PRB: Unable to Set CodeView Breakpoint on Desired Line

• Microsoft CodeView for MS-DOS, versions 2.2, 3.0, 3.11, 3.14, 4.0, 4.01, 4.05, and 4.1
• Microsoft CodeView for OS/2, versions 2.2, 3.0, 3.11, 3.12, and 3.5
• Microsoft CodeView for Windows, versions 3.0, 3.05, 3.06, 3.07, 4.0, 4.01, and 4.1
• Microsoft CodeView for Win32s, version 4.25

SYMPTOMS

In CodeView, an attempt to set a breakpoint on a specified line fails.

CAUSE

The compiler command line did not specify both the /Od and /Zi option switches. Some compiler optimizations concatenate code in the executable file unless the command line specifies /Od to disable all optimizations.

RESOLUTION

Recompile the code with the correct options specified.

MORE INFORMATION

The code example below demonstrates this problem. When the code is compiled with only the /Zi switch, you cannot set a breakpoint on the indicated line.

Sample Code

/*
 * Compile options needed: /Zi
 */

#include <stdio.h>

int func();

void main(void)

   int a, b, c;

   a = func();  // You cannot set a breakpoint on this line because
                // the default optimization concatenates it with the
                // following line to form the expression:
                //    b = (a = func()) + c
   b = a + c;

int func()

   return(10);