PKGBUILDs/extra/libreoffice-still/adapt-o3tl-span-to-newer-libstdc++.patch

From 99354a1c4b6f56871d50d07421ba1773fce0d928 Mon Sep 17 00:00:00 2001
From: Stephan Bergmann <sbergman@redhat.com>
Date: Fri, 6 Dec 2019 16:36:01 +0100
Subject: [PATCH 1/2] Adapt o3tl::span to P1872R0

..."span should have size_type, not index_type"
(<http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1872r0.pdf>), as
implemented by libc++ since <https://github.com/llvm/llvm-project/commit/
1466335cf4b2854a0be1defcf279fe50772bad6f> "[libc++][P1872] span should have
size_type, not index_type."

All uses of index_type had been added to mitigate the previous std::span change
from signed (ptrdiff_t) to unsigned (size_t) index_type, see
6ef8420fdbf8dff16de13147c5ab833bc5e01121 "Adapt o3tl::span to updated C++2a
std::span".  There is no easy solution to transparently support all three
std::span variants currently out there (signed index_type, unsigned index_type,
unsigned size_type), without causing compilation failures due to
CPPUNIT_ASSERT_EQUAL with arguments of different types, or compiler warnings
about mixed signed/unsigned comparisons.  So rule out the oldest std::span
variant (signed index_type) in configure.ac (so that o3tl::span will use its
own hand-rolled code in that case) and simplify the uses of index_type to
std::size_t (as had already been mentioned in
6ef8420fdbf8dff16de13147c5ab833bc5e01121).

Change-Id: I6ddf424ffb7941da3f69ad66fd29ecd35f09afae
Reviewed-on: https://gerrit.libreoffice.org/84652
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

(cherry picked from commit 8e6865188242bccb3d8aa857ddc990d72a058d3d)
---
 config_host/config_global.h.in   |  3 +++
 configure.ac                     | 16 ++++++++++++++++
 include/o3tl/span.hxx            | 14 ++++++++------
 o3tl/qa/test-span.cxx            |  7 ++++---
 sfx2/source/control/dispatch.cxx |  3 ++-
 5 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/config_host/config_global.h.in b/config_host/config_global.h.in
index 2e986fbe24b6..0b44ad05373e 100644
--- a/config_host/config_global.h.in
+++ b/config_host/config_global.h.in
@@ -24,6 +24,9 @@ Any change in this header will cause a rebuild of almost everything.
 /* Guaranteed copy elision (C++17), __cpp_guaranteed_copy_elision (C++2a): */
 #define HAVE_CPP_GUARANTEED_COPY_ELISION 0
 
+// Useable C++2a <span>:
+#define HAVE_CPP_SPAN 0
+
 /* GCC bug <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87150> "move ctor wrongly chosen in return
    stmt (derived vs. base)": */
 #define HAVE_GCC_BUG_87150 0
diff --git a/configure.ac b/configure.ac
index 052782189056..704fff55a7ec 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6760,6 +6760,22 @@ AC_COMPILE_IFELSE([AC_LANG_SOURCE([
 CXXFLAGS=$save_CXXFLAGS
 AC_LANG_POP([C++])
 
+AC_MSG_CHECKING([whether $CXX supports C++2a <span> with unsigned size_type])
+AC_LANG_PUSH([C++])
+save_CXXFLAGS=$CXXFLAGS
+CXXFLAGS="$CXXFLAGS $CXXFLAGS_CXX11"
+AC_COMPILE_IFELSE([AC_LANG_SOURCE([
+        #include <span>
+        #include <type_traits>
+        // Don't check size_type directly, as it was called index_type before P1872R0:
+        void f(std::span<int> s) { static_assert(std::is_unsigned_v<decltype(s.size())>); };
+    ])], [
+        AC_DEFINE([HAVE_CPP_SPAN],[1])
+        AC_MSG_RESULT([yes])
+    ], [AC_MSG_RESULT([no])])
+CXXFLAGS=$save_CXXFLAGS
+AC_LANG_POP([C++])
+
 AC_MSG_CHECKING([whether $CXX has GCC bug 87150])
 AC_LANG_PUSH([C++])
 save_CXXFLAGS=$CXXFLAGS
diff --git a/include/o3tl/span.hxx b/include/o3tl/span.hxx
index 1618b86df897..b19d2d847ac7 100644
--- a/include/o3tl/span.hxx
+++ b/include/o3tl/span.hxx
@@ -12,7 +12,9 @@
 
