diff --git a/src/arch/isa_parser.py b/src/arch/isa_parser.py index 42f51d806..08449235e 100755 --- a/src/arch/isa_parser.py +++ b/src/arch/isa_parser.py @@ -36,702 +36,221 @@ from types import * from m5.util.grammar import Grammar -class ISAParser(Grammar): - def __init__(self, *args, **kwargs): - super(ISAParser, self).__init__(*args, **kwargs) - self.templateMap = {} - - ##################################################################### - # - # Lexer - # - # The PLY lexer module takes two things as input: - # - A list of token names (the string list 'tokens') - # - A regular expression describing a match for each token. The - # regexp for token FOO can be provided in two ways: - # - as a string variable named t_FOO - # - as the doc string for a function named t_FOO. In this case, - # the function is also executed, allowing an action to be - # associated with each token match. - # - ##################################################################### - - # Reserved words. These are listed separately as they are matched - # using the same regexp as generic IDs, but distinguished in the - # t_ID() function. The PLY documentation suggests this approach. - reserved = ( - 'BITFIELD', 'DECODE', 'DECODER', 'DEFAULT', 'DEF', 'EXEC', 'FORMAT', - 'HEADER', 'LET', 'NAMESPACE', 'OPERAND_TYPES', 'OPERANDS', - 'OUTPUT', 'SIGNED', 'TEMPLATE' - ) - - # List of tokens. The lex module requires this. - tokens = reserved + ( - # identifier - 'ID', - - # integer literal - 'INTLIT', - - # string literal - 'STRLIT', - - # code literal - 'CODELIT', - - # ( ) [ ] { } < > , ; . : :: * - 'LPAREN', 'RPAREN', - 'LBRACKET', 'RBRACKET', - 'LBRACE', 'RBRACE', - 'LESS', 'GREATER', 'EQUALS', - 'COMMA', 'SEMI', 'DOT', 'COLON', 'DBLCOLON', - 'ASTERISK', - - # C preprocessor directives - 'CPPDIRECTIVE' - - # The following are matched but never returned. commented out to - # suppress PLY warning - # newfile directive - # 'NEWFILE', - - # endfile directive - # 'ENDFILE' - ) - - # Regular expressions for token matching - t_LPAREN = r'\(' - t_RPAREN = r'\)' - t_LBRACKET = r'\[' - t_RBRACKET = r'\]' - t_LBRACE = r'\{' - t_RBRACE = r'\}' - t_LESS = r'\<' - t_GREATER = r'\>' - t_EQUALS = r'=' - t_COMMA = r',' - t_SEMI = r';' - t_DOT = r'\.' - t_COLON = r':' - t_DBLCOLON = r'::' - t_ASTERISK = r'\*' - - # Identifiers and reserved words - reserved_map = { } - for r in reserved: - reserved_map[r.lower()] = r - - def t_ID(self, t): - r'[A-Za-z_]\w*' - t.type = self.reserved_map.get(t.value, 'ID') - return t - - # Integer literal - def t_INTLIT(self, t): - r'-?(0x[\da-fA-F]+)|\d+' - try: - t.value = int(t.value,0) - except ValueError: - error(t.lexer.lineno, 'Integer value "%s" too large' % t.value) - t.value = 0 - return t - - # String literal. Note that these use only single quotes, and - # can span multiple lines. - def t_STRLIT(self, t): - r"(?m)'([^'])+'" - # strip off quotes - t.value = t.value[1:-1] - t.lexer.lineno += t.value.count('\n') - return t - - - # "Code literal"... like a string literal, but delimiters are - # '{{' and '}}' so they get formatted nicely under emacs c-mode - def t_CODELIT(self, t): - r"(?m)\{\{([^\}]|}(?!\}))+\}\}" - # strip off {{ & }} - t.value = t.value[2:-2] - t.lexer.lineno += t.value.count('\n') - return t - - def t_CPPDIRECTIVE(self, t): - r'^\#[^\#].*\n' - t.lexer.lineno += t.value.count('\n') - return t - - def t_NEWFILE(self, t): - r'^\#\#newfile\s+"[\w/.-]*"' - fileNameStack.push((t.value[11:-1], t.lexer.lineno)) - t.lexer.lineno = 0 - - def t_ENDFILE(self, t): - r'^\#\#endfile' - (old_filename, t.lexer.lineno) = fileNameStack.pop() - - # - # The functions t_NEWLINE, t_ignore, and t_error are - # special for the lex module. - # - - # Newlines - def t_NEWLINE(self, t): - r'\n+' - t.lexer.lineno += t.value.count('\n') - - # Comments - def t_comment(self, t): - r'//.*' - - # Completely ignored characters - t_ignore = ' \t\x0c' - - # Error handler - def t_error(self, t): - error(t.lexer.lineno, "illegal character '%s'" % t.value[0]) - t.skip(1) - - ##################################################################### - # - # Parser - # - # Every function whose name starts with 'p_' defines a grammar - # rule. The rule is encoded in the function's doc string, while - # the function body provides the action taken when the rule is - # matched. The argument to each function is a list of the values - # of the rule's symbols: t[0] for the LHS, and t[1..n] for the - # symbols on the RHS. For tokens, the value is copied from the - # t.value attribute provided by the lexer. For non-terminals, the - # value is assigned by the producing rule; i.e., the job of the - # grammar rule function is to set the value for the non-terminal - # on the LHS (by assigning to t[0]). - ##################################################################### - - # The LHS of the first grammar rule is used as the start symbol - # (in this case, 'specification'). Note that this rule enforces - # that there will be exactly one namespace declaration, with 0 or - # more global defs/decls before and after it. The defs & decls - # before the namespace decl will be outside the namespace; those - # after will be inside. The decoder function is always inside the - # namespace. - def p_specification(self, t): - 'specification : opt_defs_and_outputs name_decl opt_defs_and_outputs decode_block' - global_code = t[1] - isa_name = t[2] - namespace = isa_name + "Inst" - # wrap the decode block as a function definition - t[4].wrap_decode_block(''' -StaticInstPtr -%(isa_name)s::decodeInst(%(isa_name)s::ExtMachInst machInst) -{ - using namespace %(namespace)s; -''' % vars(), '}') - # both the latter output blocks and the decode block are in - # the namespace - namespace_code = t[3] + t[4] - # pass it all back to the caller of yacc.parse() - t[0] = (isa_name, namespace, global_code, namespace_code) - - # ISA name declaration looks like "namespace ;" - def p_name_decl(self, t): - 'name_decl : NAMESPACE ID SEMI' - t[0] = t[2] - - # 'opt_defs_and_outputs' is a possibly empty sequence of - # def and/or output statements. - def p_opt_defs_and_outputs_0(self, t): - 'opt_defs_and_outputs : empty' - t[0] = GenCode() - - def p_opt_defs_and_outputs_1(self, t): - 'opt_defs_and_outputs : defs_and_outputs' - t[0] = t[1] - - def p_defs_and_outputs_0(self, t): - 'defs_and_outputs : def_or_output' - t[0] = t[1] - - def p_defs_and_outputs_1(self, t): - 'defs_and_outputs : defs_and_outputs def_or_output' - t[0] = t[1] + t[2] - - # The list of possible definition/output statements. - def p_def_or_output(self, t): - '''def_or_output : def_format - | def_bitfield - | def_bitfield_struct - | def_template - | def_operand_types - | def_operands - | output_header - | output_decoder - | output_exec - | global_let''' - t[0] = t[1] - - # Output blocks 'output {{...