Date: Thu, 12 Jan 2012 17:49:43 GMT From: Peter Wemm <peter@FreeBSD.org> To: Perforce Change Reviews <perforce@freebsd.org> Subject: PERFORCE change 204470 for review Message-ID: <201201121749.q0CHnhx4016384@skunkworks.freebsd.org>
next in thread | raw e-mail | index | archive | help
http://p4web.freebsd.org/@@204470?ac=10 Change 204470 by peter@peter_overcee on 2012/01/12 17:49:20 IFC @204468 Affected files ... .. //depot/projects/hammer/contrib/gperf/doc/gperf.texi#2 integrate .. //depot/projects/hammer/contrib/gperf/doc/gpl.texinfo#2 integrate .. //depot/projects/hammer/contrib/llvm/LICENSE.TXT#3 branch .. //depot/projects/hammer/contrib/llvm/lib/Support/COPYRIGHT.regex#3 branch .. //depot/projects/hammer/contrib/llvm/tools/clang/LICENSE.TXT#3 branch .. //depot/projects/hammer/contrib/llvm/tools/clang/lib/StaticAnalyzer/Core/Checker.cpp#3 branch .. //depot/projects/hammer/tools/build/options/WITHOUT_PROFILE#2 integrate Differences ... ==== //depot/projects/hammer/contrib/gperf/doc/gperf.texi#2 (text+ko) ==== @@ -7,9 +7,9 @@ @c some day we should @include version.texi instead of defining @c these values at hand. -@set UPDATED 26 September 2000 -@set EDITION 2.7.2 -@set VERSION 2.7.2 +@set UPDATED 31 March 2007 +@set EDITION 3.0.3 +@set VERSION 3.0.3 @c --------------------- @c remove the black boxes generated in the GPL appendix. @@ -28,7 +28,7 @@ This file documents the features of the GNU Perfect Hash Function Generator @value{VERSION}. -Copyright @copyright{} 1989-2000 Free Software Foundation, Inc. +Copyright @copyright{} 1989-2006 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are @@ -62,10 +62,11 @@ @subtitle The GNU Perfect Hash Function Generator @subtitle Edition @value{EDITION}, @value{UPDATED} @author Douglas C. Schmidt +@author Bruno Haible @page @vskip 0pt plus 1filll -Copyright @copyright{} 1989-2000 Free Software Foundation, Inc. +Copyright @copyright{} 1989-2007 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of @@ -98,13 +99,12 @@ * Copying:: GNU @code{gperf} General Public License says how you can copy and share @code{gperf}. * Contributors:: People who have contributed to @code{gperf}. -* Motivation:: Static search structures and GNU GPERF. +* Motivation:: The purpose of @code{gperf}. * Search Structures:: Static search structures and GNU @code{gperf} * Description:: High-level discussion of how GPERF functions. * Options:: A description of options to the program. * Bugs:: Known bugs and limitations with GPERF. * Projects:: Things still left to do. -* Implementation:: Implementation Details for GNU GPERF. * Bibliography:: Material Referenced in this Report. * Concept Index:: @@ -115,14 +115,21 @@ * Input Format:: Input Format to @code{gperf} * Output Format:: Output Format for Generated C Code with @code{gperf} -* Binary Strings:: Use of NUL characters +* Binary Strings:: Use of NUL bytes Input Format to @code{gperf} -* Declarations:: @code{struct} Declarations and C Code Inclusion. +* Declarations:: Declarations. * Keywords:: Format for Keyword Entries. * Functions:: Including Additional C Functions. +* Controls for GNU indent:: Where to place directives for GNU @code{indent}. +Declarations + +* User-supplied Struct:: Specifying keywords with attributes. +* Gperf Declarations:: Embedding command line options in the input. +* C Code Inclusion:: Including C declarations and definitions. + Invoking @code{gperf} * Input Details:: Options that affect Interpretation of the Input File @@ -147,15 +154,13 @@ @item @cindex Bugs The GNU @code{gperf} perfect hash function generator utility was -originally written in GNU C++ by Douglas C. Schmidt. It is now also -available in a highly-portable ``old-style'' C version. The general +written in GNU C++ by Douglas C. Schmidt. The general idea for the perfect hash function generator was inspired by Keith Bostic's algorithm written in C, and distributed to net.sources around 1984. The current program is a heavily modified, enhanced, and extended implementation of Keith's basic idea, created at the University of California, Irvine. Bugs, patches, and suggestions should be reported -to both @code{<bug-gnu-utils@@gnu.org>} and -@code{<gperf-bugs@@lists.sourceforge.net>}. +to @code{<bug-gnu-gperf@@gnu.org>}. @item Special thanks is extended to Michael Tiemann and Doug Lea, for @@ -166,8 +171,9 @@ that greatly helped improve the quality and functionality of @code{gperf}. @item -A testsuite was added by Bruno Haible. He also rewrote the output -routines for better reliability. +Bruno Haible enhanced and optimized the search algorithm. He also rewrote +the input routines and the output routines for better reliability, and +added a testsuite. @end itemize @node Motivation, Search Structures, Contributors, Top @@ -176,8 +182,8 @@ @code{gperf} is a perfect hash function generator written in C++. It transforms an @var{n} element user-specified keyword set @var{W} into a perfect hash function @var{F}. @var{F} uniquely maps keywords in -@var{W} onto the range 0..@var{k}, where @var{k} >= @var{n}. If @var{k} -= @var{n} then @var{F} is a @emph{minimal} perfect hash function. +@var{W} onto the range 0..@var{k}, where @var{k} >= @var{n-1}. If @var{k} += @var{n-1} then @var{F} is a @emph{minimal} perfect hash function. @code{gperf} generates a 0..