Add IRGen APIs to fetch ctor/dtor helper functions for non-trivial structs.

Patch by Tony Allevato!

llvm-svn: 358132

clang/include/clang/CodeGen/CodeGenABITypes.h

@@ -30,6 +30,7 @@
 namespace llvm {
   class DataLayout;
   class Module;
+  class Function;
   class FunctionType;
   class Type;
 }
@@ -83,6 +84,59 @@ llvm::Type *convertTypeForMemory(CodeGenModule &CGM, QualType T);
 unsigned getLLVMFieldNumber(CodeGenModule &CGM,
                             const RecordDecl *RD, const FieldDecl *FD);
 
+/// Returns the default constructor for a C struct with non-trivially copyable
+/// fields, generating it if necessary. The returned function uses the `cdecl`
+/// calling convention, returns void, and takes a single argument that is a
+/// pointer to the address of the struct.
+llvm::Function *getNonTrivialCStructDefaultConstructor(CodeGenModule &GCM,
+                                                       CharUnits DstAlignment,
+                                                       bool IsVolatile,
+                                                       QualType QT);
+
+/// Returns the copy constructor for a C struct with non-trivially copyable
+/// fields, generating it if necessary. The returned function uses the `cdecl`
+/// calling convention, returns void, and takes two arguments: pointers to the
+/// addresses of the destination and source structs, respectively.
+llvm::Function *getNonTrivialCStructCopyConstructor(CodeGenModule &CGM,
+                                                    CharUnits DstAlignment,
+                                                    CharUnits SrcAlignment,
+                                                    bool IsVolatile,
+                                                    QualType QT);
+
+/// Returns the move constructor for a C struct with non-trivially copyable
+/// fields, generating it if necessary. The returned function uses the `cdecl`
+/// calling convention, returns void, and takes two arguments: pointers to the
+/// addresses of the destination and source structs, respectively.
+llvm::Function *getNonTrivialCStructMoveConstructor(CodeGenModule &CGM,
+                                                    CharUnits DstAlignment,
+                                                    CharUnits SrcAlignment,
+                                                    bool IsVolatile,
+                                                    QualType QT);
+
+/// Returns the copy assignment operator for a C struct with non-trivially
+/// copyable fields, generating it if necessary. The returned function uses the
+/// `cdecl` calling convention, returns void, and takes two arguments: pointers
+/// to the addresses of the destination and source structs, respectively.
+llvm::Function *getNonTrivialCStructCopyAssignmentOperator(
+    CodeGenModule &CGM, CharUnits DstAlignment, CharUnits SrcAlignment,
+    bool IsVolatile, QualType QT);
+
+/// Return the move assignment operator for a C struct with non-trivially
+/// copyable fields, generating it if necessary. The returned function uses the
+/// `cdecl` calling convention, returns void, and takes two arguments: pointers
+/// to the addresses of the destination and source structs, respectively.
+llvm::Function *getNonTrivialCStructMoveAssignmentOperator(
+    CodeGenModule &CGM, CharUnits DstAlignment, CharUnits SrcAlignment,
+    bool IsVolatile, QualType QT);
+
+/// Returns the destructor for a C struct with non-trivially copyable fields,
+/// generating it if necessary. The returned function uses the `cdecl` calling
+/// convention, returns void, and takes a single argument that is a pointer to
+/// the address of the struct.
+llvm::Function *getNonTrivialCStructDestructor(CodeGenModule &CGM,
+                                               CharUnits DstAlignment,
+                                               bool IsVolatile, QualType QT);
+
 }  // end namespace CodeGen
 }  // end namespace clang
 

clang/lib/CodeGen/CGNonTrivialStruct.cpp

@@ -14,6 +14,7 @@
 #include "CodeGenFunction.h"
 #include "CodeGenModule.h"
 #include "clang/AST/NonTrivialTypeVisitor.h"
+#include "clang/CodeGen/CodeGenABITypes.h"
 #include "llvm/Support/ScopedPrinter.h"
 #include <array>
 
@@ -822,6 +823,29 @@ static void callSpecialFunction(G &&Gen, StringRef FuncName, QualType QT,
   Gen.callFunc(FuncName, QT, Addrs, CGF);
 }
 
