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diff --git a/gcc/ada/g-regpat.ads b/gcc/ada/g-regpat.ads new file mode 100644 index 00000000000..5d6c4b76499 --- /dev/null +++ b/gcc/ada/g-regpat.ads @@ -0,0 +1,548 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT LIBRARY COMPONENTS -- +-- -- +-- G N A T . R E G P A T -- +-- -- +-- S p e c -- +-- -- +-- $Revision: 1.27 $ +-- -- +-- Copyright (C) 1986 by University of Toronto. -- +-- Copyright (C) 1996-2001 Ada Core Technologies, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 2, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT 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 distributed with GNAT; see file COPYING. If not, write -- +-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- +-- MA 02111-1307, USA. -- +-- -- +-- As a special exception, if other files instantiate generics from this -- +-- unit, or you link this unit with other files to produce an executable, -- +-- this unit does not by itself cause the resulting executable to be -- +-- covered by the GNU General Public License. This exception does not -- +-- however invalidate any other reasons why the executable file might be -- +-- covered by the GNU Public License. -- +-- -- +-- GNAT is maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- -- +------------------------------------------------------------------------------ + +-- This package implements roughly the same set of regular expressions as +-- are available in the Perl or Python programming languages. + +-- This is an extension of the original V7 style regular expression library +-- written in C by Henry Spencer. Apart from the translation to Ada, the +-- interface has been considerably changed to use the Ada String type +-- instead of C-style nul-terminated strings. + +------------------------------------------------------------ +-- Summary of Pattern Matching Packages in GNAT Hierarchy -- +------------------------------------------------------------ + +-- There are three related packages that perform pattern maching functions. +-- the following is an outline of these packages, to help you determine +-- which is best for your needs. + +-- GNAT.Regexp (files g-regexp.ads/g-regexp.adb) +-- This is a simple package providing Unix-style regular expression +-- matching with the restriction that it matches entire strings. It +-- is particularly useful for file name matching, and in particular +-- it provides "globbing patterns" that are useful in implementing +-- unix or DOS style wild card matching for file names. + +-- GNAT.Regpat (files g-regpat.ads/g-regpat.adb) +-- This is a more complete implementation of Unix-style regular +-- expressions, copied from the Perl regular expression engine, +-- written originally in C by Henry Spencer. It is functionally the +-- same as that library. + +-- GNAT.Spitbol.Patterns (files g-spipat.ads/g-spipat.adb) +-- This is a completely general pattern matching package based on the +-- pattern language of SNOBOL4, as implemented in SPITBOL. The pattern +-- language is modeled on context free grammars, with context sensitive +-- extensions that provide full (type 0) computational capabilities. + +package GNAT.Regpat is +pragma Preelaborate (Regpat); + + -- The grammar is the following: + + -- regexp ::= expr + -- ::= ^ expr -- anchor at the beginning of string + -- ::= expr $ -- anchor at the end of string + -- expr ::= term + -- ::= term | term -- alternation (term or term ...) + -- term ::= item + -- ::= item item ... -- concatenation (item then item) + -- item ::= elmt -- match elmt + -- ::= elmt * -- zero or more elmt's + -- ::= elmt + -- one or more elmt's + -- ::= elmt ? -- matches elmt or nothing + -- ::= elmt *? -- zero or more times, minimum number + -- ::= elmt +? -- one or more times, minimum number + -- ::= elmt ?? -- zero or one time, minimum number + -- ::= elmt { num } -- matches elmt exactly num times + -- ::= elmt { num , } -- matches elmt at least num times + -- ::= elmt { num , num2 } -- matches between num and num2 times + -- ::= elmt { num }? -- matches elmt exactly num times + -- ::= elmt { num , }? -- matches elmt at least num times + -- non-greedy version + -- ::= elmt { num , num2 }? -- matches between num and num2 times + -- non-greedy version + -- elmt ::= nchr -- matches given character + -- ::= [range range ...] -- matches any character listed + -- ::= [^ range range ...] -- matches any character not listed + -- ::= . -- matches any single character + -- -- except newlines + -- ::= ( expr ) -- parens used for grouping + -- ::= \ num -- reference to num-th parenthesis + -- range ::= char - char -- matches chars in given range + -- ::= nchr + -- ::= [: posix :] -- any character in the POSIX range + -- ::= [:^ posix :] -- not in the POSIX range + -- posix ::= alnum -- alphanumeric characters + -- ::= alpha -- alphabetic characters + -- ::= ascii -- ascii characters (0 .. 127) + -- ::= cntrl -- control chars (0..31, 127..159) + -- ::= digit -- digits ('0' .. '9') + -- ::= graph -- graphic chars (32..126, 160..255) + -- ::= lower -- lower case characters + -- ::= print -- printable characters (32..127) + -- ::= punct -- printable, except alphanumeric + -- ::= space -- space characters + -- ::= upper -- upper case characters + -- ::= word -- alphanumeric characters + -- ::= xdigit -- hexadecimal chars (0..9, a..f) + + -- char ::= any character, including special characters + -- ASCII.NUL is not supported. + -- nchr ::= any character except \()[].*+?^ or \char to match char + -- \n means a newline (ASCII.LF) + -- \t means a tab (ASCII.HT) + -- \r means a return (ASCII.CR) + -- \b matches the empty string at the beginning or end of a + -- word. A word is defined as a set of alphanumerical + -- characters (see \w below). + -- \B matches the empty string only when *not* at the + -- beginning or end of a word. + -- \d matches any digit character ([0-9]) + -- \D matches any non digit character ([^0-9]) + -- \s matches any white space character. This is equivalent + -- to [ \t\n\r\f\v] (tab, form-feed, vertical-tab,... + -- \S matches any non-white space character. + -- \w matches any alphanumeric character or underscore. + -- This include accented letters, as defined in the + -- package Ada.Characters.Handling. + -- \W matches any non-alphanumeric character. + -- \A match the empty string only at the beginning of the + -- string, whatever flags are used for Compile (the + -- behavior of ^ can change, see Regexp_Flags below). + -- \G match the empty string only at the end of the + -- string, whatever flags are used for Compile (the + -- behavior of $ can change, see Regexp_Flags below). + -- ... ::= is used to indication repetition (one or more terms) + + -- Embedded newlines are not matched by the ^ operator. + -- It is possible to retrieve the substring matched a parenthesis + -- expression. Although the depth of parenthesis is not limited in the + -- regexp, only the first 9 substrings can be retrieved. + + -- The highest value possible for the arguments to the curly operator ({}) + -- are given by the constant Max_Curly_Repeat below. + + -- The operators '*', '+', '?' and '{}' always match the longest possible + -- substring. They all have a non-greedy version (with an extra ? after the + -- operator), which matches the shortest possible substring. + + -- For instance: + -- regexp="<.*>" string="<h1>title</h1>" matches="<h1>title</h1>" + -- regexp="<.*?>" string="<h1>title</h1>" matches="<h1>" + -- + -- '{' and '}' are only considered as special characters if they appear + -- in a substring that looks exactly like '{n}', '{n,m}' or '{n,}', where + -- n and m are digits. No space is allowed. In other contexts, the curly + -- braces will simply be treated as normal characters. + + -- Compiling Regular Expressions + -- ============================= + + -- To use this package, you first need to compile the regular expression + -- (a string) into a byte-code program, in a Pattern_Matcher structure. + -- This first step checks that the regexp is valid, and optimizes the + -- matching algorithms of the second step. + + -- Two versions of the Compile subprogram are given: one in which this + -- package will compute itself the best possible size to allocate for the + -- byte code; the other where you must allocate enough memory yourself. An + -- exception is raised if there is not enough memory. + + -- declare + -- Regexp : String := "a|b"; + + -- Matcher : Pattern_Matcher := Compile (Regexp); + -- -- The