getDefines: Find the constants defined via the pre-processor
In omegahat/RGCCTranslationUnit: R interface to GCC source code information

Description Usage Arguments Author(s) See Also

This attempts to find the definitions of literal constants that are created by the C/C++ pre-processor and not in the C/C++ language. This finds entries such as #define FOO 1 or #define STR "my string". It does not handle conditional definitions, i.e. within #ifdef statements.

This works by making a system call to grep on the files in the target directory. (It does not work recursively, but could easily do so if that was useful rather than excessive.) It discards lines that start with a C++ comment or with #include. Then it delegates the identification of literal constant definitions to the internal function processDefines which looks for all lines that start with #define.

A "better" approach is to use getCppDefines which works directly from the output of the pre-processor.

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getDefines(dir = character(), pattern = ".*", files = "*",
           class = c("TopLevelConstants", "DefineConstants"),
           removeDuplicates = TRUE, getSkipped = FALSE)

`dir`	the directory containing the header files
`pattern`	pattern for `grep`.
`files`	shell glob pattern to identify the files to search
`class`	the class of the resulting object. Currently ignored.
`removeDuplicates`	a logical value that controls whether to remove duplicate definitions, leaving the last ones.
`getSkipped`	a logical value.