/WL (Enable One-Line Diagnostics)

Appends additional information to an error or warning message.




Error and warning messages from the C++ compiler can be followed by additional information that appears, by default, on a new line. When you compile from the command line, the extra line of information can be appended to the error or warning message. It's useful if you capture your build output to a log file and then process that log to find all errors and warnings. A semicolon will separate the error or warning message from the additional line.

Not all error and warning messages have an extra line of information. The following code will generate an error that has another line of information. It lets you test the effect when you use /WL.

// compiler_option_WL.cpp
// compile with: /WL
#include <queue>
int main() {
   std::queue<int> q;
   q.fromthecontinuum();   // C2039

To set this compiler 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 Configuration Properties > Linker > Command Line property page.

  3. Enter the compiler option in the Additional Options box.

To set this compiler option programmatically

See also

MSVC Compiler Options
MSVC Compiler Command-Line Syntax