<div dir="ltr"><div dir="ltr"><div dir="ltr">This also breaks building libc++ [1]. Reverted for now in r359858.</div><div dir="ltr"><br></div><div dir="ltr">1:<div><div>FAILED: obj/buildtools/third_party/libc++/libc++/new.o </div><div>../../third_party/llvm-build/Release+Asserts/bin/clang++ -MMD -MF obj/buildtools/third_party/libc++/libc++/new.o.d -D_LIBCPP_BUILDING_LIBRARY -DLIBCXX_BUILDING_LIBCXXABI -DUSE_UDEV -DUSE_AURA=1 -DUSE_GLIB=1 -DUSE_NSS_CERTS=1 -DUSE_X11=1 -DFULL_SAFE_BROWSING -DSAFE_BROWSING_CSD -DSAFE_BROWSING_DB_LOCAL -DCHROMIUM_BUILD -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_GNU_SOURCE -DCR_CLANG_REVISION=\"359857-0\" -DCOMPONENT_BUILD -D_LIBCPP_ABI_UNSTABLE -D_LIBCPP_ABI_VERSION=Cr -D_LIBCPP_ENABLE_NODISCARD -DCR_LIBCXX_REVISION=358423 -DCR_SYSROOT_HASH=e7c53f04bd88d29d075bfd1f62b073aeb69cbe09 -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -I../.. -Igen -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -funwind-tables -fPIC -B../../third_party/binutils/Linux_x64/Release/bin -pthread -fcolor-diagnostics -fmerge-all-constants -fcrash-diagnostics-dir=../../tools/clang/crashreports -Xclang -mllvm -Xclang -instcombine-lower-dbg-declare=0 -fcomplete-member-pointers -m64 -march=x86-64 -Wno-builtin-macro-redefined -D__DATE__= -D__TIME__= -D__TIMESTAMP__= -Xclang -fdebug-compilation-dir -Xclang . -no-canonical-prefixes -O2 -fno-ident -fdata-sections -ffunction-sections -fno-omit-frame-pointer -g2 -ggnu-pubnames -Wheader-hygiene -Wstring-conversion -Wtautological-overlap-compare -fstrict-aliasing -fPIC -Werror -Wall -Wno-unused-variable -Wno-missing-field-initializers -Wno-unused-parameter -Wno-c++11-narrowing -Wno-unneeded-internal-declaration -Wno-undefined-var-template -Wno-ignored-pragma-optimize -fvisibility=default -std=c++14 -nostdinc++ -isystem../../buildtools/third_party/libc++/trunk/include -isystem../../buildtools/third_party/libc++abi/trunk/include --sysroot=../../build/linux/debian_sid_amd64-sysroot -fexceptions -frtti -c ../../buildtools/third_party/libc++/trunk/src/new.cpp -o obj/buildtools/third_party/libc++/libc++/new.o</div><div>In file included from ../../buildtools/third_party/libc++/trunk/src/new.cpp:12:</div><div>../../buildtools/third_party/libc++/trunk/src/include/atomic_support.h:55:8: error: '__visibility__' attribute is ignored on a non-external symbol [-Werror,-Wignored-attributes]</div><div>inline _LIBCPP_INLINE_VISIBILITY</div><div> ^</div><div>../../buildtools/third_party/libc++/trunk/include/__config:820:35: note: expanded from macro '_LIBCPP_INLINE_VISIBILITY'</div><div>#define _LIBCPP_INLINE_VISIBILITY _LIBCPP_HIDE_FROM_ABI</div><div> ^</div><div>../../buildtools/third_party/libc++/trunk/include/__config:805:35: note: expanded from macro '_LIBCPP_HIDE_FROM_ABI'</div><div># define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION</div><div> ^</div><div>../../buildtools/third_party/libc++/trunk/include/__config:695:44: note: expanded from macro '_LIBCPP_HIDDEN'</div><div># define _LIBCPP_HIDDEN __attribute__ ((__visibility__("hidden")))</div><div> ^</div></div></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, May 2, 2019 at 10:35 PM via cfe-commits <<a href="mailto:cfe-commits@lists.llvm.org">cfe-commits@lists.llvm.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="auto"><div>Hi Richard,</div><div dir="auto"><br></div><div dir="auto">Thank you for the heads up. Feel free to revert, or I can when I can get back to a terminal. I'm not sure where the right place is to warn if using the linkage calculator here is too early, so it might take a bit of time for me to fix the patch.</div><div dir="auto"><br></div><div dir="auto">Thanks,</div><div dir="auto">Scott<br><div class="gmail_extra" dir="auto"><br><div class="gmail_quote">On May 2, 2019 9:42 PM, Richard Smith <<a href="mailto:richard@metafoo.co.uk" target="_blank">richard@metafoo.co.uk</a>> wrote:<br type="attribution"><blockquote class="gmail-m_-2075153019004579809quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><p dir="ltr">This will trigger computation and caching the linkage of the
