Fix crash with --instrument-debug (#3704)

jackm321 · facebook-github-bot · commit c8de4b061b5d · 2019-10-30T20:11:19.000-07:00
Summary: Currently calls `IRFunction::insertInstruction` with `InstListTy::end` iterator and crashes Documentation: n/a Pull Request resolved: #3704 Test Plan: `ninja all` `./tests/InterpreterOperatorTest --instrument-debug` no crash Differential Revision: D18240758 Pulled By: jackm321 fbshipit-source-id: 85018a5f1546b8844ce7963de89cf3bb043befce
diff --git a/lib/Optimizer/IROptimizer/IROptimizer.cpp b/lib/Optimizer/IROptimizer/IROptimizer.cpp
@@ -1538,7 +1538,11 @@ static void performDebugInstrumentation(IRFunction &M) {
         name += ".";
         name += I->getKindName();
         auto *dumpInstr = new DebugPrintInst(name, Op.first);
-        M.insertInstruction(&*next, dumpInstr);
+        if (next == e) {
+          M.insertInstruction(dumpInstr);
+        } else {
+          M.insertInstruction(&*next, dumpInstr);
+        }
       }
     }
     it = next;

Original file line number	Diff line number	Diff line change
`@@ -1538,7 +1538,11 @@ static void performDebugInstrumentation(IRFunction &M) {`
`1538`	`1538`	`name += ".";`
`1539`	`1539`	`name += I->getKindName();`
`1540`	`1540`	`auto *dumpInstr = new DebugPrintInst(name, Op.first);`
`1541`		`- M.insertInstruction(&*next, dumpInstr);`
	`1541`	`+ if (next == e) {`
	`1542`	`+ M.insertInstruction(dumpInstr);`
	`1543`	`+ } else {`
	`1544`	`+ M.insertInstruction(&*next, dumpInstr);`
	`1545`	`+ }`
`1542`	`1546`	`}`
`1543`	`1547`	`}`
`1544`	`1548`	`it = next;`