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m4-utils.m4
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Niels Möller
m4: New macro m4_unquote
30 ноя 2020, 23:20
30 ноя 2020, 23:20
f220942
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divert(-1) dnl dnl m4 macros for gmp assembly code, shared by all CPUs. From gmp/mpn/asm-defs.m4 dnl Copyright 1999-2006, 2011 Free Software Foundation, Inc. dnl This file is part of the GNU MP Library. dnl dnl The GNU MP Library is free software; you can redistribute it and/or modify dnl it under the terms of either: dnl dnl * the GNU Lesser General Public License as published by the Free dnl Software Foundation; either version 3 of the License, or (at your dnl option) any later version. dnl dnl or dnl dnl * the GNU General Public License as published by the Free Software dnl Foundation; either version 2 of the License, or (at your option) any dnl later version. dnl dnl or both in parallel, as here. dnl dnl The GNU MP Library is distributed in the hope that it will be useful, but dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License dnl for more details. dnl dnl You should have received copies of the GNU General Public License and the dnl GNU Lesser General Public License along with the GNU MP Library. If not, dnl see https://www.gnu.org/licenses/. dnl These macros are designed for use with any m4 and have been used on dnl GNU, FreeBSD, NetBSD, OpenBSD and SysV. dnl dnl GNU m4 and OpenBSD 2.7 m4 will give filenames and line numbers in error dnl messages. dnl dnl dnl Macros: dnl dnl Most new m4 specific macros have an "m4_" prefix to emphasise they're dnl m4 expansions. But new defining things like deflit() and defreg() are dnl named like the builtin define(), and forloop() is named following the dnl GNU m4 example on which it's based. dnl dnl GNU m4 with the -P option uses "m4_" as a prefix for builtins, but that dnl option isn't going to be used, so there's no conflict or confusion. dnl dnl dnl Comments in output: dnl dnl The m4 comment delimiters are left at # and \n, the normal assembler dnl commenting for most CPUs. m4 passes comment text through without dnl expanding macros in it, which is generally a good thing since it stops dnl unexpected expansions and possible resultant errors. dnl dnl But note that when a quoted string is being read, a # isn't special, so dnl apostrophes in comments in quoted strings must be avoided or they'll be dnl interpreted as a closing quote mark. But when the quoted text is dnl re-read # will still act like a normal comment, suppressing macro dnl expansion. dnl dnl For example, dnl dnl # apostrophes in comments that're outside quotes are ok dnl # and using macro names like PROLOGUE is ok too dnl ... dnl ifdef(`PIC',` dnl # but apostrophes aren't ok inside quotes dnl # ^--wrong dnl ... dnl # though macro names like PROLOGUE are still ok dnl ... dnl ') dnl dnl If macro expansion in a comment is wanted, use `#' in the .asm (ie. a dnl quoted hash symbol), which will turn into # in the .s but get dnl expansions done on that line. This can make the .s more readable to dnl humans, but it won't make a blind bit of difference to the assembler. dnl dnl All the above applies, mutatis mutandis, when changecom() is used to dnl select @ ! ; or whatever other commenting. dnl dnl dnl Variations in m4 affecting gmp: dnl dnl $# - When a macro is called as "foo" with no brackets, BSD m4 sets $# dnl to 1, whereas GNU or SysV m4 set it to 0. In all cases though dnl "foo()" sets $# to 1. This is worked around in various places. dnl dnl len() - When "len()" is given an empty argument, BSD m4 evaluates to dnl nothing, whereas GNU, SysV, and the new OpenBSD, evaluate to 0. dnl See m4_length() below which works around this. dnl dnl translit() - GNU m4 accepts character ranges like A-Z, and the new dnl OpenBSD m4 does under option -g, but basic BSD and SysV don't. dnl dnl popdef() - in BSD and SysV m4 popdef() takes multiple arguments and dnl pops each, but GNU m4 only takes one argument. dnl dnl push back - BSD m4 has some