We define the abstract syntax trees (ASTs) that represent Common Lisp code. The AST is a very close representation of the source code, except that the environment is no longer present, so that there are no longer any different namespaces for functions and variables. And of course, operations such as MACROLET are not present because they only alter the environment.

The AST form is the preferred representation for some operations; in particular for the first stage of PROCEDURE INTEGRATION (sometimes called INLINING). It is the first stage of IR used by Cleavir.

Particular AST classes

There is mostly a different type of AST for each Common Lisp special operator, but there are some exceptions. Here are the Common Lisp special operators: BLOCK, CATCH, EVAL-WHEN, FLET, FUNCTION, GO, IF, LABELS, LET, LET*, LOAD-TIME-VALUE, LOCALLY, MACROLET, MULTIPLE-VALUE-CALL, MULTIPLE-VALUE-PROG1, PROGN, PROGV, QUOTE, RETURN-FROM, SETQ, SYMBOL-MACROLET, TAGBODY, THE, THROW, UNWIND-PROTECT.

Some of these only influence the environment and do not need a representation as ASTs. These are: LOCALLY, MACROLET, and SYMBOL-MACROLET.

FLET and LABELS are like LET except that the symbols the bind are in the function namespace, but the distinciton between namespeces no longer exists in the AST.

A LAMBDA expression, either inside (FUNCTION (LAMBDA ...)) or when it is the CAR of a compound form, compiles into a FUNCTION-AST. The other kind of FUNCTION special form, a function lookup, will end up as either a LEXICAL-AST for local functions, or a CONSTANT-FDEFINITION-AST for global.

We also define ASTs that do not correspond to any Common Lisp special operators, because we simplify later code generation that way.

System Information

Definition Index

• CLEAVIR-AST

  No documentation provided.

  • EXTERNAL SPECIAL-VARIABLE

    *POLICY*

    Source

    No documentation provided.
  • EXTERNAL CLASS

    AST

    Source

    The base class for all abstract syntax tree classes.

  • EXTERNAL CLASS

    BLOCK-AST

    Source

    AST representing a cl:block.

  • EXTERNAL CLASS

    BRANCH-AST

    Source

    This class is a generalization of IF-AST. Based on the TEST-AST, one of the zero or more BRANCH-ASTs, or else the DEFAULT-AST, will be evaluated and its values returned.
    
    This AST can be used for example in the implementation of fast CASE or TYPECASE operations.

  • EXTERNAL CLASS

    CALL-AST

    Source

    A function call.

  • EXTERNAL CLASS

    CASE-AST

    Source

    This AST can be used to select an execution path by comparing a given object against a fixed set of immediates. COMPAREES is a sequence of sequences of objects. If the primary value returned by the ARG-AST is EQ to one of the objects in the nth sequence, the nth branch is taken; if the value doesn't match any immediate the default branch is taken instead.
    This AST can only appear in the TEST position of a BRANCH-AST.

  • EXTERNAL CLASS

    CONSTANT-AST

    Source

    This class represents Lisp constants in source code.
    
    If the constant that was found was wrapped in QUOTE, then the QUOTE is not part of the value here, because it was stripped off.
    
    If the constant that was found was a constant variable, then the value here represents the value of that constant variable at compile time.

  • EXTERNAL CLASS

    CONSTANT-DYNAMIC-BIND-AST

    Source

    This AST represents the binding of a special variable.

  • EXTERNAL CLASS

    CONSTANT-FDEFINITION-AST

    Source

    No documentation provided.
  • EXTERNAL CLASS

    CONSTANT-SYMBOL-VALUE-AST

    Source

    No documentation provided.
  • EXTERNAL CLASS

    EQ-AST

    Source

    This AST can be used to to test whether two objects are identical.
    It has two children.  This AST can only appear in the TEST position of an IF-AST.

  • EXTERNAL CLASS

    FUNCTION-AST

    Source

    A function AST represents an explicit lambda expression, but also implicit lambda expressions such as the ones found in FLET and LABELS.
    
    The lambda list is not a normal lambda list.  It has the following form:
    ([r1 .. rl [&optional o1 ..om] [&rest r] [&key k1 .. kn &allow-other-keys]]])
    
    where:
    
     - Each ri is a LEXICAL-VARIABLE.
     - r is a LEXICAL-VARIABLE.
     - Each oi is a list of two LEXICAL-VARIABLEs.  The second of the two conceptually contains a Boolean value indicating whether the first one contains a value supplied by the caller.
     - Each ki is a list of a symbol and two LEXICAL-VARIABLEs.  The symbol is the keyword-name that a caller must supply in order to pass the corresponding argument.  The second of the two LEXICAL-VARIABLEs conceptually contains a Boolean value indicating whether the first LEXICAL-VARIABLE contains a value supplied by the caller.
    
