How to set ISPP defines based on default Inno Setup variables? - preprocessor

I was trying to:
#define CommonAppData {commonappdata}
but it yields:
Compiler Error
[ISPP] Expression expected but opening brace ("{") found.
How to achieve this with Inno Setup PreProcessor?

{commonappdata} cannot be expanded at compile time, i.e. when the pre-processor runs because it is only known at runtime: It identifies the common application data directory on the machine where the compiled installer is run.
Maybe if you could clarify how you intend to use that define we might be able to help. If for example what you're really interested in is not the common app data directory on the target machine but the one on the developer machine, then you can probably use this:
#define CommonAppData GetEnv("COMMONAPPDATA")
If however you intend to use that define for populating Inno properties that are themselves capable of expanding the constant at runtime then you should use this:
#define CommonAppData "{commonappdata}"
Hope this helps.

#define is a inno setup pre-processor directive, in a pre-compile phase. It works much like a C pre-processor.
By defining a pre-processor variable, we force the compiler to see a script after the ispp defines are resolved:
Inno Setup Preprocessor (ISPP) is an add-on for Jordan Russell's Inno Setup compiler. More technically speaking, it is an additional layer between GUI (your Inno Setup script) and the compiler, which before passing the text intercepts and modifies it in a way it is told by using special directives in the script text.
That said, I can't find a source in documentation nor have time to digg into the source code, but I'm pretty sure inno setup variables are not available during this pre-compile time.
If you just want the defined variable to contain the string {commonappdata}, use it directly in your source... if you want the defined variable to have the run-time value of commonappdata, it doesn't seem possible to me, because that value is determined at runtime as its current value depends on the target machine (windows version, language, etc.).
If you think it twice, it doesn't make sense to try to use that value at pre-compile or compile time... this is just the whole fact that brings inno setup constants like {commonappdata}, {destdir} and the like to existence... that you can express in a standard way at compile time a unknown but meaningful value, which will be known and evaluated at runtime.

You'll probably need to escape the brace. Something like:
#define CommonAppData {{commonappdata}

Related

Does the preprocessor pass environment variables?

Does the preprocessor have a mechanism to access environment variables directly as defines, without the need to define them on the command line?
For instance,
SOME_VAR=foo gcc code.c
and
#if ENV_SOME_VAR == "foo"
#define SOME_VAR_IS_FOO
#endif
No, the standard C preprocessor has no such mechanism, and I'm not aware of any compiler extensions that provide such a feature either.
However, you can do this using a build system, such as Cmake or GNU Autoconf, the latter being a part of the GNU Autotools build system. A simple shell script would do this as well, though all of these options mean you'd need to test the environment variable to determine whether to define ENV_SOME_VAR, in which case, you might just define it using something like the following:
-DENV_SOME_VAR="${SOME_VAR:-unfoo}"
That would define ENV_SOME_VAR in your C file as the value of $SOME_VAR if it's set or to the string "unfoo" if $SOME_VAR is empty (null) or unset.

run-time evaluation of values in DelphiWebScript

My delphi application runs scripts using JvInterpreter (from the Jedi project).
A feature I use is runtime evaluation of expressions.
Script Example:
[...]
ShowMessage(X_SomeName);
[...]
JvInterpreter doesn't know X_SomeName.
When X_SomeName's value is required the scripter calls its OnGetValue-callback.
This points to a function I handle. There I lookup X_SomeName's value and return it.
Then JvInterpreter calls ShowMessage with the value I provided.
Now I consider switching to DelphiWebScript since it has a proper debug-interface and should also be faster than JvInterpreter.
Problem: I didn't find any obvious way to implement what JvInterpreter does with its OnGetValue/OnSetValue functions, though.
X_SomeName should be considered (and actually is, most of the time) a variable which is handled by the host application.
Any Ideas?
Thanks!
You can do that through the language extension mechanism, which has a FindUnknownName method that allows to register symbols on the spot.
It is used in the asm lib module demo, and you can also check the new "AutoExternalValues" test case in ULanguageExtensionTests, which should be closer to what you're after.

Including client files for shared file

Okay, so I have 2 projects for a game. One is the server and one is the client. I keep the shared units into a shared folder that I use to include in my client/server project. There is a problem however: I have a shared file that needs a different file for client / server. Example: mySharedLib needs to print to the console, however the client/server console is different. What are my options? Thanks
In your shared file you could use define compiler directive
For example
{$IFDEF MYSERVER}
Writeln('Server'); // this code executes
{$ELSE}
Writeln('Client'); // this code does not execute
{$ENDIF}
Then in your server project define a MYSERVER define and in your client define a MYCLIENT one, then when the shared code seperates use an {$IFDEF) statement.
From the Delphi help on conditional definitions:
The conditional directives $IFDEF, $IFNDEF, $IF, $ELSEIF, $ELSE, $ENDIF, and $IFEND allow you to compile or suppress code based on the status of a conditional symbol. $IF and $ELSEIF allow you to base conditional compilation on declared Delphi identifiers. $IFOPT compiles or suppresses code depending on whether a specified compiler switch is enabled.
This will not however work if the shared code is in a DLL or any other sort of complied shared resource such as a package.
From the Delphi help on conditional definitions:
Conditional definitions are evaluated only when source code is recompiled. If you change a conditional symbol's status and then rebuild a project, source code in unchanged units may not be recompiled. Use Project|Build All Projects to ensure everything in your project reflects the current status of conditional symbols.
If they're different, they're not really a shared file anymore.

