fix setjmp/longjmp to notice if we actually setjmped in the invocation of the function on the stack, so recursive functions can use setjmp/longjmp

3 files changed, 49 insertions, 2 deletions

diff --git a/src/jsifier.js b/src/jsifier.js
index 2791c65b..595e057c 100644
--- a/src/jsifier.js
+++ b/src/jsifier.js
@@ -619,6 +619,7 @@ 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 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 },';
@@ -637,7 +638,7 @@ 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 (!e.longjmp) throw(e); setjmpTable[e.label](e.value) }';
+              ret += ' } catch(e) { if (!setjmped) throw(e); if (!e.longjmp) throw(e); setjmpTable[e.label](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 4b6cb460..12ac0ed0 100644
--- a/src/library.js
+++ b/src/library.js
@@ -5938,7 +5938,7 @@ LibraryManager.library = {
 
   setjmp__inline: function(env) {
     // Save the label
-    return '(' + makeSetValue(env, '0', 'label', 'i32') + ', 0)';
+    return '(setjmped = true, ' + makeSetValue(env, '0', 'label', 'i32') + ', 0)';
   },
 
   longjmp: function(env, value) {
diff --git a/tests/runner.py b/tests/runner.py
index aa976652..a4bc4944 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -1987,6 +1987,52 @@ c5,de,15,8a
         else:
           self.do_run(src, 'second\nmain: 0\n')
 
+    def test_longjmp2(self):
+      src = r'''
+        #include <setjmp.h>
+        #include <stdio.h>
+
+        typedef struct {
+          jmp_buf* jmp;
+        } jmp_state;
+
+        void stack_manipulate_func(jmp_state* s, int level) {
+          jmp_buf buf;
+
+          printf("Entering stack_manipulate_func, level: %d\n", level);
+
+          if (level == 0) {
+            s->jmp = &buf;
+            if (setjmp(*(s->jmp)) == 0) {
+              printf("Setjmp normal execution path, level: %d\n", level);
+              stack_manipulate_func(s, level + 1);
+            } else {
+              printf("Setjmp error execution path, level: %d\n", level);
+            }
+          } else {
+            printf("Perform longjmp at level %d\n", level);
+            longjmp(*(s->jmp), 1);
+          }
+
+          printf("Exiting stack_manipulate_func, level: %d\n", level);
+        }
+
+        int main(int argc, char *argv[]) {
+          jmp_state s;
+          s.jmp = NULL;
+          stack_manipulate_func(&s, 0);
+
+          return 0;
+        }
+        '''
+      self.do_run(src, '''Entering stack_manipulate_func, level: 0
+Setjmp normal execution path, level: 0
+Entering stack_manipulate_func, level: 1
+Perform longjmp at level 1
+Setjmp error execution path, level: 0
+Exiting stack_manipulate_func, level: 0
+''')
+
     def test_exceptions(self):
         if Settings.QUANTUM_SIZE == 1: return self.skip("we don't support libcxx in q1")