size for matcher is automatically allocated + + -- Matcher2 : Pattern_Matcher (1000); + -- -- Some space is allocated directly. + + -- begin + -- Compile (Matcher2, Regexp); + -- ... + -- end; + + -- Note that the second version is significantly faster, since with the + -- first version the regular expression has in fact to be compiled twice + -- (first to compute the size, then to generate the byte code). + + -- Note also that you can not use the function version of Compile if you + -- specify the size of the Pattern_Matcher, since the discriminants will + -- most probably be different and you will get a Constraint_Error + + -- Matching Strings + -- ================ + + -- Once the regular expression has been compiled, you can use it as often + -- as needed to match strings. + + -- Several versions of the Match subprogram are provided, with different + -- parameters and return results. + + -- See the description under each of these subprograms. + + -- Here is a short example showing how to get the substring matched by + -- the first parenthesis pair. + + -- declare + -- Matches : Match_Array; + -- Regexp : String := "a(b|c)d"; + -- Str : String := "gacdg"; + + -- begin + -- Match (Compile (Regexp), Str, Matches); + -- return Str (Matches (1).First .. Matches (1).Last); + -- -- returns 'c' + -- end; + + -- String Substitution + -- =================== + + -- No subprogram is currently provided for string substitution. + -- However, this is easy to simulate with the parenthesis groups, as + -- shown below. + + -- This example swaps the first two words of the string: + + -- declare + -- Regexp : String := "([a-z]+) +([a-z]+)"; + -- Str : String := " first second third "; + -- Matches : Match_Array; + + -- begin + -- Match (Compile (Regexp), Str, Matches); + -- return Str (Str'First .. Matches (1).First - 1) + -- & Str (Matches (2).First .. Matches (2).Last) + -- & " " + -- & Str (Matches (1).First .. Matches (1).Last) + -- & Str (Matches (2).Last + 1 .. Str'Last); + -- -- returns " second first third " + -- end; + + --------------- + -- Constants -- + --------------- + + Expression_Error : exception; + -- This exception is raised when trying to compile an invalid + -- regular expression. All subprograms taking an expression + -- as parameter may raise Expression_Error. + + Max_Paren_Count : constant := 255; + -- Maximum number of parenthesis in a regular expression. + -- This is limited by the size of a Character, as found in the + -- byte-compiled version of regular expressions. + + Max_Program_Size : constant := 2**15 - 1; + -- Maximum size that can be allocated for a program. + + Max_Curly_Repeat : constant := 32767; + -- Maximum number of repetition for the curly operator. + -- The digits in the {n}, {n,} and {n,m } operators can not be higher + -- than this constant, since they have to fit on two characters in the + -- byte-compiled version of regular expressions. + + type Program_Size is range 0 .. Max_Program_Size; + for Program_Size'Size use 16; + -- Number of bytes allocated for the byte-compiled version of a regular + -- expression. + + type Regexp_Flags is mod 256; + for Regexp_Flags'Size use 8; + -- Flags that can be given at compile time to specify default + -- properties for the regular expression. + + No_Flags : constant Regexp_Flags; + Case_Insensitive : constant Regexp_Flags; + -- The automaton is optimized so that the matching is done in a case + -- insensitive manner (upper case characters and lower case characters + -- are all treated the same way). + + Single_Line : constant Regexp_Flags; + -- Treat the Data we are matching as a single line. This means that + -- ^ and $ will ignore \n (unless Multiple_Lines is also specified), + -- and that '.' will match \n. + + Multiple_Lines : constant Regexp_Flags; + -- Treat the Data as multiple lines. This means that ^ and $ will also + -- match on internal newlines (ASCII.LF), in addition to the beginning + -- and end of the string. + -- + -- This can be combined with Single_Line. + + ----------------- + -- Match_Array -- + ----------------- + + subtype Match_Count is Natural range 0 .. Max_Paren_Count; + + type Match_Location is record + First : Natural := 0; + Last : Natural := 0; + end record; + + type Match_Array