I work on a large codebase of code written in C for embedded processors. There are many conditionally compiled statements in the code that makes it difficult to read. I would like to know if there exists a perl script that will execute like a C pre-processor to strip away code which is not relavant based on a set of macros. The output from the script would then be used just for reading the code. I want to use PERL because I want to be able to easily modify the script. For example, in the code snippet below, I would want to include the code unmodified if the macro BCS_GFSK_TRACKING_HW_FIX if defined. I would not want to replace BCS_LINKTYPE_ACL_MDR with an actual number because I want to maintain the readability of the code. 
    #ifdef BCS_GFSK_TRACKING_HW_FIX
    // The following is HWWA for BR freq tracking    
    switch ( logicalConnInfo )
    {
        case BCS_LINKTYPE_ACL_MDR:
        case BCS_LINKTYPE_ESCO_MDR:
        {
            REG32(dcOffEstCtrl5_adr) &= ~(((UINT32)1) << TRACK_GFSK_FR
+EQ_MASK_OFFSET);
            break;
        }
        default:
        {
            REG32(dcOffEstCtrl5_adr) |= (((UINT32)1) << TRACK_GFSK_FRE
+Q_MASK_OFFSET);
            break;
        }
    }
    #endif

[download]
I found a script at the location below, but it does not appear to handle complex statements such as: 
    #if (defined(BCM20702) || defined(BCM20733)) && !defined(FPGA_BD_2
+045)

[download]
http://software.hixie.ch/utilities/unix/preprocessor/

In reply to C code pre-processor by dgsmith_50

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