[Libreoffice-commits] core.git: compilerplugins/clang configure.ac include/tools

[Stephan Bergmann (via logerrit)]

 compilerplugins/clang/test/doubleconvert.cxx |    2 +-
 configure.ac                                 |   10 +++++++++-
 include/tools/color.hxx                      |   10 ++++++++--
 3 files changed, 18 insertions(+), 4 deletions(-)

New commits:
commit af34108d90bbbce90cf00c4b23961787599c7fa5
Author:     Stephan Bergmann <sbergman at redhat.com>
AuthorDate: Wed Jan 20 11:29:18 2021 +0100
Commit:     Stephan Bergmann <sbergman at redhat.com>
CommitDate: Thu Jan 21 07:58:02 2021 +0100

    Use C++20 consteval for the Color(sal_uInt32) ctor
    
    ...to make it more obvious that, since 63a68064bb33f180b8a231f7524d99405d910226
    "make the Color constructors explicitly specify transparency", it should only be
    called when the argument is known at compile-time to have no transparency/alpha
    channel.
    
    (This revealed a GCC bug causing bogus
    
    > xmloff/source/chart/ColorPropertySet.cxx: In constructor ‘xmloff::chart::ColorPropertySet::ColorPropertySet(Color)’:
    > xmloff/source/chart/ColorPropertySet.cxx:81:9: error: ‘this’ is not a constant expression
    >    81 |         m_nDefaultColor( 0x0099ccff )  // blue 8
    >       |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    
    so in configure.ac suppress HAVE_CPP_CONSTEVAL when the compiler is found
    broken.)
    
    Change-Id: I68df7bd5fbd9b2dcf2243b5a4bde4064d3d665fd
    Reviewed-on: https://gerrit.libreoffice.org/c/core/+/109697
    Tested-by: Jenkins
    Reviewed-by: Stephan Bergmann <sbergman at redhat.com>

diff --git a/compilerplugins/clang/test/doubleconvert.cxx b/compilerplugins/clang/test/doubleconvert.cxx
index 17bd49aa4f6f..12763d966c21 100644
--- a/compilerplugins/clang/test/doubleconvert.cxx
+++ b/compilerplugins/clang/test/doubleconvert.cxx
@@ -12,7 +12,7 @@
 
 int main()
 {
-    Color col1;
+    constexpr Color col1;
     Color col2;
     col2 = sal_Int32(
         col1); // expected-error at -1 {{redundant double conversion [loplugin:doubleconvert]}}
diff --git a/configure.ac b/configure.ac
index 458a4857b378..f60c1ae5a199 100644
--- a/configure.ac
+++ b/configure.ac
@@ -7189,7 +7189,9 @@ AC_SUBST([HAVE_GCC_FNO_SIZED_DEALLOCATION])
 
 AC_MSG_CHECKING([whether $CXX_BASE supports a working C++20 consteval])
 dnl ...that does not suffer from <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96994> "Missing code
-dnl from consteval constructor initializing const variable":
+dnl from consteval constructor initializing const variable" or
+dnl <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98752> "wrong 'error: ‘this’ is not a constant
+dnl expression' with consteval constructor":
 AC_LANG_PUSH([C++])
 save_CXXFLAGS=$CXXFLAGS
 CXXFLAGS="$CXXFLAGS $CXXFLAGS_CXX11"
@@ -7199,6 +7201,12 @@ AC_RUN_IFELSE([AC_LANG_PROGRAM([
             int i = 0;
         };
         S const s;
+
+        struct S1 { consteval S1(int) {} };
+        struct S2 {
+            S1 x;
+            S2(): x(0) {}
+        };
     ], [
         return (s.i == 1) ? 0 : 1;
     ])], [
diff --git a/include/tools/color.hxx b/include/tools/color.hxx
index 209ed34169a8..cd472fd472ee 100644
--- a/include/tools/color.hxx
+++ b/include/tools/color.hxx
@@ -22,6 +22,7 @@
 #include <sal/types.h>
 #include <tools/toolsdllapi.h>
 #include <com/sun/star/uno/Any.hxx>
+#include <config_global.h>
 #include <basegfx/color/bcolor.hxx>
 #include <osl/endian.h>
 
@@ -72,7 +73,12 @@ public:
         : mValue(0) // black
     {}
 
-    constexpr Color(const sal_uInt32 nColor)
+#if HAVE_CPP_CONSTEVAL
+    consteval
+#else
+    constexpr
+#endif
+    Color(const sal_uInt32 nColor)
         : mValue(nColor)
     {
         assert(nColor <= 0xffffff && "don't pass transparency to this constructor, use the Color(ColorTransparencyTag,...) or Color(ColorAlphaTag,...) constructor to make it explicit");
@@ -211,7 +217,7 @@ public:
       */
     Color GetRGBColor() const
     {
-        return mValue & 0x00FFFFFF;
+        return {R, G, B};
     }
 
     /* Comparison and operators */