.. Copyright 2011, 2012 David Malcolm <dmalcolm@redhat.com>
Copyright 2011, 2012 Red Hat, Inc.
This is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see
<http://www.gnu.org/licenses/>.
gcc.Tree and its subclasses
===========================
The various language front-ends for GCC emit "tree" structures (which I believe
are actually graphs), used throughout the rest of the internal representation of
the code passing through GCC.
.. py:class:: gcc.Tree
A ``gcc.Tree`` is a wrapper around GCC's `tree` type
.. py:method:: debug()
Dump the tree to stderr, using GCC's own diagnostic routines
.. py:attribute:: type
Instance of :py:class:`gcc.Tree` giving the type of the node
.. py:attribute:: addr
(long) The address of the underlying GCC object in memory
The __str__ method is implemented using GCC's own pretty-printer for trees,
so e.g.::
str(t)
might return::
'int <T531> (int, char * *)'
for a `gcc.FunctionDecl`
.. py:attribute:: str_no_uid
A string representation of this object, like str(), but without
including any internal UIDs.
This is intended for use in selftests that compare output against some
expected value, to avoid embedding values that change into the expected
output.
For example, given the type declaration above, where `str(t)` might
return::
'int <T531> (int, char * *)'
where the UID "531" is liable to change from compile to compile, whereas
`t.str_no_uid` has value::
'int <Txxx> (int, char * *)'
which won't arbitrarily change each time.
There are numerous subclasses of :py:class:`gcc.Tree`, some with numerous
subclasses of their own. Some important parts of the class hierarchy include:
================================== =======================================
Subclass Meaning
================================== =======================================
:py:class:`gcc.Binary` A binary arithmetic expression, with
numerous subclasses
:py:class:`gcc.Block` A symbol-binding block
:py:class:`gcc.Comparison` A relational operators (with various
subclasses)
:py:class:`gcc.Constant` Subclasses for constants
:py:class:`gcc.Constructor` An aggregate value (e.g. in C, a
structure or array initializer)
:py:class:`gcc.Declaration` Subclasses relating to declarations
(variables, functions, etc)
:py:class:`gcc.Expression` Subclasses relating to expressions
:py:class:`gcc.IdentifierNode` A name
:py:class:`gcc.Reference` Subclasses for relating to reference to
storage (e.g. pointer values)
:py:class:`gcc.SsaName` A variable reference for SSA analysis
:py:class:`gcc.Statement` Subclasses for statement expressions,
which have side-effects
:py:class:`gcc.Type` Subclasses for describing the types of
variables
:py:class:`gcc.Unary` Subclasses for unary arithmetic
expressions
================================== =======================================
.. note::
Each subclass of :py:class:`gcc.Tree` is typically named
after either one of the `enum tree_code_class` or `enum tree_code` values,
with the names converted to Camel Case:
For example a :py:class:`gcc.Binary` is a wrapper around a `tree` of type
`tcc_binary`, and a :py:class:`gcc.PlusExpr` is a wrapper around a `tree`
of type `PLUS_EXPR`.
As of this writing, only a small subset of the various fields of the different
subclasses have been wrapped yet, but it's generally easy to add new ones. To
add new fields, I've found it easiest to look at `gcc/tree.h` and
`gcc/print-tree.c` within the GCC source tree and use the `print_node` function
to figure out what the valid fields are. With that information, you should
then look at `generate-tree-c.py`, which is the code that generates the Python
wrapper classes (it's used when building the plugin to create
`autogenerated-tree.c`). Ideally when exposing a field to Python you should
also add it to the API documentation, and add a test case.
.. py:function:: gccutils.pformat(tree)
This function attempts to generate a debug dump of a :py:class:`gcc.Tree`
and all of its "interesting" attributes, recursively. It's loosely modelled
on Python's `pprint` module and GCC's own `debug_tree` diagnostic routine
using indentation to try to show the structure.
It returns a string.
It differs from :py:meth:`gcc.Tree.debug()` in that it shows the Python
wrapper objects, rather than the underlying GCC data structures
themselves. For example, it can't show attributes that haven't been
wrapped yet.
Objects that have already been reported within this call are abbreviated
to "..." to try to keep the output readable.