@var{k} element static lookup table and a pair of C functions. These functions determine whether a given character string @var{s} occurs in @var{W}, using at most one probe into @@ -185,11 +191,12 @@ @code{gperf} currently generates the reserved keyword recognizer for lexical analyzers in several production and research compilers and -language processing tools, including GNU C, GNU C++, GNU Pascal, GNU -Modula 3, and GNU indent. Complete C++ source code for @code{gperf} is -available via anonymous ftp from @code{ftp://ftp.gnu.org/pub/gnu/gperf/}. +language processing tools, including GNU C, GNU C++, GNU Java, GNU Pascal, +GNU Modula 3, and GNU indent. Complete C++ source code for @code{gperf} is +available from @code{http://ftp.gnu.org/pub/gnu/gperf/}. A paper describing @code{gperf}'s design and implementation in greater -detail is available in the Second USENIX C++ Conference proceedings. +detail is available in the Second USENIX C++ Conference proceedings +or from @code{http://www.cs.wustl.edu/~schmidt/resume.html}. @node Search Structures, Description, Motivation, Top @chapter Static search structures and GNU @code{gperf} @@ -198,7 +205,7 @@ A @dfn{static search structure} is an Abstract Data Type with certain fundamental operations, e.g., @emph{initialize}, @emph{insert}, and @emph{retrieve}. Conceptually, all insertions occur before any -retrievals. In practice, @code{gperf} generates a @code{static} array +retrievals. In practice, @code{gperf} generates a @emph{static} array containing search set keywords and any associated attributes specified by the user. Thus, there is essentially no execution-time cost for the insertions. It is a useful data structure for representing @emph{static @@ -254,8 +261,8 @@ search structures by hand. It has proven a useful and practical tool for serious programming projects. Output from @code{gperf} is currently used in several production and research compilers, including GNU C, GNU -C++, GNU Pascal, and GNU Modula 3. The latter two compilers are not yet -part of the official GNU distribution. Each compiler utilizes +C++, GNU Java, GNU Pascal, and GNU Modula 3. The latter two compilers are +not yet part of the official GNU distribution. Each compiler utilizes @code{gperf} to automatically generate static search structures that efficiently identify their respective reserved keywords. @@ -265,11 +272,11 @@ @menu * Input Format:: Input Format to @code{gperf} * Output Format:: Output Format for Generated C Code with @code{gperf} -* Binary Strings:: Use of NUL characters +* Binary Strings:: Use of NUL bytes @end menu The perfect hash function generator @code{gperf} reads a set of -``keywords'' from a @dfn{keyfile} (or from the standard input by +``keywords'' from an input file (or from the standard input by default). It attempts to derive a perfect hashing function that recognizes a member of the @dfn{static keyword set} with at most a single probe into the lookup table. If @code{gperf} succeeds in @@ -288,7 +295,7 @@ using a C @code{switch} may actually speed up the keyword retrieval time somewhat. Actual results depend on your C compiler, of course. -In general, @code{gperf} assigns values to the characters it is using +In general, @code{gperf} assigns values to the bytes it is using for hashing until some set of values gives each keyword a unique value. A helpful heuristic is that the larger the hash value range, the easier it is for @code{gperf} to find and generate a perfect hash function. @@ -300,7 +307,7 @@ @cindex Declaration section @cindex Keywords section @cindex Functions section -You can control the input keyfile format by varying certain command-line +You can control the input file format by varying certain command-line arguments, in particular the @samp{-t} option. The input's appearance is similar to GNU utilities @code{flex} and @code{bison} (or UNIX utilities @code{lex} and @code{yacc}). Here's an outline of the general @@ -316,34 +323,64 @@ @end group @end example -@emph{Unlike} @code{flex} or @code{bison}, all sections of -@code{gperf}'s input are optional. The following sections describe the +@emph{Unlike} @code{flex} or @code{bison}, the declarations section and +the functions section are optional. The following sections describe the input format for each section. @menu -* Declarations:: @code{struct} Declarations and C Code Inclusion. +* Declarations:: Declarations. * Keywords:: Format for Keyword Entries. * Functions:: Including Additional C Functions. +* Controls for GNU indent:: Where to place directives for GNU @code{indent}. @end menu +It is possible to omit the declaration section entirely, if the @samp{-t} +option is not given. In this case the input file begins directly with the +first keyword line, e.g.: + +@example +@group +january +february +march +april +... +@end group +@end example + @node Declarations, Keywords, Input Format, Input Format -@subsection @code{struct} Declarations and C Code Inclusion +@subsection Declarations The keyword input file optionally contains a section for including -arbitrary C declarations and definitions, as well as provisions for -providing a user-supplied @code{struct}. If the @samp{-t} option +arbitrary C declarations and definitions, @code{gperf} declarations that +act like command-line options, as well as for providing a user-supplied +@code{struct}. + +@menu +* User-supplied Struct:: Specifying keywords with attributes. +* Gperf Declarations:: Embedding command line options in the input. +* C Code Inclusion:: Including C declarations and