is array (Match_Count range <>) of Match_Location; + -- The substring matching a given pair of parenthesis. + -- Index 0 is the whole substring that matched the full regular + -- expression. + -- + -- For instance, if your regular expression is something like: + -- "a(b*)(c+)", then Match_Array(1) will be the indexes of the + -- substring that matched "b*" and Match_Array(2) will be the substring + -- that matched "c+". + -- + -- The number of parenthesis groups that can be retrieved is unlimited, + -- and all the Match subprograms below can use a Match_Array of any size. + -- Indexes that do not have any matching parenthesis are set to + -- No_Match. + + No_Match : constant Match_Location := (First => 0, Last => 0); + -- The No_Match constant is (0, 0) to differentiate between + -- matching a null string at position 1, which uses (1, 0) + -- and no match at all. + + ------------------------------ + -- Pattern_Matcher Creation -- + ------------------------------ + + type Pattern_Matcher (Size : Program_Size) is private; + -- Type used to represent a regular expression compiled into byte code + + Never_Match : constant Pattern_Matcher; + -- A regular expression that never matches anything + + function Compile + (Expression : String; + Flags : Regexp_Flags := No_Flags) + return Pattern_Matcher; + -- Compile a regular expression into internal code. + -- Raises Expression_Error if Expression is not a legal regular expression. + -- The appropriate size is calculated automatically, but this means that + -- the regular expression has to be compiled twice (the first time to + -- calculate the size, the second time to actually generate the byte code). + -- + -- Flags is the default value to use to set properties for Expression (case + -- sensitivity,...). + + procedure Compile + (Matcher : out Pattern_Matcher; + Expression : String; + Final_Code_Size : out Program_Size; + Flags : Regexp_Flags := No_Flags); + -- Compile a regular expression into into internal code + -- This procedure is significantly faster than the function + -- Compile, as there is a known maximum size for the matcher. + -- This function raises Storage_Error if Matcher is too small + -- to hold the resulting code, or Expression_Error is Expression + -- is not a legal regular expression. + -- + -- Flags is the default value to use to set properties for Expression (case + -- sensitivity,...). + + procedure Compile + (Matcher : out Pattern_Matcher; + Expression : String; + Flags : Regexp_Flags := No_Flags); + -- Same procedure as above, expect it does not return the final + -- program size. + + function Paren_Count (Regexp : Pattern_Matcher) return Match_Count; + pragma Inline (Paren_Count); + + -- Return the number of parenthesis pairs in Regexp. + + -- This is the maximum index that will be filled if a Match_Array is + -- used as an argument to Match. + -- + -- Thus, if you want to be sure to get all the parenthesis, you should + -- do something like: + -- + -- declare + -- Regexp : Pattern_Matcher := Compile ("a(b*)(c+)"); + -- Matched : Match_Array (0 .. Paren_Count (Regexp)); + -- begin + -- Match (Regexp, "a string", Matched); + -- end; + + ------------- + -- Quoting -- + ------------- + + function Quote (Str : String) return String; + -- Return a version of Str so that every special character is quoted. + -- The resulting string can be used in a regular expression to match + -- exactly Str, whatever character was present in Str. + + -------------- + -- Matching -- + -------------- + + procedure Match + (Expression : String; + Data : String; + Matches : out Match_Array; + Size : Program_Size := 0); + -- Match Expression against Data and store result in Matches. + -- Function raises Storage_Error if Size is too small for Expression, + -- or Expression_Error if Expression is not a legal regular expression. + -- If Size is 0, then the appropriate size is automatically calculated + -- by this package, but this is slightly slower. + -- + -- At most Matches'Length parenthesis are returned. + + function Match + (Expression : String; + Data : String; + Size : Program_Size := 0) + return Natural; + -- Return the position where Data matches, or (Data'First - 1) if there is + -- no match. + -- Function raises Storage_Error