Example output::
<FunctionDecl
repr() = gcc.FunctionDecl('main')
superclasses = (<type 'gcc.Declaration'>, <type 'gcc.Tree'>)
.function = gcc.Function('main')
.location = /home/david/coding/gcc-python/test.c:15
.name = 'main'
.type = <FunctionType
repr() = <gcc.FunctionType object at 0x2f62a60>
str() = 'int <T531> (int, char * *)'
superclasses = (<type 'gcc.Type'>, <type 'gcc.Tree'>)
.name = None
.type = <IntegerType
repr() = <gcc.IntegerType object at 0x2f629d0>
str() = 'int'
superclasses = (<type 'gcc.Type'>, <type 'gcc.Tree'>)
.const = False
.name = <TypeDecl
repr() = gcc.TypeDecl('int')
superclasses = (<type 'gcc.Declaration'>, <type 'gcc.Tree'>)
.location = None
.name = 'int'
.pointer = <PointerType
repr() = <gcc.PointerType object at 0x2f62b80>
str() = ' *'
superclasses = (<type 'gcc.Type'>, <type 'gcc.Tree'>)
.dereference = ... ("gcc.TypeDecl('int')")
.name = None
.type = ... ("gcc.TypeDecl('int')")
>
.type = ... ('<gcc.IntegerType object at 0x2f629d0>')
>
.precision = 32
.restrict = False
.type = None
.unsigned = False
.volatile = False
>
>
>
.. py:function:: gccutils.pprint(tree)
Similar to :py:meth:`gccutils.pformat()`, but prints the output to stdout.
(should this be stderr instead? probably should take a stream as an arg, but
what should the default be?)
Blocks
------
.. py:class:: gcc.Block
A symbol binding block, such as the global symbols within a compilation unit.
.. py:attribute:: vars
The list of :py:class:`gcc.Tree` for the declarations and labels in this
block
Declarations
------------
.. py:class:: gcc.Declaration
A subclass of :py:class:`gcc.Tree` indicating a declaration
Corresponds to the `tcc_declaration` value of `enum tree_code_class` within
GCC's own C sources.
.. py:attribute:: name
(string) the name of this declaration
.. py:attribute:: location
The :py:class:`gcc.Location` for this declaration
.. py:class:: gcc.FieldDecl
A subclass of :py:class:`gcc.Declaration` indicating the declaration of a
field within a structure.
.. py:attribute:: name
(string) The name of this field
.. py:class:: gcc.FunctionDecl
A subclass of :py:class:`gcc.Declaration` indicating the declaration of a
function. Internally, this wraps a `(struct tree_function_decl *)`
.. py:attribute:: function
The :py:class:`gcc.Function` for this declaration
.. py:attribute:: arguments
List of :py:class:`gcc.ParmDecl` representing the arguments of this
function
.. py:attribute:: result
The :py:class:`gcc.ResultDecl` representing the return value of this
function
.. py:attribute:: fullname
.. note:: This attribute is only usable with C++ code. Attempting to use
it from another language will lead to a `RuntimeError` exception.
(string) The "full name" of this function, including the scope, return
type and default arguments.
For example, given this code:
.. code-block:: c++
namespace Example {
struct Coord {
int x;
int y;
};
class Widget {
public:
void set_location(const struct Coord& coord);
};
};
`set_location`'s fullname is::
'void Example::Widget::set_location(const Example::Coord&)'
.. py:attribute:: callgraph_node
The :py:class:`gcc.CallgraphNode` for this function declaration, or
`None`
.. py:attribute:: is_public
(bool) For C++: is this declaration "public"
.. py:attribute:: is_private
(bool) For C++: is this declaration "private"
.. py:attribute:: is_protected
(bool) For C++: is this declaration "protected"
.. py:attribute:: is_static
(bool) For C++: is this declaration "static"
.. py:class:: gcc.ParmDecl
A subclass of :py:class:`gcc.Declaration` indicating the declaration of a
parameter to a function or method.
.. py:class:: gcc.ResultDecl
A subclass of :py:class:`gcc.Declaration` declararing a dummy variable that
will hold the return value from a function.
.. py:class:: gcc.VarDecl
A subclass of :py:class:`gcc.Declaration` indicating the declaration of a
variable (e.g. a global or a local).
.. py:attribute:: initial
The initial value for this variable as a :py:class:`gcc.Constructor`,
or None
.. py:attribute:: static
(boolean) Is this variable to be allocated with static storage?
.. Declaration
.. ClassMethodDecl
.. ConstDecl
.. DebugExprDecl
.. FieldDecl
.. FunctionDecl
.. ImportedDecl
.. InstanceMethodDecl
.. KeywordDecl
.. LabelDecl
.. NamespaceDecl
.. ParmDecl
.. PropertyDecl
.. ResultDecl
.. TemplateDecl
.. TranslationUnitDecl
.. TypeDecl
.. UsingDecl
.. VarDecl
Types
-----
.. py:class:: gcc.Type
A subclass of `gcc.Tree` indicating a type
Corresponds to the `tcc_type` value of `enum tree_code_class` within
GCC's own C sources.
.. py:attribute:: name
The :py:class:`gcc.IdentifierNode` for the name of the type, or `None`.
.. py:attribute:: pointer
The :py:class:`gcc.PointerType` representing the `(this_type *)` type
.. py:attribute:: attributes
The user-defined attributes on this type (using GCC's `__attribute`
syntax), as a dictionary (mapping from attribute names to list of
values). Typically this will be the empty dictionary.
