[PATCH 1/2] configure: detect 64 bit time_t

[David Bremner]

Certain tests involving timestamps > 32bits cannot pass with the
current libnotmuch API. We will avoid this isssue for now by disabling
those tests on "old" architectures with 32bit time_t.
---
 configure | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/configure b/configure
index 05ade05b..ecb0bdb7 100755
--- a/configure
+++ b/configure
@@ -1045,6 +1045,34 @@ else
 fi
 rm -f compat/have_timegm
 
+cat <<EOF > _time_t.c
+#include <time.h>
+#include <stdio.h>
+int main(int argc, char**argv) {
+  printf("%d\n",sizeof(time_t) >= 8);
+}
+EOF
+
+printf "Checking for 64 bit time_t... "
+if ${CC} _time_t.c -o _time_t > /dev/null 2>&1;
+then
+    have_64bit_time_t=$(./_time_t)
+    if [ $have_64bit_time_t -eq 1 ]
+    then
+        printf "Yes.\n"
+    else
+        printf "No.\n"
+    fi
+else
+    cat <<EOF
+
+*** Error: compilation failed.  Please try running configure again in
+a clean environment, and if the problem persists, report a bug.
+EOF
+    rm -f _time_t _time_t.c exit 1
+fi
+
+
 printf "Checking for dirent.d_type... "
 if ${CC} -o compat/have_d_type "$srcdir"/compat/have_d_type.c > /dev/null 2>&1
 then
@@ -1128,7 +1156,7 @@ for flag in -Wmissing-declarations; do
 done
 printf "\n\t%s\n" "${WARN_CFLAGS}"
 
-rm -f minimal minimal.c _libversion.c _libversion _libversion.sh _check_session_keys.c _check_session_keys _check_x509_validity.c _check_x509_validity
+rm -f minimal minimal.c _time_t _time_t.c _libversion.c _libversion _libversion.sh _check_session_keys.c _check_session_keys _check_x509_validity.c _check_x509_validity
 
 # construct the Makefile.config
 cat > Makefile.config <<EOF
@@ -1429,6 +1457,9 @@ NOTMUCH_HAVE_MAN=$((have_sphinx))
 NOTMUCH_HAVE_BASH=${have_bash}
 NOTMUCH_BASH_ABSOLUTE=${bash_absolute}
 
+# Whether time_t is 64 bits (or more)
+NOTMUCH_HAVE_64BIT_TIME_T=${have_64bit_time_t}
+
 # Whether perl exists, and if so where
 NOTMUCH_HAVE_PERL=${have_perl}
 NOTMUCH_PERL_ABSOLUTE=${perl_absolute}
-- 
2.27.0