}}' (C++ code blocks) are copied - # directly to the appropriate output section. - - # Massage output block by substituting in template definitions and - # bit operators. We handle '%'s embedded in the string that don't - # indicate template substitutions (or CPU-specific symbols, which - # get handled in GenCode) by doubling them first so that the - # format operation will reduce them back to single '%'s. - def process_output(self, s): - s = protect_non_subst_percents(s) - # protects cpu-specific symbols too - s = protect_cpu_symbols(s) - return substBitOps(s % self.templateMap) - - def p_output_header(self, t): - 'output_header : OUTPUT HEADER CODELIT SEMI' - t[0] = GenCode(header_output = self.process_output(t[3])) - - def p_output_decoder(self, t): - 'output_decoder : OUTPUT DECODER CODELIT SEMI' - t[0] = GenCode(decoder_output = self.process_output(t[3])) - - def p_output_exec(self, t): - 'output_exec : OUTPUT EXEC CODELIT SEMI' - t[0] = GenCode(exec_output = self.process_output(t[3])) - - # global let blocks 'let {{...}}' (Python code blocks) are - # executed directly when seen. Note that these execute in a - # special variable context 'exportContext' to prevent the code - # from polluting this script's namespace. - def p_global_let(self, t): - 'global_let : LET CODELIT SEMI' - updateExportContext() - exportContext["header_output"] = '' - exportContext["decoder_output"] = '' - exportContext["exec_output"] = '' - exportContext["decode_block"] = '' - try: - exec fixPythonIndentation(t[2]) in exportContext - except Exception, exc: - error(t.lexer.lineno, - 'error: %s in global let block "%s".' % (exc, t[2])) - t[0] = GenCode(header_output = exportContext["header_output"], - decoder_output = exportContext["decoder_output"], - exec_output = exportContext["exec_output"], - decode_block = exportContext["decode_block"]) - - # Define the mapping from operand type extensions to C++ types and - # bit widths (stored in operandTypeMap). - def p_def_operand_types(self, t): - 'def_operand_types : DEF OPERAND_TYPES CODELIT SEMI' - try: - user_dict = eval('{' + t[3] + '}') - except Exception, exc: - error(t.lexer.lineno, - 'error: %s in def operand_types block "%s".' % (exc, t[3])) - buildOperandTypeMap(user_dict, t.lexer.lineno) - t[0] = GenCode() # contributes nothing to the output C++ file - - # Define the mapping from operand names to operand classes and - # other traits. Stored in operandNameMap. - def p_def_operands(self, t): - 'def_operands : DEF OPERANDS CODELIT SEMI' - if not globals().has_key('operandTypeMap'): - error(t.lexer.lineno, - 'error: operand types must be defined before operands') - try: - user_dict = eval('{' + t[3] + '}', exportContext) - except Exception, exc: - error(t.lexer.lineno, - 'error: %s in def operands block "%s".' % (exc, t[3])) - buildOperandNameMap(user_dict, t.lexer.lineno) - t[0] = GenCode() # contributes nothing to the output C++ file - - # A bitfield definition looks like: - # 'def [signed] bitfield [:]' - # This generates a preprocessor macro in the output file. - def p_def_bitfield_0(self, t): - 'def_bitfield : DEF opt_signed BITFIELD ID LESS INTLIT COLON INTLIT GREATER SEMI' - expr = 'bits(machInst, %2d, %2d)' % (t[6], t[8]) - if (t[2] == 'signed'): - expr = 'sext<%d>(%s)' % (t[6] - t[8] + 1, expr) - hash_define = '#undef %s\n#define %s\t%s\n' % (t[4], t[4], expr) - t[0] = GenCode(header_output = hash_define) - - # alternate form for single bit: 'def [signed] bitfield []' - def p_def_bitfield_1(self, t): - 'def_bitfield : DEF opt_signed BITFIELD ID LESS INTLIT GREATER SEMI' - expr = 'bits(machInst, %2d, %2d)' % (t[6], t[6]) - if (t[2] == 'signed'): - expr = 'sext<%d>(%s)' % (1, expr) - hash_define = '#undef %s\n#define %s\t%s\n' % (t[4], t[4], expr) - t[0] = GenCode(header_output = hash_define) - - # alternate form for structure member: 'def bitfield ' - def p_def_bitfield_struct(self, t): - 'def_bitfield_struct : DEF opt_signed BITFIELD ID id_with_dot SEMI' - if (t[2] != ''): - error(t.lexer.lineno, - 'error: structure bitfields are always unsigned.') - expr = 'machInst.%s' % t[5] - hash_define = '#undef %s\n#define %s\t%s\n' % (t[4], t[4], expr) - t[0] = GenCode(header_output = hash_define) - - def p_id_with_dot_0(self, t): - 'id_with_dot : ID' - t[0] = t[1] - - def p_id_with_dot_1(self, t): - 'id_with_dot : ID DOT id_with_dot' - t[0] = t[1] + t[2] + t[3] - - def p_opt_signed_0(self, t): - 'opt_signed : SIGNED' - t[0] = t[1] - - def p_opt_signed_1(self, t): - 'opt_signed : empty' - t[0] = '' - - def p_def_template(self, t): - 'def_template : DEF TEMPLATE ID CODELIT SEMI' - self.templateMap[t[3]] = Template(t[4]) - t[0] = GenCode() - - # An instruction format definition looks like - # "def format () {{...}};" - def p_def_format(self, t): - 'def_format : DEF FORMAT ID LPAREN param_list RPAREN CODELIT SEMI' - (id, params, code) = (t[3], t[5], t[7]) - defFormat(id, params, code, t.lexer.lineno) - t[0] = GenCode() - - # The formal parameter list for an instruction format is a - # possibly empty list of comma-separated parameters. Positional - # (standard, non-keyword) parameters must come first, followed by - # keyword parameters, followed by a '*foo' parameter that gets - # excess positional arguments (as in Python). Each of these three - # parameter categories is optional. - # - # Note that we do not support the '**foo' parameter for collecting - # otherwise undefined keyword args. Otherwise the parameter list - # is (I believe) identical to what is supported in Python. - # - # The param list generates a tuple, where the first element is a - # list of the positional params and the second element is a dict - # containing the keyword params. - def p_param_list_0(self, t): - 'param_list : positional_param_list COMMA nonpositional_param_list' - t[0] = t[1] + t[3] - - def p_param_list_1(self, t): - '''param_list : positional_param_list - | nonpositional_param_list''' - t[0] = t[1] - - def p_positional_param_list_0(self, t): - 'positional_param_list : empty' - t[0] = [] - - def p_positional_param_list_1(self, t): - 'positional_param_list : ID' - t[0] = [t[1]] - - def p_positional_param_list_2(self, t): - 'positional_param_list : positional_param_list COMMA ID' - t[0] = t[1] + [t[3]] - - def p_nonpositional_param_list_0(self, t): - 'nonpositional_param_list : keyword_param_list COMMA excess_args_param' - t[0] = t[1] + t[3] - - def p_nonpositional_param_list_1(self, t): - '''nonpositional_param_list : keyword_param_list - | excess_args_param''' - t[0] = t[1] - - def p_keyword_param_list_0(self, t): - 'keyword_param_list : keyword_param' - t[0] = [t[1]] - - def p_keyword_param_list_1(self, t): - 'keyword_param_list : keyword_param_list COMMA keyword_param' - t[0] = t[1] + [t[3]] - - def p_keyword_param(self, t): - 'keyword_param : ID EQUALS expr' - t[0] = t[1] + ' = ' + t[3].