RFR: 8274329: Fix non-portable HotSpot code in MethodMatcher::parse_method_pattern

[Jie Fu]

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

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

Commit messages:
 - 8274329: Fix non-portable HotSpot code in MethodMatcher::parse_method_pattern

Changes: https://git.openjdk.java.net/jdk/pull/5704/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5704&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8274329
  Stats: 13 lines in 1 file changed: 0 ins; 12 del; 1 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