rewrite setjmp code to identify, uniquely, each setjmp and match it to a longjmp. add testcase for #747, works in unoptimized builds

4 files changed, 57 insertions, 4 deletions

diff --git a/src/jsifier.js b/src/jsifier.js
index d4d60cee..8b3c9683 100644
--- a/src/jsifier.js
+++ b/src/jsifier.js
@@ -620,7 +620,7 @@ function JSify(data, functionsOnly, givenFunctions) {
             } // otherwise, should have been set before!
             if (func.setjmpTable) {
               var setjmpTable = {};
-              ret += indent + 'var setjmped = false;'; // set to true if we setjmp in this invocation
+              ret += indent + 'var mySetjmpIds = {};\n';
               ret += indent + 'var setjmpTable = {';
               func.setjmpTable.forEach(function(triple) { // original label, label we created for right after the setjmp, variable setjmp result goes into
                 ret += '"' + getLabelId(triple[0]) + '": ' + 'function(value) { label = ' + getLabelId(triple[1]) + '; ' + triple[2] + ' = value },';
@@ -639,7 +639,7 @@ function JSify(data, functionsOnly, givenFunctions) {
             }).join('\n');
             ret += '\n' + indent + '  default: assert(0, "bad label: " + label);\n' + indent + '}';
             if (func.setjmpTable) {
-              ret += ' } catch(e) { if (!setjmped) throw(e); setjmped = false; if (!e.longjmp) throw(e); setjmpTable[e.label](e.value) }';
+              ret += ' } catch(e) { if (!e.longjmp || !(e.id in mySetjmpIds)) throw(e); setjmpTable[setjmpLabels[e.id]](e.value) }';
             }
           } else {
             ret += (SHOW_LABELS ? indent + '/* ' + block.entries[0] + ' */' : '') + '\n' + getLabelLines(block.labels[0], indent);
diff --git a/src/library.js b/src/library.js
index 5a8a9ae7..1bdd840d 100644
--- a/src/library.js
+++ b/src/library.js
@@ -5940,11 +5940,11 @@ LibraryManager.library = {
 
   setjmp__inline: function(env) {
     // Save the label
-    return '(setjmped = true, ' + makeSetValue(env, '0', 'label', 'i32') + ', 0)';
+    return '(tempInt = setjmpId++, mySetjmpIds[tempInt] = 1, setjmpLabels[tempInt] = label,' + makeSetValue(env, '0', 'tempInt', 'i32') + ', 0)';
   },
 
   longjmp: function(env, value) {
-    throw { longjmp: true, label: {{{ makeGetValue('env', '0', 'i32') }}}, value: value || 1 };
+    throw { longjmp: true, id: {{{ makeGetValue('env', '0', 'i32') }}}, value: value || 1 };
   },
 
   // ==========================================================================
diff --git a/src/preamble.js b/src/preamble.js
index 9342bf2b..0917f977 100644
--- a/src/preamble.js
+++ b/src/preamble.js
@@ -276,6 +276,8 @@ Module['printProfiling'] = printProfiling;
 //========================================
 
 var __THREW__ = false; // Used in checking for thrown exceptions.
+var setjmpId = 1; // Used in setjmp/longjmp
+var setjmpLabels = {};
 
 var ABORT = false;
 
diff --git a/tests/runner.py b/tests/runner.py
index 5cdc9497..6832d41e 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -2130,6 +2130,57 @@ setjmp exception execution path, level: 0
 Exiting setjmp function, level: 0
 ''')
 
+    def test_longjmp4(self):
+      src = r'''
+        #include <setjmp.h>
+        #include <stdio.h>
+
+        typedef struct {
+          jmp_buf* jmp;
+        } jmp_state;
+
+        void second_func(jmp_state* s);
+
+        void first_func(jmp_state* s) {
+          jmp_buf* prev_jmp = s->jmp;
+          jmp_buf c_jmp;
+          int once = 0;
+
+          if (setjmp(c_jmp) == 0) {
+            printf("Normal execution path of first function!\n");
+
+            s->jmp = &c_jmp;
+            second_func(s);
+          } else {
+            printf("Exception execution path of first function! %d\n", once);
+
+            if (!once) {
+              printf("Calling longjmp the second time!\n");
+              once = 1;
+              longjmp(*(s->jmp), 1);
+            }
+          }
+        }
+
+        void second_func(jmp_state* s) {
+          longjmp(*(s->jmp), 1);
+        }
+
+        int main(int argc, char *argv[]) {
+          jmp_state s;
+          s.jmp = NULL;
+
+          first_func(&s);
+
+          return 0;
+        }
+        '''
+      self.do_run(src, '''Normal execution path of first function!
+Exception execution path of first function! 0
+Calling longjmp the second time!
+Exception execution path of first function! 1
+''')
+
     def test_exceptions(self):
         if Settings.QUANTUM_SIZE == 1: return self.skip("we don't support libcxx in q1")