 #include <sal/config.h>
 
-#if __has_include(<span>)
+#include <config_global.h>
+
+#if HAVE_CPP_SPAN
 
 #include <span>
 
@@ -40,7 +42,7 @@ public:
     using iterator = pointer;
     using const_reverse_iterator = std::reverse_iterator<const_iterator>;
     using reverse_iterator = std::reverse_iterator<iterator>;
-    using index_type = std::size_t;
+    using size_type = std::size_t;
     using difference_type = std::ptrdiff_t;
 
     constexpr span() noexcept : data_(nullptr), size_(0) {}
@@ -48,7 +50,7 @@ public:
     template<std::size_t N>
     constexpr span (T (&a)[N]) noexcept : data_(a), size_(N) {}
 
-    constexpr span (T *a, index_type len) noexcept
+    constexpr span (T *a, size_type len) noexcept
         : data_(a), size_(len)
     {
         // not terribly sure about this, might need to strengthen it
@@ -72,9 +74,9 @@ public:
     { return rbegin(); }
     constexpr const_reverse_iterator crend() const noexcept { return rend(); }
 
-    constexpr index_type size() const noexcept { return size_; }
+    constexpr size_type size() const noexcept { return size_; }
 
-    constexpr reference operator [](index_type pos) const {
+    constexpr reference operator [](size_type pos) const {
         assert(pos < size());
         return data_[pos];
     }
@@ -83,7 +85,7 @@ public:
 
 private:
     pointer    data_;
-    index_type size_;
+    size_type size_;
 };
 
 } // namespace o3tl
diff --git a/o3tl/qa/test-span.cxx b/o3tl/qa/test-span.cxx
index 7ec67fa7fd91..3cb78ace1db2 100644
--- a/o3tl/qa/test-span.cxx
+++ b/o3tl/qa/test-span.cxx
@@ -9,6 +9,7 @@
 
 #include <sal/config.h>
 
+#include <cstddef>
 #include <utility>
 
 #include <cppunit/TestAssert.h>
@@ -42,7 +43,7 @@ private:
         CPPUNIT_ASSERT_EQUAL(3, *v.crbegin());
         CPPUNIT_ASSERT_EQUAL(
             o3tl::span<int>::difference_type(3), v.crend() - v.crbegin());
-        CPPUNIT_ASSERT_EQUAL(o3tl::span<int>::index_type(3), v.size());
+        CPPUNIT_ASSERT_EQUAL(std::size_t(3), v.size());
         CPPUNIT_ASSERT(!v.empty());
         CPPUNIT_ASSERT_EQUAL(2, v[1]);
         CPPUNIT_ASSERT_EQUAL(1, *v.data());
@@ -52,8 +53,8 @@ private:
             o3tl::span<int const> v1( d1 );
             o3tl::span<int const> v2( d2 );
             std::swap(v1, v2);
-            CPPUNIT_ASSERT_EQUAL(o3tl::span<int>::index_type(4), v1.size());
-            CPPUNIT_ASSERT_EQUAL(o3tl::span<int>::index_type(2), v2.size());
+            CPPUNIT_ASSERT_EQUAL(std::size_t(4), v1.size());
+            CPPUNIT_ASSERT_EQUAL(std::size_t(2), v2.size());
         }
     }
 };
diff --git a/sfx2/source/control/dispatch.cxx b/sfx2/source/control/dispatch.cxx
index 702e6064f157..c3f3ad60c10c 100644
--- a/sfx2/source/control/dispatch.cxx
+++ b/sfx2/source/control/dispatch.cxx
@@ -20,6 +20,7 @@
 #include <config_features.h>
 
