Super-group for data-structures representing the kinds of expressions that Verilog has. More...

Modules
	Expression Primaries
	Expresses primary terms of expressions. These can be sub-expressions, numbers, identifiers etc.

Data Structures
struct	ast_expression
	Storage type for an entire expression / subexpression tree. More...

Enumerations
enum	ast_expression_type { PRIMARY_EXPRESSION, UNARY_EXPRESSION, BINARY_EXPRESSION, RANGE_EXPRESSION_UP_DOWN, RANGE_EXPRESSION_INDEX, MINTYPMAX_EXPRESSION, CONDITIONAL_EXPRESSION, MODULE_PATH_PRIMARY_EXPRESSION, MODULE_PATH_BINARY_EXPRESSION, MODULE_PATH_UNARY_EXPRESSION, MODULE_PATH_CONDITIONAL_EXPRESSION, MODULE_PATH_MINTYPMAX_EXPRESSION, STRING_EXPRESSION }
	Describes the kind of expression a node contains. More...

Functions
char *	ast_expression_tostring (ast_expression *exp)
	A utility function for converting an ast expression tree back into a string representation. More...

ast_expression *	ast_new_binary_expression (ast_expression left, ast_expression right, ast_operator operation, ast_node_attributes *attr, ast_boolean constant)
	Creates a new binary infix expression with the supplied operands. More...

ast_expression *	ast_new_conditional_expression (ast_expression condition, ast_expression if_true, ast_expression if_false, ast_node_attributes attr)
	Creates a new conditional expression node. More...

ast_expression *	ast_new_expression_primary (ast_primary *p)
	Creates and returns a new expression primary. More...

ast_expression *	ast_new_index_expression (ast_expression *left)
	Creates a new range index expression with the supplied operands. More...

ast_expression *	ast_new_mintypmax_expression (ast_expression min, ast_expression typ, ast_expression *max)
	Creates a new (min,typical,maximum) expression. More...

ast_expression *	ast_new_range_expression (ast_expression left, ast_expression right)
	Creates a new range expression with the supplied operands. More...

ast_expression *	ast_new_string_expression (ast_string string)
	Creates a new string expression. More...

ast_expression *	ast_new_unary_expression (ast_primary operand, ast_operator operation, ast_node_attributes attr, ast_boolean constant)
	Creates a new unary expression with the supplied operation. More...

char *	ast_operator_tostring (ast_operator op)
	Returns the string representation of an operator;.

Detailed Description

Super-group for data-structures representing the kinds of expressions that Verilog has.

Enumeration Type Documentation

enum ast_expression_type

Describes the kind of expression a node contains.

Enumerator
PRIMARY_EXPRESSION	A straight value.
UNARY_EXPRESSION	A unary op: "~bits" for example.
BINARY_EXPRESSION	The "normal" expression.
RANGE_EXPRESSION_UP_DOWN	Bit range expression.
RANGE_EXPRESSION_INDEX	Bit index expression.
MINTYPMAX_EXPRESSION	Minimum typical maximum.
CONDITIONAL_EXPRESSION	Conditional expression.
STRING_EXPRESSION	Just a normal string. No operations.

Function Documentation

char* ast_expression_tostring ( ast_expression * exp )

A utility function for converting an ast expression tree back into a string representation.

Parameters

[in] exp - The expression to turn into a string.

Returns: The string representation of the passed expression or an empty string if exp is NULL.

Parameters

[in] exp - The expression to turn into a string.

ast_expression* ast_new_binary_expression	(	ast_expression *	left,
		ast_expression *	right,
		ast_operator	operation,
		ast_node_attributes *	attr,
		ast_boolean	constant
	)

Creates a new binary infix expression with the supplied operands.

Parameters

[in]	left	- LHS of the infix operation.
[in]	right	- RHS of the infix operation.
[in]	operation	- What do we do?!
[in]	attr	- Attributes applied to the expression.
[in]	constant	- Is this a constant expression we can simplify?

Creates a new binary infix expression with the supplied operands.

Note: Sets the type of the expression

ast_expression* ast_new_conditional_expression	(	ast_expression *	condition,
		ast_expression *	if_true,
		ast_expression *	if_false,
		ast_node_attributes *	attr
	)

Creates a new conditional expression node.

Parameters

[in]	condition	- Decides which result expression is presented.
[in]	if_true	- executed if condition == true (!0)
[in]	if_false	- executed if condition == false (0).
[in]	attr	- Attributes

Note: The condition is stored in the aux member, if_true in left, and if_false on the right.

Can be used to represent ternary operations:

1 assign stall = mem_error || mem_stall ? 1'b0 : global_stall;

Note: The condition is stored in the aux member, if_true in left, and if_false on the right.

ast_expression* ast_new_expression_primary ( ast_primary * p )

Creates and returns a new expression primary.

This is simply an expression instance wrapped around a primary instance for the purposes of mirroring the expression tree gramamr. Whether or not the expression is constant is denoted by the type member of the passed primary.

Parameters

[in] p - The primary to insert into the expression.

This is simply an expression instance wrapped around a primary instance for the purposes of mirroring the expression tree gramamr. Whether or not the expression is constant is denoted by the type member of the passed primary.

ast_expression* ast_new_index_expression ( ast_expression * left )

Creates a new range index expression with the supplied operands.

Parameters

[in] left - The single expression index into an array.

Used to represent code like...

1 wire [32:0] adder_result;

2 assign overflow = adder_result[32];

Here, accessing the 32nd bit of adder_result is an index expression.

ast_expression* ast_new_mintypmax_expression	(	ast_expression *	min,
		ast_expression *	typ,
		ast_expression *	max
	)

Creates a new (min,typical,maximum) expression.

If the mintypmax expression only specifies a typical value, then the min and max arguments should be NULL, and only typ set.

Parameters

[in]	min	- Minimum value in the distribution.
[in]	typ	- Typical / average.
[in]	max	- Maximum value in the distribution.

If the mintypmax expression only specifies a typical value, then the min and max arguments should be NULL, and only typ set.

ast_expression* ast_new_range_expression	(	ast_expression *	left,
		ast_expression *	right
	)

Creates a new range expression with the supplied operands.

Parameters

[in]	left	- The Upper range of the expression
[in]	right	- The lower range of the expression.

For example, when specifying a simple bus in verilog:

1 wire [31:0] bus_data;

Then the 31 would go into left, and the 0 into the right.

ast_expression* ast_new_string_expression ( ast_string string )

Creates a new string expression.

Parameters

[in] string - The string. Duh.

ast_expression* ast_new_unary_expression	(	ast_primary *	operand,
		ast_operator	operation,
		ast_node_attributes *	attr,
		ast_boolean	constant
	)

Creates a new unary expression with the supplied operation.

Parameters

[in]	operand	- The thing to operate on.
[in]	operation	- What do we do?!
[in]	attr	- Expression attributes.
[in]	constant	- Is this a constant expression we can simplify?

Modules

Data Structures

Enumerations

Functions

Detailed Description

Enumeration Type Documentation

Function Documentation