Provide basic type safety for array_pod_sort comparators.

This makes using array_pod_sort significantly safer. The implementation relies
on function pointer casting but that should be safe as we're dealing with void*
here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191175 91177308-0d34-0410-b5e6-96231b3b80d8

11 files changed, 38 insertions, 42 deletions

diff --git a/include/llvm/ADT/STLExtras.h b/include/llvm/ADT/STLExtras.h
index bfe1392a67..3aa8183353 100644
--- a/include/llvm/ADT/STLExtras.h
+++ b/include/llvm/ADT/STLExtras.h
@@ -293,12 +293,16 @@ inline void array_pod_sort(IteratorTy Start, IteratorTy End) {
         get_array_pod_sort_comparator(*Start));
 }
 
-template<class IteratorTy>
-inline void array_pod_sort(IteratorTy Start, IteratorTy End,
-                                  int (*Compare)(const void*, const void*)) {
+template <class IteratorTy>
+inline void array_pod_sort(
+    IteratorTy Start, IteratorTy End,
+    int (*Compare)(
+        const typename std::iterator_traits<IteratorTy>::value_type *,
+        const typename std::iterator_traits<IteratorTy>::value_type *)) {
   // Don't dereference start iterator of empty sequence.
   if (Start == End) return;
-  qsort(&*Start, End-Start, sizeof(*Start), Compare);
+  qsort(&*Start, End - Start, sizeof(*Start),
+        reinterpret_cast<int (*)(const void *, const void *)>(Compare));
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/include/llvm/Support/PassNameParser.h b/include/llvm/Support/PassNameParser.h
index a73dc8ff28..c0914b1f2f 100644
--- a/include/llvm/Support/PassNameParser.h
+++ b/include/llvm/Support/PassNameParser.h
@@ -86,10 +86,9 @@ public:
 
 private:
   // ValLessThan - Provide a sorting comparator for Values elements...
-  static int ValLessThan(const void *VT1, const void *VT2) {
-    typedef PassNameParser::OptionInfo ValType;
-    return std::strcmp(static_cast<const ValType *>(VT1)->Name,
-                       static_cast<const ValType *>(VT2)->Name);
+  static int ValLessThan(const PassNameParser::OptionInfo *VT1,
+                         const PassNameParser::OptionInfo *VT2) {
+    return std::strcmp(VT1->Name, VT2->Name);
   }
 };
 
diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp
index d429b37334..c776dd3122 100644
--- a/lib/CodeGen/RegisterCoalescer.cpp
+++ b/lib/CodeGen/RegisterCoalescer.cpp
@@ -2040,9 +2040,8 @@ struct MBBPriorityInfo {
 // block (the unsigned), and then on the MBB number.
 //
 // EnableGlobalCopies assumes that the primary sort key is loop depth.
-static int compareMBBPriority(const void *L, const void *R) {
-  const MBBPriorityInfo *LHS = static_cast<const MBBPriorityInfo*>(L);
-  const MBBPriorityInfo *RHS = static_cast<const MBBPriorityInfo*>(R);
+static int compareMBBPriority(const MBBPriorityInfo *LHS,
+                              const MBBPriorityInfo *RHS) {
   // Deeper loops first
   if (LHS->Depth != RHS->Depth)
     return LHS->Depth > RHS->Depth ? -1 : 1;
diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp
index 2db59acd50..402a6167f5 100644
--- a/lib/MC/ELFObjectWriter.cpp
+++ b/lib/MC/ELFObjectWriter.cpp
@@ -1104,11 +1104,10 @@ void ELFObjectWriter::WriteRelocationsFragment(const MCAssembler &Asm,
   }
 }
 
-static int compareBySuffix(const void *a, const void *b) {
-  const MCSectionELF *secA = *static_cast<const MCSectionELF* const *>(a);
-  const MCSectionELF *secB = *static_cast<const MCSectionELF* const *>(b);
-  const StringRef &NameA = secA->getSectionName();
-  const StringRef &NameB = secB->getSectionName();
+static int compareBySuffix(const MCSectionELF *const *a,
+                           const MCSectionELF *const *b) {
+  const StringRef &NameA = (*a)->getSectionName();
+  const StringRef &NameB = (*b)->getSectionName();
   const unsigned sizeA = NameA.size();
   const unsigned sizeB = NameB.size();
   const unsigned len = std::min(sizeA, sizeB);
diff --git a/lib/MC/MCELFObjectTargetWriter.cpp b/lib/MC/MCELFObjectTargetWriter.cpp
index ec7397d748..0c39e4a17e 100644
--- a/lib/MC/MCELFObjectTargetWriter.cpp
+++ b/lib/MC/MCELFObjectTargetWriter.cpp
@@ -42,9 +42,9 @@ const MCSymbol *MCELFObjectTargetWriter::undefinedExplicitRelSym(const MCValue &
 // ELF doesn't require relocations to be in any order. We sort by the r_offset,
 // just to match gnu as for easier comparison. The use type and index is an
 // arbitrary way of making the sort deterministic.
-static int cmpRel(const void *AP, const void *BP) {
-  const ELFRelocationEntry &A = *(const ELFRelocationEntry *)AP;
-  const ELFRelocationEntry &B = *(const ELFRelocationEntry *)BP;
+static int cmpRel(const ELFRelocationEntry *AP, const ELFRelocationEntry *BP) {
+  const ELFRelocationEntry &A = *AP;
+  const ELFRelocationEntry &B = *BP;
   if (A.r_offset != B.r_offset)
     return B.r_offset - A.r_offset;
   if (B.Type != A.Type)
diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index dcf54b0b94..c1f825ae78 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -4059,9 +4059,8 @@ bool AsmParser::parseDirectiveMSAlign(SMLoc IDLoc, ParseStatementInfo &Info) {
 
