << 32) + 5678;
+    return x;
+}
diff --git a/tests/return64bit/testbind.js b/tests/return64bit/testbind.js
new file mode 100644
index 00000000..f2cc0e7b
--- /dev/null
+++ b/tests/return64bit/testbind.js
@@ -0,0 +1,18 @@
+// This code represents a simple native JavaScript binding to a test C function
+// that returns a 64 bit long. Notice that the least significant 32 bits are
+// returned in the normal return value, but the most significant 32 bits are
+// returned via the accessor method Runtime.getTempRet0()
+
+var Module = {
+    'noExitRuntime' : true
+};
+
+Module['runtest'] = function() {
+    var low = _test();
+    var high = Runtime.getTempRet0();
+
+    console.log("low = " + low);
+    console.log("high = " + high);
+};
+
+
diff --git a/tests/return64bit/testbindend.js b/tests/return64bit/testbindend.js
new file mode 100644
index 00000000..2218f14d
--- /dev/null
+++ b/tests/return64bit/testbindend.js
@@ -0,0 +1,2 @@
+
+})(); // End of self calling lambda used to wrap library.
diff --git a/tests/return64bit/testbindstart.js b/tests/return64bit/testbindstart.js
new file mode 100644
index 00000000..4956806b
--- /dev/null
+++ b/tests/return64bit/testbindstart.js
@@ -0,0 +1,3 @@
+
+(function() { // Start of self-calling lambda used to avoid polluting global namespace.
+
diff --git a/tests/test_core.py b/tests/test_core.py
index fb53897a..04271192 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -6528,6 +6528,28 @@ def process(filename):
     if self.emcc_args is None: return self.skip('needs emcc')
     self.do_run_from_file(path_from_root('tests', 'test_locale.c'), path_from_root('tests', 'test_locale.out'))
 
+  def test_64bit_return_value(self):
+    # This test checks that the most significant 32 bits of a 64 bit long are correctly made available
+    # to native JavaScript applications that wish to interact with compiled code returning 64 bit longs.
+    # The MS 32 bits should be available in Runtime.getTempRet0() even when compiled with -O2 --closure 1
+    # Run with ./runner.py test_64bit_return_value
+
+    # Compile test.c and wrap it in a native JavaScript binding so we can call our compiled function from JS.
+    Popen([PYTHON, EMCC, path_from_root('tests', 'return64bit', 'test.c'), '--pre-js', path_from_root('tests', 'return64bit', 'testbindstart.js'), '--pre-js', path_from_root('tests', 'return64bit', 'testbind.js'), '--post-js', path_from_root('tests', 'return64bit', 'testbindend.js'), '-s', 'EXPORTED_FUNCTIONS=["_test"]', '-o', 'test.js', '-O2', '--closure', '1'], stdout=PIPE, stderr=PIPE).communicate()
+
+    # Simple test program to load the test.js binding library and call the binding to the
+    # C function returning the 64 bit long.
+    open(os.path.join(self.get_dir(), 'testrun.js'), 'w').write('''
+      var test = require("./test.js");
+      test.runtest();
+    ''')
+
+    # Run the test and confirm the output is as expected.
+    if NODE_JS in JS_ENGINES:
+      out = run_js('testrun.js', engine=NODE_JS, full_output=True)
+      assert "low = 5678" in out
+      assert "high = 1234" in out
+
 # Generate tests for everything
 def make_run(fullname, name=-1, compiler=-1, embetter=0, quantum_size=0,
     typed_arrays=0, emcc_args=None, env=None):