definitions. +@end menu + +@node User-supplied Struct, Gperf Declarations, Declarations, Declarations +@subsubsection User-supplied @code{struct} + +If the @samp{-t} option (or, equivalently, the @samp{%struct-type} declaration) @emph{is} enabled, you @emph{must} provide a C @code{struct} as the last -component in the declaration section from the keyfile file. The first -field in this struct must be a @code{char *} or @code{const char *} -identifier called @samp{name}, although it is possible to modify this -field's name with the @samp{-K} option described below. +component in the declaration section from the input file. The first +field in this struct must be of type @code{char *} or @code{const char *} +if the @samp{-P} option is not given, or of type @code{int} if the option +@samp{-P} (or, equivalently, the @samp{%pic} declaration) is enabled. +This first field must be called @samp{name}, although it is possible to modify +its name with the @samp{-K} option (or, equivalently, the +@samp{%define slot-name} declaration) described below. Here is a simple example, using months of the year and their attributes as input: @example @group -struct months @{ char *name; int number; int days; int leap_days; @}; +struct month @{ char *name; int number; int days; int leap_days; @}; %% january, 1, 31, 31 february, 2, 28, 29 @@ -366,6 +403,236 @@ appearing left justified in the first column, as in the UNIX utility @code{lex}. +If the @code{struct} has already been declared in an include file, it can +be mentioned in an abbreviated form, like this: + +@example +@group +struct month; +%% +january, 1, 31, 31 +... +@end group +@end example + +@node Gperf Declarations, C Code Inclusion, User-supplied Struct, Declarations +@subsubsection Gperf Declarations + +The declaration section can contain @code{gperf} declarations. They +influence the way @code{gperf} works, like command line options do. +In fact, every such declaration is equivalent to a command line option. +There are three forms of declarations: + +@enumerate +@item +Declarations without argument, like @samp{%compare-lengths}. + +@item +Declarations with an argument, like @samp{%switch=@var{count}}. + +@item +Declarations of names of entities in the output file, like +@samp{%define lookup-function-name @var{name}}. +@end enumerate + +When a declaration is given both in the input file and as a command line +option, the command-line option's value prevails. + +The following @code{gperf} declarations are available. + +@table @samp +@item %delimiters=@var{delimiter-list} +@cindex @samp{%delimiters} +Allows you to provide a string containing delimiters used to +separate keywords from their attributes. The default is ",". This +option is essential if you want to use keywords that have embedded +commas or newlines. + +@item %struct-type +@cindex @samp{%struct-type} +Allows you to include a @code{struct} type declaration for generated +code; see above for an example. + +@item %ignore-case +@cindex @samp{%ignore-case} +Consider upper and lower case ASCII characters as equivalent. The string +comparison will use a case insignificant character comparison. Note that +locale dependent case mappings are ignored. + +@item %language=@var{language-name} +@cindex @samp{%language} +Instructs @code{gperf} to generate code in the language specified by the +option's argument. Languages handled are currently: + +@table @samp +@item KR-C +Old-style K&R C. This language is understood by old-style C compilers and +ANSI C compilers, but ANSI C compilers may flag warnings (or even errors) +because of lacking @samp{const}. + +@item C +Common C. This language is understood by ANSI C compilers, and also by +old-style C compilers, provided that you @code{#define const} to empty +for compilers which don't know about this keyword. + +@item ANSI-C +ANSI C. This language is understood by ANSI C compilers and C++ compilers. + +@item C++ +C++. This language is understood by C++ compilers. +@end table + +The default is C. + +@item %define slot-name @var{name} +@cindex @samp{%define slot-name} +This declaration is only useful when option @samp{-t} (or, equivalently, the +@samp{%struct-type} declaration) has been given. +By default, the program assumes the structure component identifier for +the keyword is @samp{name}. This option allows an arbitrary choice of +identifier for this component, although it still must occur as the first +field in your supplied @code{struct}. + +@item %define initializer-suffix @var{initializers} +@cindex @samp{%define initializer-suffix} +This declaration is only useful when option @samp{-t} (or, equivalently, the +@samp{%struct-type} declaration) has been given. +It permits to specify initializers for the structure members following +@var{slot-name} in empty hash table entries. The list of initializers +should start with a comma. By default, the emitted code will +zero-initialize structure members following @var{slot-name}. + +@item %define hash-function-name @var{name} +@cindex @samp{%define hash-function-name} +Allows you to specify the name for the generated hash function. Default +name is @samp{hash}. This option permits the use of two hash tables in +the same file. + +@item %define lookup-function-name @var{name} +@cindex @samp{%define lookup-function-name} +Allows you to specify the name for the generated lookup function. +Default name is @samp{in_word_set}. This option permits