I am currently using MSVC 6.0, circa 1999, as my primary development
IDE/compiler for number of reasons.
Its _MSC_VER is 1200:
int iWinVer = _MSC_VER;
result: iWinVer == 1200;
I have not used any earlier Microsoft compilers since 1999. I cannot
speak to their _MSC_VER versions.
MSVC 6.0 is 32-bit, essentially C99 . The same source will compile in VC
2019 as 64-bit.
In my case I have copied and modified zic and relevant portions of glibc
code into their own library, that is, I am not attempting to compile the
TzDb code directly. I have also created a c++ wrapper class containing
those components with their own POSIX environment so that multiple
independent instantiations can be created in an application.
I would remind that the compiler switches should include both _UNICODE
and UNICODE to create a proper Windows executable. Windows has been
UNICODE since NT4 and it's important that the CRT compiles as UNICODE.
>> "Microsoft says[1] that it didn't add support for C99-style compound
literals until Visual Studio 2013."
I'm not sure when Microsoft came to support compound literals, but with
MSVC 6.0 you have to watch out for and work-around that.
I don't know about C89, but I believe you may want to consider support
of at least C99.
Hope this might help.
-Brooks
On 2025-01-13 04:32 PM, Paul Eggert via tz wrote:
On 1/13/25 05:17, Manuela Friedrich wrote:
It seems that your commit 1ee9daa91818f5d4ab6937352453813fa333e105
fails with:
localtime.c(309): error C2099: initializer is not a constant
Thanks for reporting that. Which compiler are you using and what
version and what compiler flags are you using?
Does the following uninstalled patch fix things for you? If not,
what's the value of _MSC_VER when you use your compiler flags?
diff --git a/private.h b/private.h
index 0a546e02..3e64da4e 100644
--- a/private.h
+++ b/private.h
@@ -26,7 +26,11 @@
because RHEL 7 (whose GCC defaults to C89) extended life cycle
support (ELS) is scheduled to end on 2028-06-30. */
#ifndef PORT_TO_C89
-# define PORT_TO_C89 0
+# if defined _MSC_VER && _MSC_VER < 1800
+# define PORT_TO_C89 1
+# else
+# define PORT_TO_C89 0
+# endif
#endif
/* SUPPORT_C89 means the tzcode library should support C89 callers
Perhaps we could use the patch with a different value in place of
1800, or perhaps we should just remove the " && _MSC_VER < 1800".
Microsoft says[1] that it didn't add support for C99-style compound
literals until Visual Studio 2013. Are you using an older version of
MSVC? If so, it's past end-of-life[2] and I doubt whether we should
worry about it.
[1]:
https://learn.microsoft.com/en-us/previous-versions/visualstudio/visual-studio-2013/hh409293(v=vs.120)?redirectedfrom=MSDN
[2]:
https://devblogs.microsoft.com/visualstudio/support-ends-for-older-versions-of-visual-studio-feb2022/
