Please refer these Code Examples for GPIO usage in PSoC6, this will give an idea of all the possibility of usage available in PSoC6:
From the document you pointed out:
The preferred read method for use with ModusToolbox is using #defines provided by the configuration tool pin names. Pin name
#defines are located in \\<ProjectName>_config\GeneratedSource\cycfg_pins.h.
The problem is the THERE IS NO SUCH FILE. Searched all the generated files for any kind of reference to
the ALIAS names I gave the pins, but with 0 result...
You will get this \GeneratedSource\cycfg_pins.h. file by following the steps which as follows:
Go to File->new -> ModusToolbox Application
and then select the Device .
then Import the ModusToolbox based CE project .
modus.mk is the project file to be imported or opened.
I did so and I was able to see the file as shown in this image below:
Note: Ensure that your psoc6pdl_Cortex-M4 file is opened.
I don't have any Modus Toolbox in the File->new selection ???
You should find something like this as highlighted
If you are unable to find so please try uninstalling and then installing ModusToolbox from this link: