'extern template' should mean that the relevant symbols are never emitted. But in this case we were assuming that DECL_EXTERNAL was already set on the variable, so we just needed to clear DECL_NOT_REALLY_EXTERN. Since DECL_EXTERNAL was not set, we emitted a definition of npos.
Tested x86_64-pc-linux-gnu, applying to trunk. gcc/cp/ChangeLog: PR c++/99066 * pt.c (mark_decl_instantiated): Set DECL_EXTERNAL. gcc/testsuite/ChangeLog: PR c++/99066 * g++.dg/cpp0x/extern_template-6.C: New test. --- gcc/cp/pt.c | 5 ++++- gcc/testsuite/g++.dg/cpp0x/extern_template-6.C | 17 +++++++++++++++++ 2 files changed, 21 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/extern_template-6.C diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 1d19a59dd62..396e622c4db 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -24204,7 +24204,10 @@ mark_decl_instantiated (tree result, int extern_p) DECL_COMDAT (result) = 0; if (extern_p) - DECL_NOT_REALLY_EXTERN (result) = 0; + { + DECL_EXTERNAL (result) = 1; + DECL_NOT_REALLY_EXTERN (result) = 0; + } else { mark_definable (result); diff --git a/gcc/testsuite/g++.dg/cpp0x/extern_template-6.C b/gcc/testsuite/g++.dg/cpp0x/extern_template-6.C new file mode 100644 index 00000000000..8aff3ae6b02 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/extern_template-6.C @@ -0,0 +1,17 @@ +// PR c++/99066 +// { dg-do compile { target c++11 } } + +template <typename a> struct basic_string { + static const int npos = 1; +}; +template <typename a> const int basic_string<a>::npos; + +struct e { template <bool> int f() const; }; + +template <bool> int e::f() const { + return basic_string<char>::npos; +} + +extern template class basic_string<char>; + +// { dg-final { scan-assembler-not "_ZN12basic_stringIcE4nposE" } } base-commit: a99a7b0afe9a1f6f866e25b8572856ae8c1d3f8d -- 2.27.0