    The LEXICAL-VARIABLEs in the lambda list are potentially unrelated to the variables that were given in the original lambda expression, and they are LEXICAL-VARIABLEs independently of whether the corresponding variable that was given in the original lambda expression is a lexical variable or a special variable.
    
    The body of the FUNCTION-AST must contain code that tests the second of the two LEXICAL-VARIABLEs and initializes variables if needed.  The if the second LEXICAL-VARIABLE in any oi contains FALSE, then the code in the body is not allowed to test the second LEXICAL-VARIABLEs of any of the ki because they may not be set correctly (conceptually, they all have the value FALSE then).

  • EXTERNAL CLASS

    GO-AST

    Source

    AST for a cl:go.
    Includes the destination TAG-AST directly, rather than a name. Note that the TAG-AST is not a child (subform).

  • EXTERNAL CLASS

    IF-AST

    Source

    This AST corresponds directly to the IF special operator.

  • EXTERNAL CLASS

    INLINE-AST

    Source

    An AST inserted around an inline function's AST, used to separate the inlined function from the rest of the code for AST-to-BIR.

  • EXTERNAL CLASS

    LEXICAL-AST

    Source

    A reference to a lexical variable.

  • EXTERNAL CLASS

    LEXICAL-BIND-AST

    Source

    AST representing the binding of a lexical variable.

  • EXTERNAL CLASS

    LEXICAL-VARIABLE

    Source

    Representation of a lexical variable.

  • EXTERNAL CLASS

    LOAD-TIME-VALUE-AST

    Source

    This AST corresponds directly to the LOAD-TIME-VALUE special operator. It has no child and it produces a single value.
    
    The optional argument READ-ONLY-P is not a child of the AST because it can only be a Boolean which is not evaluated, so we know at AST creation time whether it is true or false.

  • EXTERNAL CLASS

    MULTIPLE-VALUE-CALL-AST

    Source

    AST for cl:multiple-value-call. Unlike the special operator, only actual functions are acceptable, not all function designators.

  • EXTERNAL CLASS

    MULTIPLE-VALUE-PROG1-AST

    Source

    AST for cl:multiple-value-prog1

  • EXTERNAL CLASS

    PRIMOP-AST

    Source

    A PRIMOP-AST represents the invocation of a primitive operator.
    See the cleavir-primop system for more information.

  • EXTERNAL CLASS

    PROGN-AST

    Source

    An AST representing a cl:progn.

  • EXTERNAL CLASS

    RETURN-FROM-AST

    Source

    AST representing cl:return-from.
    This points directly to the corresponding BLOCK-AST rather than recording the name of the block. Note that the BLOCK-AST is not a child (subform).

  • EXTERNAL CLASS

    SET-CONSTANT-SYMBOL-VALUE-AST

    Source

    No documentation provided.
  • EXTERNAL CLASS

    SETQ-AST

    Source

    AST representing SETQ of a lexical variable.

  • EXTERNAL CLASS

    TAG-AST

    Source

    The TAG-AST includes the tag itself, and also the code following it that is not after another tag.

  • EXTERNAL CLASS

    TAGBODY-AST

    Source

    AST for a cl:tagbody.

  • EXTERNAL CLASS

    THE-AST

    Source

    This AST can be generated by from the THE special operator, but also implicitly from type declarations and assignments to variables with type declarations.

  • EXTERNAL CLASS

    TOP-LEVEL-FUNCTION-AST

    Source

    This AST is a subclass of FUNCTION-AST.  It is used when an AST is transformed by hoisting all the LOAD-TIME-VALUE-ASTs in the tree by turning them into LEXIAL-ASTs that are also required parameters of the TOP-LEVEL-FUNCTION-AST.
    
    This AST class supplies a slot that contains a list of the forms that were contained in the LOAD-TIME-VALUE-ASTs.  In order to evaluate the original AST, the transformed AST must be called with the values of those forms as arguments.

  • EXTERNAL CLASS

    TYPEQ-AST

    Source

    This AST can be thought of as a translation to an AST of a special form (TYPEQ <form> <type-specifier>) which is like the function TYPEP, except that the type specifier is not evaluated.

  • EXTERNAL CLASS

    UNREACHABLE-AST

    Source

    This AST indicates an unreachable control point. Control that leads inevitably from or to this AST is declared to be impossible.
    This impossibility is used by the analyzer without checking.

  • EXTERNAL CLASS

    UNWIND-PROTECT-AST

    Source

    AST for a cl:unwind-protect.
    The cleanup is represented by a FUNCTION-AST with no arguments.