 #include <algorithm>
+#include <cstddef>
 #include <deque>
 #include <vector>
 
@@ -1547,7 +1548,7 @@ void SfxDispatcher::SetSlotFilter(SfxSlotFilterState nEnable,
 {
 #ifdef DBG_UTIL
     // Check Array
-    for ( o3tl::span<sal_uInt16 const>::index_type n = 1; n < pSIDs.size(); ++n )
+    for ( std::size_t n = 1; n < pSIDs.size(); ++n )
         DBG_ASSERT( pSIDs[n] > pSIDs[n-1], "SetSlotFilter: SIDs not sorted" );
 #endif
 

From 3bf38cc5f6d61f43509d8dc500479d66b8233bab Mon Sep 17 00:00:00 2001
From: Stephan Bergmann <sbergman@redhat.com>
Date: Sat, 22 Feb 2020 17:29:15 +0100
Subject: [PATCH 2/2] Adapt o3tl::span to removal of std::span::cbegin et al

<https://cplusplus.github.io/LWG/issue3320> "span::cbegin/cend methods produce
different results than std::[ranges::]cbegin/cend", as implemented now in
<https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;a=commit;
h=247f410b83797a1840573840cc2a539ef9d7f96b> "libstdc++: Remove std::span::cbegin
and std::span::cend (LWG 3320)".

Turns out we only used the removed member functions in o3tl/qa/test-span.cxx.

Change-Id: I6c73797594b4e0e753a88840033d54961e271df5
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/89261
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

(cherry picked from commit 6fbfad6b00e8c35346ee59cd32a0d7ccc0d8c19c)
---
 include/o3tl/span.hxx | 7 -------
 o3tl/qa/test-span.cxx | 6 ------
 2 files changed, 13 deletions(-)

diff --git a/include/o3tl/span.hxx b/include/o3tl/span.hxx
index b19d2d847ac7..8af8ba846b65 100644
--- a/include/o3tl/span.hxx
+++ b/include/o3tl/span.hxx
@@ -62,18 +62,11 @@ public:
     constexpr iterator begin() const noexcept { return data_; }
     constexpr iterator end() const noexcept { return begin() + size(); }
 
-    constexpr const_iterator cbegin() const noexcept { return begin(); }
-    constexpr const_iterator cend() const noexcept { return end(); }
-
     reverse_iterator rbegin() const noexcept
     { return reverse_iterator(end()); }
     reverse_iterator rend() const noexcept
     { return reverse_iterator(begin()); }
 
-    constexpr const_reverse_iterator crbegin() const noexcept
-    { return rbegin(); }
-    constexpr const_reverse_iterator crend() const noexcept { return rend(); }
-
     constexpr size_type size() const noexcept { return size_; }
 
     constexpr reference operator [](size_type pos) const {
diff --git a/o3tl/qa/test-span.cxx b/o3tl/qa/test-span.cxx
index 3cb78ace1db2..26eedfc21938 100644
--- a/o3tl/qa/test-span.cxx
+++ b/o3tl/qa/test-span.cxx
@@ -34,15 +34,9 @@ private:
         CPPUNIT_ASSERT_EQUAL(1, *v.begin());
         CPPUNIT_ASSERT_EQUAL(
             o3tl::span<int>::difference_type(3), v.end() - v.begin());
-        CPPUNIT_ASSERT_EQUAL(1, *v.cbegin());
-        CPPUNIT_ASSERT_EQUAL(
-            o3tl::span<int>::difference_type(3), v.cend() - v.cbegin());
         CPPUNIT_ASSERT_EQUAL(3, *v.rbegin());
         CPPUNIT_ASSERT_EQUAL(
             o3tl::span<int>::difference_type(3), v.rend() - v.rbegin());
-        CPPUNIT_ASSERT_EQUAL(3, *v.crbegin());
-        CPPUNIT_ASSERT_EQUAL(
-            o3tl::span<int>::difference_type(3), v.crend() - v.crbegin());
         CPPUNIT_ASSERT_EQUAL(std::size_t(3), v.size());
         CPPUNIT_ASSERT(!v.empty());
         CPPUNIT_ASSERT_EQUAL(2, v[1]);