multiple +generated hash functions to be used in the same application. + +@item %define class-name @var{name} +@cindex @samp{%define class-name} +This option is only useful when option @samp{-L C++} (or, equivalently, +the @samp{%language=C++} declaration) has been given. It +allows you to specify the name of generated C++ class. Default name is +@code{Perfect_Hash}. + +@item %7bit +@cindex @samp{%7bit} +This option specifies that all strings that will be passed as arguments +to the generated hash function and the generated lookup function will +solely consist of 7-bit ASCII characters (bytes in the range 0..127). +(Note that the ANSI C functions @code{isalnum} and @code{isgraph} do +@emph{not} guarantee that a byte is in this range. Only an explicit +test like @samp{c >= 'A' && c <= 'Z'} guarantees this.) + +@item %compare-lengths +@cindex @samp{%compare-lengths} +Compare keyword lengths before trying a string comparison. This option +is mandatory for binary comparisons (@pxref{Binary Strings}). It also might +cut down on the number of string comparisons made during the lookup, since +keywords with different lengths are never compared via @code{strcmp}. +However, using @samp{%compare-lengths} might greatly increase the size of the +generated C code if the lookup table range is large (which implies that +the switch option @samp{-S} or @samp{%switch} is not enabled), since the length +table contains as many elements as there are entries in the lookup table. + +@item %compare-strncmp +@cindex @samp{%compare-strncmp} +Generates C code that uses the @code{strncmp} function to perform +string comparisons. The default action is to use @code{strcmp}. + +@item %readonly-tables +@cindex @samp{%readonly-tables} +Makes the contents of all generated lookup tables constant, i.e., +``readonly''. Many compilers can generate more efficient code for this +by putting the tables in readonly memory. + +@item %enum +@cindex @samp{%enum} +Define constant values using an enum local to the lookup function rather +than with #defines. This also means that different lookup functions can +reside in the same file. Thanks to James Clark @code{<jjc@@ai.mit.edu>}. + +@item %includes +@cindex @samp{%includes} +Include the necessary system include file, @code{<string.h>}, at the +beginning of the code. By default, this is not done; the user must +include this header file himself to allow compilation of the code. + +@item %global-table +@cindex @samp{%global-table} +Generate the static table of keywords as a static global variable, +rather than hiding it inside of the lookup function (which is the +default behavior). + +@item %pic +@cindex @samp{%pic} +Optimize the generated table for inclusion in shared libraries. This +reduces the startup time of programs using a shared library containing +the generated code. If the @samp{%struct-type} declaration (or, +equivalently, the option @samp{-t}) is also given, the first field of the +user-defined struct must be of type @samp{int}, not @samp{char *}, because +it will contain offsets into the string pool instead of actual strings. +To convert such an offset to a string, you can use the expression +@samp{stringpool + @var{o}}, where @var{o} is the offset. The string pool +name can be changed through the @samp{%define string-pool-name} declaration. + +@item %define string-pool-name @var{name} +@cindex @samp{%define string-pool-name} +Allows you to specify the name of the generated string pool created by +the declaration @samp{%pic} (or, equivalently, the option @samp{-P}). +The default name is @samp{stringpool}. This declaration permits the use of +two hash tables in the same file, with @samp{%pic} and even when the +@samp{%global-table} declaration (or, equivalently, the option @samp{-G}) +is given. + +@item %null-strings +@cindex @samp{%null-strings} +Use NULL strings instead of empty strings for empty keyword table entries. +This reduces the startup time of programs using a shared library containing +the generated code (but not as much as the declaration @samp{%pic}), at the +expense of one more test-and-branch instruction at run time. + +@item %define word-array-name @var{name} +@cindex @samp{%define word-array-name} +Allows you to specify the name for the generated array containing the +hash table. Default name is @samp{wordlist}. This option permits the +use of two hash tables in the same file, even when the option @samp{-G} +(or, equivalently, the @samp{%global-table} declaration) is given. + +@item %define length-table-name @var{name} +@cindex @samp{%define length-table-name} +Allows you to specify the name for the generated array containing the +length table. Default name is @samp{lengthtable}. This option permits the +use of two length tables in the same file, even when the option @samp{-G} +(or, equivalently, the @samp{%global-table} declaration) is given. + +@item %switch=@var{count} +@cindex @samp{%switch} +Causes the generated C code to use a @code{switch} statement scheme, +rather than an array lookup table. This can lead to a reduction in both +time and space requirements for some input files. The argument to this +option determines how many @code{switch} statements are generated. A +value of 1 generates 1 @code{switch} containing all the elements, a +value of 2 generates 2 tables with 1/2 the elements in each +@code{switch}, etc. This is useful since many C compilers cannot +correctly generate