> Hi all,
> 
> I tried to build OpenJDK on Cygwin (Windows 2016 + VS2019).
> However, I failed with C4474 and C4778 warnings as below:
> 
> Compiling 100 properties into resource bundles for java.desktop
> Compiling 3038 files for java.base
> e:\jiefu\ws\jdk\src\hotspot\share\compiler\methodMatcher.cpp(269): error 
> C2220: the following warning is treated as an error
> e:\jiefu\ws\jdk\src\hotspot\share\compiler\methodMatcher.cpp(269): warning 
> C4778: 'sscanf' : unterminated format string 
> '%255[*\x01\x02\x03\x04\x05\x06\a\b\n\v\f\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f!"#$%&'*+,-0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\^_`abcdefghijklmnopqrstuvwxyz{|}~\xe2\x82\xac\xe4\xba\x97\xe5\x84\x8e\xe5\x8e\x97%n'
> e:\jiefu\ws\jdk\src\hotspot\share\compiler\methodMatcher.cpp(269): warning 
> C4474: 'sscanf' : too many arguments passed for format string
> e:\jiefu\ws\jdk\src\hotspot\share\compiler\methodMatcher.cpp(269): note: 
> placeholders and their parameters expect 1 variadic arguments, but 3 were 
> provided
> e:\jiefu\ws\jdk\src\hotspot\share\compiler\methodMatcher.cpp(319): warning 
> C4778: 'sscanf' : unterminated format string 
> '%1022[[);/\x01\x02\x03\x04\x05\x06\a\b\n\v\f\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f!"#$%&'*+,-0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\^_`abcdefghijklmnopqrstuvwxyz{|}~\xe2\x82\xac\xe4\xba\x97\xe5\x84\x8e\xe5\x8e%n'
> e:\jiefu\ws\jdk\src\hotspot\share\compiler\methodMatcher.cpp(319): warning 
> C4474: 'sscanf' : too many arguments passed for format string
> e:\jiefu\ws\jdk\src\hotspot\share\compiler\methodMatcher.cpp(319): note: 
> placeholders and their parameters expect 0 variadic arguments, but 2 were 
> provided
> 
> 
> The failure is caused by non-ASCII chars in the format string of sscanf 
> [1][2], which is non-portable on our Windows platform.
> In fact, these non-ASCII coding also triggers C4819 warning, which had been 
> disabled in JDK-8216154 [3].
> And I also found an article showing that sscanf may fail with non-ASCII in 
> the format string [4].
> 
> So it would be nice to remove these non-ASCII chars  (`\x80 ~ \xef`).
> And I think it's safe to do so.
> 
> This is because:
>  1) There are actually no non-ASCII chars for package/class/method/signature 
> names.
>  2) I don't think there is a use case, in which people will input non-ASCII 
> for `CompileCommand`.
> 
> You may argue that the non-ASCII may be used by the parser itself.
> But I didn't find that usage at all. (Please let me know if I miss something.)
> 
> So I suggest to remove these non-ASCII code to make HotSpot to be more 
> portable.
> And if we do so, we can also remove the only one 
> `PRAGMA_DISABLE_MSVC_WARNING(4819)` [5].
> 
> Testing:
>  - Build tests on Windows
>  - tier1~3 on Linux/x64
> 
> Thanks.
> Best regards,
> Jie
> 
> [1] 
> https://github.com/openjdk/jdk/blob/master/src/hotspot/share/compiler/methodMatcher.cpp#L269
> [2] 
> https://github.com/openjdk/jdk/blob/master/src/hotspot/share/compiler/methodMatcher.cpp#L319
> [3] 
> https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2019-January/032014.html
> [4] https://jeffpar.github.io/kbarchive/kb/047/Q47369/
> [5] 
> https://github.com/openjdk/jdk/blob/master/src/hotspot/share/compiler/methodMatcher.cpp#L246

Jie Fu has updated the pull request incrementally with one additional commit 
since the last revision:

  Disable non-ASCII for Windows only

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5704/files
  - new: https://git.openjdk.java.net/jdk/pull/5704/files/d4b84f2b..e1271085

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5704&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5704&range=00-01

  Stats: 30 lines in 1 file changed: 30 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5704.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5704/head:pull/5704

PR: https://git.openjdk.java.net/jdk/pull/5704

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