记录一下编译qt-everywhere-src-5.15.2中qtwebengine遇到的问题。
第一、在windows上用vs2019编译qtwebengine的时候需要patch其中的3个文件，否则会报错。错误看起来好像是：
ninja: build stopped: subcommand failed. NMAKE : fatal error U1077: 'call' : return code '0x1' NMAKE : fatal error U1077: '"...\nmake.exe"' : return code '0x2' Stop. NMAKE : fatal error U1077: '(' : return code '0x2' Stop. NMAKE : fatal error U1077: 'cd' : return code '0x2' Stop. NMAKE : fatal error U1077: 'cd' : return code '0x2' Stop
但实际问题是代码在vs2019的cl里编译出错了，C4244警告被当成错误报出：
FAILED: obj/third_party/angle/angle_common/mathutil.obj ... ../../3rdparty/chromium/third_party/angle/src/common/mathutil.cpp(75): error C4244: '=': conversion from 'double' to 'float', possible loss of data ../../3rdparty/chromium/third_party/angle/src/common/mathutil.cpp(77): error C4244: '=': conversion from 'double' to 'float', possible loss of data ../../3rdparty/chromium/third_party/angle/src/common/mathutil.cpp(79): error C4244: '=': conversion from 'double' to 'float', possible loss of data
所以需要打个补丁，手动修改也行吧，代码量很少：https://codereview.qt-project.org/c/qt/qtwebengine-chromium/+/321741
From 138a7203f16cf356e9d4dac697920a22437014b0 Mon Sep 17 00:00:00 2001 From: Peter Varga <pvarga@inf.u-szeged.hu> Date: Fri, 13 Nov 2020 11:09:23 +0100 Subject: [PATCH] Fix build with msvc2019 16.8.0 Fixes: QTBUG-88708 Change-Id: I3554ceec0437801b4861f68edd504d01fc01cf93 Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io> --- diff --git a/chromium/third_party/angle/src/common/mathutil.cpp b/chromium/third_party/angle/src/common/mathutil.cpp index 306cde1..d4f1034 100644 --- a/chromium/third_party/angle/src/common/mathutil.cpp +++ b/chromium/third_party/angle/src/common/mathutil.cpp @@ -72,11 +72,11 @@ const RGB9E5Data *inputData = reinterpret_cast<const RGB9E5Data *>(&input); *red = - inputData->R * pow(2.0f, (int)inputData->E - g_sharedexp_bias - g_sharedexp_mantissabits); + inputData->R * (float)pow(2.0f, (int)inputData->E - g_sharedexp_bias - g_sharedexp_mantissabits); *green = - inputData->G * pow(2.0f, (int)inputData->E - g_sharedexp_bias - g_sharedexp_mantissabits); + inputData->G * (float)pow(2.0f, (int)inputData->E - g_sharedexp_bias - g_sharedexp_mantissabits); *blue = - inputData->B * pow(2.0f, (int)inputData->E - g_sharedexp_bias - g_sharedexp_mantissabits); + inputData->B * (float)pow(2.0f, (int)inputData->E - g_sharedexp_bias - g_sharedexp_mantissabits); } } // namespace gl diff --git a/chromium/third_party/blink/renderer/platform/graphics/lab_color_space.h b/chromium/third_party/blink/renderer/platform/graphics/lab_color_space.h index 78c316e..136c796 100644 --- a/chromium/third_party/blink/renderer/platform/graphics/lab_color_space.h +++ b/chromium/third_party/blink/renderer/platform/graphics/lab_color_space.h @@ -130,7 +130,7 @@ // https://en.wikipedia.org/wiki/CIELAB_color_space#Forward_transformation. FloatPoint3D toXYZ(const FloatPoint3D& lab) const { auto invf = [](float x) { - return x > kSigma ? pow(x, 3) : 3 * kSigma2 * (x - 4.0f / 29.0f); + return x > kSigma ? (float)pow(x, 3) : 3 * kSigma2 * (x - 4.0f / 29.0f); }; FloatPoint3D v = {clamp(lab.X(), 0.0f, 100.0f), diff --git a/chromium/third_party/perfetto/src/trace_processor/timestamped_trace_piece.h b/chromium/third_party/perfetto/src/trace_processor/timestamped_trace_piece.h index 02363d0..8860287 100644 --- a/chromium/third_party/perfetto/src/trace_processor/timestamped_trace_piece.h +++ b/chromium/third_party/perfetto/src/trace_processor/timestamped_trace_piece.h @@ -198,6 +198,20 @@ return *this; } +#if PERFETTO_BUILDFLAG(PERFETTO_COMPILER_MSVC) + TimestampedTracePiece& operator=(TimestampedTracePiece&& ttp) const + { + if (this != &ttp) { + // First invoke the destructor and then invoke the move constructor + // inline via placement-new to implement move-assignment. + this->~TimestampedTracePiece(); + new (const_cast<TimestampedTracePiece*>(this)) TimestampedTracePiece(std::move(ttp)); + } + + return const_cast<TimestampedTracePiece&>(*this); + } +#endif // PERFETTO_BUILDFLAG(PERFETTO_COMPILER_MSVC) + ~TimestampedTracePiece() { switch (type) { case Type::kInvalid:
第二、在Windows上编译blink的pch也会有些问题，报错找不到头文件：
qt5/qtwebengine/src/3rdparty/chromium/third_party/WebKit/Source/core/win/Precompile-core.cpp: fatal error C1083: Cannot open include file: '../../../../../qt5srcgit/qt5/qtwebengine/src/3rdparty/chromium/third_party/WebKit/Source/core/Precompile-core.h': No such file or directory
需要patch两个文件blink/renderer/platform/BUILD.gn 和 blink/renderer/core/BUILD.gn
--- qtwebengine/src/3rdparty/chromium/third_party/blink/renderer/platform/BUILD.gn +++ qtwebengine/src/3rdparty/chromium/third_party/blink/renderer/platform/BUILD.gn @@ -204,7 +204,7 @@ config("blink_platform_pch") { if (enable_precompiled_headers) { - if (is_win) { + if (false) { # This is a string rather than a file GN knows about. It has to match # exactly what's in the /FI flag below, and what might appear in the # source code in quotes for an #include directive.