code for large @code{switch} statements. This option +was inspired in part by Keith Bostic's original C program. + +@item %omit-struct-type +@cindex @samp{%omit-struct-type} +Prevents the transfer of the type declaration to the output file. Use +this option if the type is already defined elsewhere. +@end table + +@node C Code Inclusion, , Gperf Declarations, Declarations +@subsubsection C Code Inclusion + @cindex @samp{%@{} @cindex @samp{%@}} Using a syntax similar to GNU utilities @code{flex} and @code{bison}, it @@ -380,9 +647,9 @@ %@{ #include <assert.h> /* This section of code is inserted directly into the output. */ -int return_month_days (struct months *months, int is_leap_year); +int return_month_days (struct month *months, int is_leap_year); %@} -struct months @{ char *name; int number; int days; int leap_days; @}; +struct month @{ char *name; int number; int days; int leap_days; @}; %% january, 1, 31, 31 february, 2, 28, 29 @@ -391,32 +658,21 @@ @end group @end example -It is possible to omit the declaration section entirely. In this case -the keyfile begins directly with the first keyword line, e.g.: - -@example -@group -january, 1, 31, 31 -february, 2, 28, 29 -march, 3, 31, 31 -april, 4, 30, 30 -... -@end group -@end example - @node Keywords, Functions, Declarations, Input Format @subsection Format for Keyword Entries -The second keyfile format section contains lines of keywords and any +The second input file format section contains lines of keywords and any associated attributes you might supply. A line beginning with @samp{#} in the first column is considered a comment. Everything following the -@samp{#} is ignored, up to and including the following newline. +@samp{#} is ignored, up to and including the following newline. A line +beginning with @samp{%} in the first column is an option declaration and +must not occur within the keywords section. -The first field of each non-comment line is always the key itself. It +The first field of each non-comment line is always the keyword itself. It can be given in two ways: as a simple name, i.e., without surrounding string quotation marks, or as a string enclosed in double-quotes, in C syntax, possibly with backslash escapes like @code{\"} or @code{\234} -or @code{\xa8}. In either case, it must start right at the beginning +or @code{\xa8}. In either case, it must start right at the beginning of the line, without leading whitespace. In this context, a ``field'' is considered to extend up to, but not include, the first blank, comma, or newline. Here is a simple @@ -445,11 +701,12 @@ should be separated by commas, and terminate at the end of line. What these fields mean is entirely up to you; they are used to initialize the elements of the user-defined @code{struct} provided by you in the -declaration section. If the @samp{-t} option is @emph{not} enabled +declaration section. If the @samp{-t} option (or, equivalently, the +@samp{%struct-type} declaration) is @emph{not} enabled these fields are simply ignored. All previous examples except the last one contain keyword attributes. -@node Functions, , Keywords, Input Format +@node Functions, Controls for GNU indent, Keywords, Input Format @subsection Including Additional C Functions The optional third section also corresponds closely with conventions @@ -459,12 +716,58 @@ it is your responsibility to ensure that the code contained in this section is valid C. +@node Controls for GNU indent, , Functions, Input Format +@subsection Where to place directives for GNU @code{indent}. + +If you want to invoke GNU @code{indent} on a @code{gperf} input file, +you will see that GNU @code{indent} doesn't understand the @samp{%%}, +@samp{%@{} and @samp{%@}} directives that control @code{gperf}'s +interpretation of the input file. Therefore you have to insert some +directives for GNU @code{indent}. More precisely, assuming the most +general input file structure + +@example +@group +declarations part 1 +%@{ +verbatim code +%@} +declarations part 2 +%% +keywords +%% +functions +@end group +@end example + +@noindent +you would insert @samp{*INDENT-OFF*} and @samp{*INDENT-ON*} comments +as follows: + +@example +@group +/* *INDENT-OFF* */ +declarations part 1 +%@{ +/* *INDENT-ON* */ +verbatim code +/* *INDENT-OFF* */ +%@} +declarations part 2 +%% +keywords +%% +/* *INDENT-ON* */ +functions +@end group +@end example + @node Output Format, Binary Strings, Input Format, Description @section Output Format for Generated C Code with @code{gperf} @cindex hash table Several options control how the generated C code appears on the standard -output. Two C function are generated. They are called @code{hash} and +output. Two C functions are generated. They are called @code{hash} and @code{in_word_set}, although you may modify their names with a command-line option. Both functions require two arguments, a string, @code{char *} @var{str}, and a length parameter, @code{int} @var{len}. Their default @@ -472,26 +775,28 @@ @deftypefun {unsigned int} hash (const char * @var{str}, unsigned int @var{len}) By default, the generated @code{hash} function returns an integer value -created by adding @var{len} to several user-specified @var{str} key +created by adding @var{len} to several user-specified @var{str} byte positions indexed into an @dfn{associated values} table stored in a local static array. The associated values table is constructed internally by @code{gperf} and later output as a static local C array -called @samp{hash_table}; its meaning and properties are described below -(@pxref{Implementation}). The relevant key positions are specified via -the @samp{-k} option when running @code{gperf}, as detailed in the -@emph{Options} section below(@pxref{Options}). +called @samp{hash_table}. The relevant selected positions (i.e. indices +into @var{str}) are specified via the @samp{-k} option when running +@code{gperf}, as detailed in the @emph{Options} section below (@pxref{Options}). @end deftypefun @deftypefun {} in_word_set (const char * @var{str}, unsigned int @var{len}) If @var{str} is in the keyword set, returns a pointer to that -keyword. More exactly, if the option @samp{-t} was given, it returns -a pointer to the matching keyword's structure. Otherwise it returns +keyword. More exactly, if the option @samp{-t} (or, equivalently, the +@samp{%struct-type} declaration) was given, it returns +a pointer to the matching keyword's structure. Otherwise it returns @code{NULL}. @end deftypefun -If the option @samp{-c} is not used, @var{str} must be a NUL terminated -string of exactly length @var{len}. If @samp{-c} is used, @var{str} must -simply be an array of @var{len} characters and does not need to be NUL +If the option @samp{-c} (or, equivalently, the @samp{%compare-strncmp} +declaration) is not used, @var{str} must be a NUL terminated +string of exactly length @var{len}. If @samp{-c} (or, equivalently, the +@samp{%compare-strncmp} declaration) is used, @var{str} must +simply be an array of @var{len} bytes and does not need to be NUL terminated. The code generated for these two functions is affected by the following @@ -512,44 +817,50 @@ code. @end table -If the @samp{-t} and @samp{-S} options are omitted, the default action -is to generate a @code{char *} array containing the keys, together with -additional null strings used for padding the array. By experimenting +If the @samp{-t} and @samp{-S} options (or, equivalently, the +@samp{%struct-type} and @samp{%switch} declarations) are omitted, the default +action +is to generate a @code{char *} array containing the keywords, together with +additional empty strings used for padding the array. By experimenting with the various input and output options, and timing the resulting C code, you can determine the best option choices for different keyword set characteristics. @node Binary Strings, , Output Format, Description -@section Use of NUL characters +@section Use of NUL bytes @cindex NUL By default, the code generated by @code{gperf} operates on zero -terminated strings, the usual representation of strings in C. This means -that the keywords in the input file must not contain NUL characters, +terminated strings, the usual representation of strings in C. This means +that the keywords in the input file must not contain NUL bytes, and the @var{str} argument passed to @code{hash} or @code{in_word_set} must be NUL terminated and have exactly length @var{len}. -If option @samp{-c} is used, then the @var{str} argument does not need -to be NUL terminated. The code generated by @code{gperf} will only +If option @samp{-c} (or, equivalently, the @samp{%compare-strncmp} +declaration) is used, then the @var{str} argument does not need +to be NUL terminated. The code generated by @code{gperf} will only access the first @var{len}, not @var{len+1}, bytes starting at @var{str}. However, the keywords in the input file still must not contain NUL -characters. +bytes. -If option @samp{-l} is used, then the hash table performs binary -comparison. The keywords in the input file may contain NUL characters, +If option @samp{-l} (or, equivalently, the @samp{%compare-lengths} +declaration) is used, then the hash table performs binary +comparison. The keywords in the input file may contain NUL bytes, written in string syntax as @code{\000} or @code{\x00}, and the code -generated by @code{gperf} will treat NUL like any other character. -Also, in this case the @samp{-c} option is ignored. +generated by @code{gperf} will treat NUL like any other byte. +Also, in this case the @samp{-c} option (or, equivalently, the +@samp{%compare-strncmp} declaration) is ignored. @node Options, Bugs, Description, Top @chapter Invoking @code{gperf} There are @emph{many} options to @code{gperf}. They were added to make the program more convenient for use with real applications. ``On-line'' -help is readily available via the @samp{-h} option. Here is the +help is readily available via the @samp{--help} option. Here is the complete list of options. @menu +* Output File:: Specifying the Location of the Output File * Input Details:: Options that affect Interpretation of the Input File * Output Language:: Specifying the Language for the Output Code * Output Details:: Fine tuning Details in the Output Code @@ -557,15 +868,29 @@ * Verbosity:: Informative Output @end menu -@node Input Details, Output Language, Options, Options +@node Output File, Input Details, Options, Options +@section Specifying the Location of the Output File + +@table @samp +@item --output-file=@var{file} +Allows you to specify the name of the file to which the output is written to. +@end table + +The results are written to standard output if no output file is specified +or if it is @samp{-}. + +@node Input Details, Output Language, Output File, Options @section Options that affect Interpretation of the Input