Don't do tail calls in a function that call setjmp. The stack might be

corrupted when setjmp returns again.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131399 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 33 insertions, 0 deletions

diff --git a/lib/VMCore/Function.cpp b/lib/VMCore/Function.cpp
index 013c458..ce2186f 100644
--- a/lib/VMCore/Function.cpp
+++ b/lib/VMCore/Function.cpp
@@ -24,6 +24,7 @@
 #include "llvm/Support/Threading.h"
 #include "SymbolTableListTraitsImpl.h"
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
 using namespace llvm;
 
@@ -406,4 +407,36 @@ bool Function::hasAddressTaken(const User* *PutOffender) const {
   return false;
 }
 
+/// callsFunctionThatReturnsTwice - Return true if the function has a call to
+/// setjmp or other function that gcc recognizes as "returning twice".
+///
+/// FIXME: Remove after <rdar://problem/8031714> is fixed.
+/// FIXME: Is the obove FIXME valid?
+bool Function::callsFunctionThatReturnsTwice() const {
+  const Module *M = this->getParent();
+  static const char *ReturnsTwiceFns[] = {
+    "_setjmp",
+    "setjmp",
+    "sigsetjmp",
+    "setjmp_syscall",
+    "savectx",
+    "qsetjmp",
+    "vfork",
+    "getcontext"
+  };
+
+  for (unsigned I = 0; I < array_lengthof(ReturnsTwiceFns); ++I)
+    if (const Function *Callee = M->getFunction(ReturnsTwiceFns[I])) {
+      if (!Callee->use_empty())
+        for (Value::const_use_iterator
+               I = Callee->use_begin(), E = Callee->use_end();
+             I != E; ++I)
+          if (const CallInst *CI = dyn_cast<CallInst>(*I))
+            if (CI->getParent()->getParent() == this)
+              return true;
+    }
+
+  return false;
+}
+
 // vim: sw=2 ai