Update basic block iterator after deleting instruction; add test case

2 files changed, 32 insertions, 8 deletions

diff --git a/lib/Module/IntrinsicCleaner.cpp b/lib/Module/IntrinsicCleaner.cpp
index 19683ab4..92107f4f 100644
--- a/lib/Module/IntrinsicCleaner.cpp
+++ b/lib/Module/IntrinsicCleaner.cpp
@@ -205,14 +205,15 @@ bool IntrinsicCleanerPass::runOnBasicBlock(BasicBlock &b, Module &M) {
         Builder.CreateCall(F);
         Builder.CreateUnreachable();
 
-        ii->eraseFromParent();
-
-       	//check if the instruction after the one we just replaced is not the end of the basic block
-        //and if it is not (i.e. it is a valid instruction), delete it and all remaining 
-        //because the cleaner just introduced a terminating instruction (unreachable)
-        //otherwise llvm will assert in Verifier::visitTerminatorInstr
-        while(i != ie){  // i was already incremented above.
-          (i++)->eraseFromParent();
+        i = ii->eraseFromParent();
+
+        // check if the instruction after the one we just replaced is not the
+        // end of the basic block and if it is not (i.e. it is a valid
+        // instruction), delete it and all remaining because the cleaner just
+        // introduced a terminating instruction (unreachable) otherwise llvm will
+        // assert in Verifier::visitTerminatorInstr
+        while (i != ie) { // i was already incremented above.
+          i = i->eraseFromParent();
         }
 
         dirty = true;
diff --git a/test/regression/2019-08-01-trap-instruction.ll b/test/regression/2019-08-01-trap-instruction.ll
new file mode 100644
index 00000000..2ef57aa2
--- /dev/null
+++ b/test/regression/2019-08-01-trap-instruction.ll
@@ -0,0 +1,23 @@
+; RUN: rm -rf %t.klee-out
+; RUN: llvm-as -f %s -o - | %klee --output-dir=%t.klee-out
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; @foo is not known yet
+@foo2 = alias i32 (...), i32 (...)* @foo
+@foo = alias i32 (...), bitcast (i32 ()* @__foo to i32 (...)*)
+
+define i32 @__foo() {
+entry:
+  call void @llvm.trap() noreturn nounwind
+  ret i32 42
+}
+
+define i32 @main() {
+entry:
+  call i32 (...) @foo()
+  call i32 (...) @foo2()
+  ret i32 0
+}
+
+declare void @llvm.trap() noreturn nounwind
\ No newline at end of file