limits on the amount of text that can be dnl pushed back. The limit is reasonably big and so long as macros dnl don't gratuitously duplicate big arguments it isn't a problem. dnl Normally an error message is given, but sometimes it just hangs. dnl dnl eval() &,|,^ - GNU and SysV m4 have bitwise operators &,|,^ available, dnl but BSD m4 doesn't (contrary to what the man page suggests) and dnl instead ^ is exponentiation. dnl dnl eval() ?: - The C ternary operator "?:" is available in BSD m4, but not dnl in SysV or GNU m4 (as of GNU m4 1.4 and betas of 1.5). dnl dnl eval() -2^31 - BSD m4 has a bug where an eval() resulting in -2^31 dnl (ie. -2147483648) gives "-(". Using -2147483648 within an dnl expression is ok, it just can't be a final result. "-(" will of dnl course upset parsing, with all sorts of strange effects. dnl dnl eval() <<,>> - SysV m4 doesn't support shift operators in eval() (on dnl Solaris 7 /usr/xpg4/m4 has them but /usr/ccs/m4 doesn't). See dnl m4_lshift() and m4_rshift() below for workarounds. dnl dnl ifdef() - OSF 4.0 m4 considers a macro defined to a zero value `0' or dnl `00' etc as not defined. See m4_ifdef below for a workaround. dnl dnl m4wrap() sequence - in BSD m4, m4wrap() replaces any previous m4wrap() dnl string, in SysV m4 it appends to it, and in GNU m4 it prepends. dnl See m4wrap_prepend() below which brings uniformity to this. dnl dnl m4wrap() 0xFF - old versions of BSD m4 store EOF in a C "char" under an dnl m4wrap() and on systems where char is unsigned by default a dnl spurious 0xFF is output. This has been observed on recent Cray dnl Unicos Alpha, Apple MacOS X, and HPUX 11 systems. An autoconf dnl test is used to check for this, see the m4wrap handling below. It dnl might work to end the m4wrap string with a dnl to consume the dnl 0xFF, but that probably induces the offending m4's to read from an dnl already closed "FILE *", which could be bad on a glibc style dnl stdio. dnl dnl __file__,__line__ - GNU m4 and OpenBSD 2.7 m4 provide these, and dnl they're used here to make error messages more informative. GNU m4 dnl gives an unhelpful "NONE 0" in an m4wrap(), but that's worked dnl around. dnl dnl __file__ quoting - OpenBSD m4, unlike GNU m4, doesn't quote the dnl filename in __file__, so care should be taken that no macro has dnl the same name as a file, or an unwanted expansion will occur when dnl printing an error or warning. dnl dnl changecom() - BSD m4 changecom doesn't quite work like the man page dnl suggests, in particular "changecom" or "changecom()" doesn't dnl disable the comment feature, and multi-character comment sequences dnl don't seem to work. If the default `#' and newline aren't dnl suitable it's necessary to change it to something else, dnl eg. changecom(;). dnl dnl OpenBSD 2.6 m4 - in this m4, eval() rejects decimal constants containing dnl an 8 or 9, making it pretty much unusable. The bug is confined to dnl version 2.6 (it's not in 2.5, and was fixed in 2.7). dnl dnl SunOS /usr/bin/m4 - this m4 lacks a number of desired features, dnl including $# and $@, defn(), m4exit(), m4wrap(), pushdef(), dnl popdef(). /usr/5bin/m4 is a SysV style m4 which should always be dnl available, and "configure" will reject /usr/bin/m4 in favour of dnl /usr/5bin/m4 (if necessary). dnl dnl The sparc code actually has modest m4 requirements currently and dnl could manage with /usr/bin/m4, but there's no reason to put our dnl macros through contortions when /usr/5bin/m4 is available or GNU dnl m4 can be installed. dnl -------------------------------------------------------------------------- dnl Basic error handling things. dnl Usage: m4_dollarhash_1_if_noparen_p dnl dnl Expand to 1 if a call "foo" gives $# set to 1 (as opposed to 0 like GNU dnl and SysV m4 give). define(m4_dollarhash_1_if_noparen_test,`$#') define(m4_dollarhash_1_if_noparen_p, eval(m4_dollarhash_1_if_noparen_test==1)) undefine(`m4_dollarhash_1_if_noparen_test') define(m4_error, `errprint($@ )m4exit(1)') dnl Usage: m4_assert_numargs(num) dnl dnl Put this unquoted on a line on its own at the start