[gambit-list] Warnings Compiling Gambit Under Windows

[MichaelL at frogware.com]

Gambit is generating some warnings under Windows. Some of them look like 
real errors:

1       d:\tools\Scheme\proj\gambc40b13\lib\os_tty.c(7344) : warning 
C4113: 'BOOL (__stdcall *)()' differs in parameter lists from 
'PHANDLER_ROUTINE'
2       d:\tools\Scheme\proj\gambc40b13\lib\os_tty.c(7362) : warning 
C4113: 'BOOL (__stdcall *)()' differs in parameter lists from 
'PHANDLER_ROUTINE'
3       d:\tools\Scheme\proj\gambc40b13\lib\os_time.c(234) : warning 
C4307: '*' : integral constant overflow
4       d:\tools\Scheme\proj\gambc40b13\lib\os_time.c(234) : warning 
C4244: 'initializing' : conversion from 'LONGLONG' to 'int', possible loss 
of data
5       d:\tools\Scheme\proj\gambc40b13\lib\os_time.c(235) : warning 
C4244: 'initializing' : conversion from 'LONGLONG' to 'int', possible loss 
of data
6       d:\tools\Scheme\proj\gambc40b13\lib\os_time.c(1316) : warning 
C4113: 'DWORD (__stdcall *)()' differs in parameter lists from 
'LPTHREAD_START_ROUTINE'
7       d:\tools\Scheme\proj\gambc40b13\lib\os_shell.c(177) : warning 
C4244: '=' : conversion from 'unsigned short' to 'char', possible loss of 
data
8       d:\tools\Scheme\proj\gambc40b13\lib\os_shell.c(444) : warning 
C4244: '=' : conversion from 'unsigned short' to 'char', possible loss of 
data
9       d:\tools\Scheme\proj\gambc40b13\lib\os_shell.c(466) : warning 
C4244: '=' : conversion from 'unsigned short' to 'char', possible loss of 
data
10      d:\tools\Scheme\proj\gambc40b13\lib\os_shell.c(594) : warning 
C4244: '=' : conversion from 'unsigned short' to 'char', possible loss of 
data
11      d:\tools\scheme\proj\gambc40b13\lib\os_io.c(5527) : warning C4700: 
local variable 'dev' used without having been initialized

There are two other warnings that appear about 200 times building the 
library. I presume they're intentional:

12      d:\tools\Scheme\proj\gambc40b13\lib\_std.c(2011) : warning C4146: 
unary minus operator applied to unsigned type, result still unsigned
13      d:\tools\Scheme\proj\gambc40b13\lib\_std.c(21221) : warning C4244: 
'=' : conversion from 'double' to 'float', possible loss of data

Here's an example of the first:

        ___BIGFIX1(-0x80000000L)

Here's an example of the second:

        ___F32VECTORSET(___R1,___R3,___F64V1)

==================================================

Problems 1, 2, and 6 are happening because __STDC__ isn't defined by 
default under MSVC. MS thinks that because they define various extensions 
they aren't strict ANSI C, so by default they define _MSC_EXTENSIONS 
instead. Here are the relevant bits from the docs:

        __STDC__ 
        Indicates full conformance with the ANSI C standard. Defined as 
the integer constant 1 
        only if the /Za compiler option is given and you are not compiling 
C++ code; otherwise is 
        undefined. 

        _MSC_EXTENSIONS 
        This macro is defined when compiling with the /Ze compiler option 
(the default). Its 
        value, when defined, is 1. 

Because of all of the above, __P falls through to the #else at 1150 in 
gambit.h and treats params as K&R, which is wrong.

The problem can be fixed by either looking specifically for something like 
_MFC_VER or _MSC_EXTENSIONS or by forcing a #define of __STDC__. (I took 
the second route in my project file.)

Problem 11 looks legit.

(The problem with ___REGISTER_HOST_ENTRY was described elsewhere.)