reset the stack top when CATCH_EXIT_CODE

3 files changed, 54 insertions, 1 deletions

diff --git a/src/postamble.js b/src/postamble.js
index 83a4daa6..5f541733 100644
--- a/src/postamble.js
+++ b/src/postamble.js
@@ -18,10 +18,14 @@ Module.callMain = function callMain(args) {
   argv = allocate(argv, 'i32', ALLOC_STATIC);
 
 #if CATCH_EXIT_CODE
+  var initialStackTop = STACKTOP;
   try {
     return Module['_main'](argc, argv, 0);
   }
   catch(e) { if (e.name == "ExitStatus") return e.status; throw e; }
+  finally {
+    STACKTOP = initialStackTop;
+  }
 #else
   return Module['_main'](argc, argv, 0);
 #endif
diff --git a/src/settings.js b/src/settings.js
index 84d64167..11af4692 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -118,7 +118,9 @@ var INLINING_LIMIT = 50; // A limit on inlining. If 0, we will inline normally i
 var CATCH_EXIT_CODE = 0; // If set, causes exit() to throw an exception object which is caught
                          // in a try..catch block and results in the exit status being
                          // returned from run(). If zero (the default), the program is just
-                         // terminated with an error message.
+                         // terminated with an error message, that is, the exception thrown
+                         // by exit() is not handled in any way (in particular, the stack
+                         // position will not be reset).
 
 // Generated code debugging options
 var SAFE_HEAP = 0; // Check each write to the heap, for example, this will give a clear
diff --git a/tests/runner.py b/tests/runner.py
index e55a3f60..742ddf1f 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -2471,6 +2471,53 @@ setjmp exception execution path, level: 0, prev_jmp: -1
 Exiting setjmp function, level: 0, prev_jmp: -1
 ''')
 
+    def test_exit_stack(self):
+      if self.emcc_args is None: return self.skip('requires emcc')
+      if Settings.ASM_JS: return self.skip('uses report_stack without exporting')
+
+      Settings.CATCH_EXIT_CODE = 1
+
+      src = r'''
+        #include <stdio.h>
+        #include <stdlib.h>
+
+        extern "C" {
+          extern void report_stack(int x);
+        }
+
+        char moar() {
+          char temp[125];
+          for (int i = 0; i < 125; i++) temp[i] = i*i;
+          for (int i = 1; i < 125; i++) temp[i] += temp[i-1]/2;
+          if (temp[100] != 99) exit(1);
+          return temp[120];
+        }
+
+        int main(int argc, char *argv[]) {
+          report_stack((int)alloca(4));
+          printf("*%d*\n", moar());
+          return 0;
+        }
+      '''
+
+      open(os.path.join(self.get_dir(), 'pre.js'), 'w').write('''
+        var initialStack = -1;
+        var _report_stack = function(x) {
+          Module.print('reported');
+          initialStack = x;
+        }
+        var Module = {
+          postRun: function() {
+            Module.print('postRun');
+            assert(initialStack == STACKTOP, [initialStack, STACKTOP]);
+            Module.print('ok.');
+          }
+        };
+      ''')
+
+      self.emcc_args += ['--pre-js', 'pre.js']
+      self.do_run(src, '''reported\npostRun\nok.\nExit Status: 1\n''')
+
     def test_class(self):
         src = '''
           #include <stdio.h>