fix: LLVM 3.5, begin_user() instead of begin_use()

With version 3.5, LLVM introduced a subtle semantic change in the API of
`Value`. With that change, `use_begin()` is renamed to `user_begin()`.
Additionally, a new method `use_begin()` with a different meaning was
introduced. Now, `use_begin()` actually iterates over `Use`s, whereas
before, dereferencing it would give a `User *`. For further details,
please refer to https://reviews.llvm.org/rL203364.

Due to the reintroduction of `use_begin()`, existing code may still
compile, although the semantics have changed.  In the code changed with
this patch, all `dyn_cast`s for `Use` fail and the else branch is
always taken.

1 files changed, 9 insertions, 5 deletions

diff --git a/lib/Module/ModuleUtil.cpp b/lib/Module/ModuleUtil.cpp
index 4912ca94..deb5a3e2 100644
--- a/lib/Module/ModuleUtil.cpp
+++ b/lib/Module/ModuleUtil.cpp
@@ -306,9 +306,13 @@ Function *klee::getDirectCallTarget(CallSite cs, bool moduleIsFullyLinked) {
 }
 
 static bool valueIsOnlyCalled(const Value *v) {
-  for (Value::const_use_iterator it = v->use_begin(), ie = v->use_end();
-       it != ie; ++it) {
-    if (const Instruction *instr = dyn_cast<Instruction>(*it)) {
+#if LLVM_VERSION_CODE < LLVM_VERSION(3, 5)
+  for (auto it = v->use_begin(), ie = v->use_end(); it != ie; ++it) {
+    auto user = *it;
+#else
+  for (auto user : v->users()) {
+#endif
+    if (const Instruction *instr = dyn_cast<Instruction>(user)) {
       if (instr->getOpcode()==0) continue; // XXX function numbering inst
 
       // Make sure the instruction is a call or invoke.
@@ -320,12 +324,12 @@ static bool valueIsOnlyCalled(const Value *v) {
       if (cs.hasArgument(v))
         return false;
     } else if (const llvm::ConstantExpr *ce =
-               dyn_cast<llvm::ConstantExpr>(*it)) {
+               dyn_cast<llvm::ConstantExpr>(user)) {
       if (ce->getOpcode()==Instruction::BitCast)
         if (valueIsOnlyCalled(ce))
           continue;
       return false;
-    } else if (const GlobalAlias *ga = dyn_cast<GlobalAlias>(*it)) {
+    } else if (const GlobalAlias *ga = dyn_cast<GlobalAlias>(user)) {
       // XXX what about v is bitcast of aliasee?
       if (v==ga->getAliasee() && !valueIsOnlyCalled(ga))
         return false;