/DEBUG (Generate debug info)

The /DEBUG linker option creates a debugging information file for the executable.

Syntax

/DEBUG[:{FASTLINK|FULL|NONE}]

Remarks

The /DEBUG option puts the debugging information from linked object and library files into a program database (PDB) file. It updates the PDB during subsequent builds of the program.

An executable (an EXE or DLL file) created for debugging contains the name and path of the corresponding PDB. The debugger reads the embedded name and uses the PDB when you debug the program. The linker uses the base name of the program and the extension .pdb to name the program database, and embeds the path where it was created. To override this default, set the /PDB option and specify a different file name.

The /DEBUG:FASTLINK option is available in Visual Studio 2017 and later. This option generates a limited PDB that indexes into the debug information in the object files and libraries used to build the executable instead of making a full copy. You can only use this limited PDB to debug from the computer where the binary and its libraries were built. If you deploy the binary elsewhere, you may debug it remotely from the build computer, but not directly on the test computer. Since Visual Studio 2019, /DEBUG:FULL linking times have improved significantly, and /DEBUG:FASTLINK isn't always faster than /DEBUG:FULL. Since /DEBUG:FASTLINK no longer provides large build time improvements and results in a slower debugging experience versus /DEBUG:FULL, this option is no longer recommended.

A /DEBUG:FASTLINK PDB can be converted to a full PDB that you can deploy to a test machine for local debugging. In Visual Studio, use the Property Pages dialog as described below to create a full PDB for the project or solution. In a developer command prompt, you can use the mspdbcmf.exe tool to create a full PDB.

The /DEBUG:FULL option moves all private symbol information from individual compilation products (object files and libraries) into a single PDB, and can be the most time-consuming part of the link. However, the full PDB can be used to debug the executable when no other build products are available, such as when the executable is deployed.

The /DEBUG:NONE option doesn't generate a PDB.

Specifying /DEBUG with no extra arguments is equivalent to specifying /DEBUG:FULL.

The compiler's /Z7 (C7 Compatible) option causes the compiler to leave the debugging information in the object (OBJ) files. You can also use the /Zi (Program Database) compiler option to store the debugging information in a PDB for the OBJ file. The linker looks for the object's PDB first in the absolute path written in the OBJ file, and then in the directory that contains the OBJ file. You can't specify an object's PDB file name or location to the linker.

/INCREMENTAL is implied when /DEBUG is specified.

/DEBUG changes the defaults for the /OPT option from REF to NOREF and from ICF to NOICF, so if you want the original defaults, you must explicitly specify /OPT:REF or /OPT:ICF after the /DEBUG option.

It isn't possible to create an EXE or DLL that contains debug information. Debug information is always placed in an OBJ or PDB file.

To set this linker option in the Visual Studio development environment

  1. Open the project's Property Pages dialog box. For details, see Set C++ compiler and build properties in Visual Studio.

  2. Select the Linker > Debugging property page.

  3. Modify the Generate Debug Info property to enable or disable PDB generation. This property enables /DEBUG:FASTLINK by default in Visual Studio 2017 and later.

  4. Modify the Generate Full Program Database File property to enable /DEBUG:FULL for full PDB generation for every incremental build.

To set this linker option programmatically

  1. See GenerateDebugInformation.

See also

MSVC linker reference
MSVC linker options