From 9b5699737a6b587546239d586832f420cf7f2dea Mon Sep 17 00:00:00 2001
From: Tony Cook <tony@develop-help.com>
Date: Fri, 9 Jul 2021 10:22:40 +1000
Subject: detect struct stat.st_dev's size and signedness, and return it safely

On FreeBSD dev_t (and hence the st_dev member of struct stat) is an
unsigned 64-bit integer, and the previous simple PUSHi() corrupted
that.

A previous version of this reflected the st_ino code and implemented
our own number to string conversion, but a system with such a large
st_dev should be assumed to have inttypes.h, and an intmax_t which is
no smaller than st_dev.

The st_ino code could probably be changed similarly, but 64-bit inode
numbers are not a new thing, so it may be riskier.
---
 Configure | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

(limited to 'Configure')

diff --git a/Configure b/Configure
index 55e2ebb50f..08f2445a40 100755
--- a/Configure
+++ b/Configure
@@ -1321,6 +1321,8 @@ shsharp=''
 spitshell=''
 src=''
 ssizetype=''
+st_dev_sign=''
+st_dev_size=''
 st_ino_sign=''
 st_ino_size=''
 startperl=''
@@ -22744,6 +22746,74 @@ else
 fi
 $rm_try
 
+: Check the size of st_dev
+$echo " "
+$echo "Checking the size of st_dev..." >&4
+$cat > try.c <<EOCP
+#include <sys/stat.h>
+#include <stdio.h>
+#$i_stdlib I_STDLIB
+#ifdef I_STDLIB
+#include <stdlib.h>
+#endif
+int main() {
+    struct stat st;
+    printf("%d\n", (int)sizeof(st.st_dev));
+    exit(0);
+}
+EOCP
+set try
+if eval $compile_ok; then
+	val=`$run ./try`
+	case "$val" in
+	'')	st_dev_size=4
+		$echo "(I can't execute the test program--guessing $st_dev_size.)" >&4
+		;;
+	*)	st_dev_size=$val
+		$echo "Your st_dev is $st_dev_size bytes long."
+		;;
+	esac
+else
+	st_dev_size=4
+	$echo "(I can't compile the test program--guessing $st_dev_size.)" >&4
+fi
+$rm_try
+
+: Check if st_dev is signed
+$echo " "
+$echo "Checking the sign of st_dev..." >&4
+$cat > try.c <<EOCP
+#include <sys/stat.h>
+#include <stdio.h>
+int main() {
+	struct stat foo;
+        foo.st_dev = -1;
+	if (foo.st_dev < 0)
+		printf("-1\n");
+	else
+		printf("1\n");
+}
+EOCP
+set try
+if eval $compile; then
+	val=`$run ./try`
+	case "$val" in
+	'')	st_dev_sign=1
+		$echo "(I can't execute the test program--guessing unsigned.)" >&4
+		;;
+	*)	st_dev_sign=$val
+		case "$st_dev_sign" in
+		 1) $echo "Your st_dev is unsigned." ;;
+		-1) $echo "Your st_dev is signed."   ;;
+		esac
+		;;
+	esac
+else
+	st_dev_sign=1
+	$echo "(I can't compile the test program--guessing unsigned.)" >&4
+fi
+$rm_try
+
 : see what type of char stdio uses.
 echo " "
 echo '#include <stdio.h>' | $cppstdin $cppminus > stdioh
@@ -25299,6 +25369,8 @@ srand48_r_proto='$srand48_r_proto'
 srandom_r_proto='$srandom_r_proto'
 src='$src'
 ssizetype='$ssizetype'
+st_dev_sign='$st_dev_sign'
+st_dev_size='$st_dev_size'
 st_ino_sign='$st_ino_sign'
 st_ino_size='$st_ino_size'
 startperl='$startperl'
-- 
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