func buildSettings()

in Sources/PackageLoading/PackageBuilder.swift [914:988]
59 lines of code
20 McCabe index (conditional complexity)

    func buildSettings(for target: TargetDescription?, targetRoot: AbsolutePath) throws -> BuildSettings.AssignmentTable {
        var table = BuildSettings.AssignmentTable()
        guard let target = target else { return table }

        // Process each setting.
        for setting in target.settings {
            let decl: BuildSettings.Declaration

            // Compute appropriate declaration for the setting.
            switch setting.name {
            case .headerSearchPath:

                switch setting.tool {
                case .c, .cxx:
                    decl = .HEADER_SEARCH_PATHS
                case .swift, .linker:
                    throw InternalError("unexpected tool for setting type \(setting)")
                }

                // Ensure that the search path is contained within the package.
                let subpath = try RelativePath(validating: setting.value[0])
                guard targetRoot.appending(subpath).isDescendantOfOrEqual(to: packagePath) else {
                    throw ModuleError.invalidHeaderSearchPath(subpath.pathString)
                }

            case .define:
                switch setting.tool {
                case .c, .cxx:
                    decl = .GCC_PREPROCESSOR_DEFINITIONS
                case .swift:
                    decl = .SWIFT_ACTIVE_COMPILATION_CONDITIONS
                case .linker:
                    throw InternalError("unexpected tool for setting type \(setting)")
                }

            case .linkedLibrary:
                switch setting.tool {
                case .c, .cxx, .swift:
                    throw InternalError("unexpected tool for setting type \(setting)")
                case .linker:
                    decl = .LINK_LIBRARIES
                }

            case .linkedFramework:
                switch setting.tool {
                case .c, .cxx, .swift:
                    throw InternalError("unexpected tool for setting type \(setting)")
                case .linker:
                    decl = .LINK_FRAMEWORKS
                }

            case .unsafeFlags:
                switch setting.tool {
                case .c:
                    decl = .OTHER_CFLAGS
                case .cxx:
                    decl = .OTHER_CPLUSPLUSFLAGS
                case .swift:
                    decl = .OTHER_SWIFT_FLAGS
                case .linker:
                    decl = .OTHER_LDFLAGS
                }
            }

            // Create an assignment for this setting.
            var assignment = BuildSettings.Assignment()
            assignment.value = setting.value
            assignment.conditions = buildConditions(from: setting.condition)

            // Finally, add the assignment to the assignment table.
            table.add(assignment, for: decl)
        }

        return table
    }