Compiler warnings seen in the build logs:

Linux:

/usr/bin/gcc -g -O2 -fno-strict-aliasing -fPIC -W -Wall -Wno-unused -Wno-parentheses -fno-omit-frame-pointer -D_LITTLE_ENDIAN -DUSE_MMAP -DDEBUG -DLOGGING -DARCH='"i586"' -Di586 -DLINUX -DRELEASE='"1.7.0-ea-fastdebug"' -D_LARGEFILE64_SOURCE -D_GNU_SOURCE -D_REENTRANT -I. -I/BUILD_AREA/jdk7/build/linux-i586/../linux-i586-fastdebug/tmp/sun/java.util.zip/zip/CClassHeaders -I../../../src/solaris/javavm/export -I../../../src/share/javavm/export -I../../../src/share/native/common -I../../../src/solaris/native/common -I../../../src/share/native/java/util/zip -I../../../src/solaris/native/java/util/zip -UDEBUG -I../../../src/share/native/java/util/zip/zlib-1.2.3 -I../../../src/share/native/java/io -I../../../src/solaris/native/java/io -c -o /BUILD_AREA/jdk7/build/linux-i586/../linux-i586-fastdebug/tmp/sun/java.util.zip/zip/obj_gO/zip_util.o ../../../src/share/native/java/util/zip/zip_util.c
../../../src/share/native/java/util/zip/zip_util.c: In function 'isMetaName':
../../../src/share/native/java/util/zip/zip_util.c:429: warning: comparison between signed and unsigned

Solaris x86:

/localtools/i586/SUNWspro/SS12u1/bin/cc -g -xO2 -L/BUILD_AREA/jdk7/build/solaris-i586/../solaris-i586-fastdebug/tmp/sun/java.util.zip/zip/obj_gO -xc99=%none -xCC -errshort=tags -Xa -v -mt -xstrconst -W0,-noglobal -m32 -erroff=E_BAD_PRAGMA_PACK_VALUE -KPIC -DUSE_MMAP -DDEBUG -DLOGGING -DDBINFO -D__solaris__ -Di586 -DcpuIntel -D_LITTLE_ENDIAN= -Di386 -DTRACING -DMACRO_MEMSYS_OPS -DBREAKPTS -I. -I/BUILD_AREA/jdk7/build/solaris-i586/../solaris-i586-fastdebug/tmp/sun/java.util.zip/zip/CClassHeaders -I../../../src/solaris/javavm/export -I../../../src/share/javavm/export -I../../../src/share/native/common -I../../../src/solaris/native/common -I../../../src/share/native/java/util/zip -I../../../src/solaris/native/java/util/zip -UDEBUG -I../../../src/share/native/java/util/zip/zlib-1.2.3 -I../../../src/share/native/java/io -I../../../src/solaris/native/java/io -c -o /BUILD_AREA/jdk7/build/solaris-i586/../solaris-i586-fastdebug/tmp/sun/java.util.zip/zip/obj_gO/zcrc32.o ../../../src/share/native/java/util/zip/zlib-1.2.3/zcrc32.c
"../../../src/share/native/java/util/zip/zlib-1.2.3/zcrc32.c", line 409: warning: constant promoted to unsigned long


Windows:

C:/PROGRA~1/MICROS~2.0/Common7/Tools/../../Vc/Bin/cl -Od -Zi -nologo -MD /D _STATIC_CPPLIB -Zc:wchar_t- -FdC:/BUILD_~1/jdk7/build/windows-i586/../windows-i586-fastdebug/tmp/sun/java.util.zip/zip/obj_gO/zip_util.pdb -FmC:/BUILD_~1/jdk7/build/windows-i586/../windows-i586-fastdebug/tmp/sun/java.util.zip/zip/obj_gO/zip_util.map -wd4800 -W3 -D _CRT_SECURE_NO_DEPRECATE -DDEBUG -DLOGGING -DWIN32 -DIAL -D_LITTLE_ENDIAN -D_X86_ -Dx86 -DWIN32_LEAN_AND_MEAN -I. -IC:/BUILD_~1/jdk7/build/windows-i586/../windows-i586-fastdebug/tmp/sun/java.util.zip/zip/CClassHeaders -I../../../src/windows/javavm/export -I../../../src/share/javavm/export -I../../../src/share/native/common -I../../../src/windows/native/common -I../../../src/share/native/java/util/zip -I../../../src/windows/native/java/util/zip -I../../../src/share/native/java/util/zip/zlib-1.2.3 -I../../../src/share/native/java/io -I../../../src/windows/native/java/io -c -FoC:/BUILD_~1/jdk7/build/windows-i586/../windows-i586-fastdebug/tmp/sun/java.util.zip/zip/obj_gO/zip_util.obj ../../../src/share/native/java/util/zip/zip_util.c
zip_util.c
../../../src/share/native/java/util/zip/zip_util.c(231) : warning C4996: 'strdup': The POSIX name for this item is deprecated. Instead, use the ISO C++ conformant name: _strdup. See online help for details.
        C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\string.h(238) : see declaration of 'strdup'
../../../src/share/native/java/util/zip/zip_util.c(317) : warning C4244: 'function' : conversion from 'jlong' to 'size_t', possible loss of data
../../../src/share/native/java/util/zip/zip_util.c(915) : warning C4244: '=' : conversion from 'jlong' to 'jint', possible loss of data
../../../src/share/native/java/util/zip/zip_util.c(1279) : warning C4244: '=' : conversion from 'jlong' to 'jint', possible loss of data
../../../src/share/native/java/util/zip/zip_util.c(1333) : warning C4244: '=' : conversion from 'jlong' to 'uInt', possible loss of data
../../../src/share/native/java/util/zip/zip_util.c(1336) : warning C4244: 'initializing' : conversion from 'jlong' to 'jint', possible loss of data
../../../src/share/native/java/util/zip/zip_util.c(1317) : warning C4101: 'status' : unreferenced local variable
../../../src/share/native/java/util/zip/zip_util.c(1376) : warning C4244: '=' : conversion from 'jlong' to 'jint', possible loss of data

