Constify interfaces. NFC

include/clad/Differentiator/CladUtils.h

@@ -126,7 +126,7 @@ namespace clad {
     /// such declaration context is found, then returns `nullptr`.
     clang::DeclContext* FindDeclContext(clang::Sema& semaRef,
                                         clang::DeclContext* DC1,
-                                        clang::DeclContext* DC2);
+                                        const clang::DeclContext* DC2);
 
     /// Finds the qualified name `name` in the declaration context `DC`.
     ///

include/clad/Differentiator/DerivativeBuilder.h

@@ -117,7 +117,7 @@ namespace clad {
     /// null otherwise.
     clang::Expr* BuildCallToCustomDerivativeOrNumericalDiff(
         const std::string& Name, llvm::SmallVectorImpl<clang::Expr*>& CallArgs,
-        clang::Scope* S, clang::DeclContext* originalFnDC,
+        clang::Scope* S, const clang::DeclContext* originalFnDC,
         bool forCustomDerv = true, bool namespaceShouldExist = true,
         clang::Expr* CUDAExecConfig = nullptr);
     bool noOverloadExists(clang::Expr* UnresolvedLookup,
@@ -150,7 +150,7 @@ namespace clad {
     /// \returns The lookup result of the custom derivative or numerical
     /// differentiation function.
     clang::LookupResult LookupCustomDerivativeOrNumericalDiff(
-        const std::string& Name, clang::DeclContext* originalFnDC,
+        const std::string& Name, const clang::DeclContext* originalFnDC,
         clang::CXXScopeSpec& SS, bool forCustomDerv = true,
         bool namespaceShouldExist = true);
 
@@ -160,7 +160,7 @@ namespace clad {
     /// \returns The custom derivative function if found, nullptr otherwise.
     clang::FunctionDecl*
     LookupCustomDerivativeDecl(const std::string& Name,
-                               clang::DeclContext* originalFnDC,
+                               const clang::DeclContext* originalFnDC,
                                clang::QualType functionType);
 
   public:

lib/Differentiator/BaseForwardModeVisitor.cpp

@@ -1227,7 +1227,7 @@ StmtDiff BaseForwardModeVisitor::VisitCallExpr(const CallExpr* CE) {
       clad::utils::ComputeEffectiveFnName(FD) + GetPushForwardFunctionSuffix();
   callDiff = m_Builder.BuildCallToCustomDerivativeOrNumericalDiff(
       customPushforward, customDerivativeArgs, getCurrentScope(),
-      const_cast<DeclContext*>(FD->getDeclContext()));
+      FD->getDeclContext());
   // Custom derivative templates can be written in a
   // general way that works for both vectorized and non-vectorized
   // modes. We have to also look for the pushforward with the regular name.
@@ -1236,7 +1236,7 @@ StmtDiff BaseForwardModeVisitor::VisitCallExpr(const CallExpr* CE) {
         clad::utils::ComputeEffectiveFnName(FD) + "_pushforward";
     callDiff = m_Builder.BuildCallToCustomDerivativeOrNumericalDiff(
         customPushforward, customDerivativeArgs, getCurrentScope(),
-        const_cast<DeclContext*>(FD->getDeclContext()));
+        FD->getDeclContext());
   }
   if (!isLambda) {
     // Check if it is a recursive call.
@@ -2315,11 +2315,9 @@ clang::Expr* BaseForwardModeVisitor::BuildCustomDerivativeConstructorPFCall(
   std::string customPushforwardName =
       clad::utils::ComputeEffectiveFnName(CE->getConstructor()) +
       GetPushForwardFunctionSuffix();
-  // FIXME: We should not use const_cast to get the decl context here.
-  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast)
   Expr* pushforwardCall = m_Builder.BuildCallToCustomDerivativeOrNumericalDiff(
       customPushforwardName, customPushforwardArgs, getCurrentScope(),
-      const_cast<DeclContext*>(CE->getConstructor()->getDeclContext()));
+      CE->getConstructor()->getDeclContext());
   return pushforwardCall;
 }
 } // end namespace clad

lib/Differentiator/CladUtils.cpp

@@ -187,8 +187,8 @@ namespace clad {
     }
 
     DeclContext* FindDeclContext(clang::Sema& semaRef, clang::DeclContext* DC1,
-                                 clang::DeclContext* DC2) {
-      llvm::SmallVector<clang::DeclContext*, 4> contexts;
+                                 const clang::DeclContext* DC2) {
+      llvm::SmallVector<const clang::DeclContext*, 4> contexts;
       assert((isa<NamespaceDecl>(DC1) || isa<TranslationUnitDecl>(DC1)) &&
              "DC1 can only be extended if it is a "
              "namespace or translation unit decl.");
@@ -240,7 +240,7 @@ namespace clad {
       }
       DeclContext* DC = DC1;
       for (int i = contexts.size() - 1; i >= 0; --i) {
-        NamespaceDecl* ND = cast<NamespaceDecl>(contexts[i]);
+        const auto* ND = cast<NamespaceDecl>(contexts[i]);
         if (ND->getIdentifier())
           DC = LookupNSD(semaRef, ND->getIdentifier()->getName(),
                          /*shouldExist=*/false, DC1);

lib/Differentiator/DerivativeBuilder.cpp

@@ -30,6 +30,7 @@
 #include "llvm/Support/SaveAndRestore.h"
 