<br>
declaration too early (before we actually know it) in some cases. For
<br>
instance, I believe this is causing a rejects-valid on:
<br>
<br>
typedef struct __attribute__((visibility("hidden"))) {} A;
<br>
<br>
... which we used to accept but now reject with:
<br>
<br>
<stdin>:1:31: warning: 'visibility' attribute is ignored on a
<br>
non-external symbol [-Wignored-attributes]
<br>
typedef struct __attribute__((visibility("hidden"))) {} A;
<br>
^
<br>
<stdin>:1:57: error: unsupported: typedef changes linkage of anonymous
<br>
type, but linkage was already computed
<br>
typedef struct __attribute__((visibility("hidden"))) {} A;
<br>
^
<br>
<stdin>:1:15: note: use a tag name here to establish linkage prior to definition
<br>
typedef struct __attribute__((visibility("hidden"))) {} A;
<br>
^
<br>
A
<br>
<br>
In addition to the error, note that the warning is wrong, because the
<br>
linkage was computed too early (before it was known).
<br>
<br>
On Thu, 2 May 2019 at 12:01, Scott Linder via cfe-commits
<br>
<<a href="mailto:cfe-commits@lists.llvm.org" target="_blank">cfe-commits@lists.llvm.org</a>> wrote:
<br>
>
<br>
> Author: scott.linder
<br>
> Date: Thu May 2 12:03:57 2019
<br>
> New Revision: 359814
<br>
>
<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project?rev=359814&view=rev" target="_blank">http://llvm.org/viewvc/llvm-project?rev=359814&view=rev</a>
<br>
> Log:
<br>
> [Sema] Emit warning for visibility attribute on internal-linkage declaration
<br>
>
<br>
> GCC warns on these cases, but we currently just silently ignore the attribute.
<br>
>
<br>
> Differential Revision: <a href="https://reviews.llvm.org/D61097" target="_blank">https://reviews.llvm.org/D61097</a>
<br>
>
<br>
> Modified:
<br>
> cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
<br>
> cfe/trunk/lib/Sema/SemaDeclAttr.cpp
<br>
> cfe/trunk/test/Sema/attr-visibility.c
<br>
> cfe/trunk/test/SemaCXX/ast-print.cpp
<br>
> cfe/trunk/test/SemaCXX/attr-visibility.cpp
<br>
>
<br>
> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=359814&r1=359813&r2=359814&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=359814&r1=359813&r2=359814&view=diff</a>
<br>
> ==============================================================================
<br>
> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
<br>
> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Thu May 2 12:03:57 2019
<br>
> @@ -2778,6 +2778,9 @@ def warn_attribute_ignored : Warning<"%0
<br>
> def warn_attribute_ignored_on_inline :
<br>
> Warning<"%0 attribute ignored on inline function">,
<br>
> InGroup<IgnoredAttributes>;
<br>
> +def warn_attribute_ignored_on_non_external :
<br>
> + Warning<"%0 attribute is ignored on a non-external symbol">,
<br>
> + InGroup<IgnoredAttributes>;
<br>
> def warn_nocf_check_attribute_ignored :
<br>
> Warning<"'nocf_check' attribute ignored; use -fcf-protection to enable the attribute">,
<br>
> InGroup<IgnoredAttributes>;
<br>
>
<br>
> Modified: cfe/trunk/lib/Sema/SemaDeclAttr.cpp
<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclAttr.cpp?rev=359814&r1=359813&r2=359814&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclAttr.cpp?rev=359814&r1=359813&r2=359814&view=diff</a>
<br>
> ==============================================================================
<br>
> --- cfe/trunk/lib/Sema/SemaDeclAttr.cpp (original)
<br>
> +++ cfe/trunk/lib/Sema/SemaDeclAttr.cpp Thu May 2 12:03:57 2019
<br>
> @@ -2615,6 +2615,14 @@ static void handleVisibilityAttr(Sema &S
<br>
> return;
<br>
> }
<br>
>
<br>
> + // Visibility attributes have no effect on symbols with internal linkage.