.. py:attribute:: sizeof
`sizeof()` this type, as an `int`, or raising `TypeError` for those
types which don't have a well-defined size
The standard C types are accessible via class methods of :py:class:`gcc.Type`.
They are only created by GCC after plugins are loaded, and so they're
only visible during callbacks, not during the initial run of the code.
(yes, having them as class methods is slightly clumsy).
Each of the following returns a :py:class:`gcc.Type` instance representing
the given type (or None at startup before any passes, when the types don't
yet exist)
============================= =====================
Class method C Type
============================= =====================
gcc.Type.void() `void`
gcc.Type.size_t() `size_t`
gcc.Type.char() `char`
gcc.Type.signed_char() `signed char`
gcc.Type.unsigned_char() `unsigned char`
gcc.Type.double() `double`
gcc.Type.float() `float`
gcc.Type.short() `short`
gcc.Type.unsigned_short() `unsigned short`
gcc.Type.int() `int`
gcc.Type.unsigned_int() `unsigned int`
gcc.Type.long() `long`
gcc.Type.unsigned_long() `unsigned long`
gcc.Type.long_double() `long double`
gcc.Type.long_long() `long long`
gcc.Type.unsigned_long_long() `unsigned long long`
gcc.Type.int128() `int128`
gcc.Type.unsigned_int128() `unsigned int128`
gcc.Type.uint32() `uint32`
gcc.Type.uint64() `uint64`
============================= =====================
.. py:class:: gcc.IntegerType
Subclass of :py:class:`gcc.Type`, adding a few properties:
.. py:attribute:: unsigned
(Boolean) True for 'unsigned', False for 'signed'
.. py:attribute:: precision
(int) The precision of this type in bits, as an int (e.g. 32)
.. py:attribute:: signed_equivalent
The gcc.IntegerType for the signed version of this type
.. py:attribute:: unsigned_equivalent
The gcc.IntegerType for the unsigned version of this type
.. py:attribute:: max_value
The maximum possible value for this type, as a
:py:class:`gcc.IntegerCst`
.. py:attribute:: min_value
The minimum possible value for this type, as a
:py:class:`gcc.IntegerCst`
.. py:class:: gcc.FloatType
Subclass of :py:class:`gcc.Type` representing C's `float` and `double` types
.. py:attribute:: precision
(int) The precision of this type in bits (32 for `float`; 64 for
`double`)
.. py:class:: gcc.PointerType
Subclass of :py:class:`gcc.Type` representing a pointer type, such as
an `int *`
.. py:attribute:: dereference
The :py:class:`gcc.Type` that this type points to. In the above
example (`int *`), this would be the `int` type.
.. py:class:: gcc.ArrayType
Subclass of :py:class:`gcc.Type` representing an array type. For example,
in a C declaration such as::
char buf[16]
we have a :py:class:`gcc.VarDecl` for `buf`, and its type is an instance of
:py:class:`gcc.ArrayType`, representing `char [16]`.
.. py:attribute:: dereference
The :py:class:`gcc.Type` that this type points to. In the above
example, this would be the `char` type.
.. py:attribute:: range
The :py:class:`gcc.Type` that represents the range of the
array's indices. If the array has a known range, then this will
ordinarily be an :py:class:`gcc.IntegerType` whose `min_value`
and `max_value` are the (inclusive) bounds of the array. If the
array does not have a known range, then this attribute will be
`None`.
That is, in the example above, `range.min_val` is `0`, and
`range.max_val` is `15`.
But, for a C declaration like::
extern char array[];
the type's `range` would be `None`.
.. py:class:: gcc.VectorType
.. py:attribute:: dereference
The :py:class:`gcc.Type` that this type points to
Additional attributes for various :py:class:`gcc.Type` subclasses:
.. py:attribute:: const
(Boolean) Does this type have the `const` modifier?
.. py:attribute:: const_equivalent
The :py:class:`gcc.Type` for the `const` version of this type
.. py:attribute:: volatile
(Boolean) Does this type have the `volatile` modifier?
.. py:attribute:: volatile_equivalent
The :py:class:`gcc.Type` for the `volatile` version of this type
.. py:attribute:: restrict
(Boolean) Does this type have the `restrict` modifier?
.. py:attribute:: restrict_equivalent
The :py:class:`gcc.Type` for the `restrict` version of this type
.. py:class:: gcc.FunctionType
Subclass of :py:class:`gcc.Type` representing the type of a given function
(or or a typedef to a function type, e.g. for callbacks).
See also :py:class:`gcc.FunctionType`
The `type` attribute holds the return type.
.. py:attribute:: argument_types
A tuple of :py:class:`gcc.Type` instances, representing the function's
argument types
.. py:function:: gccutils.get_nonnull_arguments(funtype)
This is a utility function for working with the `"nonnull"` custom
attribute on function types:
http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
Return a `frozenset` of 0-based integers, giving the arguments for
which we can assume "nonnull-ness", handling the various cases of:
* the attribute isn't present (returning the empty frozenset)
* the attribute is present, without args (all pointer args are
non-NULL)
* the attribute is present, with a list of 1-based argument indices
(Note that the result is still 0-based)
.. py:class:: gcc.MethodType
Subclass of :py:class:`gcc.Type` representing the type of a given method.
