CMake bracket escape character for custom target command

Question

I am in need of the bracket escape character used to avoid quoting special characters in CMake when parsing make commands to add_custom_target. This is more of a syntax problem that from my understanding, is not covered in CMake documentation.

An example case is:

add_custom_target ( defined_path ALL .exe <args1> | ( ! grep ... )

In this example, the extension to <args1> is resolved as | "(" grep ... ")". Unfortunately appending backslash before the brackets only works for string cases, i.e. assigning to a variable with set: set ( something "\(" ). Even then the variable itself is resolved in the build.make surrounded by quotations. Likewise parsing a pre-formatted list using separate_arguments also resolves with quotations.

The full command without the make formatting is executed successfully.

Answer 1

Cmake requires an explicit call to shell in the target command