__repr__() - - def p_excess_args_param(self, t): - 'excess_args_param : ASTERISK ID' - # Just concatenate them: '*ID'. Wrap in list to be consistent - # with positional_param_list and keyword_param_list. - t[0] = [t[1] + t[2]] - - # End of format definition-related rules. - ############## - - # - # A decode block looks like: - # decode [, ]* [default ] { ... } - # - def p_decode_block(self, t): - 'decode_block : DECODE ID opt_default LBRACE decode_stmt_list RBRACE' - default_defaults = defaultStack.pop() - codeObj = t[5] - # use the "default defaults" only if there was no explicit - # default statement in decode_stmt_list - if not codeObj.has_decode_default: - codeObj += default_defaults - codeObj.wrap_decode_block('switch (%s) {\n' % t[2], '}\n') - t[0] = codeObj - - # The opt_default statement serves only to push the "default - # defaults" onto defaultStack. This value will be used by nested - # decode blocks, and used and popped off when the current - # decode_block is processed (in p_decode_block() above). - def p_opt_default_0(self, t): - 'opt_default : empty' - # no default specified: reuse the one currently at the top of - # the stack - defaultStack.push(defaultStack.top()) - # no meaningful value returned - t[0] = None - - def p_opt_default_1(self, t): - 'opt_default : DEFAULT inst' - # push the new default - codeObj = t[2] - codeObj.wrap_decode_block('\ndefault:\n', 'break;\n') - defaultStack.push(codeObj) - # no meaningful value returned - t[0] = None - - def p_decode_stmt_list_0(self, t): - 'decode_stmt_list : decode_stmt' - t[0] = t[1] - - def p_decode_stmt_list_1(self, t): - 'decode_stmt_list : decode_stmt decode_stmt_list' - if (t[1].has_decode_default and t[2].has_decode_default): - error(t.lexer.lineno, 'Two default cases in decode block') - t[0] = t[1] + t[2] - - # - # Decode statement rules - # - # There are four types of statements allowed in a decode block: - # 1. Format blocks 'format { ... }' - # 2. Nested decode blocks - # 3. Instruction definitions. - # 4. C preprocessor directives. - - - # Preprocessor directives found in a decode statement list are - # passed through to the output, replicated to all of the output - # code streams. This works well for ifdefs, so we can ifdef out - # both the declarations and the decode cases generated by an - # instruction definition. Handling them as part of the grammar - # makes it easy to keep them in the right place with respect to - # the code generated by the other statements. - def p_decode_stmt_cpp(self, t): - 'decode_stmt : CPPDIRECTIVE' - t[0] = GenCode(t[1], t[1], t[1], t[1]) - - # A format block 'format { ... }' sets the default - # instruction format used to handle instruction definitions inside - # the block. This format can be overridden by using an explicit - # format on the instruction definition or with a nested format - # block. - def p_decode_stmt_format(self, t): - 'decode_stmt : FORMAT push_format_id LBRACE decode_stmt_list RBRACE' - # The format will be pushed on the stack when 'push_format_id' - # is processed (see below). Once the parser has recognized - # the full production (though the right brace), we're done - # with the format, so now we can pop it. - formatStack.pop() - t[0] = t[4] - - # This rule exists so we can set the current format (& push the - # stack) when we recognize the format name part of the format - # block. - def p_push_format_id(self, t): - 'push_format_id : ID' - try: - formatStack.push(formatMap[t[1]]) - t[0] = ('', '// format %s' % t[1]) - except KeyError: - error(t.lexer.lineno, - 'instruction format "%s" not defined.' % t[1]) - - # Nested decode block: if the value of the current field matches - # the specified constant, do a nested decode on some other field. - def p_decode_stmt_decode(self, t): - 'decode_stmt : case_label COLON decode_block' - label = t[1] - codeObj = t[3] - # just wrap the decoding code from the block as a case in the - # outer switch statement. - codeObj.wrap_decode_block('\n%s:\n' % label) - codeObj.has_decode_default = (label == 'default') - t[0] = codeObj - - # Instruction definition (finally!). - def p_decode_stmt_inst(self, t): - 'decode_stmt : case_label COLON inst SEMI' - label = t[1] - codeObj = t[3] - codeObj.wrap_decode_block('\n%s:' % label, 'break;\n') - codeObj.has_decode_default = (label == 'default') - t[0] = codeObj - - # The case label is either a list of one or more constants or - # 'default' - def p_case_label_0(self, t): - 'case_label : intlit_list' - def make_case(intlit): - if intlit >= 2**32: - return 'case ULL(%#x)' % intlit - else: - return 'case %#x' % intlit - t[0] = ': '.join(map(make_case, t[1])) - - def p_case_label_1(self, t): - 'case_label : DEFAULT' - t[0] = 'default' - - # - # The constant list for a decode case label must be non-empty, but - # may have one or more comma-separated integer literals in it. - # - def p_intlit_list_0(self, t): - 'intlit_list : INTLIT' - t[0] = [t[1]] - - def p_intlit_list_1(self, t): - 'intlit_list : intlit_list COMMA INTLIT' - t[0] = t[1] - t[0].append(t[3]) - - # Define an instruction using the current instruction format - # (specified by an enclosing format block). - # "()" - def p_inst_0(self, t): - 'inst : ID LPAREN arg_list RPAREN' - # Pass the ID and arg list to the current format class to deal with. - currentFormat = formatStack.top() - codeObj = currentFormat.defineInst(t[1], t[3], t.lexer.lineno) - args = ','.join(map(str, t[3])) - args = re.sub('(?m)^', '//', args) - args = re.sub('^//', '', args) - comment = '\n// %s::%s(%s)\n' % (currentFormat.id, t[1], args) - codeObj.prepend_all(comment) - t[0] = codeObj - - # Define an instruction using an explicitly specified format: - # "::()" - def p_inst_1(self, t): - 'inst : ID DBLCOLON ID LPAREN arg_list RPAREN' - try: - format = formatMap[t[1]] - except KeyError: - error(t.lexer.lineno, - 'instruction format "%s" not defined.' % t[1]) - codeObj = format.defineInst(t[3], t[5], t.lexer.lineno) - comment = '\n// %s::%s(%s)\n' % (t[1], t[3], t[5]) - codeObj.prepend_all(comment) - t[0] = codeObj - - # The arg list generates a tuple, where the first element is a - # list of the positional args and the second element is a dict - # containing the keyword args. - def p_arg_list_0(self, t): - 'arg_list : positional_arg_list COMMA keyword_arg_list' - t[0] = ( t[1], t[3] ) - - def p_arg_list_1(self, t): - 'arg_list : positional_arg_list' - t[0] = ( t[1], {} ) - - def p_arg_list_2(self, t): - 'arg_list : keyword_arg_list' - t[0] = ( [], t[1] ) - - def p_positional_arg_list_0(self, t): - 'positional_arg_list : empty' - t[0] = [] - - def p_positional_arg_list_1(self, t): - 'positional_arg_list : expr' - t[0] = [t[1]] - - def p_positional_arg_list_2(self, t): - 'positional_arg_list : positional_arg_list COMMA expr' - t[0] = t[1] + [t[3]] - - def p_keyword_arg_list_0(self, t): - 'keyword_arg_list : keyword_arg' - t[0] = t[1] - - def p_keyword_arg_list_1(self, t): - 'keyword_arg_list : keyword_arg_list COMMA keyword_arg' - t[0] = t[1] - t[0].update(t[3]) - - def p_keyword_arg(self, t): - 'keyword_arg : ID EQUALS expr' - t[0] = { t[1] : t[3] } - - # - # Basic expressions. These constitute the argument values of - # "function calls" (i.e. instruction definitions in the decode - # block) and default values for formal parameters of format - # functions. - # - # Right now, these are either strings, integers, or (recursively) - # lists of exprs (using Python square-bracket list syntax). Note - # that bare identifiers are trated as string constants here (since - # there isn't really a variable namespace to refer to). - # - def p_expr_0(self, t): - '''expr : ID - | INTLIT - | STRLIT - | CODELIT''' - t[0] = t[1] - - def p_expr_1(self, t): - '''expr : LBRACKET list_expr RBRACKET''' - t[0] = t[2] - - def p_list_expr_0(self, t): - 'list_expr : expr' - t[0] = [t[1]] - - def p_list_expr_1(self, t): - 'list_expr : list_expr COMMA expr' - t[0] = t[1] + [t[3]] - - def p_list_expr_2(self, t): - 'list_expr : empty' - t[0] = [] - - # - # Empty production... use in other rules for readability. - # - def p_empty(self, t): - 'empty :' - pass - - # Parse error handler. Note that the argument here is the - # offending *token*, not a grammar symbol (hence the need to use - # t.value) - def p_error(self, t): - if t: - error(t.lexer.lineno, "syntax error at '%s'" % t.value) +################### +# Utility functions + +# +# Indent every line in string 's' by two spaces +# (except preprocessor directives). +# Used to make nested code blocks look pretty. +# +def indent(s): + return re.sub(r'(?m)^(?!#)', ' ', s) + +# +# Munge a somewhat arbitrarily formatted piece of Python code +# (e.g. from a format 'let' block) into something whose indentation +# will get by the Python parser. +# +# The two keys here are that Python will give a syntax error if +# there's any whitespace at the beginning of the first line, and that +# all lines at the same lexical nesting level must have identical +# indentation. Unfortunately the way code literals work, an entire +# let block tends to have some initial indentation. Rather than +# trying to figure out what that is and strip it off, we prepend 'if +# 1:' to make the let code the nested block inside the if (and have +# the parser automatically deal with the indentation for us). +# +# We don't want to do this if (1) the code block is empty or (2) the +# first line of the block doesn't have any whitespace at the front. + +def fixPythonIndentation(s): + # get rid of blank lines first + s = re.sub(r'(?m)^\s*\n', '', s); + if (s != '' and re.match(r'[ \t]', s[0])): + s = 'if 1:\n' + s + return s + +# Error handler. Just call exit. Output formatted to work under +# Emacs compile-mode. Optional 'print_traceback' arg, if set to True, +# prints a Python stack backtrace too (can be handy when trying to +# debug the parser itself). +def error(lineno, string, print_traceback = False): + spaces = "" + for (filename, line) in fileNameStack[0:-1]: + print spaces + "In file included from " + filename + ":" + spaces += " " + # Print a Python stack backtrace if requested. + if (print_traceback): + traceback.print_exc() + if lineno != 0: + line_str = "%d:" % lineno + else: + line_str = "" + sys.exit(spaces + "%s:%s %s" % (fileNameStack[-1][0], line_str, string)) + +#################### +# Template objects. +# +# Template objects are format strings that allow substitution from +# the attribute spaces of other objects (e.g. InstObjParams instances). + +labelRE = re.compile(r'(? 1: + Name += name[1:] + context.update({ 'name': name, 'Name': Name }) + try: + vars = self.func(self.user_code, context, *args[0], **args[1]) + except Exception, exc: + error(lineno, 'error defining "%s": %s.' % (name, exc)) + for k in vars.keys(): + if k not in ('header_output', 'decoder_output', + 'exec_output', 'decode_block'): + del vars[k] + return GenCode(**vars) + +# Special null format to catch an implicit-format instruction +# definition outside of any format block. +class NoFormat(object): + def __init__(self): + self.defaultInst = '' + + def defineInst(self, name, args, lineno): + error(lineno, + 'instruction definition "%s" with no active format!' % name) + +# This dictionary maps format name strings to Format objects. +formatMap = {} + +# Define a new format +def defFormat(id, params, code, lineno): + # make sure we haven't already defined this one + if formatMap.get(id, None) != None: + error(lineno, 'format %s redefined.' % id) + # create new object and store in global map + formatMap[id] = Format(id, params, code) ##################################################################### # @@ -833,164 +352,6 @@ class GenCode(object): def wrap_decode_block(self, pre, post = ''): self.decode_block = pre + indent(self.decode_block) + post -################ -# Format object. -# -# A format object encapsulates an instruction format. It must provide -# a defineInst() method that generates the code for an instruction -# definition. - -exportContextSymbols = ('InstObjParams', 'makeList', 're', 'string') - -exportContext = {} - -def