Changeset 225896 in webkit

Timestamp:

Dec 14, 2017 12:17:56 AM (6 years ago)

Author:

Yusuke Suzuki

Message:

REGRESSION(r225769): Build errors with constexpr std::tie on older gcc
​https://bugs.webkit.org/show_bug.cgi?id=180692

Reviewed by Carlos Garcia Campos.

Source/WebCore:

• platform/graphics/FontSelectionAlgorithm.h:

(WebCore::FontSelectionRange::operator== const):
(WebCore::FontSelectionRequest::tied const):
(WebCore::FontSelectionCapabilities::tied const):
(WebCore::FontSelectionSpecifiedCapabilities:: const):

Source/WTF:

Due to libstdc++'s bug[1], std::tie is not annotated with constexpr in libstdc++ 5.
This patch adds WTF::tie for a work around. Since we do not want to
include <tuple> in StdLibExtras.h, we define this function for all
the compilers.

[1]: ​https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65978

• wtf/StdLibExtras.h:

Location:

trunk/Source

Files:

• WTF/ChangeLog (modified) (1 diff)
• WTF/wtf/StdLibExtras.h (modified) (1 diff)
• WebCore/ChangeLog (modified) (1 diff)
• WebCore/platform/graphics/FontSelectionAlgorithm.h (modified) (4 diffs)

trunk/Source/WTF/ChangeLog

@@ +1 @@
+2017-12-12  Yusuke Suzuki  <utatane.tea@gmail.com>
+
+        REGRESSION(r225769): Build errors with constexpr std::tie on older gcc
+        https://bugs.webkit.org/show_bug.cgi?id=180692
+
+        Reviewed by Carlos Garcia Campos.
+
+        Due to libstdc++'s bug[1], std::tie is not annotated with constexpr in libstdc++ 5.
+        This patch adds WTF::tie for a work around. Since we do not want to
+        include <tuple> in StdLibExtras.h, we define this function for all
+        the compilers.
+
+        [1]: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65978
+
+        * wtf/StdLibExtras.h:
+
 2017-12-13  Mark Lam  <mark.lam@apple.com>
 

trunk/Source/WTF/wtf/StdLibExtras.h

@@ -446 +446 @@
 }
 
+// libstdc++5 does not have constexpr std::tie. Since we cannot redefine std::tie with constexpr, we define WTF::tie instead.
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65978
+template <class ...Args>
+inline constexpr std::tuple<Args&...> tie(Args&... values) noexcept
+{
+    return std::tuple<Args&...>(values...);
+}
+
 } // namespace WTF
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2017-12-12  Yusuke Suzuki  <utatane.tea@gmail.com>
+
+        REGRESSION(r225769): Build errors with constexpr std::tie on older gcc
+        https://bugs.webkit.org/show_bug.cgi?id=180692
+
+        Reviewed by Carlos Garcia Campos.
+
+        * platform/graphics/FontSelectionAlgorithm.h:
+        (WebCore::FontSelectionRange::operator== const):
+        (WebCore::FontSelectionRequest::tied const):
+        (WebCore::FontSelectionCapabilities::tied const):
+        (WebCore::FontSelectionSpecifiedCapabilities:: const):
+
 2017-12-13  Daniel Bates  <dabates@apple.com>
 

trunk/Source/WebCore/platform/graphics/FontSelectionAlgorithm.h

@@ -284 +284 @@
     constexpr bool operator==(const FontSelectionRange& other) const
     {
-        return std::tie(minimum, maximum) == std::tie(other.minimum, other.maximum);
+        return WTF::tie(minimum, maximum) == WTF::tie(other.minimum, other.maximum);
     }
 
@@ -335 +335 @@
     constexpr std::tuple<Value, Value, Value> tied() const
     {
-        return std::tie(weight, width, slope);
+        return WTF::tie(weight, width, slope);
     }
 
@@ -372 +372 @@
     constexpr std::tuple<Range, Range, Range> tied() const
     {
-        return std::tie(weight, width, slope);
+        return WTF::tie(weight, width, slope);
     }
 
@@ -420 +420 @@
     constexpr std::tuple<OptionalRange&, OptionalRange&, OptionalRange&> tied()
     {
-        return std::tie(weight, width, slope);
+        return WTF::tie(weight, width, slope);
     }
 
     constexpr std::tuple<const OptionalRange&, const OptionalRange&, const OptionalRange&> tied() const
     {
-        return std::tie(weight, width, slope);
+        return WTF::tie(weight, width, slope);
     }