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Better handling of function call symbol tables
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@dhower-qc
dhower-qc committed Jul 15, 2024
1 parent 26f0430 commit 04c6e42
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Showing 7 changed files with 180 additions and 109 deletions.
2 changes: 1 addition & 1 deletion cfgs/generic_rv64/arch_overlay/csr/marchid.yaml
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Original file line number Diff line number Diff line change
Expand Up @@ -3,4 +3,4 @@
marchid:
fields:
Architecture:
reset_value: 0xcafebabe
description: My custom description.
31 changes: 22 additions & 9 deletions lib/arch_def.rb
View file
Original file line number Diff line number Diff line change
Expand Up @@ -127,6 +127,8 @@ def type
parent: "#{csr.name}.#{name}"
)

sym_table.push # for consistency with template functions

begin
case ast.return_value(sym_table)
when 0
Expand All @@ -148,6 +150,8 @@ def type
warn "In parsing #{csr.name}.#{name}::type()"
warn " Return of type() function cannot be evaluated at compile time"
raise e
ensure
sym_table.pop
end
end
end
Expand Down Expand Up @@ -218,13 +222,20 @@ def reset_value_func
def reset_value
return @reset_value unless @reset_value.nil?

@reset_value =
if @data.key?("reset_value")
@data["reset_value"]
else
puts "evaluating #{name}"
reset_value_func.return_value(arch_def.sym_table)
end
symtab = arch_def.sym_table

symtab.push # for consistency with template functions

begin
@reset_value =
if @data.key?("reset_value")
@data["reset_value"]
else
reset_value_func.return_value(arch_def.sym_table)
end
ensure
symtab.pop
end
end

# @param effective_xlen [Integer] The effective xlen, needed since some fields change location with XLEN. If the field location is not determined by XLEN, then this parameter can be nil
Expand Down Expand Up @@ -385,7 +396,6 @@ def length(effective_xlen = nil)

effective_xlen
else
puts arch_def.implemented_csrs.map { |c| c.name }
raise "CSR #{name} is not implemented" if arch_def.implemented_csrs.none? { |c| c.name == name }
raise "CSR #{name} is not implemented" if arch_def.config_params["SXLEN"].nil?

Expand Down Expand Up @@ -1213,6 +1223,9 @@ class ArchDef
# @return [Idl::Compiler] The IDL compiler
attr_reader :idl_compiler

# @return [Idl::AstNode] Abstract syntax tree of global scope
attr_reader :global_ast

# Initialize a new configured architecture defintiion
#
# @params config_name [#to_s] The name of a configuration, which must correspond
Expand All @@ -1237,7 +1250,7 @@ def initialize(config_name)
@idl_compiler = Idl::Compiler.new(self)

# load the globals into the symbol table
@idl_compiler.compile_file(
@global_ast = @idl_compiler.compile_file(
$root / "arch" / "isa" / "globals.isa",
@sym_table
)
Expand Down
137 changes: 50 additions & 87 deletions lib/idl/ast.rb
View file
Original file line number Diff line number Diff line change
Expand Up @@ -27,26 +27,6 @@ def has_template_ancestor?
# @return [Boolean] whether or not this SyntaxNode represents a function name (overriden in the parser)
def is_function_name? = false

# @return [Boolean] whether or not this SyntaxNode is being parsed as a template argument
# without being enclosed in parenthesis
def parsing_in_template?
# since this is called in the middle of parsing, the parent pointer hasn't been set up yet
puts self.class.ancestors
puts "text = #{text_value}"
puts parent.class.name
exit
if parent.nil?
nil
elsif parent.is_a?(ParenExpressionAst)
false # once we hit a paren expression, we are cleared
elsif parent.is_a?(BitsTypeAst)
puts "FOund bits!!"
true # must be the expression on the BitsType
else
parent.parsing_in_template?
end
end

# Fix up left recursion for the PEG
#
# This is the default for anything that isn't a left-recursive binary op
Expand Down Expand Up @@ -442,7 +422,6 @@ class GlobalWithInitializationAst < AstNode
include Executable

def type_check(symtab)
puts "global #{text_value}"
single_declaration_with_initialization.type_check(symtab)
end

Expand Down Expand Up @@ -942,11 +921,15 @@ def rhs
end

def execute(symtab)
var = symtab.get(var.text_value)
if var.is_a?(CsrWriteAst)
value_error "CSR writes are never compile-time-known"
else
variable = symtab.get(var.text_value)

internal_error "Call type check first" if var.nil?
internal_error "No variable #{var.text_value}" if variable.nil?

var.value = rval.value(symtab)
variable.value = rval.value(symtab)
end
end

# @!macro to_idl
Expand Down Expand Up @@ -1209,7 +1192,7 @@ def type_check(symtab)
end

def execute(symtab)
values = functin_call.execute(symtab)
values = function_call.execute(symtab)

i = 0
vars.each do |v|
Expand Down Expand Up @@ -1520,7 +1503,9 @@ def value(symtab)
element_name = expression.text_value.split(":")[2]
etype.enum_class.value(element_name)
when :csr
internal_error "TODO"
expression.value(symtab)
else
internal_error "TODO: Bits cast for #{etype.kind}"
end
end

Expand Down Expand Up @@ -2334,7 +2319,21 @@ def expected_return_type(symtab)

symtab.get("__expected_return_type")
else
func_def.return_type(symtab)
# need to find the type to get the right symbol table
func_type = symtab.get_global(func_def.name)
internal_error "Couldn't find function type for '#{func_def.name}' #{symtab.keys} " if func_type.nil?