updateExportContext(): - exportContext.update(exportDict(*exportContextSymbols)) - exportContext.update(parser.templateMap) - -def exportDict(*symNames): - return dict([(s, eval(s)) for s in symNames]) - - -class Format(object): - def __init__(self, id, params, code): - # constructor: just save away arguments - self.id = id - self.params = params - label = 'def format ' + id - self.user_code = compile(fixPythonIndentation(code), label, 'exec') - param_list = string.join(params, ", ") - f = '''def defInst(_code, _context, %s): - my_locals = vars().copy() - exec _code in _context, my_locals - return my_locals\n''' % param_list - c = compile(f, label + ' wrapper', 'exec') - exec c - self.func = defInst - - def defineInst(self, name, args, lineno): - context = {} - updateExportContext() - context.update(exportContext) - if len(name): - Name = name[0].upper() - if len(name) > 1: - Name += name[1:] - context.update({ 'name': name, 'Name': Name }) - try: - vars = self.func(self.user_code, context, *args[0], **args[1]) - except Exception, exc: - error(lineno, 'error defining "%s": %s.' % (name, exc)) - for k in vars.keys(): - if k not in ('header_output', 'decoder_output', - 'exec_output', 'decode_block'): - del vars[k] - return GenCode(**vars) - -# Special null format to catch an implicit-format instruction -# definition outside of any format block. -class NoFormat(object): - def __init__(self): - self.defaultInst = '' - - def defineInst(self, name, args, lineno): - error(lineno, - 'instruction definition "%s" with no active format!' % name) - -# This dictionary maps format name strings to Format objects. -formatMap = {} - -# Define a new format -def defFormat(id, params, code, lineno): - # make sure we haven't already defined this one - if formatMap.get(id, None) != None: - error(lineno, 'format %s redefined.' % id) - # create new object and store in global map - formatMap[id] = Format(id, params, code) - - -############## -# Stack: a simple stack object. Used for both formats (formatStack) -# and default cases (defaultStack). Simply wraps a list to give more -# stack-like syntax and enable initialization with an argument list -# (as opposed to an argument that's a list). - -class Stack(list): - def __init__(self, *items): - list.__init__(self, items) - - def push(self, item): - self.append(item); - - def top(self): - return self[-1] - -# The global format stack. -formatStack = Stack(NoFormat()) - -# The global default case stack. -defaultStack = Stack( None ) - -# Global stack that tracks current file and line number. -# Each element is a tuple (filename, lineno) that records the -# *current* filename and the line number in the *previous* file where -# it was included. -fileNameStack = Stack() - -################### -# Utility functions - -# -# Indent every line in string 's' by two spaces -# (except preprocessor directives). -# Used to make nested code blocks look pretty. -# -def indent(s): - return re.sub(r'(?m)^(?!#)', ' ', s) - -# -# Munge a somewhat arbitrarily formatted piece of Python code -# (e.g. from a format 'let' block) into something whose indentation -# will get by the Python parser. -# -# The two keys here are that Python will give a syntax error if -# there's any whitespace at the beginning of the first line, and that -# all lines at the same lexical nesting level must have identical -# indentation. Unfortunately the way code literals work, an entire -# let block tends to have some initial indentation. Rather than -# trying to figure out what that is and strip it off, we prepend 'if -# 1:' to make the let code the nested block inside the if (and have -# the parser automatically deal with the indentation for us). -# -# We don't want to do this if (1) the code block is empty or (2) the -# first line of the block doesn't have any whitespace at the front. - -def fixPythonIndentation(s): - # get rid of blank lines first - s = re.sub(r'(?m)^\s*\n', '', s); - if (s != '' and re.match(r'[ \t]', s[0])): - s = 'if 1:\n' + s - return s - -# Error handler. Just call exit. Output formatted to work under -# Emacs compile-mode. Optional 'print_traceback' arg, if set to True, -# prints a Python stack backtrace too (can be handy when trying to -# debug the parser itself). -def error(lineno, string, print_traceback = False): - spaces = "" - for (filename, line) in fileNameStack[0:-1]: - print spaces + "In file included from " + filename + ":" - spaces += " " - # Print a Python stack backtrace if requested. - if (print_traceback): - traceback.print_exc() - if lineno != 0: - line_str = "%d:" % lineno - else: - line_str = "" - sys.exit(spaces + "%s:%s %s" % (fileNameStack[-1][0], line_str, string)) - - ##################################################################### # # Bitfield Operator Support @@ -1032,94 +393,6 @@ def substBitOps(code): return code -#################### -# Template objects. -# -# Template objects are format strings that allow substitution from -# the attribute spaces of other objects (e.g. InstObjParams instances). - -labelRE = re.compile(r'(? , ; . : :: * + 'LPAREN', 'RPAREN', + 'LBRACKET', 'RBRACKET', + 'LBRACE', 'RBRACE', + 'LESS', 'GREATER', 'EQUALS', + 'COMMA', 'SEMI', 'DOT', 'COLON', 'DBLCOLON', + 'ASTERISK', + + # C preprocessor directives + 'CPPDIRECTIVE' + + # The following are matched but never returned. commented out to + # suppress PLY warning + # newfile directive + # 'NEWFILE', + + # endfile directive + # 'ENDFILE' + ) + + # Regular expressions for token matching + t_LPAREN = r'\(' + t_RPAREN = r'\)' + t_LBRACKET = r'\[' + t_RBRACKET = r'\]' + t_LBRACE = r'\{' + t_RBRACE = r'\}' + t_LESS = r'\<' + t_GREATER = r'\>' + t_EQUALS = r'=' + t_COMMA = r',' + t_SEMI = r';' + t_DOT = r'\.' + t_COLON = r':' + t_DBLCOLON = r'::' + t_ASTERISK = r'\*' + + # Identifiers and reserved words + reserved_map = { } + for r in reserved: + reserved_map[r.lower()] = r + + def t_ID(self, t): + r'[A-Za-z_]\w*' + t.type = self.reserved_map.get(t.value, 'ID') + return t + + # Integer literal + def t_INTLIT(self, t): + r'-?(0x[\da-fA-F]+)|\d+' + try: + t.value = int(t.value,0) + except ValueError: + error(t.lexer.lineno, 'Integer value "%s" too large' % t.value) + t.value = 0 + return t + + # String literal. Note that these use only single quotes, and + # can span multiple lines. + def t_STRLIT(self, t): + r"(?m)'([^'])+'" + # strip off quotes + t.value = t.value[1:-1] + t.lexer.lineno += t.value.count('\n') + return t + + + # "Code literal"... like a string literal, but delimiters are + # '{{' and '}}' so they get formatted nicely under emacs c-mode + def t_CODELIT(self, t): + r"(?m)\{\{([^\}]|}(?!