File +These options are also available as declarations in the input file +(@pxref{Gperf Declarations}). + @table @samp @item -e @var{keyword-delimiter-list} @itemx --delimiters=@var{keyword-delimiter-list} @cindex Delimiters -Allows the user to provide a string containing delimiters used to -separate keywords from their attributes. The default is ",\n". This +Allows you to provide a string containing delimiters used to +separate keywords from their attributes. The default is ",". This option is essential if you want to use keywords that have embedded commas or newlines. One useful trick is to use -e'TAB', where TAB is the literal tab character. @@ -578,11 +903,25 @@ this, one group of fields per line. A set of examples for generating perfect hash tables and functions for Ada, C, C++, Pascal, Modula 2, Modula 3 and JavaScript reserved words are distributed with this release. + +@item --ignore-case +Consider upper and lower case ASCII characters as equivalent. The string +comparison will use a case insignificant character comparison. Note that +locale dependent case mappings are ignored. This option is therefore not +suitable if a properly internationalized or locale aware case mapping +should be used. (For example, in a Turkish locale, the upper case equivalent +of the lowercase ASCII letter @samp{i} is the non-ASCII character +@samp{capital i with dot above}.) For this case, it is better to apply +an uppercase or lowercase conversion on the string before passing it to +the @code{gperf} generated function. @end table @node Output Language, Output Details, Input Details, Options @section Options to specify the Language for the Output Code +These options are also available as declarations in the input file +(@pxref{Gperf Declarations}). + @table @samp @item -L @var{generated-language-name} @itemx --language=@var{generated-language-name} @@ -591,41 +930,45 @@ @table @samp @item KR-C -Old-style K&R C. This language is understood by old-style C compilers and +Old-style K&R C. This language is understood by old-style C compilers and ANSI C compilers, but ANSI C compilers may flag warnings (or even errors) because of lacking @samp{const}. @item C -Common C. This language is understood by ANSI C compilers, and also by +Common C. This language is understood by ANSI C compilers, and also by old-style C compilers, provided that you @code{#define const} to empty for compilers which don't know about this keyword. @item ANSI-C -ANSI C. This language is understood by ANSI C compilers and C++ compilers. +ANSI C. This language is understood by ANSI C compilers and C++ compilers. @item C++ -C++. This language is understood by C++ compilers. +C++. This language is understood by C++ compilers. @end table The default is C. @item -a This option is supported for compatibility with previous releases of -@code{gperf}. It does not do anything. +@code{gperf}. It does not do anything. @item -g This option is supported for compatibility with previous releases of -@code{gperf}. It does not do anything. +@code{gperf}. It does not do anything. @end table @node Output Details, Algorithmic Details, Output Language, Options @section Options for fine tuning Details in the Output Code +Most of these options are also available as declarations in the input file +(@pxref{Gperf Declarations}). + @table @samp -@item -K @var{key-name} -@itemx --slot-name=@var{key-name} +@item -K @var{slot-name} +@itemx --slot-name=@var{slot-name} @cindex Slot name -This option is only useful when option @samp{-t} has been given. +This option is only useful when option @samp{-t} (or, equivalently, the +@samp{%struct-type} declaration) has been given. By default, the program assumes the structure component identifier for the keyword is @samp{name}. This option allows an arbitrary choice of identifier for this component, although it still must occur as the first @@ -634,29 +977,30 @@ @item -F @var{initializers} @itemx --initializer-suffix=@var{initializers} @cindex Initializers -This option is only useful when option @samp{-t} has been given. +This option is only useful when option @samp{-t} (or, equivalently, the +@samp{%struct-type} declaration) has been given. It permits to specify initializers for the structure members following -@var{key name} in empty hash table entries. The list of initializers +@var{slot-name} in empty hash table entries. The list of initializers should start with a comma. By default, the emitted code will -zero-initialize structure members following @var{key name}. +zero-initialize structure members following @var{slot-name}. @item -H @var{hash-function-name} -@itemx --hash-fn-name=@var{hash-function-name} +@itemx --hash-function-name=@var{hash-function-name} Allows you to specify the name for the generated hash function. Default name is @samp{hash}. This option permits the use of two hash tables in the same file. @item -N @var{lookup-function-name} -@itemx --lookup-fn-name=@var{lookup-function-name} +@itemx --lookup-function-name=@var{lookup-function-name} Allows you to specify the name for the generated lookup function. -Default name is @samp{in_word_set}. This option permits completely -automatic generation of perfect hash functions, especially when multiple -generated hash functions are used in the same application. +Default name is @samp{in_word_set}. This option permits multiple +generated hash functions to be used in the same application. @item -Z @var{class-name} @itemx --class-name=@var{class-name} @cindex Class name -This option is only useful when option @samp{-L C++} has been given. It +This option is only useful when option @samp{-L C++} (or, equivalently, +the @samp{%language=C++} declaration) has been given. It allows you to specify the name of generated C++ class. Default name is @code{Perfect_Hash}. @@ -664,12 +1008,23 @@ @itemx --seven-bit This option specifies that all strings that will be passed as arguments to the generated hash function and the generated lookup function will -solely consist of 7-bit ASCII characters (characters in the range 0..127). +solely consist of 7-bit ASCII characters (bytes in the range 0..127). (Note that the ANSI C functions @code{isalnum} and @code{isgraph} do -@emph{not} guarantee that a character is in this range. Only an explicit +@emph{not} guarantee that a byte is in this range. Only an explicit test like @samp{c >= 'A' && c <= 'Z'} guarantees this.) This was the default in versions of @code{gperf} earlier than 2.7; now the default is -to assume 8-bit characters. +to support 8-bit and multibyte characters. + +@item -l +@itemx --compare-lengths +Compare keyword lengths before trying a string comparison. This option +is mandatory for binary comparisons (@pxref{Binary Strings}). It also might +cut down on the number of string comparisons made during the lookup, since +keywords with different lengths are never compared via @code{strcmp}. +However, using @samp{-l} might greatly increase the size of the +generated C code if the lookup table range is large (which implies that +the switch option @samp{-S} or @samp{%switch} is not enabled), since the length +table contains as many elements as there are entries in the lookup table. @item -c @itemx --compare-strncmp @@ -695,30 +1050,63 @@ include this header file himself to allow compilation of the code. @item -G -@itemx --global +@itemx --global-table Generate the static table of keywords as a static global variable, rather than hiding it inside of the lookup function (which is the default behavior). +@item -P +@itemx --pic +Optimize the generated table for inclusion in shared libraries. This +reduces the startup time of programs using a shared library containing +the generated code. If the option @samp{-t} (or, equivalently, the +@samp{%struct-type} declaration) is also given, the first field of the +user-defined struct must be of type @samp{int}, not @samp{char *}, because +it will contain offsets into the string pool instead of actual strings. +To convert such an offset to a string, you can use the expression +@samp{stringpool + @var{o}}, where @var{o} is the offset. The string pool +name can be changed through the option @samp{--string-pool-name}. + +@item -Q @var{string-pool-name} +@itemx --string-pool-name=@var{string-pool-name} +Allows you to specify the name of the generated string pool created by +option @samp{-P}. The default name is @samp{stringpool}. This option +permits the use of two hash tables in the same file, with @samp{-P} and +even when the option @samp{-G} (or, equivalently, the @samp{%global-table} +declaration) is given. + +@item --null-strings +Use NULL strings instead of empty strings for empty keyword table entries. +This reduces the startup time of programs using a shared library containing +the generated code (but not as much as option @samp{-P}), at the expense +of one more test-and-branch instruction at run time. + @item -W @var{hash-table-array-name} @itemx --word-array-name=@var{hash-table-array-name} @cindex Array name Allows you to specify the name for the generated array containing the hash table. Default name is @samp{wordlist}. This option permits the use of two hash tables in the same file, even when the option @samp{-G} -is given. +(or, equivalently, the @samp{%global-table} declaration) is given. + +@itemx --length-table-name=@var{length-table-array-name} +@cindex Array name +Allows you to specify the name for the generated array containing the +length table. Default name is @samp{lengthtable}. This option permits the +use of two length tables in the same file, even when the option @samp{-G} +(or, equivalently, the @samp{%global-table} declaration) is given. @item -S @var{total-switch-statements} @itemx --switch=@var{total-switch-statements} @cindex @code{switch} Causes the generated C code to use a @code{switch} statement scheme, rather than an array lookup table. This can lead to a reduction in both -time and space requirements for some keyfiles. The argument to this -option determines how many @code{switch} statements are generated. A +time and space requirements for some input files. The argument to this +option determines how many @code{switch} statements are generated. A value of 1 generates 1 @code{switch} containing all the elements, a value of 2 generates 2 tables with 1/2 the elements in each @code{switch}, etc. This is useful since many C compilers cannot -correctly generate code for large @code{switch} statements. This option +correctly generate code for large @code{switch} statements. This option was inspired in part by Keith Bostic's original C program. @item -T @@ -728,93 +1116,73 @@ @item -p This option is supported for compatibility with previous releases of -@code{gperf}. It does not do anything. >>> TRUNCATED FOR MAIL (1000 lines) <<<
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201201121749.q0CHnhx4016384>