+template <size_t N> std::array<Address, N> createNullAddressArray();
+
+template <> std::array<Address, 1> createNullAddressArray() {
+  return std::array<Address, 1>({Address(nullptr, CharUnits::Zero())});
+}
+
+template <> std::array<Address, 2> createNullAddressArray() {
+  return std::array<Address, 2>({Address(nullptr, CharUnits::Zero()),
+                                 Address(nullptr, CharUnits::Zero())});
+}
+
+template <class G, size_t N>
+static llvm::Function *
+getSpecialFunction(G &&Gen, StringRef FuncName, QualType QT, bool IsVolatile,
+                   std::array<CharUnits, N> Alignments, CodeGenModule &CGM) {
+  QT = IsVolatile ? QT.withVolatile() : QT;
+  // The following call requires an array of addresses as arguments, but doesn't
+  // actually use them (it overwrites them with the addresses of the arguments
+  // of the created function).
+  return Gen.getFunction(FuncName, QT, createNullAddressArray<N>(), Alignments,
+                         CGM);
+}
+
 // Functions to emit calls to the special functions of a non-trivial C struct.
 void CodeGenFunction::callCStructDefaultConstructor(LValue Dst) {
   bool IsVolatile = Dst.isVolatile();
@@ -907,3 +931,69 @@ void CodeGenFunction::callCStructMoveAssignmentOperator(LValue Dst, LValue Src
   callSpecialFunction(GenMoveAssignment(getContext()), FuncName, QT, IsVolatile,
                       *this, std::array<Address, 2>({{DstPtr, SrcPtr}}));
 }
+
+llvm::Function *clang::CodeGen::getNonTrivialCStructDefaultConstructor(
+    CodeGenModule &CGM, CharUnits DstAlignment, bool IsVolatile, QualType QT) {
+  ASTContext &Ctx = CGM.getContext();
+  GenDefaultInitializeFuncName GenName(DstAlignment, Ctx);
+  std::string FuncName = GenName.getName(QT, IsVolatile);
+  return getSpecialFunction(GenDefaultInitialize(Ctx), FuncName, QT, IsVolatile,
+                            std::array<CharUnits, 1>({{DstAlignment}}), CGM);
+}
+
+llvm::Function *clang::CodeGen::getNonTrivialCStructCopyConstructor(
+    CodeGenModule &CGM, CharUnits DstAlignment, CharUnits SrcAlignment,
+    bool IsVolatile, QualType QT) {
+  ASTContext &Ctx = CGM.getContext();
+  GenBinaryFuncName<false> GenName("__copy_constructor_", DstAlignment,
+                                   SrcAlignment, Ctx);
+  std::string FuncName = GenName.getName(QT, IsVolatile);
+  return getSpecialFunction(
+      GenCopyConstructor(Ctx), FuncName, QT, IsVolatile,
+      std::array<CharUnits, 2>({{DstAlignment, SrcAlignment}}), CGM);
+}
+
+llvm::Function *clang::CodeGen::getNonTrivialCStructMoveConstructor(
+    CodeGenModule &CGM, CharUnits DstAlignment, CharUnits SrcAlignment,
+    bool IsVolatile, QualType QT) {
+  ASTContext &Ctx = CGM.getContext();
+  GenBinaryFuncName<true> GenName("__move_constructor_", DstAlignment,
+                                  SrcAlignment, Ctx);
+  std::string FuncName = GenName.getName(QT, IsVolatile);
+  return getSpecialFunction(
+      GenMoveConstructor(Ctx), FuncName, QT, IsVolatile,
+      std::array<CharUnits, 2>({{DstAlignment, SrcAlignment}}), CGM);
+}
+
+llvm::Function *clang::CodeGen::getNonTrivialCStructCopyAssignmentOperator(
+    CodeGenModule &CGM, CharUnits DstAlignment, CharUnits SrcAlignment,
+    bool IsVolatile, QualType QT) {
+  ASTContext &Ctx = CGM.getContext();
+  GenBinaryFuncName<false> GenName("__copy_assignment_", DstAlignment,
+                                   SrcAlignment, Ctx);
+  std::string FuncName = GenName.getName(QT, IsVolatile);
+  return getSpecialFunction(
+      GenCopyAssignment(Ctx), FuncName, QT, IsVolatile,
+      std::array<CharUnits, 2>({{DstAlignment, SrcAlignment}}), CGM);
+}
+
+llvm::Function *clang::CodeGen::getNonTrivialCStructMoveAssignmentOperator(
+    CodeGenModule &CGM, CharUnits DstAlignment, CharUnits SrcAlignment,
+    bool IsVolatile, QualType QT) {
+  ASTContext &Ctx = CGM.getContext();
+  GenBinaryFuncName<true> GenName("__move_assignment_", DstAlignment,
+                                  SrcAlignment, Ctx);
+  std::string FuncName = GenName.getName(QT, IsVolatile);
+  return getSpecialFunction(
+      GenMoveAssignment(Ctx), FuncName, QT, IsVolatile,
+      std::array<CharUnits, 2>({{DstAlignment, SrcAlignment}}), CGM);
+}
+
+llvm::Function *clang::CodeGen::getNonTrivialCStructDestructor(
+    CodeGenModule &CGM, CharUnits DstAlignment, bool IsVolatile, QualType QT) {
+  ASTContext &Ctx = CGM.getContext();
+  GenDestructorFuncName GenName("__destructor_", DstAlignment, Ctx);
+  std::string FuncName = GenName.getName(QT, IsVolatile);
+  return getSpecialFunction(GenDestructor(Ctx), FuncName, QT, IsVolatile,
+                            std::array<CharUnits, 1>({{DstAlignment}}), CGM);
+}