\}))+\}\}" + # strip off {{ & }} + t.value = t.value[2:-2] + t.lexer.lineno += t.value.count('\n') + return t + + def t_CPPDIRECTIVE(self, t): + r'^\#[^\#].*\n' + t.lexer.lineno += t.value.count('\n') + return t + + def t_NEWFILE(self, t): + r'^\#\#newfile\s+"[\w/.-]*"' + fileNameStack.push((t.value[11:-1], t.lexer.lineno)) + t.lexer.lineno = 0 + + def t_ENDFILE(self, t): + r'^\#\#endfile' + (old_filename, t.lexer.lineno) = fileNameStack.pop() + + # + # The functions t_NEWLINE, t_ignore, and t_error are + # special for the lex module. + # + + # Newlines + def t_NEWLINE(self, t): + r'\n+' + t.lexer.lineno += t.value.count('\n') + + # Comments + def t_comment(self, t): + r'//.*' + + # Completely ignored characters + t_ignore = ' \t\x0c' + + # Error handler + def t_error(self, t): + error(t.lexer.lineno, "illegal character '%s'" % t.value[0]) + t.skip(1) + + ##################################################################### + # + # Parser + # + # Every function whose name starts with 'p_' defines a grammar + # rule. The rule is encoded in the function's doc string, while + # the function body provides the action taken when the rule is + # matched. The argument to each function is a list of the values + # of the rule's symbols: t[0] for the LHS, and t[1..n] for the + # symbols on the RHS. For tokens, the value is copied from the + # t.value attribute provided by the lexer. For non-terminals, the + # value is assigned by the producing rule; i.e., the job of the + # grammar rule function is to set the value for the non-terminal + # on the LHS (by assigning to t[0]). + ##################################################################### + + # The LHS of the first grammar rule is used as the start symbol + # (in this case, 'specification'). Note that this rule enforces + # that there will be exactly one namespace declaration, with 0 or + # more global defs/decls before and after it. The defs & decls + # before the namespace decl will be outside the namespace; those + # after will be inside. The decoder function is always inside the + # namespace. + def p_specification(self, t): + 'specification : opt_defs_and_outputs name_decl opt_defs_and_outputs decode_block' + global_code = t[1] + isa_name = t[2] + namespace = isa_name + "Inst" + # wrap the decode block as a function definition + t[4].wrap_decode_block(''' +StaticInstPtr +%(isa_name)s::decodeInst(%(isa_name)s::ExtMachInst machInst) +{ + using namespace %(namespace)s; +''' % vars(), '}') + # both the latter output blocks and the decode block are in + # the namespace + namespace_code = t[3] + t[4] + # pass it all back to the caller of yacc.parse() + t[0] = (isa_name, namespace, global_code, namespace_code) + + # ISA name declaration looks like "namespace ;" + def p_name_decl(self, t): + 'name_decl : NAMESPACE ID SEMI' + t[0] = t[2] + + # 'opt_defs_and_outputs' is a possibly empty sequence of + # def and/or output statements. + def p_opt_defs_and_outputs_0(self, t): + 'opt_defs_and_outputs : empty' + t[0] = GenCode() + + def p_opt_defs_and_outputs_1(self, t): + 'opt_defs_and_outputs : defs_and_outputs' + t[0] = t[1] + + def p_defs_and_outputs_0(self, t): + 'defs_and_outputs : def_or_output' + t[0] = t[1] + + def p_defs_and_outputs_1(self, t): + 'defs_and_outputs : defs_and_outputs def_or_output' + t[0] = t[1] + t[2] + + # The list of possible definition/output statements. + def p_def_or_output(self, t): + '''def_or_output : def_format + | def_bitfield + | def_bitfield_struct + | def_template + | def_operand_types + | def_operands + | output_header + | output_decoder + | output_exec + | global_let''' + t[0] = t[1] + + # Output blocks 'output {{...}}' (C++ code blocks) are copied + # directly to the appropriate output section. + + # Massage output block by substituting in template definitions and + # bit operators. We handle '%'s embedded in the string that don't + # indicate template substitutions (or CPU-specific symbols, which + # get handled in GenCode) by doubling them first so that the + # format operation will reduce them back to single '%'s. + def process_output(self, s): + s = protect_non_subst_percents(s) + # protects cpu-specific symbols too + s = protect_cpu_symbols(s) + return substBitOps(s % self.templateMap) + + def p_output_header(self, t): + 'output_header : OUTPUT HEADER CODELIT SEMI' + t[0] = GenCode(header_output = self.process_output(t[3])) + + def p_output_decoder(self, t): + 'output_decoder : OUTPUT DECODER CODELIT SEMI' + t[0] = GenCode(decoder_output = self.process_output(t[3])) + + def p_output_exec(self, t): + 'output_exec : OUTPUT EXEC CODELIT SEMI' + t[0] = GenCode(exec_output = self.process_output(t[3])) + + # global let blocks 'let {{...}}' (Python code blocks) are + # executed directly when seen. Note that these execute in a + # special variable context 'exportContext' to prevent the code + # from polluting this script's namespace. + def p_global_let(self, t): + 'global_let : LET CODELIT SEMI' + updateExportContext() + exportContext["header_output"] = '' + exportContext["decoder_output"] = '' + exportContext["exec_output"] = '' + exportContext["decode_block"] = '' + try: + exec fixPythonIndentation(t[2]) in exportContext + except Exception, exc: + error(t.lexer.lineno, + 'error: %s in global let block "%s".' % (exc, t[2])) + t[0] = GenCode(header_output = exportContext["header_output"], + decoder_output = exportContext["decoder_output"], + exec_output = exportContext["exec_output"], + decode_block = exportContext["decode_block"]) + + # Define the mapping from operand type extensions to C++ types and + # bit widths (stored in operandTypeMap). + def p_def_operand_types(self, t): + 'def_operand_types : DEF OPERAND_TYPES CODELIT SEMI' + try: + user_dict = eval('{' + t[3] + '}') + except Exception, exc: + error(t.lexer.lineno, + 'error: %s in def operand_types block "%s".' % (exc, t[3])) + buildOperandTypeMap(user_dict, t.lexer.lineno) + t[0] = GenCode() # contributes nothing to the output C++ file + + # Define the mapping from operand names to operand classes and + # other traits. Stored in operandNameMap. + def p_def_operands(self, t): + 'def_operands : DEF OPERANDS CODELIT SEMI' + if not globals().has_key('operandTypeMap'): + error(t.lexer.lineno, + 