Similar to :py:class:`gcc.FunctionType`
The `type` attribute holds the return type.
.. py:attribute:: argument_types
A tuple of :py:class:`gcc.Type` instances, representing the function's
argument types
.. py:class:: gcc.RecordType
A compound type, such as a C `struct`
.. py:attribute:: fields
The fields of this type, as a list of :py:class:`gcc.FieldDecl` instances
You can look up C structures by looking within the top-level
:py:class:`gcc.Block` within the current translation unit. For example,
given this sample C code:
.. literalinclude:: ../tests/examples/c/struct/input.c
:lines: 20-30
:language: c
then the following Python code:
.. literalinclude:: ../tests/examples/c/struct/script.py
:lines: 21-40
will generate this output:
.. literalinclude:: ../tests/examples/c/struct/stdout.txt
Constants
---------
.. py:class:: gcc.Constant
Subclass of :py:class:`gcc.Tree` indicating a constant value.
Corresponds to the `tcc_constant` value of `enum tree_code_class` within
GCC's own C sources.
.. py:attribute:: constant
The actual value of this constant, as the appropriate Python type:
============================== ===============
Subclass Python type
============================== ===============
.. py:class:: ComplexCst
.. py:class:: FixedCst
.. py:class:: IntegerCst `int` or `long`
.. py:class:: PtrmemCst
.. py:class:: RealCst `float`
.. py:class:: StringCst `str`
.. py:class:: VectorCst
============================== ===============
Binary Expressions
------------------
.. py:class:: gcc.Binary
Subclass of :py:class:`gcc.Tree` indicating a binary expression.
Corresponds to the `tcc_binary` value of `enum tree_code_class` within
GCC's own C sources.
.. py:attribute:: location
The :py:class:`gcc.Location` for this binary expression
.. py:classmethod:: get_symbol()
Get the symbol used in debug dumps for this :py:class:`gcc.Binary`
subclass, if any, as a `str`. A table showing these strings can be
seen :ref:`here <get_symbols>`.
Has subclasses for the various kinds of binary expression. These
include:
.. These tables correspond to GCC's "tree.def"
Simple arithmetic:
============================ ====================== ==============
Subclass C/C++ operators enum tree_code
============================ ====================== ==============
.. py:class:: gcc.PlusExpr `+` PLUS_EXPR
.. py:class:: gcc.MinusExpr `-` MINUS_EXPR
.. py:class:: gcc.MultExpr `*` MULT_EXPR
============================ ====================== ==============
Pointer addition:
================================= ================= =================
Subclass C/C++ operators enum tree_code
================================= ================= =================
.. py:class:: gcc.PointerPlusExpr POINTER_PLUS_EXPR
================================= ================= =================
Various division operations:
============================== ===============
Subclass C/C++ operators
============================== ===============
.. py:class:: gcc.TruncDivExr
.. py:class:: gcc.CeilDivExpr
.. py:class:: gcc.FloorDivExpr
.. py:class:: gcc.RoundDivExpr
============================== ===============
The remainder counterparts of the above division operators:
============================== ===============
Subclass C/C++ operators
============================== ===============
.. py:class:: gcc.TruncModExpr
.. py:class:: gcc.CeilModExpr
.. py:class:: gcc.FloorModExpr
.. py:class:: gcc.RoundModExpr
============================== ===============
Division for reals:
=================================== ======================
Subclass C/C++ operators
=================================== ======================
.. py:class:: gcc.RdivExpr
=================================== ======================
Division that does not need rounding (e.g. for pointer subtraction in C):
=================================== ======================
Subclass C/C++ operators
=================================== ======================
.. py:class:: gcc.ExactDivExpr
=================================== ======================
Max and min:
=================================== ======================
Subclass C/C++ operators
=================================== ======================
.. py:class:: gcc.MaxExpr
.. py:class:: gcc.MinExpr
=================================== ======================
Shift and rotate operations:
=================================== ======================
Subclass C/C++ operators
=================================== ======================
.. py:class:: gcc.LrotateExpr
.. py:class:: gcc.LshiftExpr `<<`, `<<=`
.. py:class:: gcc.RrotateExpr
.. py:class:: gcc.RshiftExpr `>>`, `>>=`
=================================== ======================
Bitwise binary expressions:
=================================== =========================
Subclass C/C++ operators
=================================== =========================
.. py:class:: gcc.BitAndExpr `&`, `&=` (bitwise "and")
.. py:class:: gcc.BitIorExpr `|`, `|=` (bitwise "or")
.. py:class:: gcc.BitXorExpr `^`, `^=` (bitwise "xor")
=================================== =========================
Other gcc.Binary subclasses:
======================================== ==================================
Subclass Usage
======================================== ==================================
.. py:class:: gcc.CompareExpr
.. py:class:: gcc.CompareGExpr
.. py:class:: gcc.CompareLExpr
.. py:class:: gcc.ComplexExpr
.. py:class:: gcc.MinusNomodExpr
.. py:class:: gcc.PlusNomodExpr
.. py:class:: gcc.RangeExpr
.. py:class:: gcc.UrshiftExpr
.. py:class:: gcc.VecExtractevenExpr
.. py:class:: gcc.VecExtractoddExpr
.. py:class:: gcc.VecInterleavehighExpr
.. py:class:: gcc.VecInterleavelowExpr
.. py:class:: gcc.VecLshiftExpr
.. py:class:: gcc.VecPackFixTruncExpr
.. py:class:: gcc.VecPackSatExpr
.. py:class:: gcc.VecPackTruncExpr
.. py:class:: gcc.VecRshiftExpr
.. py:class:: gcc.WidenMultExpr
.. py:class:: gcc.WidenMultHiExpr
.. py:class:: gcc.WidenMultLoExpr
.. py:class:: gcc.WidenSumExpr
======================================== ==================================
Unary Expressions
-----------------
.. py:class:: gcc.Unary
Subclass of :py:class:`gcc.Tree` indicating a unary expression (i.e. taking a
single argument).