of a macro dnl definition to add some code to check that num many arguments get passed dnl to the macro. For example, dnl dnl define(foo, dnl m4_assert_numargs(2) dnl `something `$1' and `$2' blah blah') dnl dnl Then a call like foo(one,two,three) will provoke an error like dnl dnl file:10: foo expected 2 arguments, got 3 arguments dnl dnl Here are some calls and how many arguments they're interpreted as passing. dnl dnl foo(abc,def) 2 dnl foo(xyz) 1 dnl foo() 0 dnl foo -1 dnl dnl The -1 for no parentheses at all means a macro that's meant to be used dnl that way can be checked with m4_assert_numargs(-1). For example, dnl dnl define(SPECIAL_SUFFIX, dnl m4_assert_numargs(-1) dnl `ifdef(`FOO',`_foo',`_bar')') dnl dnl But as an alternative see also deflit() below where parenthesized dnl expressions following a macro are passed through to the output. dnl dnl Note that in BSD m4 there's no way to differentiate calls "foo" and dnl "foo()", so in BSD m4 the distinction between the two isn't enforced. dnl (In GNU and SysV m4 it can be checked, and is.) dnl m4_assert_numargs is able to check its own arguments by calling dnl assert_numargs_internal directly. dnl dnl m4_doublequote($`'0) expands to ``$0'', whereas ``$`'0'' would expand dnl to `$`'0' and do the wrong thing, and likewise for $1. The same is dnl done in other assert macros. dnl dnl $`#' leaves $# in the new macro being defined, and stops # being dnl interpreted as a comment character. dnl dnl `dnl ' means an explicit dnl isn't necessary when m4_assert_numargs is dnl used. The space means that if there is a dnl it'll still work. dnl Usage: m4_doublequote(x) expands to ``x'' define(m4_doublequote, `m4_assert_numargs_internal(`$0',1,$#,len(`$1'))``$1''') define(m4_assert_numargs, `m4_assert_numargs_internal(`$0',1,$#,len(`$1'))dnl `m4_assert_numargs_internal'(m4_doublequote($`'0),$1,$`#',`len'(m4_doublequote($`'1)))`dnl '') dnl Called: m4_assert_numargs_internal(`macroname',wantargs,$#,len(`$1')) define(m4_assert_numargs_internal, `m4_assert_numargs_internal_check(`$1',`$2',m4_numargs_count(`$3',`$4'))') dnl Called: m4_assert_numargs_internal_check(`macroname',wantargs,gotargs) dnl dnl If m4_dollarhash_1_if_noparen_p (BSD m4) then gotargs can be 0 when it dnl should be -1. If wantargs is -1 but gotargs is 0 and the two can't be dnl distinguished then it's allowed to pass. dnl define(m4_assert_numargs_internal_check, `ifelse(eval($2 == $3 || ($2==-1 && $3==0 && m4_dollarhash_1_if_noparen_p)),0, `m4_error(`$1 expected 'm4_Narguments(`$2')`, got 'm4_Narguments(`$3') )')') dnl Called: m4_numargs_count($#,len(`$1')) dnl If $#==0 then -1 args, if $#==1 but len(`$1')==0 then 0 args, otherwise dnl $# args. define(m4_numargs_count, `ifelse($1,0, -1, `ifelse(eval($1==1 && $2-0==0),1, 0, $1)')') dnl Usage: m4_Narguments(N) dnl "$1 argument" or "$1 arguments" with the plural according to $1. define(m4_Narguments, `$1 argument`'ifelse(`$1',1,,s)') dnl -------------------------------------------------------------------------- dnl Additional error checking things. dnl Usage: m4_assert_onearg() dnl dnl Put this, unquoted, at the start of a macro definition to add some code dnl to check that one argument is passed to the macro, but with that dnl argument allowed to be empty. For example, dnl dnl define(foo, dnl m4_assert_onearg() dnl `blah blah $1 blah blah') dnl dnl Calls "foo(xyz)" or "foo()" are accepted. A call "foo(xyz,abc)" fails. dnl A call "foo" fails too, but BSD m4 can't detect this case (GNU and SysV dnl m4 can). define(m4_assert_onearg, m4_assert_numargs(0) `m4_assert_onearg_internal'(m4_doublequote($`'0),$`#')`dnl ') dnl Called: m4_assert_onearg(`macroname',$#) define(m4_assert_onearg_internal, `ifelse($2,1,, `m4_error(`$1 expected 1 argument, got 'm4_Narguments(`$2') )')') dnl -------------------------------------------------------------------------- dnl Various generic m4 things. dnl Usage: m4_unquote(macro) dnl dnl Allow the argument text to be re-evaluated. This is useful for "token dnl pasting" like m4_unquote(foo`'bar). define(m4_unquote, m4_assert_onearg() `$1') dnl