'error: operand types must be defined before operands') + try: + user_dict = eval('{' + t[3] + '}', exportContext) + except Exception, exc: + error(t.lexer.lineno, + 'error: %s in def operands block "%s".' % (exc, t[3])) + buildOperandNameMap(user_dict, t.lexer.lineno) + t[0] = GenCode() # contributes nothing to the output C++ file + + # A bitfield definition looks like: + # 'def [signed] bitfield [:]' + # This generates a preprocessor macro in the output file. + def p_def_bitfield_0(self, t): + 'def_bitfield : DEF opt_signed BITFIELD ID LESS INTLIT COLON INTLIT GREATER SEMI' + expr = 'bits(machInst, %2d, %2d)' % (t[6], t[8]) + if (t[2] == 'signed'): + expr = 'sext<%d>(%s)' % (t[6] - t[8] + 1, expr) + hash_define = '#undef %s\n#define %s\t%s\n' % (t[4], t[4], expr) + t[0] = GenCode(header_output = hash_define) + + # alternate form for single bit: 'def [signed] bitfield []' + def p_def_bitfield_1(self, t): + 'def_bitfield : DEF opt_signed BITFIELD ID LESS INTLIT GREATER SEMI' + expr = 'bits(machInst, %2d, %2d)' % (t[6], t[6]) + if (t[2] == 'signed'): + expr = 'sext<%d>(%s)' % (1, expr) + hash_define = '#undef %s\n#define %s\t%s\n' % (t[4], t[4], expr) + t[0] = GenCode(header_output = hash_define) + + # alternate form for structure member: 'def bitfield ' + def p_def_bitfield_struct(self, t): + 'def_bitfield_struct : DEF opt_signed BITFIELD ID id_with_dot SEMI' + if (t[2] != ''): + error(t.lexer.lineno, + 'error: structure bitfields are always unsigned.') + expr = 'machInst.%s' % t[5] + hash_define = '#undef %s\n#define %s\t%s\n' % (t[4], t[4], expr) + t[0] = GenCode(header_output = hash_define) + + def p_id_with_dot_0(self, t): + 'id_with_dot : ID' + t[0] = t[1] + + def p_id_with_dot_1(self, t): + 'id_with_dot : ID DOT id_with_dot' + t[0] = t[1] + t[2] + t[3] + + def p_opt_signed_0(self, t): + 'opt_signed : SIGNED' + t[0] = t[1] + + def p_opt_signed_1(self, t): + 'opt_signed : empty' + t[0] = '' + + def p_def_template(self, t): + 'def_template : DEF TEMPLATE ID CODELIT SEMI' + self.templateMap[t[3]] = Template(t[4]) + t[0] = GenCode() + + # An instruction format definition looks like + # "def format () {{...}};" + def p_def_format(self, t): + 'def_format : DEF FORMAT ID LPAREN param_list RPAREN CODELIT SEMI' + (id, params, code) = (t[3], t[5], t[7]) + defFormat(id, params, code, t.lexer.lineno) + t[0] = GenCode() + + # The formal parameter list for an instruction format is a + # possibly empty list of comma-separated parameters. Positional + # (standard, non-keyword) parameters must come first, followed by + # keyword parameters, followed by a '*foo' parameter that gets + # excess positional arguments (as in Python). Each of these three + # parameter categories is optional. + # + # Note that we do not support the '**foo' parameter for collecting + # otherwise undefined keyword args. Otherwise the parameter list + # is (I believe) identical to what is supported in Python. + # + # The param list generates a tuple, where the first element is a + # list of the positional params and the second element is a dict + # containing the keyword params. + def p_param_list_0(self, t): + 'param_list : positional_param_list COMMA nonpositional_param_list' + t[0] = t[1] + t[3] + + def p_param_list_1(self, t): + '''param_list : positional_param_list + | nonpositional_param_list''' + t[0] = t[1] + + def p_positional_param_list_0(self, t): + 'positional_param_list : empty' + t[0] = [] + + def p_positional_param_list_1(self, t): + 'positional_param_list : ID' + t[0] = [t[1]] + + def p_positional_param_list_2(self, t): + 'positional_param_list : positional_param_list COMMA ID' + t[0] = t[1] + [t[3]] + + def p_nonpositional_param_list_0(self, t): + 'nonpositional_param_list : keyword_param_list COMMA excess_args_param' + t[0] = t[1] + t[3] + + def p_nonpositional_param_list_1(self, t): + '''nonpositional_param_list : keyword_param_list + | excess_args_param''' + t[0] = t[1] + + def p_keyword_param_list_0(self, t): + 'keyword_param_list : keyword_param' + t[0] = [t[1]] + + def p_keyword_param_list_1(self, t): + 'keyword_param_list : keyword_param_list COMMA keyword_param' + t[0] = t[1] + [t[3]] + + def p_keyword_param(self, t): + 'keyword_param : ID EQUALS expr' + t[0] = t[1] + ' = ' + t[3].__repr__() + + def p_excess_args_param(self, t): + 'excess_args_param : ASTERISK ID' + # Just concatenate them: '*ID'. Wrap in list to be consistent + # with positional_param_list and keyword_param_list. + t[0] = [t[1] + t[2]] + + # End of format definition-related rules. + ############## + + # + # A decode block looks like: + # decode [, ]* [default ] { ... } + # + def p_decode_block(self, t): + 'decode_block : DECODE ID opt_default LBRACE decode_stmt_list RBRACE' + default_defaults = defaultStack.pop() + codeObj = t[5] + # use the "default defaults" only if there was no explicit + # default statement in decode_stmt_list + if not codeObj.has_decode_default: + codeObj += default_defaults + codeObj.wrap_decode_block('switch (%s) {\n' % t[2], '}\n') + t[0] = codeObj + + # The opt_default statement serves only to push the "default + # defaults" onto defaultStack. This value will be used by nested + # decode blocks, and used and popped off when the current + # decode_block is processed (in p_decode_block() above). + def p_opt_default_0(self, t): + 'opt_default : empty' + # no default specified: reuse the one currently at the top of + # the stack + defaultStack.push(defaultStack.top()) + # no meaningful value returned + t[0] = None + + def p_opt_default_1(self, t): + 'opt_default : DEFAULT inst' + # push the new default + codeObj = t[2] + codeObj.wrap_decode_block('\ndefault:\n', 'break;\n') + defaultStack.push(codeObj) + # no meaningful value returned + t[0] = None + + def p_decode_stmt_list_0(self, t): + 'decode_stmt_list : decode_stmt' + t[0] = t[1] + + def p_decode_stmt_list_1(self, t): + 'decode_stmt_list : decode_stmt decode_stmt_list' + if (t[1].has_decode_default and t[2].has_decode_default): + error(t.lexer.lineno, 'Two default cases in decode block') + t[0] = t[1] + t[2] + + # + # Decode statement rules + # + # There are four types of statements allowed in a decode block: + # 1. Format blocks 'format { ... }' + # 2. Nested decode blocks + # 3. Instruction definitions. + # 4. C preprocessor directives. + + + # Preprocessor directives found in a decode statement list are + # passed through to the output, replicated to all of the