Corresponds to the `tcc_unary` value of `enum tree_code_class` within
GCC's own C sources.
.. py:attribute:: operand
The operand of this operator, as a :py:class:`gcc.Tree`.
.. py:attribute:: location
The :py:class:`gcc.Location` for this unary expression
.. py:classmethod:: get_symbol()
Get the symbol used in debug dumps for this :py:class:`gcc.Unary`
subclass, if any, as a `str`. A table showing these strings can be
seen :ref:`here <get_symbols>`.
Subclasses include:
====================================== ==================================================
Subclass Meaning; C/C++ operators
====================================== ==================================================
.. py:class:: gcc.AbsExpr Absolute value
.. py:class:: gcc.AddrSpaceConvertExpr Conversion of pointers between address spaces
.. py:class:: gcc.BitNotExpr `~` (bitwise "not")
.. py:class:: gcc.CastExpr
.. py:class:: gcc.ConjExpr For complex types: complex conjugate
.. py:class:: gcc.ConstCastExpr
.. py:class:: gcc.ConvertExpr
.. py:class:: gcc.DynamicCastExpr
.. py:class:: gcc.FixTruncExpr Convert real to fixed-point, via truncation
.. py:class:: gcc.FixedConvertExpr
.. py:class:: gcc.FloatExpr Convert integer to real
.. py:class:: gcc.NegateExpr Unary negation
.. py:class:: gcc.NoexceptExpr
.. py:class:: gcc.NonLvalueExpr
.. py:class:: gcc.NopExpr
.. py:class:: gcc.ParenExpr
.. py:class:: gcc.ReducMaxExpr
.. py:class:: gcc.ReducMinExpr
.. py:class:: gcc.ReducPlusExpr
.. py:class:: gcc.ReinterpretCastExpr
.. py:class:: gcc.StaticCastExpr
.. py:class:: gcc.UnaryPlusExpr
====================================== ==================================================
Comparisons
------------
.. py:class:: gcc.Comparison
Subclass of :py:class:`gcc.Tree` for comparison expressions
Corresponds to the `tcc_comparison` value of `enum tree_code_class` within
GCC's own C sources.
.. py:attribute:: location
The :py:class:`gcc.Location` for this comparison
.. py:classmethod:: get_symbol()
Get the symbol used in debug dumps for this :py:class:`gcc.Comparison`
subclass, if any, as a `str`. A table showing these strings can be
seen :ref:`here <get_symbols>`.
Subclasses include:
===================================== ======================
Subclass C/C++ operators
===================================== ======================
.. py:class:: EqExpr `==`
.. py:class:: GeExpr `>=`
.. py:class:: GtExpr `>`
.. py:class:: LeExpr `<=`
.. py:class:: LtExpr `<`
.. py:class:: LtgtExpr
.. py:class:: NeExpr `!=`
.. py:class:: OrderedExpr
.. py:class:: UneqExpr
.. py:class:: UngeExpr
.. py:class:: UngtExpr
.. py:class:: UnleExpr
.. py:class:: UnltExpr
.. py:class:: UnorderedExpr
===================================== ======================
References to storage
---------------------
.. py:class:: gcc.Reference
Subclass of :py:class:`gcc.Tree` for expressions involving a reference to
storage.
Corresponds to the `tcc_reference` value of `enum tree_code_class` within
GCC's own C sources.
