readme.md

编译 gn 的时候遇到一些问题：

环境 win10 17763.1.amd64fre.rs5_release.180914-1434 + visual studio 2019 + vs dev cmd

1. 含有 utf8 编码的字符，导致 C4819 警告，需要显示指定编码
2. 找不到 last_commit_position.h 头文件， gen.py 的 --out-path 参数需要传绝对路径
3. 链接 fatal error LNK1112: module machine type 'X86' conflicts with target machine type 'x64' 需要显示地设置 /MACHINE:x86

gn.diff

diff --git a/build/build_win.ninja.template b/build/build_win.ninja.template
index 3edfb6a4..0f8cb372 100644
--- a/build/build_win.ninja.template
+++ b/build/build_win.ninja.template
@@ -1,12 +1,12 @@
 rule cc
-  command = ninja -t msvc -- $cc /nologo /showIncludes /FC @${out}.rsp /c ${in} /Fo${out}
+  command = ninja -t msvc -- $cc /nologo /showIncludes /FC @${out}.rsp /c ${in} /Fo${out}  /source-charset:utf-8 /execution-charset:utf-8
   description = CC ${out}
   rspfile = ${out}.rsp
   rspfile_content = ${defines} ${includes} ${cflags} ${cflags_c}
   deps = msvc

 rule cxx
-  command = ninja -t msvc -- $cxx /nologo /showIncludes /FC @${out}.rsp /c ${in} /Fo${out}
+  command = ninja -t msvc -- $cxx /nologo /showIncludes /FC @${out}.rsp /c ${in} /Fo${out} /source-charset:utf-8 /execution-charset:utf-8
   description = CXX ${out}
   rspfile = ${out}.rsp
   rspfile_content = ${defines} ${includes} ${cflags} ${cflags_cc}
@@ -19,7 +19,7 @@ rule alink_thin
   rspfile_content = ${in_newline} ${libflags}

 rule link
-  command = ninja -t msvc -- $ld /nologo /OUT:${out} /PDB:${out}.pdb @${out}.rsp
+  command = ninja -t msvc -- $ld /nologo /OUT:${out} /PDB:${out}.pdb @${out}.rsp /MACHINE:x86
   description = LINK ${out}
   rspfile = ${out}.rsp
   rspfile_content = ${in_newline} ${libs} ${solibs} ${ldflags}
diff --git a/build/gen.py b/build/gen.py
index eeb7cb55..b473687c 100755
--- a/build/gen.py
+++ b/build/gen.py
@@ -274,7 +274,9 @@ def WriteGNNinja(path, platform, host, options):
   cflags_cc = os.environ.get('CXXFLAGS', '').split()
   ldflags = os.environ.get('LDFLAGS', '').split()
   libflags = os.environ.get('LIBFLAGS', '').split()
+  #include_dirs = [REPO_ROOT, os.path.abspath(os.path.dirname(path))] or you can python gen.py --out-path=ABS_PATH 
   include_dirs = [REPO_ROOT, os.path.dirname(path)]
+
   libs = []

   if not platform.is_msvc():