Address a constexpr template point of instantiation issue

...that hits at least when building with Clang and --with-latest-c++ against
recent libc++ or MSVC standard library (where C++20 and esp. C++23 made more and
more class template member functions constexpr).  My understanding is that there
is some leeway at what point a compiler should instantiate such function
specializations, and Clang decides to instantiate constexpr ones early (cf.
<https://github.com/llvm/llvm-project/commit/242ad89a15d5466d166d47978bfff983d40ab511>
"C++11 half of r147023: In C++11, additionally eagerly instantiate:" and its "Do
not defer instantiations of constexpr functions" comment, and the discussion at
<https://discourse.llvm.org/t/point-of-instantiation-of-constexpr-function-template/65129>).

> In file included from basic/source/comp/codegen.cxx:21:
> In file included from include/basic/sberrors.hxx:23:
> In file included from include/vcl/errcode.hxx:23:
> In file included from include/rtl/ustring.hxx:34:
> In file included from ~/llvm/inst/bin/../include/c++/v1/ostream:168:
> ~/llvm/inst/bin/../include/c++/v1/__memory/unique_ptr.h:47:19: error: invalid application of 'sizeof' to an incomplete type 'SbiExprList'
>     static_assert(sizeof(_Tp) >= 0, "cannot delete an incomplete type");
>                   ^~~~~~~~~~~
> ~/llvm/inst/bin/../include/c++/v1/__memory/unique_ptr.h:281:7: note: in instantiation of member function 'std::default_delete<SbiExprList>::operator()' requested here
>       __ptr_.second()(__tmp);
>       ^
> ~/llvm/inst/bin/../include/c++/v1/__memory/unique_ptr.h:247:75: note: in instantiation of member function 'std::unique_ptr<SbiExprList>::reset' requested here
>   _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX23 ~unique_ptr() { reset(); }
>                                                                           ^
> basic/source/inc/expr.hxx:118:66: note: in instantiation of member function 'std::unique_ptr<SbiExprList>::~unique_ptr' requested here
>     SbiExprNode( const SbiSymDef&, SbxDataType, SbiExprListPtr = nullptr );
>                                                                  ^
> basic/source/inc/expr.hxx:30:7: note: forward declaration of 'SbiExprList'
> class SbiExprList;
>       ^

Change-Id: I3bde85164ae6b829b7c24d9645fd412ed3fd815d
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/141810
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

1 files changed, 19 insertions, 19 deletions

diff --git a/basic/source/inc/expr.hxx b/basic/source/inc/expr.hxx
index d5130c39dae9..d1e7fbcfa25d 100644
--- a/basic/source/inc/expr.hxx
+++ b/basic/source/inc/expr.hxx
@@ -85,6 +85,25 @@ enum RecursiveMode
     PREVENT_CALL
 };
 
+class SbiExprList final {            // class for parameters and dims
+    std::vector<std::unique_ptr<SbiExpression>> aData;
+    short nDim;
+    bool  bError;
+    bool  bBracket;
+public:
+    SbiExprList();
+    ~SbiExprList();
+    static SbiExprListPtr ParseParameters(SbiParser*, bool bStandaloneExpression = false, bool bPar = true);
+    static SbiExprListPtr ParseDimList( SbiParser* );
+    bool  IsBracket() const         { return bBracket;        }
+    bool  IsValid() const           { return !bError; }
+    short GetSize() const           { return aData.size();    }
+    short GetDims() const           { return nDim;            }
+    SbiExpression* Get( size_t );
+    void  Gen( SbiCodeGen& rGen);                    // code generation
+    void addExpression( std::unique_ptr<SbiExpression>&& pExpr  );
+};
+
 class SbiExprNode final {           // operators (and operands)
     friend class SbiExpression;
     friend class SbiConstExpression;
@@ -205,23 +224,4 @@ public:                             // numeric constant
     short GetShortValue();
 };
 
-class SbiExprList final {            // class for parameters and dims
-    std::vector<std::unique_ptr<SbiExpression>> aData;
-    short nDim;
-    bool  bError;
-    bool  bBracket;
-public:
-    SbiExprList();
-    ~SbiExprList();
-    static SbiExprListPtr ParseParameters(SbiParser*, bool bStandaloneExpression = false, bool bPar = true);
-    static SbiExprListPtr ParseDimList( SbiParser* );
-    bool  IsBracket() const         { return bBracket;        }
-    bool  IsValid() const           { return !bError; }
-    short GetSize() const           { return aData.size();    }
-    short GetDims() const           { return nDim;            }
-    SbiExpression* Get( size_t );
-    void  Gen( SbiCodeGen& rGen);                    // code generation
-    void addExpression( std::unique_ptr<SbiExpression>&& pExpr  );
-};
-
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */