Macro param name scope?

I see a lot of macros that have very simple param names. What happens if one of those symbols is already defined or is the same name as a param used in another macro?
I have really long macro param names cause I have been using:
filename_macroname_paramname

But if I can get away with shorter names I would use them for readability.

I did the below test and it acts kind of funny. If I make the !define someBlah "adefine" without the space, then it compiles correctly and outputs "test" then "adefine".

OutFile testSymbol.exe

Page components

Page directory

Page instfiles



!define someBlah "a define"



!macro DoSomethin someBlah

  DetailPrint "${someBlah}"

!macroend





Section mySection

  !insertmacro DoSomethin "test"

  DetailPrint "${someBlah}"

SectionEnd

The compile log:

OutFile: "testSymbol.exe"

Page: components

Page: directory

Page: instfiles

!define: "someBlah"="a define"

Section: "mySection"

!insertmacro: DoSomethin

DetailPrint: "test"

!insertmacro: end of DoSomethin

DetailPrint expects 1 parameters, got 2.

Usage: DetailPrint message

Macro parameters override global defines.