output + # code streams. This works well for ifdefs, so we can ifdef out + # both the declarations and the decode cases generated by an + # instruction definition. Handling them as part of the grammar + # makes it easy to keep them in the right place with respect to + # the code generated by the other statements. + def p_decode_stmt_cpp(self, t): + 'decode_stmt : CPPDIRECTIVE' + t[0] = GenCode(t[1], t[1], t[1], t[1]) + + # A format block 'format { ... }' sets the default + # instruction format used to handle instruction definitions inside + # the block. This format can be overridden by using an explicit + # format on the instruction definition or with a nested format + # block. + def p_decode_stmt_format(self, t): + 'decode_stmt : FORMAT push_format_id LBRACE decode_stmt_list RBRACE' + # The format will be pushed on the stack when 'push_format_id' + # is processed (see below). Once the parser has recognized + # the full production (though the right brace), we're done + # with the format, so now we can pop it. + formatStack.pop() + t[0] = t[4] + + # This rule exists so we can set the current format (& push the + # stack) when we recognize the format name part of the format + # block. + def p_push_format_id(self, t): + 'push_format_id : ID' + try: + formatStack.push(formatMap[t[1]]) + t[0] = ('', '// format %s' % t[1]) + except KeyError: + error(t.lexer.lineno, + 'instruction format "%s" not defined.' % t[1]) + + # Nested decode block: if the value of the current field matches + # the specified constant, do a nested decode on some other field. + def p_decode_stmt_decode(self, t): + 'decode_stmt : case_label COLON decode_block' + label = t[1] + codeObj = t[3] + # just wrap the decoding code from the block as a case in the + # outer switch statement. + codeObj.wrap_decode_block('\n%s:\n' % label) + codeObj.has_decode_default = (label == 'default') + t[0] = codeObj + + # Instruction definition (finally!). + def p_decode_stmt_inst(self, t): + 'decode_stmt : case_label COLON inst SEMI' + label = t[1] + codeObj = t[3] + codeObj.wrap_decode_block('\n%s:' % label, 'break;\n') + codeObj.has_decode_default = (label == 'default') + t[0] = codeObj + + # The case label is either a list of one or more constants or + # 'default' + def p_case_label_0(self, t): + 'case_label : intlit_list' + def make_case(intlit): + if intlit >= 2**32: + return 'case ULL(%#x)' % intlit + else: + return 'case %#x' % intlit + t[0] = ': '.join(map(make_case, t[1])) + + def p_case_label_1(self, t): + 'case_label : DEFAULT' + t[0] = 'default' + + # + # The constant list for a decode case label must be non-empty, but + # may have one or more comma-separated integer literals in it. + # + def p_intlit_list_0(self, t): + 'intlit_list : INTLIT' + t[0] = [t[1]] + + def p_intlit_list_1(self, t): + 'intlit_list : intlit_list COMMA INTLIT' + t[0] = t[1] + t[0].append(t[3]) + + # Define an instruction using the current instruction format + # (specified by an enclosing format block). + # "()" + def p_inst_0(self, t): + 'inst : ID LPAREN arg_list RPAREN' + # Pass the ID and arg list to the current format class to deal with. + currentFormat = formatStack.top() + codeObj = currentFormat.defineInst(t[1], t[3], t.lexer.lineno) + args = ','.join(map(str, t[3])) + args = re.sub('(?m)^', '//', args) + args = re.sub('^//', '', args) + comment = '\n// %s::%s(%s)\n' % (currentFormat.id, t[1], args) + codeObj.prepend_all(comment) + t[0] = codeObj + + # Define an instruction using an explicitly specified format: + # "::()" + def p_inst_1(self, t): + 'inst : ID DBLCOLON ID LPAREN arg_list RPAREN' + try: + format = formatMap[t[1]] + except KeyError: + error(t.lexer.lineno, + 'instruction format "%s" not defined.' % t[1]) + codeObj = format.defineInst(t[3], t[5], t.lexer.lineno) + comment = '\n// %s::%s(%s)\n' % (t[1], t[3], t[5]) + codeObj.prepend_all(comment) + t[0] = codeObj + + # The arg list generates a tuple, where the first element is a + # list of the positional args and the second element is a dict + # containing the keyword args. + def p_arg_list_0(self, t): + 'arg_list : positional_arg_list COMMA keyword_arg_list' + t[0] = ( t[1], t[3] ) + + def p_arg_list_1(self, t): + 'arg_list : positional_arg_list' + t[0] = ( t[1], {} ) + + def p_arg_list_2(self, t): + 'arg_list : keyword_arg_list' + t[0] = ( [], t[1] ) + + def p_positional_arg_list_0(self, t): + 'positional_arg_list : empty' + t[0] = [] + + def p_positional_arg_list_1(self, t): + 'positional_arg_list : expr' + t[0] = [t[1]] + + def p_positional_arg_list_2(self, t): + 'positional_arg_list : positional_arg_list COMMA expr' + t[0] = t[1] + [t[3]] + + def p_keyword_arg_list_0(self, t): + 'keyword_arg_list : keyword_arg' + t[0] = t[1] + + def p_keyword_arg_list_1(self, t): + 'keyword_arg_list : keyword_arg_list COMMA keyword_arg' + t[0] = t[1] + t[0].update(t[3]) + + def p_keyword_arg(self, t): + 'keyword_arg : ID EQUALS expr' + t[0] = { t[1] : t[3] } + + # + # Basic expressions. These constitute the argument values of + # "function calls" (i.e. instruction definitions in the decode + # block) and default values for formal parameters of format + # functions. + # + # Right now, these are either strings, integers, or (recursively) + # lists of exprs (using Python square-bracket list syntax). Note + # that bare identifiers are trated as string constants here (since + # there isn't really a variable namespace to refer to). + # + def p_expr_0(self, t): + '''expr : ID + | INTLIT + | STRLIT + | CODELIT''' + t[0] = t[1] + + def p_expr_1(self, t): + '''expr : LBRACKET list_expr RBRACKET''' + t[0] = t[2] + + def p_list_expr_0(self, t): + 'list_expr : expr' + t[0] = [t[1]] + + def p_list_expr_1(self, t): + 'list_expr : list_expr COMMA expr' + t[0] = t[1] + [t[3]] + + def p_list_expr_2(self, t): + 'list_expr : empty' + t[0] = [] + + # + # Empty production... use in other rules for readability. + # + def p_empty(self, t): + 'empty :' + pass + + # Parse error handler. Note that the argument here is the + # offending *token*, not a grammar symbol (hence the need to use + # t.value) + def p_error(self, t): + if t: + error(t.lexer.lineno, "syntax error at '%s'" % t.value) + else: + error(0, "unknown syntax error", True) + + # END OF GRAMMAR RULES + +# Now build the parser. +parser = ISAParser() # Update the output file only if the new contents are different from # the current contents. Minimizes the files that need to be rebuilt