Usage: m4_length(string) dnl dnl Determine the length of a string. This is the same as len(), but dnl always expands to a number, working around the BSD len() which dnl evaluates to nothing given an empty argument. define(m4_length, m4_assert_onearg() `eval(len(`$1')-0)') dnl Usage: m4_incr_or_decr(n,last) dnl dnl Do an incr(n) or decr(n), whichever is in the direction of "last". dnl Both n and last must be numbers of course. define(m4_incr_or_decr, m4_assert_numargs(2) `ifelse(eval($1<$2),1,incr($1),decr($1))') dnl Usage: forloop(i, first, last, statement) dnl dnl Based on GNU m4 examples/forloop.m4, but extended. dnl dnl statement is expanded repeatedly, with i successively defined as dnl dnl first, first+1, ..., last-1, last dnl dnl Or if first > last, then it's dnl dnl first, first-1, ..., last+1, last dnl dnl If first == last, then one expansion is done. dnl dnl A pushdef/popdef of i is done to preserve any previous definition (or dnl lack of definition). first and last are eval()ed and so can be dnl expressions. dnl dnl forloop_first is defined to 1 on the first iteration, 0 on the rest. dnl forloop_last is defined to 1 on the last iteration, 0 on the others. dnl Nested forloops are allowed, in which case forloop_first and dnl forloop_last apply to the innermost loop that's open. dnl dnl A simple example, dnl dnl forloop(i, 1, 2*2+1, `dnl dnl iteration number i ... ifelse(forloop_first,1,FIRST) dnl ') dnl "i" and "statement" are carefully quoted, but "first" and "last" are dnl just plain numbers once eval()ed. define(`forloop', m4_assert_numargs(4) `pushdef(`$1',eval(`$2'))dnl pushdef(`forloop_first',1)dnl pushdef(`forloop_last',0)dnl forloop_internal(`$1',eval(`$3'),`$4')`'dnl popdef(`forloop_first')dnl popdef(`forloop_last')dnl popdef(`$1')') dnl Called: forloop_internal(`var',last,statement) define(`forloop_internal', m4_assert_numargs(3) `ifelse($1,$2, `define(`forloop_last',1)$3', `$3`'dnl define(`forloop_first',0)dnl define(`$1',m4_incr_or_decr($1,$2))dnl forloop_internal(`$1',$2,`$3')')') dnl Usage: deflit(name,value) dnl dnl Like define(), but "name" expands like a literal, rather than taking dnl arguments. For example "name(%eax)" expands to "value(%eax)". dnl dnl Limitations: dnl dnl $ characters in the value part must have quotes to stop them looking dnl like macro parameters. For example, deflit(reg,`123+$`'4+567'). See dnl defreg() below for handling simple register definitions like $7 etc. dnl dnl "name()" is turned into "name", unfortunately. In GNU and SysV m4 an dnl error is generated when this happens, but in BSD m4 it will happen dnl silently. The problem is that in BSD m4 $# is 1 in both "name" or dnl "name()", so there's no way to differentiate them. Because we want dnl plain "name" to turn into plain "value", we end up with "name()" dnl turning into plain "value" too. dnl dnl "name(foo)" will lose any whitespace after commas in "foo", for example dnl "disp(%eax, %ecx)" would become "128(%eax,%ecx)". dnl dnl These parentheses oddities shouldn't matter in assembler text, but if dnl they do the suggested workaround is to write "name ()" or "name (foo)" dnl to stop the parentheses looking like a macro argument list. If a space dnl isn't acceptable in the output, then write "name`'()" or "name`'(foo)". dnl The `' is stripped when read, but again stops the parentheses looking dnl like parameters. dnl Quoting for deflit_emptyargcheck is similar to m4_assert_numargs. The dnl stuff in the ifelse gives a $#, $1 and $@ evaluated in the new macro dnl created, not in deflit. define(deflit, m4_assert_numargs(2) `define(`$1', `deflit_emptyargcheck'(``$1'',$`#',m4_doublequote($`'1))`dnl $2`'dnl ifelse(eval($'`#>1 || m4_length('m4_doublequote($`'1)`)!=0),1,($'`@))')') dnl Called: deflit_emptyargcheck(macroname,$#,`$1') define(deflit_emptyargcheck, `ifelse(eval($2==1 && !m4_dollarhash_1_if_noparen_p && m4_length(`$3')==0),1, `m4_error(`dont use a deflit as $1() because it loses the brackets (see deflit in asm-defs.m4 for more information) ')')') divert`'dnl