.. py:attribute:: location
The :py:class:`gcc.Location` for this storage reference
.. py:classmethod:: get_symbol()
Get the symbol used in debug dumps for this :py:class:`gcc.Reference`
subclass, if any, as a `str`. A table showing these strings can be
seen :ref:`here <get_symbols>`.
.. py:class:: gcc.ArrayRef
A subclass of :py:class:`gcc.Reference` for expressions involving an array
reference:
.. code-block:: c
unsigned char buffer[4096];
...
/* The left-hand side of this gcc.GimpleAssign is a gcc.ArrayRef: */
buffer[42] = 0xff;
.. py:attribute:: array
The :py:class:`gcc.Tree` for the array within the reference
(`gcc.VarDecl('buffer')` in the example above)
.. py:attribute:: index
The :py:class:`gcc.Tree` for the index within the reference
(`gcc.IntegerCst(42)` in the example above)
.. py:class:: gcc.ComponentRef
A subclass of :py:class:`gcc.Reference` for expressions involving a field
lookup.
This can mean either a direct field lookup, as in:
.. code-block:: c
struct mystruct s;
...
s.idx = 42;
or dereferenced field lookup:
.. code-block:: c
struct mystruct *p;
...
p->idx = 42;
.. py:attribute:: target
The :py:class:`gcc.Tree` for the container of the field (either `s` or
`*p` in the examples above)
.. py:attribute:: field
The :py:class:`gcc.FieldDecl` for the field within the target.
.. py:class:: gcc.MemRef
A subclass of :py:class:`gcc.Reference` for expressions involving
dereferencing a pointer:
.. code-block:: c
int p, *q;
...
p = *q;
.. py:attribute:: operand
The :py:class:`gcc.Tree` for the expression describing the target of the
pointer
Other subclasses of :py:class:`gcc.Reference` include:
===================================== ======================
Subclass C/C++ operators
===================================== ======================
.. py:class:: ArrayRangeRef
.. py:class:: AttrAddrExpr
.. py:class:: BitFieldRef
.. py:class:: ImagpartExpr
.. py:class:: IndirectRef
.. py:class:: MemberRef
.. py:class:: OffsetRef
.. py:class:: RealpartExpr
.. py:class:: ScopeRef
.. py:class:: TargetMemRef
.. py:class:: UnconstrainedArrayRef
.. py:class:: ViewConvertExpr
===================================== ======================
Other expression subclasses
---------------------------
.. py:class:: gcc.Expression
Subclass of :py:class:`gcc.Tree` indicating an expression that doesn't fit
into the other categories.
Corresponds to the `tcc_expression` value of `enum tree_code_class` within
GCC's own C sources.
.. py:attribute:: location
The :py:class:`gcc.Location` for this expression
.. py:classmethod:: get_symbol()
Get the symbol used in debug dumps for this :py:class:`gcc.Expression`
subclass, if any, as a `str`. A table showing these strings can be
seen :ref:`here <get_symbols>`.
Subclasses include:
===================================== ======================
Subclass C/C++ operators
===================================== ======================
.. py:class:: gcc.AddrExpr
.. py:class:: gcc.AlignofExpr
.. py:class:: gcc.ArrowExpr
.. py:class:: gcc.AssertExpr
.. py:class:: gcc.AtEncodeExpr
.. py:class:: gcc.BindExpr
.. py:class:: gcc.CMaybeConstExpr
.. py:class:: gcc.ClassReferenceExpr
.. py:class:: gcc.CleanupPointExpr
.. py:class:: gcc.CompoundExpr
.. py:class:: gcc.CompoundLiteralExpr
.. py:class:: gcc.CondExpr
.. py:class:: gcc.CtorInitializer
.. py:class:: gcc.DlExpr
.. py:class:: gcc.DotProdExpr
.. py:class:: gcc.DotstarExpr
.. py:class:: gcc.EmptyClassExpr
.. py:class:: gcc.ExcessPrecisionExpr
.. py:class:: gcc.ExprPackExpansion
