Module: Prism::LibRubyParser
Do not use. This module is for internal use only.
Relationships & Source Files | |
Namespace Children | |
Classes:
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Super Chains via Extension / Inclusion / Inheritance | |
Class Chain:
self,
FFI::Library
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Defined in: | lib/prism/ffi.rb |
Class Method Summary
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.load_exported_functions_from(header, *functions)
Read through the given header file and find the declaration of each of the given functions.
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.resolve_type(type)
Convert a native C type declaration into a symbol that FFI understands.
Class Method Details
.load_exported_functions_from(header, *functions)
Read through the given header file and find the declaration of each of the given functions. For each one, define a function with the same name and signature as the C function.
# File 'lib/prism/ffi.rb', line 35
def self.load_exported_functions_from(header, *functions) File.foreach(File. ("../../include/#{header}", __dir__)) do |line| # We only want to attempt to load exported functions. next unless line.start_with?("PRISM_EXPORTED_FUNCTION ") # We only want to load the functions that we are interested in. next unless functions.any? { |function| line.include?(function) } # Parse the function declaration. unless /^PRISM_EXPORTED_FUNCTION (?<return_type>.+) (?<name>\w)\((?<arg_types>.)\);$/ =~ line raise "Could not parse #{line}" end # Delete the function from the list of functions we are looking for to # mark it as having been found. functions.delete(name) # Split up the argument types into an array, ensure we handle the case # where there are no arguments (by explicit void). arg_types = arg_types.split(",").map(&:strip) arg_types = [] if arg_types == %w[void] # Resolve the type of the argument by dropping the name of the argument # first if it is present. arg_types.map! { |type| resolve_type(type.sub(/\w+$/, "")) } # Attach the function using the FFI library. attach_function name, arg_types, resolve_type(return_type) end # If we didn't find all of the functions, raise an error. raise "Could not find functions #{functions.inspect}" unless functions.empty? end
.resolve_type(type)
Convert a native C type declaration into a symbol that FFI understands. For example:
const char * -> :pointer
bool -> :bool
size_t -> :size_t
void -> :void
# File 'lib/prism/ffi.rb', line 27
def self.resolve_type(type) type = type.strip type.end_with?("*") ? :pointer : type.delete_prefix("const ").to_sym end