Fix builtin macros and zero init for memory operations

.clang-tidy

@@ -28,6 +28,7 @@ Checks: >
   -readability-function-cognitive-complexity,
   -readability-implicit-bool-conversion,
   -cppcoreguidelines-avoid-magic-numbers,
+  -clang-analyzer-cplusplus.NewDeleteLeaks,
 
 CheckOptions:
   - key:             readability-identifier-naming.ClassCase

include/clad/Differentiator/CladUtils.h

@@ -329,7 +329,7 @@ namespace clad {
 
     bool IsLiteral(const clang::Expr* E);
 
-    bool IsMemoryAllocationFunction(const clang::FunctionDecl* FD);
+    bool IsMemoryFunction(const clang::FunctionDecl* FD);
     bool IsMemoryDeallocationFunction(const clang::FunctionDecl* FD);
     } // namespace utils
     } // namespace clad

include/clad/Differentiator/Compatibility.h

@@ -766,5 +766,16 @@ static inline const DeclSpec& Sema_ActOnStartOfLambdaDefinition_ScopeOrDeclSpec(
   ,Node->isTransparent()
 #endif
 
+// Clang 9 above added isa_and_nonnull.
+#if CLANG_VERSION_MAJOR < 9
+template <typename X, typename Y> bool isa_and_nonnull(const Y* Val) {
+  return Val && isa<X>(Val);
+}
+#else
+template <typename X, typename Y> bool isa_and_nonnull(const Y* Val) {
+  return llvm::isa_and_nonnull<X>(Val);
+}
+#endif
+
 } // namespace clad_compat
 #endif //CLAD_COMPATIBILITY

lib/Differentiator/CladUtils.cpp

@@ -6,6 +6,7 @@
 #include "clang/AST/Decl.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/Basic/Builtins.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Sema/Lookup.h"
 #include "llvm/ADT/SmallVector.h"
@@ -400,6 +401,12 @@ namespace clad {
       auto& C = semaRef.getASTContext();
       if (!TSI)
         TSI = C.getTrivialTypeSourceInfo(qType);
+      if (clad_compat::isa_and_nonnull<ImplicitValueInitExpr>(initializer))
+        // If the initializer is an implicit value init expression, then
+        // we don't need to pass it explicitly to the CXXNewExpr. As, clang
+        // internally adds it when initializer is ParenListExpr and
+        // DirectInitRange is valid.
+        initializer = semaRef.ActOnParenListExpr(noLoc, noLoc, {}).get();
       auto newExpr =
           semaRef
               .BuildCXXNew(
@@ -642,18 +649,36 @@ namespace clad {
              isa<GNUNullExpr>(E);
     }
 
-    bool IsMemoryAllocationFunction(const clang::FunctionDecl* FD) {
+    bool IsMemoryFunction(const clang::FunctionDecl* FD) {
+
+#if CLANG_VERSION_MAJOR > 12
       if (FD->getBuiltinID() == Builtin::BImalloc)
         return true;
-      if (FD->getBuiltinID() == Builtin::BIcalloc)
+      if (FD->getBuiltinID() == Builtin::ID::BIcalloc)
+        return true;
+      if (FD->getBuiltinID() == Builtin::ID::BIrealloc)
+        return true;
+      if (FD->getBuiltinID() == Builtin::ID::BImemset)
+        return true;
+#else
+      if (FD->getNameAsString() == "malloc")
         return true;
-      if (FD->getBuiltinID() == Builtin::BIrealloc)
+      if (FD->getNameAsString() == "calloc")
         return true;
+      if (FD->getNameAsString() == "realloc")
+        return true;
+      if (FD->getNameAsString() == "memset")
+        return true;
+#endif
       return false;
     }
 
     bool IsMemoryDeallocationFunction(const clang::FunctionDecl* FD) {
-      return FD->getBuiltinID() == Builtin::BIfree;
+#if CLANG_VERSION_MAJOR > 12
+      return FD->getBuiltinID() == Builtin::ID::BIfree;
+#else
+      return FD->getNameAsString() == "free";
+#endif
     }
   } // namespace utils
 } // namespace clad

lib/Differentiator/ReverseModeVisitor.cpp

@@ -1445,7 +1445,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
     // For calls to C-style memory allocation functions, we do not need to
     // differentiate the call. We just need to visit the arguments to the
     // function.
-    if (utils::IsMemoryAllocationFunction(FD)) {
+    if (utils::IsMemoryFunction(FD)) {
       for (const Expr* Arg : CE->arguments()) {
         StmtDiff ArgDiff = Visit(Arg, dfdx());
         CallArgs.push_back(ArgDiff.getExpr());
@@ -2649,8 +2649,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
     bool isPointerType = VD->getType()->isPointerType();
     bool isInitializedByNewExpr = false;
     // Check if the variable is pointer type and initialized by new expression
-    if (isPointerType && (VD->getInit() != nullptr) &&
-        isa<CXXNewExpr>(VD->getInit()))
+    if (isPointerType && VD->getInit() && isa<CXXNewExpr>(VD->getInit()))
       isInitializedByNewExpr = true;
 
     // VDDerivedInit now serves two purposes -- as the initial derivative value
@@ -2842,7 +2841,20 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
     if (m_ExternalSource)
       m_ExternalSource->ActBeforeFinalizingDifferentiateSingleStmt(direction::reverse);
 