<br>
> + if (const auto *ND = dyn_cast<NamedDecl>(D)) {
<br>
> + if (!ND->isExternallyVisible())
<br>
> + S.Diag(AL.getRange().getBegin(),
<br>
> + diag::warn_attribute_ignored_on_non_external)
<br>
> + << AL;
<br>
> + }
<br>
> +
<br>
> // Check that the argument is a string literal.
<br>
> StringRef TypeStr;
<br>
> SourceLocation LiteralLoc;
<br>
>
<br>
> Modified: cfe/trunk/test/Sema/attr-visibility.c
<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/attr-visibility.c?rev=359814&r1=359813&r2=359814&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/attr-visibility.c?rev=359814&r1=359813&r2=359814&view=diff</a>
<br>
> ==============================================================================
<br>
> --- cfe/trunk/test/Sema/attr-visibility.c (original)
<br>
> +++ cfe/trunk/test/Sema/attr-visibility.c Thu May 2 12:03:57 2019
<br>
> @@ -26,3 +26,9 @@ typedef int __attribute__((visibility("d
<br>
> int x __attribute__((type_visibility("default"))); // expected-error {{'type_visibility' attribute only applies to types and namespaces}}
<br>
>
<br>
> int PR17105 __attribute__((visibility(hidden))); // expected-error {{'visibility' attribute requires a string}}
<br>
> +
<br>
> +static int test8 __attribute__((visibility("default"))); // expected-warning {{'visibility' attribute is ignored on a non-external symbol}}
<br>
> +static int test9 __attribute__((visibility("hidden"))); // expected-warning {{'visibility' attribute is ignored on a non-external symbol}}
<br>
> +static int test10 __attribute__((visibility("internal"))); // expected-warning {{'visibility' attribute is ignored on a non-external symbol}}
<br>
> +
<br>
> +static int test11() __attribute__((visibility("default"))); // expected-warning {{'visibility' attribute is ignored on a non-external symbol}}
<br>
>
<br>
> Modified: cfe/trunk/test/SemaCXX/ast-print.cpp
<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/ast-print.cpp?rev=359814&r1=359813&r2=359814&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/ast-print.cpp?rev=359814&r1=359813&r2=359814&view=diff</a>
<br>
> ==============================================================================
<br>
> --- cfe/trunk/test/SemaCXX/ast-print.cpp (original)
<br>
> +++ cfe/trunk/test/SemaCXX/ast-print.cpp Thu May 2 12:03:57 2019
<br>
> @@ -209,10 +209,8 @@ void test(int i) {
<br>
> }
<br>
> }
<br>
>
<br>
> -namespace {
<br>
> // CHECK: struct {{\[\[gnu::visibility\(\"hidden\"\)\]\]}} S;
<br>
> struct [[gnu::visibility("hidden")]] S;
<br>
> -}
<br>
>
<br>
> // CHECK: struct CXXFunctionalCastExprPrint {
<br>
> // CHECK-NEXT: } fce = CXXFunctionalCastExprPrint{};
<br>
>
<br>
> Modified: cfe/trunk/test/SemaCXX/attr-visibility.cpp
<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/attr-visibility.cpp?rev=359814&r1=359813&r2=359814&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/attr-visibility.cpp?rev=359814&r1=359813&r2=359814&view=diff</a>
<br>
> ==============================================================================
<br>
> --- cfe/trunk/test/SemaCXX/attr-visibility.cpp (original)
<br>
> +++ cfe/trunk/test/SemaCXX/attr-visibility.cpp Thu May 2 12:03:57 2019
<br>
> @@ -18,3 +18,9 @@ void foo<int>() {
<br>
> struct x3 {
<br>
> static int y;
<br>
> } __attribute((visibility("default"))); // expected-warning {{attribute 'visibility' after definition is ignored}}
<br>
> +
<br>
> +const int test4 __attribute__((visibility("default"))) = 0; // expected-warning {{'visibility' attribute is ignored on a non-external symbol}}
<br>
> +
<br>
> +namespace {
<br>
> + int test5 __attribute__((visibility("default"))); // expected-warning {{'visibility' attribute is ignored on a non-external symbol}}
<br>
> +};
<br>
>
<br>
>
<br>
> _______________________________________________
<br>
> cfe-commits mailing list
<br>
> <a href="mailto:cfe-commits@lists.llvm.org" target="_blank">cfe-commits@lists.llvm.org</a>
<br>
> <a href="https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits" target="_blank">https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits</a>
<br>
</p>
</blockquote></div><br></div></div></div>_______________________________________________<br>
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</blockquote></div>