Silence more static analyzer warnings.

Add in definedness checks for shift operators, null checks when
pointers are assumed by the code to be non-null, and explicit
unreachables.

llvm-svn: 224255

5 files changed, 20 insertions, 7 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 6863b78a0a2..db0339be745 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1492,10 +1492,12 @@ void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
 
   if (NumBits == 0) return;   // 1-byte aligned: no need to emit alignment.
 
+  assert(NumBits < std::numeric_limits<unsigned>::digits &&
+         "undefined behavior");
   if (getCurrentSection()->getKind().isText())
-    OutStreamer.EmitCodeAlignment(1 << NumBits);
+    OutStreamer.EmitCodeAlignment(1u << NumBits);
   else
-    OutStreamer.EmitValueToAlignment(1 << NumBits);
+    OutStreamer.EmitValueToAlignment(1u << NumBits);
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/llvm/lib/CodeGen/ExecutionDepsFix.cpp b/llvm/lib/CodeGen/ExecutionDepsFix.cpp
index 3680498927e..18c82c85e55 100644
--- a/llvm/lib/CodeGen/ExecutionDepsFix.cpp
+++ b/llvm/lib/CodeGen/ExecutionDepsFix.cpp
@@ -74,6 +74,8 @@ struct DomainValue {
 
   // Is domain available?
   bool hasDomain(unsigned domain) const {
+    assert(domain < std::numeric_limits<unsigned>::digits &&
+           "undefined behavior");
     return AvailableDomains & (1u << domain);
   }
 
@@ -338,9 +340,11 @@ bool ExeDepsFix::merge(DomainValue *A, DomainValue *B) {
   // All uses of B are referred to A.
   B->Next = retain(A);
 
-  for (unsigned rx = 0; rx != NumRegs; ++rx)
+  for (unsigned rx = 0; rx != NumRegs; ++rx) {
+    assert(LiveRegs && "no space allocated for live registers");
     if (LiveRegs[rx].Value == B)
       setLiveReg(rx, A);
+  }
   return true;
 }
 
@@ -645,6 +649,7 @@ void ExeDepsFix::visitSoftInstr(MachineInstr *mi, unsigned mask) {
   SmallVector<LiveReg, 4> Regs;
   for (SmallVectorImpl<int>::iterator i=used.begin(), e=used.end(); i!=e; ++i) {
     int rx = *i;
+    assert(LiveRegs && "no space allocated for live registers");
     const LiveReg &LR = LiveRegs[rx];
     // This useless DomainValue could have been missed above.
     if (!LR.Value->getCommonDomains(available)) {
@@ -684,9 +689,11 @@ void ExeDepsFix::visitSoftInstr(MachineInstr *mi, unsigned mask) {
       continue;
 
     // If latest didn't merge, it is useless now. Kill all registers using it.
-    for (SmallVectorImpl<int>::iterator i=used.begin(), e=used.end(); i!=e; ++i)
-      if (LiveRegs[*i].Value == Latest)
-        kill(*i);
+    for (int i : used) {
+      assert(LiveRegs && "no space allocated for live registers");
+      if (LiveRegs[i].Value == Latest)
+        kill(i);
+    }
   }
 
   // dv is the DomainValue we are going to use for this instruction.
diff --git a/llvm/lib/CodeGen/MachineRegisterInfo.cpp b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
index aba9e5c986d..86bb34be3fe 100644
--- a/llvm/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
@@ -129,6 +129,7 @@ void MachineRegisterInfo::verifyUseList(unsigned Reg) const {
              << " use list MachineOperand " << MO
              << " has no parent instruction.\n";
       Valid = false;
+      continue;
     }
     MachineOperand *MO0 = &MI->getOperand(0);
     unsigned NumOps = MI->getNumOperands();
diff --git a/llvm/lib/CodeGen/RegisterClassInfo.cpp b/llvm/lib/CodeGen/RegisterClassInfo.cpp
index e0d1aa2b533..ab33672d41f 100644
--- a/llvm/lib/CodeGen/RegisterClassInfo.cpp
+++ b/llvm/lib/CodeGen/RegisterClassInfo.cpp
@@ -47,6 +47,7 @@ void RegisterClassInfo::runOnMachineFunction(const MachineFunction &mf) {
   }
 
   // Does this MF have different CSRs?
+  assert(TRI && "no register info set");
   const MCPhysReg *CSR = TRI->getCalleeSavedRegs(MF);
   if (Update || CSR != CalleeSaved) {
     // Build a CSRNum map. Every CSR alias gets an entry pointing to the last
@@ -76,6 +77,7 @@ void RegisterClassInfo::runOnMachineFunction(const MachineFunction &mf) {
 /// registers filtered out. Volatile registers come first followed by CSR
 /// aliases ordered according to the CSR order specified by the target.
 void RegisterClassInfo::compute(const TargetRegisterClass *RC) const {
+  assert(RC && "no register class given");
   RCInfo &RCI = RegClass[RC->getID()];
 
   // Raw register count, including all reserved regs.
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index c573339c7bf..3c0229f2bf3 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -566,6 +566,7 @@ static void getCopyToPartsVector(SelectionDAG &DAG, SDLoc DL,
   } else if (NumParts > 0) {
     // If the intermediate type was expanded, split each the value into
     // legal parts.
+    assert(NumIntermediates != 0 && "division by zero");
     assert(NumParts % NumIntermediates == 0 &&
            "Must expand into a divisible number of parts!");
     unsigned Factor = NumParts / NumIntermediates;
@@ -1408,7 +1409,7 @@ SelectionDAGBuilder::EmitBranchForMergedCondition(const Value *Cond,
         if (TM.Options.NoNaNsFPMath)
           Condition = getFCmpCodeWithoutNaN(Condition);
       } else {
-        Condition = ISD::SETEQ; // silence warning.
+        (void)Condition; // silence warning.
         llvm_unreachable("Unknown compare instruction");
       }