os/linux/ld: add functions for querying dynamic linker

Library/Homebrew/os/linux/ld.rb

@@ -0,0 +1,75 @@
+# typed: true
+# frozen_string_literal: true
+
+module OS
+ module Linux
+ # Helper functions for querying `ld` information.
+ #
+ # @api private
+ module Ld
+ module_function
+
+ sig { returns(String) }
+ def brewed_ld_so_diagnostics
+ brewed_ld_so = HOMEBREW_PREFIX/"lib/ld.so"
+ return "" unless brewed_ld_so.exist?
+
+ ld_so_output = Utils.popen_read(brewed_ld_so, "--list-diagnostics")
+ return "" unless $CHILD_STATUS.success?
+
+ ld_so_output
+ end
+
+ sig { returns(String) }
+ def sysconfdir
+ fallback_sysconfdir = "/etc"
+
+ match = brewed_ld_so_diagnostics.match(/path.sysconfdir="(.+)"/)
+ return fallback_sysconfdir unless match
+
+ match.captures.compact.first || fallback_sysconfdir
+ end
+
+ sig { returns(T::Array[String]) }
+ def system_dirs
+ dirs = []
+
+ brewed_ld_so_diagnostics.split("\n").each do |line|
+ match = line.match(/path.system_dirs\[0x.*\]="(.*)"/)
+ next unless match
+
+ dirs << match.captures.compact.first
+ end
+
+ dirs
+ end
+
+ def library_paths(conf_path = Pathname(sysconfdir)/"ld.so.conf")
+ conf_file = Pathname(conf_path)
+ paths = Set.new
+ directory = conf_file.realpath.dirname
+
+ conf_file.readlines.each do |line|
+ # Remove comments and leading/trailing whitespace
+ line.strip!
+ line.sub!(/\s*#.*$/, "")
+
+ if line.start_with?(/\s*include\s+/)
+ include_path = Pathname(line.sub(/^\s*include\s+/, "")).expand_path
+ wildcard = include_path.absolute? ? include_path : directory/include_path
+
+ Dir.glob(wildcard.to_s).each do |include_file|
+ paths += library_paths(include_file)
+ end
+ elsif line.empty?
+ next
+ else
+ paths << line
+ end
+ end
+
+ paths.to_a
+ end
+ end
+ end
+end

Library/Homebrew/os/linux/ld.rbi

@@ -0,0 +1,9 @@
+# typed: strict
+
+module OS
+ module Linux
+ module Ld
+ requires_ancestor { Pathname }
+ end
+ end
+end