.. py:class:: gcc.ExprStmt
.. py:class:: gcc.FdescExpr
.. py:class:: gcc.FmaExpr
.. py:class:: gcc.InitExpr
.. py:class:: gcc.MessageSendExpr
.. py:class:: gcc.ModifyExpr
.. py:class:: gcc.ModopExpr
.. py:class:: gcc.MustNotThrowExpr
.. py:class:: gcc.NonDependentExpr
.. py:class:: gcc.NontypeArgumentPack
.. py:class:: gcc.NullExpr
.. py:class:: gcc.NwExpr
.. py:class:: gcc.ObjTypeRef
.. py:class:: gcc.OffsetofExpr
.. py:class:: gcc.PolynomialChrec
.. py:class:: gcc.PostdecrementExpr
.. py:class:: gcc.PostincrementExpr
.. py:class:: gcc.PredecrementExpr
.. py:class:: gcc.PredictExpr
.. py:class:: gcc.PreincrementExpr
.. py:class:: gcc.PropertyRef
.. py:class:: gcc.PseudoDtorExpr
.. py:class:: gcc.RealignLoad
.. py:class:: gcc.SaveExpr
.. py:class:: gcc.ScevKnown
.. py:class:: gcc.ScevNotKnown
.. py:class:: gcc.SizeofExpr
.. py:class:: gcc.StmtExpr
.. py:class:: gcc.TagDefn
.. py:class:: gcc.TargetExpr
.. py:class:: gcc.TemplateIdExpr
.. py:class:: gcc.ThrowExpr
.. py:class:: gcc.TruthAndExpr
.. py:class:: gcc.TruthAndifExpr
.. py:class:: gcc.TruthNotExpr
.. py:class:: gcc.TruthOrExpr
.. py:class:: gcc.TruthOrifExpr
.. py:class:: gcc.TruthXorExpr
.. py:class:: gcc.TypeExpr
.. py:class:: gcc.TypeidExpr
.. py:class:: gcc.VaArgExpr
.. py:class:: gcc.VecCondExpr
.. py:class:: gcc.VecDlExpr
.. py:class:: gcc.VecInitExpr
.. py:class:: gcc.VecNwExpr
.. py:class:: gcc.WidenMultMinusExpr
.. py:class:: gcc.WidenMultPlusExpr
.. py:class:: gcc.WithCleanupExpr
.. py:class:: gcc.WithSizeExpr
===================================== ======================
TODO
Statements
----------
.. py:class:: gcc.Statement
A subclass of :py:class:`gcc.Tree` for statements
Corresponds to the `tcc_statement` value of `enum tree_code_class` within
GCC's own C sources.
.. py:class:: gcc.CaseLabelExpr
A subclass of :py:class:`gcc.Statement` for the `case` and `default` labels
within a `switch` statement.
.. py:attribute:: low
* for single-valued case labels, the value, as a :py:class:`gcc.Tree`
* for range-valued case labels, the lower bound, as a :py:class:`gcc.Tree`
* `None` for the default label
.. py:attribute:: high
For range-valued case labels, the upper bound, as a :py:class:`gcc.Tree`.
`None` for single-valued case labels, and for the default label
.. py:attribute:: target
The target of the case label, as a :py:class:`gcc.LabelDecl`
.. Here's a dump of the class hierarchy, from help(gcc):
.. Tree
.. ArgumentPackSelect
.. Baselink
.. Binary
.. BitAndExpr
.. BitIorExpr
.. BitXorExpr
.. CeilDivExpr
.. CeilModExpr
.. CompareExpr
.. CompareGExpr
.. CompareLExpr
.. ComplexExpr
.. ExactDivExpr
.. FloorDivExpr
.. FloorModExpr
.. LrotateExpr
.. LshiftExpr
.. MaxExpr
.. MinExpr
.. MinusExpr
.. MinusNomodExpr
.. MultExpr
.. PlusExpr
.. PlusNomodExpr
.. PointerPlusExpr
.. RangeExpr
.. RdivExpr
.. RoundDivExpr
.. RoundModExpr
.. RrotateExpr
.. RshiftExpr
.. TruncDivExpr
.. TruncModExpr
.. UrshiftExpr
.. VecExtractevenExpr
.. VecExtractoddExpr
.. VecInterleavehighExpr
.. VecInterleavelowExpr
.. VecLshiftExpr
.. VecPackFixTruncExpr
.. VecPackSatExpr
.. VecPackTruncExpr
.. VecRshiftExpr
.. WidenMultExpr
.. WidenMultHiExpr
.. WidenMultLoExpr
.. WidenSumExpr
.. Block
.. Comparison
.. EqExpr
.. GeExpr
.. GtExpr
.. LeExpr
.. LtExpr
.. LtgtExpr
.. NeExpr
.. OrderedExpr
.. UneqExpr
.. UngeExpr
.. UngtExpr
.. UnleExpr
.. UnltExpr
.. UnorderedExpr
.. Constant
.. ComplexCst
.. FixedCst
.. IntegerCst
.. PtrmemCst
.. RealCst
.. StringCst
.. VectorCst
.. Constructor
.. Declaration
.. ClassMethodDecl
.. ConstDecl
