[cfe-dev] Problems compiling clang 3.7.0 with gcc 4.9

[Craig Rodrigues via cfe-dev]

Hi,

I recently tried to compile clang 3.7.0 with gcc 4.9
under FreeBSD.  I reproduced the problem with gcc 5.0.

The full build error is here:
https://jenkins.freebsd.org/job/FreeBSD_HEAD_amd64_gcc4.9/617/console

The error of interest is:


--- Module.o ---
/usr/local/bin/x86_64-portbld-freebsd10.1-g++
-isystem
/builds/FreeBSD_HEAD_amd64_gcc4.9/obj/builds/FreeBSD_HEAD_amd64_gcc4.9/tmp/usr/include
-L/builds/FreeBSD_HEAD_amd64_gcc4.9/obj/builds/FreeBSD_HEAD_amd64_gcc4.9/tmp/usr/lib
--sysroot=/builds/FreeBSD_HEAD_amd64_gcc4.9/obj/builds/FreeBSD_HEAD_amd64_gcc4.9/tmp
-B/usr/local/x86_64-freebsd/bin/
-I/builds/FreeBSD_HEAD_amd64_gcc4.9/obj/builds/FreeBSD_HEAD_amd64_gcc4.9/tmp/usr/include/c++/v1
-std=gnu++11
-L/builds/FreeBSD_HEAD_amd64_gcc4.9/obj/builds/FreeBSD_HEAD_amd64_gcc4.9/tmp/../lib/libc++
--sysroot=/builds/FreeBSD_HEAD_amd64_gcc4.9/obj/builds/FreeBSD_HEAD_amd64_gcc4.9/tmp
-B/usr/local/x86_64-freebsd/bin/  -O2 -pipe
-I/builds/FreeBSD_HEAD_amd64_gcc4.9/lib/clang/libclangbasic/../../../contrib/llvm/include
-I/builds/FreeBSD_HEAD_amd64_gcc4.9/lib/clang/libclangbasic/../../../contrib/llvm/tools/clang/include
-I/builds/FreeBSD_HEAD_amd64_gcc4.9/lib/clang/libclangbasic/../../../contrib/llvm/tools/clang/lib/Basic
-I.
-I/builds/FreeBSD_HEAD_amd64_gcc4.9/lib/clang/libclangbasic/../../../contrib/llvm/../../lib/clang/include
-DLLVM_ON_UNIX -DLLVM_ON_FREEBSD -D__STDC_LIMIT_MACROS
-D__STDC_CONSTANT_MACROS -DCLANG_ENABLE_ARCMT
-DCLANG_ENABLE_STATIC_ANALYZER -fno-strict-aliasing
-DLLVM_DEFAULT_TARGET_TRIPLE=\"x86_64-unknown-freebsd11.0\"
-DLLVM_HOST_TRIPLE=\"x86_64-unknown-freebsd11.0\" -DDEFAULT_SYSROOT=\"\"
-fstack-protector-strong  -std=c++11 -fno-exceptions -fno-rtti  -c
/builds/FreeBSD_HEAD_amd64_gcc4.9/lib/clang/libclangbasic/../../../contrib/llvm/tools/clang/lib/Basic/Module.cpp
-o Module.o
In file included from
/builds/FreeBSD_HEAD_amd64_gcc4.9/lib/clang/libclangbasic/../../../contrib/llvm/tools/clang/include/clang/Basic/SourceLocation.h:22:0,
                 from

/builds/FreeBSD_HEAD_amd64_gcc4.9/lib/clang/libclangbasic/../../../contrib/llvm/tools/clang/include/clang/Basic/Module.h:18,
                 from

/builds/FreeBSD_HEAD_amd64_gcc4.9/lib/clang/libclangbasic/../../../contrib/llvm/tools/clang/lib/Basic/Module.cpp:15:
/builds/FreeBSD_HEAD_amd64_gcc4.9/obj/builds/FreeBSD_HEAD_amd64_gcc4.9/tmp/usr/include/c++/v1/functional:1322:17:
error: '_Rp std::__1::__function::__base<_Rp(_ArgTypes
...)>::operator()(_ArgTypes&& ...) [with _Rp = void; _ArgTypes =
{clang::VisibleModuleSet::setVisible(clang::Module*, clang::SourceLocation,
clang::VisibleModuleSet::VisibleCallback,
clang::VisibleModuleSet::ConflictCallback)::Visiting}]', declared
using local type 'clang::VisibleModuleSet::setVisible(clang::Module*,
clang::SourceLocation, clang::VisibleModuleSet::VisibleCallback,
clang::VisibleModuleSet::ConflictCallback)::Visiting', is used but
never defined [-fpermissive]
     virtual _Rp operator()(_ArgTypes&& ...) = 0;
                 ^
*** [Module.o] Error code 1


I investigated this problem, and found that I could
completely eliminate the compilation failure
by moving "struct Visiting" outside of VisibleModuleSet::setVisible()

with this patch:



Index: tools/clang/lib/Basic/Module.cpp
===================================================================
--- tools/clang/lib/Basic/Module.cpp    (revision 288962)
+++ tools/clang/lib/Basic/Module.cpp    (working copy)
@@ -480,6 +480,12 @@
   print(llvm::errs());
 }

+struct Visiting {
+    Module *M;
+    Visiting *ExportedBy;
+};
+
+
 void VisibleModuleSet::setVisible(Module *M, SourceLocation Loc,
                                   VisibleCallback Vis, ConflictCallback Cb) {
   if (isVisible(M))
@@ -487,11 +493,6 @@

   ++Generation;

-  struct Visiting {
-    Module *M;
-    Visiting *ExportedBy;
-  };
-
   std::function<void(Visiting)> VisitModule = [&](Visiting V) {
     // Modules that aren't available cannot be made visible.
     if (!V.M->isAvailable())




Is this a valid fix, or is there a bug in gcc that

needs to be reported to them?

I don't know C++ enough to know.

Thanks.


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