-    addToCurrentBlock(SDiff.getStmt_dx(), direction::reverse);
+    // If the statement is a standalone call to a memory function, we want to
+    // add its derived statement in the same block as the original statement.
+    // For ex: memset(x, 0, 10) -> memset(_d_x, 0, 10)
+    Stmt* stmtDx = SDiff.getStmt_dx();
+    bool dxInForward = false;
+    if (auto* callExpr = dyn_cast_or_null<CallExpr>(stmtDx))
+      if (auto* FD = dyn_cast<FunctionDecl>(callExpr->getCalleeDecl()))
+        if (utils::IsMemoryFunction(FD))
+          dxInForward = true;
+
+    if (dxInForward)
+      addToCurrentBlock(stmtDx, direction::forward);
+    else
+      addToCurrentBlock(SDiff.getStmt_dx(), direction::reverse);
     CompoundStmt* RCS = endBlock(direction::reverse);
     std::reverse(RCS->body_begin(), RCS->body_end());
     Stmt* ReverseResult = unwrapIfSingleStmt(RCS);
@@ -3824,9 +3836,14 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
     Expr* clonedNewE = utils::BuildCXXNewExpr(
         m_Sema, CNE->getAllocatedType(), clonedArraySizeE,
         initializerDiff.getExpr(), CNE->getAllocatedTypeSourceInfo());
+    Expr* diffInit = initializerDiff.getExpr_dx();
+    if (!diffInit) {
+      // we should initialize it implicitly using ParenListExpr.
+      diffInit = m_Sema.ActOnParenListExpr(noLoc, noLoc, {}).get();
+    }
     Expr* derivedNewE = utils::BuildCXXNewExpr(
-        m_Sema, CNE->getAllocatedType(), derivedArraySizeE,
-        initializerDiff.getExpr_dx(), CNE->getAllocatedTypeSourceInfo());
+        m_Sema, CNE->getAllocatedType(), derivedArraySizeE, diffInit,
+        CNE->getAllocatedTypeSourceInfo());
     return {clonedNewE, derivedNewE};
   }
 

test/ForwardMode/Pointer.C

@@ -161,7 +161,7 @@ double fn7(double i) {
 // CHECK-NEXT:     t->i = i;
 // CHECK-NEXT:     double _d_res = *_d_p + _d_t->i;
 // CHECK-NEXT:     double res = *p + t->i;
-// CHECK-NEXT:     unsigned long _t2 = sizeof(double);
+// CHECK-NEXT:     unsigned {{(int|long)}} _t2 = sizeof(double);
 // CHECK-NEXT:     {{(clad::)?}}ValueAndPushforward<void *, void *> _t3 = clad::custom_derivatives::realloc_pushforward(p, 2 * _t2, _d_p, 0 * _t2 + 2 * sizeof(double));
 // CHECK-NEXT:     _d_p = (double *)_t3.pushforward;
 // CHECK-NEXT:     p = (double *)_t3.value;

test/Gradient/Pointers.C

@@ -363,7 +363,7 @@ double newAndDeletePointer(double i, double j) {
 // CHECK-NEXT:     double *p = new double(i);
 // CHECK-NEXT:     _d_q = new double(* _d_j);
 // CHECK-NEXT:     double *q = new double(j);
-// CHECK-NEXT:     _d_r = new double [2];
+// CHECK-NEXT:     _d_r = new double [2](/*implicit*/(double{{[ ]?}}[2])0);
 // CHECK-NEXT:     double *r = new double [2];
 // CHECK-NEXT:     _t0 = r[0];
 // CHECK-NEXT:     r[0] = i + j;
@@ -418,7 +418,7 @@ double structPointer (double x) {
 // CHECK: void structPointer_grad(double x, clad::array_ref<double> _d_x) {
 // CHECK-NEXT:     T *_d_t = 0;
 // CHECK-NEXT:     double _d_res = 0;
-// CHECK-NEXT:     _d_t = new T;
+// CHECK-NEXT:     _d_t = new T();
 // CHECK-NEXT:     T *t = new T({x, /*implicit*/(int)0});
 // CHECK-NEXT:     double res = t->x;
 // CHECK-NEXT:     goto _label0;
@@ -432,6 +432,7 @@ double structPointer (double x) {
 
 double cStyleMemoryAlloc(double x, size_t n) {
   T* t = (T*)malloc(n * sizeof(T));
+  memset(t, 0, n * sizeof(T));
   t->x = x;
   double* p = (double*)calloc(1, sizeof(double));
   *p = x;
@@ -457,6 +458,8 @@ double cStyleMemoryAlloc(double x, size_t n) {
 // CHECK-NEXT:     double _t5;
 // CHECK-NEXT:     _d_t = (T *)malloc(n * sizeof(T));
 // CHECK-NEXT:     T *t = (T *)malloc(n * sizeof(T));
+// CHECK-NEXT:     memset(_d_t, 0, n * sizeof(T));
+// CHECK-NEXT:     memset(t, 0, n * sizeof(T));
 // CHECK-NEXT:     _t0 = t->x;
 // CHECK-NEXT:     t->x = x;
 // CHECK-NEXT:     _d_p = (double *)calloc(1, sizeof(double));