From 754bbf7a25a8dda49b5d08ef0d0443bbf5af0e36 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Sun, 7 Apr 2024 13:41:34 -0500 Subject: new repository --- devdocs/c/error%2Fset_constraint_handler_s.html | 57 +++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 devdocs/c/error%2Fset_constraint_handler_s.html (limited to 'devdocs/c/error%2Fset_constraint_handler_s.html') diff --git a/devdocs/c/error%2Fset_constraint_handler_s.html b/devdocs/c/error%2Fset_constraint_handler_s.html new file mode 100644 index 00000000..d8c0c19e --- /dev/null +++ b/devdocs/c/error%2Fset_constraint_handler_s.html @@ -0,0 +1,57 @@ +

set_constraint_handler_s, constraint_handler_t

Defined in header <stdlib.h> 
constraint_handler_t set_constraint_handler_s( constraint_handler_t handler );
+		 (since C11)

Configures the handler to be called by all bounds-checked functions on a runtime constraint violation or restores the default handler (if handler is a null pointer)

+

The handler must be a pointer to function of type constraint_handler_t, which is defined as

+
Defined in header <stdlib.h> 
typedef void (*constraint_handler_t)( const char *restrict msg,
+                                      void *restrict ptr,
+                                      errno_t error);
+		 (since C11)

On a runtime constraint violation, it is called with the following arguments:

+
+1) pointer to character string that describes the error
+2) pointer to an implementation-defined object or a null pointer. Examples of implementation-defined objects are objects that give the name of the function that detected the violation and the line number when the violation was detected
+3) the error about to be returned by the calling function, if it happens to be one of the functions that return errno_t +

If set_constraint_handler_s is never called, the default handler is implementation-defined: it may be abort_handler_s, ignore_handler_s, or some other implementation-defined handler. As with all bounds-checked functions, set_constraint_handler_s and constraint_handler_t are only guaranteed to be available if __STDC_LIB_EXT1__ is defined by the implementation and if the user defines __STDC_WANT_LIB_EXT1__ to the integer constant 1 before including <stdlib.h>.

+

Parameters

+ +
handler - pointer to function of type constraint_handler_t or a null pointer

Return value

A pointer to the previously-installed runtime constraints handler. (note: this pointer is never a null pointer because calling set_constraint_handler_s(NULL) sets up the system default handler)

+

Example

#define __STDC_WANT_LIB_EXT1__ 1
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+ 
+int main(void)
+{
+#ifdef __STDC_LIB_EXT1__
+    char dst[2];
+    set_constraint_handler_s(ignore_handler_s);
+    int r = strcpy_s(dst, sizeof dst, "Too long!");
+    printf("dst = \"%s\", r = %d\n", dst, r);
+    set_constraint_handler_s(abort_handler_s);
+    r = strcpy_s(dst, sizeof dst, "Too long!");
+    printf("dst = \"%s\", r = %d\n", dst, r);
+#endif
+}

Possible output:

+
dst = "", r = 22
+abort_handler_s was called in response to a runtime-constraint violation.
+ 
+The runtime-constraint violation was caused by the following expression in strcpy_s:
+(s1max <= (s2_len=strnlen_s(s2, s1max)) ) (in string_s.c:62)
+ 
+Note to end users: This program was terminated as a result
+of a bug present in the software. Please reach out to your
+software's vendor to get more help.
+Aborted

References

See also

+ +
+
(C11)
 abort callback for the bounds-checked functions
(function)
+
(C11)
 ignore callback for the bounds-checked functions
(function)
+

+ © cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
+ https://en.cppreference.com/w/c/error/set_constraint_handler_s +

+
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