_CrtSetReportFile

Identifies the file or stream to be used by _CrtDbgReport as a destination for a specific report type (debug version only).

_HFILE _CrtSetReportFile( int reportType, _HFILE reportFile );

For additional compatibility information, see Compatibility in the Introduction.

Libraries

Return Value

Upon successful completion, _CrtSetReportFile returns the previous report file defined for the report type specified in reportType. If an error occurs, the report file for reportType is not modified and_CrtSetReportFile returns _CRTDBG_HFILE_ERROR.

Parameters

reportType

Report type: _CRT_WARN, _CRT_ERROR, _CRT_ASSERT

reportFile

New report file for reportType, see the following table

Remarks

_CrtSetReportFile is used in conjunction with the _CrtSetReportMode function to define the destination(s) for a specific report type generated by _CrtDbgReport. When _CrtSetReportMode has been called to assign the _CRTDBG_MODE_FILE reporting mode for a specific report type, _CrtSetReportFile should then be called to define the specific file or stream to use as the destination. When _DEBUG is not defined, calls to _CrtSetReportFile are removed during preprocessing.

The _CrtSetReportFile function assigns the new report file specified in reportFile to the report type specified in reportType and returns the previously defined report file for reportType. The following table lists the available choices for reportFile and the resulting behavior of _CrtDbgReport. These options are defined as bit-flags in CRTDBG.H.

When the report destination is a file, _CrtSetReportMode is called to set the file bit-flag and _CrtSetReportFile is called to define the specific file to use. The following code fragment demonstrates this configuration:

_CrtSetReportMode( _CRT_ASSERT, _CRTDBG_MODE_FILE );
_CrtSetReportFile( _CRT_ASSERT, _CRTDBG_FILE_STDERR );

The report file used by each report type can be separately controlled. For example, it is possible to specify that a reportType of _CRT_ERROR be reported to stderr, while a reportType of _CRT_ASSERT be reported to a user-defined file handle or stream.

For more information about defining the report mode(s) and file for a specific report type, see _CrtDbgReport, _CrtSetReportMode and the section Debug Reporting Functions of the C Run-Time Library.

Example

/* 
 * REPORT.C:
 * In this program, calls are made to the _CrtSetReportMode,
 * _CrtSetReportFile, and _CrtSetReportHook functions.
 * The _ASSERT macros are called to evaluate their expression.
 * When the condition fails, these macros print a diagnostic message
 * and call _CrtDbgReport to generate a debug report and the
 * client-defined reporting function is called as well.
 * The _RPTn and _RPTFn group of macros are also exercised in
 * this program, as an alternative to the printf function.
 * When these macros are called, the client-defined reporting function
 * takes care of all the reporting - _CrtDbgReport won't be called.
 */

#include <stdio.h>
#include <string.h>
#include <malloc.h>
#include <crtdbg.h>

/* 
 * Define our own reporting function.
 * We'll hook it into the debug reporting
 * process later using _CrtSetReportHook.
 *
 * Define a global int to keep track of
 * how many assertion failures occur.
 */
int gl_num_asserts=0;
int OurReportingFunction( int reportType, char *userMessage, int *retVal )
{
   /*
    * Tell the user our reporting function is being called.
    * In other words - verify that the hook routine worked.
    */
   fprintf("Inside the client-defined reporting function.\n", STDOUT);
   fflush(STDOUT);

   /*
    * When the report type is for an ASSERT,
    * we'll report some information, but we also
    * want _CrtDbgReport to get called - 
    * so we'll return TRUE.
    *
    * When the report type is a WARNing or ERROR,
    * we'll take care of all of the reporting. We don't
    * want _CrtDbgReport to get called - 
    * so we'll return FALSE.
    */
   if (reportType == _CRT_ASSERT)
   {
      gl_num_asserts++;
      fprintf("This is the number of Assertion failures that have occurred: %d \n", gl_num_asserts, STDOUT);
      fflush(STDOUT);
      fprintf("Returning TRUE from the client-defined reporting function.\n", STDOUT);
      fflush(STDOUT);
      return(TRUE);
   } else {
      fprintf("This is the debug user message: %s \n", userMessage, STDOUT);
      fflush(STDOUT);
      fprintf("Returning FALSE from the client-defined reporting function.\n", STDOUT);
      fflush(STDOUT);
      return(FALSE);
   }