# to get the return type, we need to find the template values in case this is
# a templated function definition
#
# that information should be up the stack in the symbol table
template_values = symtab.find_all(single_scope: true) do |o|
o.is_a?(Var) && o.template_value_for?(func_def.name)
end
unless template_values.size == func_type.template_names.size
internal_error "Did not find correct number of template arguments (found #{template_values.size}, need #{func_type.template_names.size}) #{symtab.keys_pretty}"
end
func_type.return_type(template_values.sort { |a, b| a.template_index <=> b.template_index }.map(&:value))
end
end

Expand Down Expand Up @@ -2622,7 +2621,7 @@ def type_check(symtab)
end
end

if func_def_type.return_type(template_values(symtab), arg_nodes, symtab).nil?
if func_def_type.return_type(template_values(symtab)).nil?
internal_error "No type determined for function"
end

Expand All @@ -2632,12 +2631,13 @@ def type_check(symtab)
# @!macro type
def type(symtab)
func_def_type = symtab.get(name)
func_def_type.return_type(template_values(symtab), arg_nodes, symtab)
func_def_type.return_type(template_values(symtab))
end

# @!macro value
def value(symtab)
func_def_type = symtab.get(name)
type_error "not a function" unless func_def_type.is_a?(FunctionType)
if func_def_type.builtin?
if name == "implemented?"
extname = arg_nodes[0].text_value
Expand All @@ -2647,38 +2647,20 @@ def value(symtab)
end
end

symtab.push

begin
template_arg_nodes.each_with_index do |targ, idx|
targ_name = func_def_type.template_names[idx]
targ_type = func_def_type.template_types[idx]
symtab.add(targ_name, Var.new(targ_name, targ_type, targ.value(symtab)))
end

arg_nodes.each_with_index do |arg, idx|
arg_name = func_def_type.argument_name(idx, template_values(symtab))
arg_type = func_def_type.argument_type(idx, template_values(symtab), arg_nodes, symtab)
begin
symtab.add!(arg_name, Var.new(arg_name, arg_type, arg.value(symtab)))
rescue SymbolTable::DuplicateSymError
type_error "Argument '#{arg_name}' shadows another symbol (level = #{symtab.levels})"
end
end

v = func_def_type.body.return_value(symtab)
ensure
symtab.pop
template_values = []
template_arg_nodes.each_with_index do |targ, idx|
# targ_name = func_def_type.template_names[idx]
# targ_type = func_def_type.template_types[idx]
template_values << targ.value(symtab)
end

v
func_def_type.return_value(template_values, arg_nodes, symtab)
end
alias execute value

def name
function_name.text_value
end

end

# class ExecutionAst < AstNode
Expand Down Expand Up @@ -2747,11 +2729,13 @@ def statements

# @!macro type_check
def type_check(symtab)
internal_error "Function bodies should be at global + 1 scope" unless symtab.levels == 2

return_value_might_be_known = true

statements.each do |s|
s.type_check(symtab)
next if return_value_might_be_known
next unless return_value_might_be_known

begin
if s.is_a?(Returns)
Expand All @@ -2771,6 +2755,8 @@ def type_check(symtab)
#
# @note arguments and template arguments must be put on the symtab before calling
def return_value(symtab)
internal_error "Function bodies should be at global + 1 scope" unless symtab.levels == 2

# go through the statements, and return the first one that has a return value
statements.each do |s|
if s.is_a?(Returns)
Expand All @@ -2781,27 +2767,10 @@ def return_value(symtab)
end
end

internal_error "No function body statement returned a value"
value_error "No function body statement returned a value"
end
alias execute return_value

# @return [Array] An array of all possible return values
#
# @note arguments and template arguments must be put on the symtab before calling
def return_values(symtab)
# go through the statements, and find all return values
rts = []
statements.each do |s|
if s.is_a?(Returns)
rts += s.return_values(symtab)
else
s.execute(symtab)
end
end

rts
end

def to_idl
result = ""
# go through the statements, and return the first one that has a return value
Expand Down Expand Up @@ -2866,21 +2835,12 @@ def arguments_list_str
list
end

# return an array of all the return types, in order
# function (or template instance) must be resolved
def return_types(symtab)
t = return_type(symtab)
if t.kind == :tuple
t.tuple_types
elsif t.kind == :void
[]
else
[t]
end
end

# return the return type, which may be a tuple of multiple types
def return_type(symtab)
unless symtab.levels == 2
internal_error "Function bodies should be at global + 1 scope (at global + #{symtab.levels - 1})"
end

if templated?
template_names.each do |tname|
internal_error "Template values missing" unless symtab.get(tname)
Expand Down Expand Up @@ -2930,6 +2890,8 @@ def name

# @param [Array<Integer>] template values to apply
def type_check_template_instance(symtab)
internal_error "Function definitions should be at global + 1 scope" unless symtab.levels == 2

internal_error "Not a template function" unless templated?

template_names.each do |tname|
Expand All @@ -2945,6 +2907,8 @@ def type_check_template_instance(symtab)
# uncalled functions, which avoids dealing with mentions of CSRs that
# may not exist in a given implmentation
def type_check_from_call(symtab)
internal_error "Function definitions should be at global + 1 scope" unless symtab.levels == 2

global_scope = symtab.deep_clone
global_scope.pop while global_scope.levels != 1

Expand All @@ -2965,7 +2929,7 @@ def type_check(symtab)
def_type = FunctionType.new(
name,
self,
symtab.deep_clone
symtab
)

# recursion isn't supported (doesn't map well to hardware), so we can add the function after type checking the body
Expand Down Expand Up @@ -3104,7 +3068,6 @@ def return_value(symtab)
v = s.s.return_value(symtab)
unless v.nil?
symtab.pop
puts "value = #{v}"
return v
end
else
Expand Down
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