 // We are comparing pointers, but the pointers are relative to a single string.
 // Thus, this should always be deterministic.
-static int rewritesSort(const void *A, const void *B) {
-  const AsmRewrite *AsmRewriteA = static_cast<const AsmRewrite *>(A);
-  const AsmRewrite *AsmRewriteB = static_cast<const AsmRewrite *>(B);
+static int rewritesSort(const AsmRewrite *AsmRewriteA,
+                        const AsmRewrite *AsmRewriteB) {
   if (AsmRewriteA->Loc.getPointer() < AsmRewriteB->Loc.getPointer())
     return -1;
   if (AsmRewriteB->Loc.getPointer() < AsmRewriteA->Loc.getPointer())
diff --git a/lib/Support/TargetRegistry.cpp b/lib/Support/TargetRegistry.cpp
index 9c81327615..0c90c17fef 100644
--- a/lib/Support/TargetRegistry.cpp
+++ b/lib/Support/TargetRegistry.cpp
@@ -135,9 +135,9 @@ const Target *TargetRegistry::getClosestTargetForJIT(std::string &Error) {
   return TheTarget;
 }
 
-static int TargetArraySortFn(const void *LHS, const void *RHS) {
-  typedef std::pair<StringRef, const Target*> pair_ty;
-  return ((const pair_ty*)LHS)->first.compare(((const pair_ty*)RHS)->first);
+static int TargetArraySortFn(const std::pair<StringRef, const Target *> *LHS,
+                             const std::pair<StringRef, const Target *> *RHS) {
+  return LHS->first.compare(RHS->first);
 }
 
 void TargetRegistry::printRegisteredTargetsForVersion() {
diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp
index 7ba7f86cb4..cf15580b03 100644
--- a/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/lib/Transforms/IPO/GlobalOpt.cpp
@@ -3042,14 +3042,8 @@ bool GlobalOpt::OptimizeGlobalCtorsList(GlobalVariable *&GCL) {
   return true;
 }
 
-static int compareNames(const void *A, const void *B) {
-  const GlobalValue *VA = *reinterpret_cast<GlobalValue* const*>(A);
-  const GlobalValue *VB = *reinterpret_cast<GlobalValue* const*>(B);
-  if (VA->getName() < VB->getName())
-    return -1;
-  if (VB->getName() < VA->getName())
-    return 1;
-  return 0;
+static int compareNames(Constant *const *A, Constant *const *B) {
+  return (*A)->getName().compare((*B)->getName());
 }
 
 static void setUsedInitializer(GlobalVariable &V,
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index 0dea844aeb..0e56904ebd 100644
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -699,9 +699,10 @@ namespace {
   };
 }
 
-static int ConstantIntSortPredicate(const void *P1, const void *P2) {
-  const ConstantInt *LHS = *(const ConstantInt*const*)P1;
-  const ConstantInt *RHS = *(const ConstantInt*const*)P2;
+static int ConstantIntSortPredicate(ConstantInt *const *P1,
+                                    ConstantInt *const *P2) {
+  const ConstantInt *LHS = *P1;
+  const ConstantInt *RHS = *P2;
   if (LHS->getValue().ult(RHS->getValue()))
     return 1;
   if (LHS->getValue() == RHS->getValue())
diff --git a/utils/TableGen/CodeGenRegisters.cpp b/utils/TableGen/CodeGenRegisters.cpp
index 43de2be977..f2eef4f68f 100644
--- a/utils/TableGen/CodeGenRegisters.cpp
+++ b/utils/TableGen/CodeGenRegisters.cpp
@@ -813,9 +813,10 @@ static bool testSubClass(const CodeGenRegisterClass *A,
 /// Register classes with the same registers, spill size, and alignment form a
 /// clique.  They will be ordered alphabetically.
 ///
-static int TopoOrderRC(const void *PA, const void *PB) {
-  const CodeGenRegisterClass *A = *(const CodeGenRegisterClass* const*)PA;
-  const CodeGenRegisterClass *B = *(const CodeGenRegisterClass* const*)PB;
+static int TopoOrderRC(CodeGenRegisterClass *const *PA,
+                       CodeGenRegisterClass *const *PB) {
+  const CodeGenRegisterClass *A = *PA;
+  const CodeGenRegisterClass *B = *PB;
   if (A == B)
     return 0;
 
diff --git a/utils/TableGen/OptParserEmitter.cpp b/utils/TableGen/OptParserEmitter.cpp
index 7fb7d65a70..cff004f569 100644
--- a/utils/TableGen/OptParserEmitter.cpp
+++ b/utils/TableGen/OptParserEmitter.cpp
@@ -41,9 +41,9 @@ static int StrCmpOptionName(const char *A, const char *B) {
   return (a < b) ? -1 : 1;
 }
 
-static int CompareOptionRecords(const void *Av, const void *Bv) {
-  const Record *A = *(const Record*const*) Av;
-  const Record *B = *(const Record*const*) Bv;
+static int CompareOptionRecords(Record *const *Av, Record *const *Bv) {
+  const Record *A = *Av;
+  const Record *B = *Bv;
 
   // Sentinel options precede all others and are only ordered by precedence.
   bool ASent = A->getValueAsDef("Kind")->getValueAsBit("Sentinel");