6.1 About the Compiler

6.1.3 Compiler messages and warnings

The Compiler provides the following types of messages and warnings:

• Compiler messages

These messages provide information about the compilation; they include the message"Compiling function...", which identifies the function that is being compiled.

Compiler messages are suppressed by default. You can turn them on by calling the functioncompile,compile-file, orcompiler-options with the keyword argument:messages specified ast.

• Compiler file messages

These messages provide information about the compilation of files; they include the messages"Reading source file..." and"Writing binary file...", which identify the file that is being compiled.

Compiler file messages are displayed by default. You can suppress them by calling the functioncompile,compile-file, orcompiler-options with the keyword argument:file-messages specified asnil.

• Compiler optimization mode messages

These messages tell you whether you are using the production mode or the development mode of the Compiler. Optimization mode messages are displayed by default. You can suppress them by calling the functioncompile,compile-file, orcompiler-options with the keyword argument:optimize-message specified asnil. If:optimize-message is specified as:terse, the Compiler displays terse mode messages.

• Compiler warnings

These messages provide warnings about certain situations, such as when an undefined function is called or when a variable is referenced out of scope. For example, if you compile a function that contains a free reference to a variable that has not been declaredspecial, the Compiler issues a warning similar to the following:

> (defun bad-function (x)
    (+ x y))
BAD-FUNCTION

> (compile 'bad-function)
;;; Warning: Free variable Y assumed to be special
BAD-FUNCTION

Unless instructed otherwise, the Compiler prints a warning for every call in the source code to a function that is not defined in the current image or in the file being compiled. You can suppress or defer undefined function warnings in various ways:

• You can suppress all undefined function warnings by calling the functioncompiler-options, the functioncompile, or the functioncompile-file with the keyword argument:undef-warnings specified asnil:

(compiler-options :undef-warnings nil)

• You can suppress undefined function warnings for specified functions by including anftype declaration in the source code. For example, if you compile code containing the following declaration, the Compiler never issues an undefined function warning formy-function, even if the function is undefined:

(declare (ftype (function (t) t) my-function))

• You can defer undefined function warnings until the end of the execution of a body of code by using the macrowith-deferred-warnings. This macro is especially useful when you are compiling many files. For example, the following expression defers undefined function warnings until all of the code inmy-file andmy-other-file has been executed:

(with-deferred-warnings (compile-file "my-file")
                        (compile-file "my-other-file"))

Generated with Harlequin WebMaker