John Reagan via llvm-dev
2019-Feb-27 21:06 UTC
[llvm-dev] Need template help building clang 3.4.2 on OpenVMS so we can bootstrap
Summary: I need some help building an older clang. I'm getting errors
with casts inside of clang/include/clang/AST/DeclBase.h. I've hit the
limit of my template programming knowledge (not that deep to begin with)
and am looking for workarounds/suggestions. I'm not even sure if it is
the Casting.h support itself or the usage of it inside clang's DeclBase.h
Background: We're porting OpenVMS to x86 using LLVM. Our build
environment is OpenVMS Itanium using an old EDG/Intel C++ compiler
(allegedly C++03). I've been able to build LLVM 3.4.2 just fine (with
only minor tweaks) and we're using that backend with our legacy
frontends. I'm now needing to also build the matching clang 3.4.2 so I
can start the bootstrapping process to get us to a newer version on our
native systems.
Should clang 3.4.2 be buildable by a C++03 compiler like LLVM is?
That's my understanding. Or is it something in LLVM's Support/Casting.h
that only clang exploits?
Any template experts to help me resolve these just so we can bootstrap?
We're looking to use clang/LLVM 3.4.2 to build 3.8.0 as the next step
(we don't have CMake on OpenVMS Itanium due to old C++ compiler)
Thanks for helping!
John
On my first build attempt (we have a bash shell, make, etc. on OpenVMS),
I got errors compiling ParseAST.cpp. Including "incomplete type is not
allowed" and "explicit specialization of class "..." must
precede its
first use. Which I resolved with adding an explicit #include
"clang/AST/DeclBase.h" in ParseAST.cpp prior to the other
#include's.
Then that yielded
return To::classof(&Val);
...............^
%CXX-E-NOTMEMBER, class "clang::Decl" has no member
"classof"
detected during:
instantiation of "bool llvm::isa_impl<To, From,
Enabler>::doit(const From &) [with To=clang::Decl,
From=llvm::remove_pointer<llvm::simplify_type<clang::Decl
Context *const>::NonConstSimpleType>::type,
Enabler=void]" at line 98 of
"LLVM$:[REAGAN.llvm-342.include.llvm.Support]Casting.h;1"
instantiation of "bool llvm::isa_impl_cl<To, const From
*>::doit(const From *) [with To=clang::Decl,
From=llvm::remove_pointer<llvm::simplify_type<clang::Decl
Context *const>::NonConstSimpleType>::type]" at
line 124
of
"LLVM$:[REAGAN.llvm-342.include.llvm.Support]Casting.h;1"
instantiation of "bool llvm::isa_impl_wrap<To, FromTy,
FromTy>::doit(const FromTy &) [with To=clang::Decl,
FromTy=llvm::simplify_type<clang::DeclContext
*const>::SimpleType]" at line 114 of
"LLVM$:[REAGAN.llvm-342.include.llvm.Support]Casting.h;1"
instantiation of "bool llvm::isa_impl_wrap<To, From,
SimpleFrom>::doit(const From &) [with
To=clang::Decl,
From=clang::DeclContext *const,
SimpleFrom=llvm::simplify_type<clang::DeclContext
*const>::SimpleType]" at line 135 of
"LLVM$:[REAGAN.llvm-342.include.llvm.Support]Casting.h;1"
instantiation of "bool llvm::isa<X,Y>(const Y &)
[with
X=clang::Decl, Y=clang::DeclContext *]" at line 239
of
"LLVM$:[REAGAN.llvm-342.include.llvm.Support]Casting.h;1"
instantiation of "llvm::cast_retty<X, Y *>::ret_type
llvm::cast<X,Y>(Y *) [with X=clang::Decl,
Y=clang::DeclContext]" at line 1064 of
"LLVM$:[REAGAN.llvm-342.tools.clang.include.clang.AST]Dec
lBase.h;1"
at line number 55 in file
LLVM$:[REAGAN.llvm-342.include.llvm.Support]Casting.h;1
The offending source in DeclBase.h is
/// getParent - Returns the containing DeclContext.
DeclContext *getParent() {
return cast<Decl>(this)->getDeclContext();
-----------^^^^^^^^^^^^
}
const DeclContext *getParent() const {
return const_cast<DeclContext*>(this)->getParent();
}
So I guessed (perhaps wrongly?) that my host compiler wanted to see a
classof() for clang::Decl so I added this to DeclBase.h in Decl's public
section which matches what is done for DeclContext's classof().
static bool classof(const Decl *D) { return true; }
but that ended up with:
return To::classof(&Val);
.......................^
%CXX-E-INCOMPATIBLEPRM, argument of type "const
llvm::remove_pointer<llvm::simplify_type<clang::DeclContext
*const>::NonConstSimpleType>::type *" is incompatible with
parameter
of type "const clang::Decl *"
detected during:
instantiation of "bool llvm::isa_impl<To, From,
Enabler>::doit(const From &) [with To=clang::Decl,
From=llvm::remove_pointer<llvm::simplify_type<clang::Decl
Context *const>::NonConstSimpleType>::type,
Enabler=void]" at line 98 of
"LLVM$:[REAGAN.llvm-342.include.llvm.Support]Casting.h;1"
instantiation of "bool llvm::isa_impl_cl<To, const From
*>::doit(const From *) [with To=clang::Decl,
From=llvm::remove_pointer<llvm::simplify_type<clang::Decl
Context *const>::NonConstSimpleType>::type]" at
line 124
of
"LLVM$:[REAGAN.llvm-342.include.llvm.Support]Casting.h;1"
instantiation of "bool llvm::isa_impl_wrap<To, FromTy,
FromTy>::doit(const FromTy &) [with To=clang::Decl,
FromTy=llvm::simplify_type<clang::DeclContext
*const>::SimpleType]" at line 114 of
"LLVM$:[REAGAN.llvm-342.include.llvm.Support]Casting.h;1"
instantiation of "bool llvm::isa_impl_wrap<To, From,
SimpleFrom>::doit(const From &) [with
To=clang::Decl,
From=clang::DeclContext *const,
SimpleFrom=llvm::simplify_type<clang::DeclContext
*const>::SimpleType]" at line 135 of
"LLVM$:[REAGAN.llvm-342.include.llvm.Support]Casting.h;1"
instantiation of "bool llvm::isa<X,Y>(const Y &)
[with
X=clang::Decl, Y=clang::DeclContext *]" at line 239
of
"LLVM$:[REAGAN.llvm-342.include.llvm.Support]Casting.h;1"
instantiation of "llvm::cast_retty<X, Y *>::ret_type
llvm::cast<X,Y>(Y *) [with X=clang::Decl,
Y=clang::DeclContext]" at line 1073 of
"LLVM$:[REAGAN.llvm-342.tools.clang.include.clang.AST]Dec
lBase.h;2"
at line number 55 in file
LLVM$:[REAGAN.llvm-342.include.llvm.Support]Casting.h;1
and still lots of other errors of the form
LEAF_TYPE(Enum)
^
%CXX-E-NOCONVERSIONFUN, no suitable conversion function from
"const clang::EnumType" to "const clang::EnumType
*" exists
at line number 115 in file
LLVM$:[REAGAN.llvm-342.tools.clang.include.clang.AST]TypeNodes.def;1
and more "incomplete type is not allowed" errors.
And why is there very different form of non-const vs const for things
like getParent() and getLexicalParent()?
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: OpenPGP digital signature
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20190227/8e61df94/attachment.sig>