  • EXTERNAL FUNCTION

    MAKE-BLOCK-AST

    • BODY-AST
    • &KEY
    • NAME
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-BRANCH-AST

    • TEST-AST
    • BRANCH-ASTS
    • DEFAULT-AST
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-CALL-AST

    • CALLEE-AST
    • ARGUMENT-ASTS
    • &KEY
    • ORIGIN
    • INLINE
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-CASE-AST

    • ARG-AST
    • COMPAREES
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-CONSTANT-AST

    • VALUE
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-CONSTANT-FDEFINITION-AST

    • NAME
    • &KEY
    • ORIGIN
    • POLICY
    • ATTRIBUTES

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-CONSTANT-SYMBOL-VALUE-AST

    • NAME
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-EQ-AST

    • ARG1-AST
    • ARG2-AST
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-FUNCTION-AST

    • BODY-AST
    • LAMBDA-LIST
    • &KEY
    • NAME
    • DOCSTRING
    • ORIGINAL-LAMBDA-LIST
    • BOUND-DECLARATIONS
    • ORIGIN
    • POLICY
    • ATTRIBUTES

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-GO-AST

    • TAG-AST
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-IF-AST

    • TEST-AST
    • THEN-AST
    • ELSE-AST
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-LEXICAL-AST

    • LEXICAL-VARIABLE
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-LEXICAL-BIND-AST

    • LEXICAL-VARIABLE
    • VALUE-AST
    • &KEY
    • IGNORE
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-LEXICAL-VARIABLE

    • NAME
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-LOAD-TIME-VALUE-AST

    • FORM
    • &OPTIONAL
    • READ-ONLY-P
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-MULTIPLE-VALUE-CALL-AST

    • FUNCTION-FORM-AST
    • FORM-ASTS
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-MULTIPLE-VALUE-PROG1-AST

    • FIRST-FORM-AST
    • FORM-ASTS
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-PROGN-AST

    • FORM-ASTS
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-RETURN-FROM-AST

    • BLOCK-AST
    • FORM-AST
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-SET-CONSTANT-SYMBOL-VALUE-AST

    • NAME
    • VALUE-AST
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-SETQ-AST

    • LEXICAL-VARIABLE
    • VALUE-AST
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-TAG-AST

    • NAME
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-TAGBODY-AST

    • PREFIX-AST
    • ITEM-ASTS
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-THE-AST

    • FORM-AST
    • CTYPE
    • TYPE-CHECK-FUNCTION-AST
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-TOP-LEVEL-FUNCTION-AST

    • BODY-AST
    • LAMBDA-LIST
    • FORMS
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-TYPEQ-AST

    • FORM-AST
    • TEST-CTYPE
    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAKE-UNREACHABLE-AST

    • &KEY
    • ORIGIN
    • POLICY

    Source

    No documentation provided.
  • EXTERNAL FUNCTION

    MAP-AST-DEPTH-FIRST-PREORDER

    • FUNCTION
    • AST

    Source

    Call FUNCTION on AST and all of its CHILDREN, in depth-first order.

  • EXTERNAL GENERIC-FUNCTION

    ARG-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    ARG1-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    ARG2-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    ARGUMENT-ASTS

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    ATTRIBUTES

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    BLOCK-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    BODY-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    (SETF BODY-AST)

    • NEW-VALUE
    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    BOUND-DECLARATIONS

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    BRANCH-ASTS

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    CALLEE-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    CHILDREN

    • AST

    Source

    Return a list of children of an AST. Children are ASTs corresponding to subforms of the AST.

  • EXTERNAL GENERIC-FUNCTION

    CLEANUP-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    COMPAREES

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    CTYPE

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    DEFAULT-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    DOCSTRING

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    ELSE-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    FIRST-FORM-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    FORM

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    FORM-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    FORM-ASTS

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    FORMS

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    FUNCTION-FORM-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    IGNORE

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    INFO

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    INLINE-DECLARATION

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    ITEM-ASTS

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    LAMBDA-LIST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    LEXICAL-VARIABLE

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    MAP-CHILDREN

    • FUNCTION
    • AST

    Source

    Call FUNCTION on all children of AST.

  • EXTERNAL GENERIC-FUNCTION

    NAME

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    (SETF NAME)

    • NEW-VALUE
    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    ORIGIN

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    (SETF ORIGIN)

    • NEW-VALUE
    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    ORIGINAL-LAMBDA-LIST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    (SETF ORIGINAL-LAMBDA-LIST)

    • NEW-VALUE
    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    POLICY

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    (SETF POLICY)

    • NEW-VALUE
    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    PREFIX-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    READ-ONLY-P

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    TAG-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    TEST-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    TEST-CTYPE

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    THEN-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    TYPE-CHECK-FUNCTION-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    VALUE

    • OBJECT

    No documentation provided.
  • EXTERNAL GENERIC-FUNCTION

    VALUE-AST

    • OBJECT

    No documentation provided.
  • EXTERNAL MACRO

    DEFINE-CHILDREN

    • AST-CLASS
    • CHILDREN-SPEC

    Source

    No documentation provided.

• CLEAVIR-AST-GRAPHVIZ

  No documentation provided.

  • EXTERNAL FUNCTION

    DRAW-AST

    • AST
    • FILENAME

    Source

    No documentation provided.