autotools, CMake: fix issues with snprintf test and sanitizers.

Avoid trying to cast negative values to unsigned types, or doing shifts
of signed types, in order not to have the test program fail if we're
building with undefined-behavior sanitizers enabled.

See the-tcpdump-group/libpcap#1396 for the equivalent libpcap issue.

(cherry picked from commit b7bd627c96f7a70446e4837ca7d5acd6d8122ce2)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 989f7eb9b867e082967b32e5937618ae1c724ffa..538e02f56a1989da264760ebc846585472f1cf91 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -539,32 +539,50 @@ if (NOT CMAKE_CROSSCOMPILING)
     #include <inttypes.h>
     #include <sys/types.h>
 
+    #if defined(_WIN32) && !defined(_SSIZE_T_DEFINED)
+    /*
+     * On UN*Xes, this is a signed integer type of the same size as size_t.
+     *
+     * It's not defined by Visual Studio; we assume that ptrdiff_t will
+     * be a type that is a signed integer type of the same size as size_t.
+     */
+    typedef ptrdiff_t ssize_t;
+    #endif
+
+    /*
+     * Avoid trying to cast negative values to unsigned types, or doing
+     * shifts of signed types, in order not to have the test program fail
+     * if we're building with undefined-behavior sanitizers enabled.
+     */
     int main()
     {
       char buf[100];
-      uint64_t t = (uint64_t)1 << 32;
+      unsigned int ui = sizeof(buf);
+      int i = sizeof(buf);
+      int64_t i64 = INT64_C(0x100000000);
+      uint64_t ui64 = UINT64_C(0x100000000);
 
-      snprintf(buf, sizeof(buf), \"%zu\", sizeof(buf));
+      snprintf(buf, sizeof(buf), \"%zu\", (size_t)ui);
       if (strncmp(buf, \"100\", sizeof(buf)))
         return 1;
 
-      snprintf(buf, sizeof(buf), \"%zd\", -sizeof(buf));
+      snprintf(buf, sizeof(buf), \"%zd\", (ssize_t)(-i));
       if (strncmp(buf, \"-100\", sizeof(buf)))
         return 2;
 
-      snprintf(buf, sizeof(buf), \"%\" PRId64, -t);
+      snprintf(buf, sizeof(buf), \"%\" PRId64, -i64);
       if (strncmp(buf, \"-4294967296\", sizeof(buf)))
         return 3;
 
-      snprintf(buf, sizeof(buf), \"0o%\" PRIo64, t);
+      snprintf(buf, sizeof(buf), \"0o%\" PRIo64, ui64);
       if (strncmp(buf, \"0o40000000000\", sizeof(buf)))
         return 4;
 
-      snprintf(buf, sizeof(buf), \"0x%\" PRIx64, t);
+      snprintf(buf, sizeof(buf), \"0x%\" PRIx64, ui64);
       if (strncmp(buf, \"0x100000000\", sizeof(buf)))
         return 5;
 
-      snprintf(buf, sizeof(buf), \"%\" PRIu64, t);
+      snprintf(buf, sizeof(buf), \"%\" PRIu64, ui64);
       if (strncmp(buf, \"4294967296\", sizeof(buf)))
         return 6;
 

diff --git a/configure.ac b/configure.ac
index 510b2624e87c9ba4a4cf5d9ed995add4cbc8061b..ae4500e9b2e9e6533c0d67ffb3b5fc114e75eb98 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -468,32 +468,50 @@ AC_RUN_IFELSE(
 #include <inttypes.h>
 #include <sys/types.h>
 
+#if defined(_WIN32) && !defined(_SSIZE_T_DEFINED)
+/*
+ * On UN*Xes, this is a signed integer type of the same size as size_t.
+ *
+ * It's not defined by Visual Studio; we assume that ptrdiff_t will
+ * be a type that is a signed integer type of the same size as size_t.
+ */
+typedef ptrdiff_t ssize_t;
+#endif
+
+/*
+ * Avoid trying to cast negative values to unsigned types, or doing
+ * shifts of signed types, in order not to have the test program fail
+ * if we're building with undefined-behavior sanitizers enabled.
+ */
 int main()
 {
   char buf[100];
-  uint64_t t = (uint64_t)1 << 32;
+  unsigned int ui = sizeof(buf);
+  int i = sizeof(buf);
+  int64_t i64 = INT64_C(0x100000000);
+  uint64_t ui64 = UINT64_C(0x100000000);
 
-  snprintf(buf, sizeof(buf), "%zu", sizeof(buf));
+  snprintf(buf, sizeof(buf), "%zu", (size_t)ui);
   if (strncmp(buf, "100", sizeof(buf)))
     return 1;
 
-  snprintf(buf, sizeof(buf), "%zd", -sizeof(buf));
+  snprintf(buf, sizeof(buf), "%zd", (ssize_t)(-i));
   if (strncmp(buf, "-100", sizeof(buf)))
     return 2;
 
-  snprintf(buf, sizeof(buf), "%" PRId64, -t);
+  snprintf(buf, sizeof(buf), "%" PRId64, -i64);
   if (strncmp(buf, "-4294967296", sizeof(buf)))
     return 3;
 
-  snprintf(buf, sizeof(buf), "0o%" PRIo64, t);
+  snprintf(buf, sizeof(buf), "0o%" PRIo64, ui64);
   if (strncmp(buf, "0o40000000000", sizeof(buf)))
     return 4;
 
-  snprintf(buf, sizeof(buf), "0x%" PRIx64, t);
+  snprintf(buf, sizeof(buf), "0x%" PRIx64, ui64);
   if (strncmp(buf, "0x100000000", sizeof(buf)))
     return 5;
 
-  snprintf(buf, sizeof(buf), "%" PRIu64, t);
+  snprintf(buf, sizeof(buf), "%" PRIu64, ui64);
   if (strncmp(buf, "4294967296", sizeof(buf)))
     return 6;