build: Check for 32-bit time_t at configure time

To warn of Y2038 problems, and suggest use of -D__MINGW_USE_VC2005_COMPAT
on mingw32. Do this instead of the previous runtime test.

Add -D__MINGW_USE_VC2005_COMPAT to the appveyor build.

Fixes msteveb/jimtcl#145

Signed-off-by: Steve Bennett <steveb@workware.net.au>

1 files changed, 15 insertions, 1 deletions

diff --git a/auto.def b/auto.def
index 4cff73a..681c913 100644
--- a/auto.def
+++ b/auto.def
@@ -99,9 +99,14 @@ if {[cctest -cflags -fno-asynchronous-unwind-tables]} {
     define-append CCOPTS -fno-asynchronous-unwind-tables
 }
 
-cc-check-includes sys/time.h sys/socket.h netinet/in.h arpa/inet.h netdb.h
+cc-check-includes time.h sys/time.h sys/socket.h netinet/in.h arpa/inet.h netdb.h
 cc-check-includes sys/un.h dlfcn.h unistd.h dirent.h crt_externs.h
 
+# Check sizeof time_t so we can warn on non-Y2038 compliance
+cc-with {-includes time.h} {
+    cc-check-sizeof time_t
+}
+
 define LDLIBS ""
 
 # Haiku needs -lnetwork, Solaris needs -lnsl
@@ -545,3 +550,12 @@ make-template build-jim-ext.in
 make-template jimtcl.pc.in
 
 catch {exec chmod +x build-jim-ext}
+
+# Finally produce any warnings
+if {[get-define SIZEOF_TIME_T] <= 4} {
+    set note ""
+    if {[have-feature windows]} {
+        set note ", consider CFLAGS=-D__MINGW_USE_VC2005_COMPAT on mingw32"
+    }
+    user-notice "Warning: sizeof(time_t) is [get-define SIZEOF_TIME_T] -- not Y2038 compliant$note"
+}