 #include <algorithm>
+#include <string>
 
 #include "clad/Differentiator/CladUtils.h"
 #include "clad/Differentiator/Compatibility.h"
@@ -167,7 +168,7 @@ static void registerDerivative(FunctionDecl* derivedFD, Sema& semaRef) {
   }
 
   LookupResult DerivativeBuilder::LookupCustomDerivativeOrNumericalDiff(
-      const std::string& Name, clang::DeclContext* originalFnDC,
+      const std::string& Name, const clang::DeclContext* originalFnDC,
       CXXScopeSpec& SS, bool forCustomDerv /*=true*/,
       bool namespaceShouldExist /*=true*/) {
 
@@ -222,7 +223,7 @@ static void registerDerivative(FunctionDecl* derivedFD, Sema& semaRef) {
   }
 
   FunctionDecl* DerivativeBuilder::LookupCustomDerivativeDecl(
-      const std::string& Name, clang::DeclContext* originalFnDC,
+      const std::string& Name, const clang::DeclContext* originalFnDC,
       QualType functionType) {
     CXXScopeSpec SS;
     LookupResult R =
@@ -246,7 +247,7 @@ static void registerDerivative(FunctionDecl* derivedFD, Sema& semaRef) {
 
   Expr* DerivativeBuilder::BuildCallToCustomDerivativeOrNumericalDiff(
       const std::string& Name, llvm::SmallVectorImpl<Expr*>& CallArgs,
-      clang::Scope* S, clang::DeclContext* originalFnDC,
+      clang::Scope* S, const clang::DeclContext* originalFnDC,
       bool forCustomDerv /*=true*/, bool namespaceShouldExist /*=true*/,
       Expr* CUDAExecConfig /*=nullptr*/) {
     CXXScopeSpec SS;

lib/Differentiator/ReverseModeVisitor.cpp

@@ -266,7 +266,6 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
         originalFnType->getExtProtoInfo());
 
     // Check if the function is already declared as a custom derivative.
-    // FIXME: We should not use const_cast to get the decl context here.
     // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast)
     auto* DC = const_cast<DeclContext*>(m_DiffReq->getDeclContext());
     if (FunctionDecl* customDerivative = m_Builder.LookupCustomDerivativeDecl(
@@ -1828,7 +1827,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
       OverloadedDerivedFn =
           m_Builder.BuildCallToCustomDerivativeOrNumericalDiff(
               customPushforward, pushforwardCallArgs, getCurrentScope(),
-              const_cast<DeclContext*>(FD->getDeclContext()),
+              FD->getDeclContext(),
               /*forCustomDerv=*/true, /*namespaceShouldExist=*/true,
               CUDAExecConfig);
       if (OverloadedDerivedFn)
@@ -1932,7 +1931,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
       OverloadedDerivedFn =
           m_Builder.BuildCallToCustomDerivativeOrNumericalDiff(
               customPullback, pullbackCallArgs, getCurrentScope(),
-              const_cast<DeclContext*>(FD->getDeclContext()),
+              FD->getDeclContext(),
               /*forCustomDerv=*/true, /*namespaceShouldExist=*/true,
               CUDAExecConfig);
       if (baseDiff.getExpr())
@@ -4248,8 +4247,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
     if (Expr* customPullbackCall =
             m_Builder.BuildCallToCustomDerivativeOrNumericalDiff(
                 customPullbackName, pullbackArgs, getCurrentScope(),
-                const_cast<DeclContext*>(
-                    CE->getConstructor()->getDeclContext()))) {
+                CE->getConstructor()->getDeclContext())) {
       curRevBlock.insert(it, customPullbackCall);
       if (m_TrackConstructorPullbackInfo) {
         setConstructorPullbackCallInfo(llvm::cast<CallExpr>(customPullbackCall),
@@ -4585,8 +4583,7 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
     args.append(derivedArgs.begin(), derivedArgs.end());
     Expr* customForwPassCE =
         m_Builder.BuildCallToCustomDerivativeOrNumericalDiff(
-            forwPassFnName, args, getCurrentScope(),
-            const_cast<DeclContext*>(FD->getDeclContext()));
+            forwPassFnName, args, getCurrentScope(), FD->getDeclContext());
     return customForwPassCE;
   }