Commit 46ca880f authored by Nico Weber's avatar Nico Weber
Browse files

clang: Don't assert on no_unique_address fields in @encode() 

Just skip (non-bitfield) zero-sized fields, like we do with empty bases.

The class->struct conversion in the test is because -std=c++20 else deletes some default methods
due to non-accessible base dtors otherwise.

As a side-effect of writing the test, I discovered that D76801 did an ABI breaking change of sorts
for Objective-C's @encode. But it's been in for a while, so I'm not sure if we want to row back on
that or now.

Fixes PR48048.

Differential Revision: https://reviews.llvm.org/D90622
parent c9e9cc3f

clang/lib/AST/ASTContext.cpp

+3 −1
Original line number Diff line number Diff line
@@ -7677,7 +7677,9 @@ void ASTContext::getObjCEncodingForStructureImpl(RecordDecl *RDecl, 
  }



  unsigned i = 0;

  for (auto *Field : RDecl->fields()) {

  for (FieldDecl *Field : RDecl->fields()) {

    if (!Field->isZeroLengthBitField(*this) && Field->isZeroSize(*this))

      continue;

    uint64_t offs = layout.getFieldOffset(i);

    FieldOrBaseOffsets.insert(FieldOrBaseOffsets.upper_bound(offs),

                              std::make_pair(offs, Field));

clang/test/CodeGenObjCXX/encode.mm

+23 −8
Original line number Diff line number Diff line 
// RUN: %clang_cc1 -std=gnu++98 %s -triple=x86_64-apple-darwin10 -emit-llvm -o - | FileCheck %s

// RUN: %clang_cc1 -Wno-objc-root-class -std=gnu++98 %s -triple=x86_64-apple-darwin10 -emit-llvm -o - | FileCheck --check-prefixes CHECK,CHECKCXX98 %s

// RUN: %clang_cc1 -Wno-objc-root-class -std=gnu++20 %s -triple=x86_64-apple-darwin10 -emit-llvm -o - | FileCheck --check-prefixes CHECK,CHECKCXX20 %s



// CHECK: v17@0:8{vector<float, float, float>=}16

// CHECK: {vector<float, float, float>=}
@@ -87,7 +88,9 @@ namespace rdar9357400 { 


  typedef vector< float,  fixed<4> > vector4f;



  // CHECK: @_ZN11rdar93574002ggE = constant [49 x i8] c"{vector<float, rdar9357400::fixed<4, -1> >=[4f]}\00"

  // FIXME: This difference is due to D76801. It was probably an unintentional change. Maybe we want to undo it?

  // CHECKCXX98: @_ZN11rdar93574002ggE = constant [49 x i8] c"{vector<float, rdar9357400::fixed<4, -1> >=[4f]}\00"

  // CHECKCXX20: @_ZN11rdar93574002ggE = constant [48 x i8] c"{vector<float, rdar9357400::fixed<4, -1>>=[4f]}\00"

  extern const char gg[] = @encode(vector4f);

}
@@ -170,21 +173,21 @@ extern const char g5[] = @encode(basic_string); 




// PR10990

class CefBase {

struct CefBase {

  virtual ~CefBase() {}

};

class CefBrowser : public virtual CefBase {};

class CefBrowserImpl : public CefBrowser {};

struct CefBrowser : public virtual CefBase {};

struct CefBrowserImpl : public CefBrowser {};

// CHECK: @g6 = constant [21 x i8] c"{CefBrowserImpl=^^?}\00"

extern const char g6[] = @encode(CefBrowserImpl);



// PR10990_2

class CefBase2 {

struct CefBase2 {

  virtual ~CefBase2() {}

  int i;

};

class CefBrowser2 : public virtual CefBase2 {};

class CefBrowserImpl2 : public CefBrowser2 {};

struct CefBrowser2 : public virtual CefBase2 {};

struct CefBrowserImpl2 : public CefBrowser2 {};

// CHECK: @g7 = constant [26 x i8] c"{CefBrowserImpl2=^^?^^?i}\00"

extern const char g7[] = @encode(CefBrowserImpl2);
@@ -245,3 +248,15 @@ const char *expand_struct() { 
  // CHECK: @{{.*}} = private unnamed_addr constant [13 x i8] c"{N={S<N>=@}}\00"

  return @encode(N);

}



#if __cplusplus >= 202002L

namespace PR48048 {

  struct F {};

  struct I {

    int m;

    [[no_unique_address]] F n;

  };

  // CHECKCXX20: @_ZN7PR480481xE = constant [6 x i8] c"{I=i}\00"

  extern const char x[] = @encode(I);

}

#endif