.. DebugExprDecl
.. FieldDecl
.. FunctionDecl
.. ImportedDecl
.. InstanceMethodDecl
.. KeywordDecl
.. LabelDecl
.. NamespaceDecl
.. ParmDecl
.. PropertyDecl
.. ResultDecl
.. TemplateDecl
.. TranslationUnitDecl
.. TypeDecl
.. UsingDecl
.. VarDecl
.. DefaultArg
.. ErrorMark
.. Expression
.. AddrExpr
.. AlignofExpr
.. ArrowExpr
.. AssertExpr
.. AtEncodeExpr
.. BindExpr
.. CMaybeConstExpr
.. ClassReferenceExpr
.. CleanupPointExpr
.. CompoundExpr
.. CompoundLiteralExpr
.. CondExpr
.. CtorInitializer
.. DlExpr
.. DotProdExpr
.. DotstarExpr
.. EmptyClassExpr
.. ExcessPrecisionExpr
.. ExprPackExpansion
.. ExprStmt
.. FdescExpr
.. FmaExpr
.. InitExpr
.. MessageSendExpr
.. ModifyExpr
.. ModopExpr
.. MustNotThrowExpr
.. NonDependentExpr
.. NontypeArgumentPack
.. NullExpr
.. NwExpr
.. ObjTypeRef
.. OffsetofExpr
.. PolynomialChrec
.. PostdecrementExpr
.. PostincrementExpr
.. PredecrementExpr
.. PredictExpr
.. PreincrementExpr
.. PropertyRef
.. PseudoDtorExpr
.. RealignLoad
.. SaveExpr
.. ScevKnown
.. ScevNotKnown
.. SizeofExpr
.. StmtExpr
.. TagDefn
.. TargetExpr
.. TemplateIdExpr
.. ThrowExpr
.. TruthAndExpr
.. TruthAndifExpr
.. TruthNotExpr
.. TruthOrExpr
.. TruthOrifExpr
.. TruthXorExpr
.. TypeExpr
.. TypeidExpr
.. VaArgExpr
.. VecCondExpr
.. VecDlExpr
.. VecInitExpr
.. VecNwExpr
.. WidenMultMinusExpr
.. WidenMultPlusExpr
.. WithCleanupExpr
.. WithSizeExpr
.. IdentifierNode
.. LambdaExpr
.. OmpClause
.. OptimizationNode
.. Overload
.. PlaceholderExpr
.. Reference
.. ArrayRangeRef
.. ArrayRef
.. AttrAddrExpr
.. BitFieldRef
.. ComponentRef
.. ImagpartExpr
.. IndirectRef
.. MemRef
.. MemberRef
.. OffsetRef
.. RealpartExpr
.. ScopeRef
.. TargetMemRef
.. UnconstrainedArrayRef
.. ViewConvertExpr
.. SsaName
.. Statement
.. AsmExpr
.. BreakStmt
.. CaseLabelExpr
.. CatchExpr
.. CleanupStmt
.. ContinueStmt
.. DeclExpr
.. DoStmt
.. EhFilterExpr
.. EhSpecBlock
.. ExitExpr
.. ExitStmt
.. ForStmt
.. GotoExpr
.. Handler
.. IfStmt
.. LabelExpr
.. LoopExpr
.. LoopStmt
.. OmpAtomic
.. OmpCritical
.. OmpFor
.. OmpMaster
.. OmpOrdered
.. OmpParallel
.. OmpSection
.. OmpSections
.. OmpSingle
.. OmpTask
.. RangeForStmt
.. ReturnExpr
.. StmtStmt
.. SwitchExpr
.. SwitchStmt
.. TryBlock
.. TryCatchExpr
.. TryFinally
.. UsingDirective
.. WhileStmt
.. StatementList
.. StaticAssert
.. TargetOptionNode
.. TemplateInfo
.. TemplateParmIndex
.. TraitExpr
.. TreeBinfo
.. TreeList
.. TreeVec
.. Type
.. ArrayType
.. BooleanType
.. BoundTemplateTemplateParm
.. CategoryImplementationType
.. CategoryInterfaceType
.. ClassImplementationType
.. ClassInterfaceType
.. ComplexType
.. DecltypeType
.. EnumeralType
.. FixedPointType
.. FunctionType
.. IntegerType
.. LangType
.. MethodType
.. NullptrType
.. OffsetType
.. PointerType
.. ProtocolInterfaceType
.. QualUnionType
.. RealType
.. RecordType
.. ReferenceType
.. TemplateTemplateParm
.. TemplateTypeParm
.. TypeArgumentPack
.. TypePackExpansion
.. TypenameType
.. TypeofType
.. UnboundClassTemplate
.. UnconstrainedArrayType
.. UnionType
.. VectorType
.. VoidType
.. Unary
.. AbsExpr
.. AddrSpaceConvertExpr
.. BitNotExpr
.. CastExpr
.. ConjExpr
.. ConstCastExpr
.. ConvertExpr
.. DynamicCastExpr
.. FixTruncExpr
.. FixedConvertExpr
.. FloatExpr
.. NegateExpr
.. NoexceptExpr
.. NonLvalueExpr
.. NopExpr
.. ParenExpr
.. ReducMaxExpr
.. ReducMinExpr
.. ReducPlusExpr
.. ReinterpretCastExpr
.. StaticCastExpr
.. UnaryPlusExpr
.. VecUnpackFloatHiExpr
.. VecUnpackFloatLoExpr
.. VecUnpackHiExpr
.. VecUnpackLoExpr
.. VlExp
.. AggrInitExpr
.. CallExpr
