Breakpoints Overview
The following sections provide some basic information on breakpoints:
Breakpoint Glyphs
Basic Breakpoints
Advanced Breakpoints
Breakpoint Limitations
Breakpoint Glyphs
The source windows and Disassembly window show breakpoint locations by displaying symbols called glyphs in the left margin. The following table describes these glyphs.
If you hover the mouse cursor over a breakpoint glyph, a breakpoint tip appears with more information. This information is especially useful for error and warning breakpoints.
| Glyph | Description |
|---|---|
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Normal breakpoint. The solid glyph indicates that the breakpoint is enabled. The hollow glyph indicates that it is disabled. |
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Advanced breakpoint. Active/disabled. The + sign indicates that the breakpoint has at least one advanced feature, such as condition, hit count, or filter, attached to it. |
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Mapped breakpoint. Active/disabled. The breakpoint is set in ASP/ASP.NET code and mapped to a breakpoint in the corresponding HTML page. |
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Tracepoint. Active/disabled. Hitting this point performs a specified action but does not break program execution. |
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Advanced tracepoint. Active/disabled. The + sign indicates that the tracepoint has at least one advanced feature, such as condition, hit count, or filter, attached to it. |
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Mapped tracepoint. Active/disabled. The tracepoint is set in ASP/ASP.NET code and mapped to a tracepoint in the corresponding HTML page. |
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Breakpoint or tracepoint error. The X indicates that the breakpoint or tracepoint could not be set due to an error condition. |
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Breakpoint or tracepoint warning. The exclamation mark indicates that a breakpoint or tracepoint could not be set due to a temporary condition. Usually, this means the code at the breakpoint or tracepoint location has not been loaded. When the code is loaded, the breakpoint will be enabled and the glyph will change. |
Basic Breakpoints
The most basic breakpoints are those set on a line of source code or on a function. The following topics describe how to set and manipulate these basic breakpoints:
How to: Set a Simple Breakpoint
How to: Set a Function Breakpoint
How to: Enable or Disable a Breakpoint
How to: Edit a Breakpoint Location
How to: Set a Breakpoint on a Function Call from the Call Stack Window
.gif) Note |
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If you have more than 64,000 lines of code in one source file, breakpoints placed on lines after 64,000 will not be hit. |
Advanced Breakpoints
If you have Visual C++ Express Edition or Visual Studio, any edition, you can set more advanced breakpoints, create breakpoints with advanced features, and manipulate breakpoints in more powerful ways.
For some tasks, the default IDE settings you chose when you set up Visual Studio may hide the required menu command. For more information, see How to: Restore Hidden Debugger Commands.
Breakpoints on Memory Addresses and Memory Changes
You can set a breakpoint on a memory address. For more information, see How to: Set an Address Breakpoint. In C/C++, you can set a breakpoint that is hit when memory changes. For more information, see How to: Set a Data Breakpoint (Native Only).
Filters, Hit Counts, and Conditions
Filters, hit counts, and conditions are advanced features that you can attach to any type of breakpoint, including tracepoints.
A filter causes a breakpoint to be set on specified machines, processes, and threads. Filters are very useful when you are debugging an application that runs on multiple processors. For more information, see How to: Specify a Breakpoint Filter.
A hit count keeps track of how many times a breakpoint is hit. By default, a breakpoint breaks execution every time it is hit. You can change this behavior so the breakpoint breaks only when the hit count equals or exceeds a specified value or when the hit count is the multiple of a given value. The specified hit count is retained only for the debugging session. For more information, see How to: Specify a Hit Count.
A condition is an expression that is evaluated to determine whether the breakpoint will break. For more information, see How to: Specify a Breakpoint Condition.
Advanced Breakpoints Interface
Power users can take advantage of advanced features in the following topics:
Breakpoint Limitations
Avoid setting breakpoints on system components when you are debugging mixed-mode, native and managed, code. Setting a breakpoint on a system component during mixed-mode debugging can cause the common language runtime to break and the debugger to stop responding. For more information, see How to: Debug Mixed-Mode Applications.