   /*
    * By setting retVal to zero, we are instructing _CrtDbgReport
    * to continue with normal execution after generating the report.
    * If we wanted _CrtDbgReport to start the debugger, we would set
    * retVal to one.
    */
   retVal = 0;
}

int main()
{
      char *p1, *p2;

   /* 
    * Hook in our client-defined reporting function.
    * Every time a _CrtDbgReport is called to generate
    * a debug report, our function will get called first.
    */
   _CrtSetReportHook( OurReportingFunction );

   /* 
    * Define the report destination(s) for each type of report
    * we are going to generate.  In this case, we are going to
    * generate a report for every report type: _CRT_WARN,
    * _CRT_ERROR, and _CRT_ASSERT.
    * The destination(s) is defined by specifying the report mode(s)
    * and report file for each report type.
    * This program sends all report types to STDOUT.
    */                                             
   _CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_FILE);
   _CrtSetReportFile(_CRT_WARN, _CRTDBG_FILE_STDOUT);
   _CrtSetReportMode(_CRT_ERROR, _CRTDBG_MODE_FILE);
   _CrtSetReportFile(_CRT_ERROR, _CRTDBG_FILE_STDOUT);
   _CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_FILE);
   _CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDOUT);

   /*
    * Allocate and assign the pointer variables
    */
   p1 = malloc(10);
   strcpy(p1, "I am p1");
   p2 = malloc(10);
   strcpy(p2, "I am p2");

   /*
    * Use the report macros as a debugging
    * warning mechanism, similar to printf.
    *
    * Use the assert macros to check if the
    * p1 and p2 variables are equivalent.
    *
    * If the expression fails, _ASSERTE will
    * include a string representation of the
    * failed expression in the report.
    *
    *  _ASSERT does not include the
    * expression in the generated report.
    */
   _RPT0(_CRT_WARN, "\n\n Use the assert macros to evaluate the expression p1 == p2.\n");
   _RPTF2(_CRT_WARN, "\n Will _ASSERT find '%s' == '%s' ?\n", p1, p2);
   _ASSERT(p1 == p2);

   _RPTF2(_CRT_WARN, "\n\n Will _ASSERTE find '%s' == '%s' ?\n", p1, p2);
   _ASSERTE(p1 == p2);

   _RPT2(_CRT_ERROR, "\n \n '%s' != '%s'\n", p1, p2);
   
   free(p2);
   free(p1);

   return 0;
}

Output

Inside the client-defined reporting function.
This is the debug user message: Use the assert macros to evaluate the expression p1 == p2
Returning FALSE from the client-defined reporting function.
Inside the client-defined reporting function.
This is the debug user message: dbgmacro.c(54) : Will _ASSERT find 'I am p1' == 'I am p2' ?
Returning FALSE from the client-defined reporting function.
Inside the client-defined reporting function.
This is the number of Assertion failures that have occurred: 1
Returning TRUE from the client-defined reporting function.
dbgmacro.c(55) : Assertion failed
Inside the client-defined reporting function.
This is the debug user message: dbgmacro.c(57) : Will _ASSERTE find 'I am p1' == 'I am p2' ?
Returning FALSE from the client-defined reporting function.
Inside the client-defined reporting function.
This is the number of Assertion failures that have occurred: 2
Returning TRUE from the client-defined reporting function.
dbgmacro.c(58) : Assertion failed: p1 == p2
Inside the client-defined reporting function.
This is the debug user message: 'I am p1' != 'I am p2'
Returning FALSE from the client-defined reporting function.

Debug Functions

See Also   _CrtDbgReport