How can I tell if a module is being called dynamically or statically?

How can I tell if a module is being called dynamically or statically?
If you are operating on z/OS, you can accomplish this, but it is non-trivial.
First, you must trace up the save area chain and use CSVQUERY to find out which program owns each save area. Every other program will be a Cobol runtime module, like IGZCPAC. Under IMS, CICS, TSO, et al, those modules might be different. That is the easy part.
Once you know who owns all the relevant save areas, you can use the OS LOADER / BINDER / LINKER utilities to discover what artifacts are in the same modules. This is the non-easy part.
The ONLY way is to look at the output of the linkage editor (IEWL) or the load module itself. If the module is being called DYNAMICALLY then it will not exist in the main module, if it is being called STATICALLY then it will be seen in the load module. Calling a working storage variable, containing a program name, does not make a DYNAMIC call. This type of calling is known as IMPLICITE calling as the name of the module is implied by the contents of the working storage variable. Calling a program name literal.
Calling a working storage variable,
containing a program name, does not
make a DYNAMIC call.
Yes it does. Call variablename is always DYNAMIC.
Call 'literal' is dynamic or static according to the DYNAM/NODYNAM compiler option.
Caveat: This applies for IBM mainframe COBOL and I believe it is also part of the standard. It may not apply to other non-standard versions of COBOL.
For Micro Focus COBOL statically linking is controlled via call-convention on the call (bit 3) or via the compiler directive LITLINK.
When linking statically the case of the program-id/entry-point and the call itself is important, so you may want to ensure it is exact and use the CASE directive.
The reverse of LITLINK directive is the NOLITLINK directive or a call-convention without bit 3 set!
On Windows you can see the exported symbols in your .dll by using the "dumpbin /exports" utility and on Unix via the 'nm' utility.
A import .lib for the .dll created via "cbllink" can be created by using the '-K'command line option on cbllink.
Look at the call statement. If the called program is described in a literal then it's a static call. It's called a dynamic call if the called program is determined at runtime:
* Static call
call "THEPROGRAM"
* Dynamic call
call wsProgramName

statically analysing Lua code for potential errors

I'm using a closed-source application that loads Lua scripts and allows some customization through modifying these scripts. Unfortunately that application is not very good at generating useful log output (all I get is 'script failed') if something goes wrong in one of the Lua scripts.
I realize that dynamic languages are pretty much resistant to static code analysis in the way C++ code can be analyzed for example.
I was hoping though, there would be a tool that runs through a Lua script and e.g. warns about variables that have not been defined in the context of a particular script.
Essentially what I'm looking for is a tool that for a script:
local a
print b
would output:
warning: script.lua(1): local 'a' is not used'
warning: script.lua(2): 'b' may not be defined'
It can only really be warnings for most things but that would still be useful! Does such a tool exist? Or maybe a Lua IDE with a feature like that build in?
Thanks, Chris
Automated static code analysis for Lua is not an easy task in general. However, for a limited set of practical problems it is quite doable.
Quick googling for "lua lint" yields these two tools: lua-checker and Lua lint.
You may want to roll your own tool for your specific needs however.
Metalua is one of the most powerful tools for static Lua code analysis. For example, please see metalint, the tool for global variable usage analysis.
Please do not hesitate to post your question on Metalua mailing list. People there are usually very helpful.
There is also lua-inspect, which is based on metalua that was already mentioned. I've integrated it into ZeroBrane Studio IDE, which generates an output very similar to what you'd expect. See this SO answer for details: https://stackoverflow.com/a/11789348/1442917.
For checking globals, see this lua-l posting. Checking locals is harder.
You need to find a parser for lua (should be available as open source) and use it to parse the script into a proper AST tree. Use that tree and a simple variable visibility tracker to find out when a variable is or isn't defined.
Usually the scoping rules are simple:
start with the top AST node and an empty scope
item look at the child statements for that node. Every variable declaration should be added in the current scope.
if a new scope is starting (for example via a { operator) create a new variable scope inheriting the variables in the current scope).
when a scope is ending (for example via } ) remove the current child variable scope and return to the parent.
Iterate carefully.
This will provide you with what variables are visible where inside the AST. You can use this information and if you also inspect the expressions AST nodes (read/write of variables) you can find out your information.
I just started using luacheck and it is excellent!
The first release was from 2015.

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