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ecd5cae2d4
A forthcoming commit (tokens: properly define the "error" token kind)
revealed a problem in the C++ generated headers: they are not
self-contained. With this file:
%language "c++"
%define api.value.type variant
%code {
static int yylex (yy::parser::semantic_type *lvalp);
}
%token <int> X
%%
exp:
X { printf ("x\n"); }
;
%%
void
yy::parser::error (const std::string& m)
{
std::cerr << m << '\n';
}
static
int yylex (yy::parser::semantic_type *lvalp)
{
static int const input[] = {yy::parser::token::X, 0};
static int toknum = 0;
return input[toknum++];
}
int
main (int argc, char const* argv[])
{
yy::parser p;
return p.parse ();
}
the generated header fails to compile cleanly (foo.cc just #includes
the generated header):
$ clang++-mp-9.0 -c -Wundefined-func-template foo.cc
In file included from foo.cc:1:
bar.tab.hh:550:12: warning: instantiation of function 'yy::parser::basic_symbol<yy::parser::by_type>::basic_symbol' required here, but no definition is available
[-Wundefined-func-template]
struct symbol_type : basic_symbol<by_type>
^
bar.tab.hh:436:7: note: forward declaration of template entity is here
basic_symbol (basic_symbol&& that);
^
bar.tab.hh:550:12: note: add an explicit instantiation declaration to suppress this warning if 'yy::parser::basic_symbol<yy::parser::by_type>::basic_symbol' is explicitly instantiated
in another translation unit
struct symbol_type : basic_symbol<by_type>
^
1 warning generated.
* data/skeletons/c++.m4 (b4_public_types_define): Move the
implementation of the basic_symbol move-ctor to...
(b4_public_types_define): here, its declaration.
* tests/headers.at (Sane headers): Use a declared token so that the
corresponding token constructor is declared. Which triggers the
aforementioned issue.