compiling C library under mingw

I have a library that compiles fine under linux.<br />But when I try to compile it under mingw on windows 7 I get the
followingerrors.<br /><br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid
rgb(204,204, 204); padding-left: 1ex;"><font size="2" style="font-family: courier new,monospace;">gcc.exe -c -O2
-I/C/PostgreSQL/9.0/include/server-I/C/PostgreSQL/9.0/include/server/utils -I/C/PostgreSQL/9.0/include/server/access
-I/C/PostgreSQL/9.0/include/server/port/win32-I/C/PostgreSQL/9.0/include  -MMD -MP -MF
build/Release/MinGW-Windows/mylib.o.d-o build/Release/MinGW-Windows/mylib.o mylib.c</font><br /></blockquote><br />The
previouscommand is successful and produces .o files (only some warnings here like: <span style="font-family: courier
new,monospace;">warning:'pg_finfo_mytype_in' redeclared without dllimport attribute: previous dllimport
ignored</span>).<br/> The following though gives errors.<br /><br /><blockquote class="gmail_quote" style="margin: 0pt
0pt0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><span style="font-family: courier
new,monospace;">gcc.exe-shared -o dist/Release/MinGW-Windows/libMyLib.dll build/Release/MinGW-Windows/mylib.o</span><br
/></blockquote><br/>Here is the log:<br /><br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex;
border-left:1px solid rgb(204, 204, 204); padding-left: 1ex;"><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x128):undefined reference to `errstart'</span><br
style="font-family:courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x13d):undefined reference to
`_imp__CurrentMemoryContext'</span><brstyle="font-family: courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x147):undefined reference to
`MemoryContextAlloc'</span><brstyle="font-family: courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x17b):undefined reference to
`timestamp_in'</span><brstyle="font-family: courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x180):undefined reference to
`DirectFunctionCall3'</span><brstyle="font-family: courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x1be):undefined reference to
`timestamp_in'</span><brstyle="font-family: courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x1c3):undefined reference to
`DirectFunctionCall3'</span><brstyle="font-family: courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x1f4):undefined reference to `errmsg'</span><br
style="font-family:courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x202):undefined reference to `errcode'</span><br
style="font-family:courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x20e):undefined reference to `errfinish'</span><br
style="font-family:courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x230):undefined reference to
`_imp__CurrentMemoryContext'</span><brstyle="font-family: courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x23a):undefined reference to
`MemoryContextAlloc'</span><brstyle="font-family: courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x251):undefined reference to
`Int64GetDatum'</span><brstyle="font-family: courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x25c):undefined reference to
`timestamp_out'</span><brstyle="font-family: courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x261):undefined reference to
`DirectFunctionCall1'</span><brstyle="font-family: courier new,monospace;" /><span style="font-family: courier
new,monospace;">build/Release/MinGW-Windows/mylib.o:mylib.c:(.text+0x284):undefined reference to
`Int64GetDatum'</span><br/></blockquote><br />