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-rw-r--r--support/extractpdfmark/m4/ax_cxx_compile_stdcxx.m479
1 files changed, 70 insertions, 9 deletions
diff --git a/support/extractpdfmark/m4/ax_cxx_compile_stdcxx.m4 b/support/extractpdfmark/m4/ax_cxx_compile_stdcxx.m4
index 9e9eaedaaa..a3d964c699 100644
--- a/support/extractpdfmark/m4/ax_cxx_compile_stdcxx.m4
+++ b/support/extractpdfmark/m4/ax_cxx_compile_stdcxx.m4
@@ -10,13 +10,13 @@
#
# Check for baseline language coverage in the compiler for the specified
# version of the C++ standard. If necessary, add switches to CXX and
-# CXXCPP to enable support. VERSION may be '11' (for the C++11 standard)
-# or '14' (for the C++14 standard).
+# CXXCPP to enable support. VERSION may be '11', '14', '17', or '20' for
+# the respective C++ standard version.
#
# The second argument, if specified, indicates whether you insist on an
# extended mode (e.g. -std=gnu++11) or a strict conformance mode (e.g.
# -std=c++11). If neither is specified, you get whatever works, with
-# preference for an extended mode.
+# preference for no added switch, and then for an extended mode.
#
# The third argument, if specified 'mandatory' or if left unspecified,
# indicates that baseline support for the specified C++ standard is
@@ -34,13 +34,16 @@
# Copyright (c) 2015 Paul Norman <penorman@mac.com>
# Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu>
# Copyright (c) 2016, 2018 Krzesimir Nowak <qdlacz@gmail.com>
+# Copyright (c) 2019 Enji Cooper <yaneurabeya@gmail.com>
+# Copyright (c) 2020 Jason Merrill <jason@redhat.com>
+# Copyright (c) 2021 Jörn Heusipp <osmanx@problemloesungsmaschine.de>
#
# Copying and distribution of this file, with or without modification, are
# permitted in any medium without royalty provided the copyright notice
# and this notice are preserved. This file is offered as-is, without any
# warranty.
-#serial 10
+#serial 15
dnl This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro
dnl (serial version number 13).
@@ -49,6 +52,7 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
m4_if([$1], [11], [ax_cxx_compile_alternatives="11 0x"],
[$1], [14], [ax_cxx_compile_alternatives="14 1y"],
[$1], [17], [ax_cxx_compile_alternatives="17 1z"],
+ [$1], [20], [ax_cxx_compile_alternatives="20"],
[m4_fatal([invalid first argument `$1' to AX_CXX_COMPILE_STDCXX])])dnl
m4_if([$2], [], [],
[$2], [ext], [],
@@ -61,6 +65,16 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
AC_LANG_PUSH([C++])dnl
ac_success=no
+ m4_if([$2], [], [dnl
+ AC_CACHE_CHECK(whether $CXX supports C++$1 features by default,
+ ax_cv_cxx_compile_cxx$1,
+ [AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])],
+ [ax_cv_cxx_compile_cxx$1=yes],
+ [ax_cv_cxx_compile_cxx$1=no])])
+ if test x$ax_cv_cxx_compile_cxx$1 = xyes; then
+ ac_success=yes
+ fi])
+
m4_if([$2], [noext], [], [dnl
if test x$ac_success = xno; then
for alternative in ${ax_cxx_compile_alternatives}; do
@@ -139,7 +153,6 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_11],
_AX_CXX_COMPILE_STDCXX_testbody_new_in_11
)
-
dnl Test body for checking C++14 support
m4_define([_AX_CXX_COMPILE_STDCXX_testbody_14],
@@ -147,12 +160,24 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_14],
_AX_CXX_COMPILE_STDCXX_testbody_new_in_14
)
+dnl Test body for checking C++17 support
+
m4_define([_AX_CXX_COMPILE_STDCXX_testbody_17],
_AX_CXX_COMPILE_STDCXX_testbody_new_in_11
_AX_CXX_COMPILE_STDCXX_testbody_new_in_14
_AX_CXX_COMPILE_STDCXX_testbody_new_in_17
)
+dnl Test body for checking C++20 support
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_20],
+ _AX_CXX_COMPILE_STDCXX_testbody_new_in_11
+ _AX_CXX_COMPILE_STDCXX_testbody_new_in_14
+ _AX_CXX_COMPILE_STDCXX_testbody_new_in_17
+ _AX_CXX_COMPILE_STDCXX_testbody_new_in_20
+)
+
+
dnl Tests for new features in C++11
m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_11], [[
@@ -164,7 +189,11 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_11], [[
#error "This is not a C++ compiler"
-#elif __cplusplus < 201103L
+// MSVC always sets __cplusplus to 199711L in older versions; newer versions
+// only set it correctly if /Zc:__cplusplus is specified as well as a
+// /std:c++NN switch:
+// https://devblogs.microsoft.com/cppblog/msvc-now-correctly-reports-__cplusplus/
+#elif __cplusplus < 201103L && !defined _MSC_VER
#error "This is not a C++11 compiler"
@@ -189,11 +218,13 @@ namespace cxx11
struct Base
{
+ virtual ~Base() {}
virtual void f() {}
};
struct Derived : public Base
{
+ virtual ~Derived() override {}
virtual void f() override {}
};
@@ -453,7 +484,7 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_14], [[
#error "This is not a C++ compiler"
-#elif __cplusplus < 201402L
+#elif __cplusplus < 201402L && !defined _MSC_VER
#error "This is not a C++14 compiler"
@@ -577,7 +608,7 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_17], [[
#error "This is not a C++ compiler"
-#elif __cplusplus < 201703L
+#elif __cplusplus < 201703L && !defined _MSC_VER
#error "This is not a C++17 compiler"
@@ -943,6 +974,36 @@ namespace cxx17
} // namespace cxx17
-#endif // __cplusplus < 201703L
+#endif // __cplusplus < 201703L && !defined _MSC_VER
+
+]])
+
+
+dnl Tests for new features in C++20
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_20], [[
+
+#ifndef __cplusplus
+
+#error "This is not a C++ compiler"
+
+#elif __cplusplus < 202002L && !defined _MSC_VER
+
+#error "This is not a C++20 compiler"
+
+#else
+
+#include <version>
+
+namespace cxx20
+{
+
+// As C++20 supports feature test macros in the standard, there is no
+// immediate need to actually test for feature availability on the
+// Autoconf side.
+
+} // namespace cxx20
+
+#endif // __cplusplus < 202002L && !defined _MSC_VER
]])