if Size is too small for Expression + -- or Expression_Error if Expression is not a legal regular expression + -- If Size is 0, then the appropriate size is automatically calculated + -- by this package, but this is slightly slower. + + function Match + (Expression : String; + Data : String; + Size : Program_Size := 0) + return Boolean; + -- Return True if Data matches Expression. Match raises Storage_Error + -- if Size is too small for Expression, or Expression_Error if Expression + -- is not a legal regular expression. + -- + -- If Size is 0, then the appropriate size is automatically calculated + -- by this package, but this is slightly slower. + + ------------------------------------------------ + -- Matching a pre-compiled regular expression -- + ------------------------------------------------ + + -- The following functions are significantly faster if you need to reuse + -- the same regular expression multiple times, since you only have to + -- compile it once. + + function Match + (Self : Pattern_Matcher; + Data : String) + return Natural; + -- Return the position where Data matches, or (Data'First - 1) if there is + -- no match. Raises Expression_Error if Expression is not a legal regular + -- expression. + + pragma Inline (Match); + -- All except the last one below. + + procedure Match + (Self : Pattern_Matcher; + Data : String; + Matches : out Match_Array); + -- Match Data using the given pattern matcher and store result in Matches. + -- Raises Expression_Error if Expression is not a legal regular expression. + -- The expression matches if Matches (0) /= No_Match. + -- + -- At most Matches'Length parenthesis are returned. + + ----------- + -- Debug -- + ----------- + + procedure Dump (Self : Pattern_Matcher); + -- Dump the compiled version of the regular expression matched by Self. + +-------------------------- +-- Private Declarations -- +-------------------------- + +private + + subtype Pointer is Program_Size; + -- The Pointer type is used to point into Program_Data + + -- Note that the pointer type is not necessarily 2 bytes + -- although it is stored in the program using 2 bytes + + type Program_Data is array (Pointer range <>) of Character; + + Program_First : constant := 1; + + -- The "internal use only" fields in regexp are present to pass + -- info from compile to execute that permits the execute phase + -- to run lots faster on simple cases. They are: + + -- First character that must begin a match or ASCII.Nul + -- Anchored true iff match must start at beginning of line + -- Must_Have pointer to string that match must include or null + -- Must_Have_Length length of Must_Have string + + -- First and Anchored permit very fast decisions on suitable + -- starting points for a match, cutting down the work a lot. + -- Must_Have permits fast rejection of lines that cannot possibly + -- match. + + -- The Must_Have tests are costly enough that Optimize + -- supplies a Must_Have only if the r.e. contains something potentially + -- expensive (at present, the only such thing detected is * or + + -- at the start of the r.e., which can involve a lot of backup). + -- The length is supplied because the test in Execute needs it + -- and Optimize is computing it anyway. + + -- The initialization is meant to fail-safe in case the user of this + -- package tries to use an uninitialized matcher. This takes advantage + -- of the knowledge that ASCII.Nul translates to the end-of-program (EOP) + -- instruction code of the state machine. + + No_Flags : constant Regexp_Flags := 0; + Case_Insensitive : constant Regexp_Flags := 1; + Single_Line : constant Regexp_Flags := 2; + Multiple_Lines : constant Regexp_Flags := 4; + + type Pattern_Matcher (Size : Pointer) is record + First : Character := ASCII.NUL; -- internal use only + Anchored : Boolean := False; -- internal use only + Must_Have : Pointer := 0; -- internal use only + Must_Have_Length : Natural := 0; -- internal use only + Paren_Count : Natural := 0; -- # paren groups + Flags : Regexp_Flags := No_Flags; + Program : Program_Data (Program_First .. Size) := + (others => ASCII.NUL); + end record; + + Never_Match : constant Pattern_Matcher := + (0, ASCII.NUL, False, 0, 0, 0, No_Flags, (others => ASCII.NUL)); + +end GNAT.Regpat; |