C:/PROGRA~1/MICROS~2.0/Common7/Tools/../../Vc/Bin/cl -Od -Zi -nologo -MD /D _STATIC_CPPLIB -Zc:wchar_t- -FdC:/BUILD_~1/jdk7/build/windows-i586/../windows-i586-fastdebug/tmp/sun/java.util.zip/zip/obj_gO/compress.pdb -FmC:/BUILD_~1/jdk7/build/windows-i586/../windows-i586-fastdebug/tmp/sun/java.util.zip/zip/obj_gO/compress.map -wd4800 -W3 -D _CRT_SECURE_NO_DEPRECATE -DDEBUG -DLOGGING -DWIN32 -DIAL -D_LITTLE_ENDIAN -D_X86_ -Dx86 -DWIN32_LEAN_AND_MEAN -I. -IC:/BUILD_~1/jdk7/build/windows-i586/../windows-i586-fastdebug/tmp/sun/java.util.zip/zip/CClassHeaders -I../../../src/windows/javavm/export -I../../../src/share/javavm/export -I../../../src/share/native/common -I../../../src/windows/native/common -I../../../src/share/native/java/util/zip -I../../../src/windows/native/java/util/zip -I../../../src/share/native/java/util/zip/zlib-1.2.3 -I../../../src/share/native/java/io -I../../../src/windows/native/java/io -c -FoC:/BUILD_~1/jdk7/build/windows-i586/../windows-i586-fastdebug/tmp/sun/java.util.zip/zip/obj_gO/compress.obj ../../../src/share/native/java/util/zip/zlib-1.2.3/compress.c
compress.c
../../../src/share/native/java/util/zip/zlib-1.2.3/compress.c(78) : warning C4244: '=' : conversion from '__int64' to 'uLongf', possible loss of data

C:/PROGRA~1/MICROS~2.0/Common7/Tools/../../Vc/Bin/cl -Od -Zi -nologo -MD /D _STATIC_CPPLIB -Zc:wchar_t- -FdC:/BUILD_~1/jdk7/build/windows-i586/../windows-i586-fastdebug/tmp/sun/java.util.zip/zip/obj_gO/uncompr.pdb -FmC:/BUILD_~1/jdk7/build/windows-i586/../windows-i586-fastdebug/tmp/sun/java.util.zip/zip/obj_gO/uncompr.map -wd4800 -W3 -D _CRT_SECURE_NO_DEPRECATE -DDEBUG -DLOGGING -DWIN32 -DIAL -D_LITTLE_ENDIAN -D_X86_ -Dx86 -DWIN32_LEAN_AND_MEAN -I. -IC:/BUILD_~1/jdk7/build/windows-i586/../windows-i586-fastdebug/tmp/sun/java.util.zip/zip/CClassHeaders -I../../../src/windows/javavm/export -I../../../src/share/javavm/export -I../../../src/share/native/common -I../../../src/windows/native/common -I../../../src/share/native/java/util/zip -I../../../src/windows/native/java/util/zip -I../../../src/share/native/java/util/zip/zlib-1.2.3 -I../../../src/share/native/java/io -I../../../src/windows/native/java/io -c -FoC:/BUILD_~1/jdk7/build/windows-i586/../windows-i586-fastdebug/tmp/sun/java.util.zip/zip/obj_gO/uncompr.obj ../../../src/share/native/java/util/zip/zlib-1.2.3/uncompr.c
uncompr.c
../../../src/share/native/java/util/zip/zlib-1.2.3/uncompr.c(81) : warning C4244: '=' : conversion from '__int64' to 'uLongf', possible loss of data