与msvc编译的差异

• 使用msvc编译里添加的许多库在使用mingw时不需要再添加声明了。
• 使用mingw的使用的win32库名与原库名稍有变化，在msvc中添加的是xxx.lib，在mingw是添加的是libxxx.a

编译相关问题

1、未正确使用相关标记。
添加-frtti即可

../third_party/icu/icu4c/source/i18n/unum.cpp:640:31: error: use of dynamic_cast requires -frtti
    const DecimalFormat* df = dynamic_cast<const DecimalFormat*>(nf);

2、MinGW不支持Windows异常处理__try

../third_party/flutter/engine/flutter/fml/thread.cc:84:3: error: use of undeclared identifier '__try'
  __try {
  ^
1 error generated

3、数据类型转换问题
在mac、ubuntu上编译只有几处报错，而使用MinGW编译时全部报错，而且是针对模板类型的构造函数。如果给构造函数赋值一个double的常量也可以正常编译，但如果是变量就会报错，使用(float)强转的话也可以正常编译；直接将一个double赋值给一个float变量也没有问题。
解决方法：添加-Wno-c++11-narrowing

../foundation/arkui/ace_engine/frameworks/core/components_ng/layout/box_layout_algorithm.cpp:43:17: error: non-constant-expression cannot be narrowed from type 'double' to 'float' in initializer list [-Wc++11-narrowing]
                layoutConstraint.maxSize.Height() - safeArea.topRect_.Height() - safeArea.bottomRect_.Height() };

4、constexpr变量的值需要在编译时就要确定，对于构造函数也需要使用constexpr进行修饰才行。

constexpr explicit Color(uint32_t value) : colorValue_(ColorParam {
     .value = value }) {
    }

../foundation/arkui/ace_engine/frameworks/core/components_ng/pattern/scroll/inner/scroll_bar.h:38:17: error: constexpr variable 'PRESSED_BLEND_COLOR' must be initialized by a constant expression
constexpr Color PRESSED_BLEND_COLOR = Color(0x19000000);
                ^                     ~~~~~~~~~~~~~~~~~

5、自定义的enum、变量名与系统gdi头文件中定义的宏冲突。
添加NOGDI宏定义解决。
defines = [ “NOGDI” ]

../third_party/one/one.h:29:5: error: expected identifier
    ALTERNATE,
    ^
C:/Users/client/Downloads/llvm-mingw-20230614-msvcrt-x86_64/include/wingdi.h:100:19: note: expanded from macro 'ALTERNATE'
#define ALTERNATE 1

6、暂不清楚是什么问题，直接注释掉了。

../foundation/arkui/ace_engine/frameworks/core/components/common/layout/grid_system_manager.cpp:121:31: error: cannot pass non-trivial object of type 'RefPtr<GridContainerInfo>' to variadic function; expected type from format string was 'void *' [-Wnon-pod-varargs]
        LOGD("parent addr:%p",parent);
                          ~~  ^~~~~~
../foundation/arkui/ace_engine/frameworks/base/log/log_wrapper.h:43:48: note: expanded from macro 'LOGD'
#define LOGD(fmt, ...) PRINT_LOG(DEBUG, fmt, ##__VA_ARGS__)
                                        ~~~    ^~~~~~~~~~~
../foundation/arkui/ace_engine/frameworks/base/log/log_wrapper.h:39:19: note: expanded from macro 'PRINT_LOG'
                ##__VA_ARGS__);                                                                                 \
                  ^~~~~~~~~~~

7、未定义的符号
使用动态库引用静态库，而静态库使用的是dllexport函数导出，动态库使用visibility(“default”)导出，导出动态库中所有函数均不能正常导出。

llvm-mingw-20230614-msvcrt-x86_64\bin/clang++ -target x86_64-pc-windows-gnu -rtlib=compiler-rt -stdlib=libc++ -lunwind -lpthread -Qunused-arguments -fuse-ld=lld -o ./test.exe @./test.exe.rsp
ld.lld: error: undefined symbol: Two::toString()

8、win32已有的函数，在项目中重新定义
根据警告信息重新声明需要添加dllimport，使用dllimport标记后，出现警告信息2：重新声明方法不能使用dllimport。这个提示前后矛盾。后尝试一个函数定义多次是可以的，但不能有多个实现。
暂未找到好的解决方案
警告提示1

In file included from ../foundation/arkui/napi/native_engine/impl/quickjs/quickjs_native_engine.cpp:38:
../third_party/bounds_checking_function/include/securec.h:527:21: warning: 'wscanf_s' redeclared without 'dllimport' attribute: previous 'dllimport' ignored [-Winconsistent-dllimport]
    SECUREC_API int wscanf_s(const wchar_t *format, ...);
                    ^
C:/Users/client/Downloads/llvm-mingw-20230614-msvcrt-x86_64/include/sec_api/wchar_s.h:278:23: note: previous declaration is here
  _CRTIMP int __cdecl wscanf_s(const wchar_t *_Format, ...);

警告提示2

In file included from ../foundation/arkui/napi/native_engine/native_safe_async_work.cpp:22:
../commonlibrary/c_utils/base/include/securec.h:106:9: warning: -------dllimport-------- [-W#pragma-messages]
#pragma message("-------dllimport--------")
        ^
../commonlibrary/c_utils/base/include/securec.h:244:21: warning: redeclaration of 'swprintf_s' should not add 'dllimport' attribute [-Wdll-attribute-on-redeclaration]
    SECUREC_API int swprintf_s(wchar_t *strDest, size_t destMax, const wchar_t *format, ...);
                    ^
C:/Users/client/Downloads/llvm-mingw-20230614-msvcrt-x86_64/include/sec_api/wchar_s.h:256:15: note: previous declaration is here
  int __cdecl swprintf_s(wchar_t *_Dst,size_t _SizeInWords,const wchar_t *_Format,...);

9、mingw头文件与win10头文件关于此方法声明不一致
暂未找到好的解决方案

    STDMETHOD(GetGlyphImageFormats)(
        UINT16 glyphId,
        UINT32 pixelsPerEmFirst,
        UINT32 pixelsPerEmLast,
        _Out_ DWRITE_GLYPH_IMAGE_FORMATS* glyphImageFormats
        ) PURE;

virtual DWRITE_GLYPH_IMAGE_FORMATS STDMETHODCALLTYPE GetGlyphImageFormats() = 0;

../third_party/flutter/skia/src/ports/SkScalerContext_win_dw.cpp:505:47: error: too many arguments to function call, expected 0, have 4
    auto rs = fontFace4->GetGlyphImageFormats(glyph.getGlyphID(), 0, UINT32_MAX, &f);
              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
C:/Users/client/Downloads/llvm-mingw-20230614-msvcrt-x86_64/include/dwrite_3.h:8577:58: note: 'GetGlyphImageFormats' declared here
    virtual DWRITE_GLYPH_IMAGE_FORMATS STDMETHODCALLTYPE GetGlyphImageFormats(

10、 undefined symbol: __declspec(dllimport) bind
添加ws2_32库即可
libs = [ “ws2_32” ]

ld.lld: error: undefined symbol: __declspec(dllimport) bind
>>> referenced by obj/third_party/openssl/crypto/bio/crypto_source/b_sock2.o:(BIO_bind)