diff options
author | David MacKenzie <djm@cygnus> | 1994-02-25 03:26:25 +0000 |
---|---|---|
committer | David MacKenzie <djm@cygnus> | 1994-02-25 03:26:25 +0000 |
commit | d4e5e3c330d5b2e7b6b972e03b1997a88270f703 (patch) | |
tree | dd57ae76fac89f06f3f85a050e9537847844d909 /ld/ld.texinfo | |
parent | b4f6f3c114e3cd2118ebb6c7e33ac65002d3255f (diff) | |
download | gdb-d4e5e3c330d5b2e7b6b972e03b1997a88270f703.zip gdb-d4e5e3c330d5b2e7b6b972e03b1997a88270f703.tar.gz gdb-d4e5e3c330d5b2e7b6b972e03b1997a88270f703.tar.bz2 |
Use getopt instead of lex and yacc to parse the command line.
* ld.texinfo (Options): Document changes to option syntax.
* Makefile.in: Update dependencies.
* ldver.c (help): Tweak dashes in usage message.
* ldgram.y (%union): Remove unused members.
Remove %tokens for command line options; add ones for input types.
(command_line): Rules removed.
(file): Instead of command line, recognize an
input type indicator, then use the nonterminal for that type.
(defsym_expr): New nonterminal from code formerly in command_line.
* ldlex.h: Declare parser input type enum and variable.
Don't declare parse_line.
* ldlex.l: Remove unused variables. Make some used ones static
and comment them.
(COMMAND): Start state and its rules removed.
At start of yylex, return input state token if at start of input.
(lex_redirect): Don't need to set yyout.
(ldlex_command): Function removed.
* ldmain.c (main): Instead of calling parse_line, set up the
redirections and call yyparse directly.
* ldmisc.c (vfinfo): If there's no input filename, print nothing, not
"command line".
* lexsup.c: Remove #if 0'd code.
(parse_line): Function removed.
(parse_args): Rewrite to use getopt_long_only.
(set_default_dirlist): New function from code formerly in
ldgram.y:command_line.
(set_section_start): New function.
* emultempl/generic.em, emultempl/gld960.em, emultempl/hppaelf.em,
emultempl/lnk960.em, emultempl/m88kbcs.em: Don't enclose
compiled-in link scripts in "{" and "}", as the grammar no longer
wants them to be.
Diffstat (limited to 'ld/ld.texinfo')
-rw-r--r-- | ld/ld.texinfo | 461 |
1 files changed, 194 insertions, 267 deletions
diff --git a/ld/ld.texinfo b/ld/ld.texinfo index 4c929ac..d2714c0 100644 --- a/ld/ld.texinfo +++ b/ld/ld.texinfo @@ -17,7 +17,7 @@ END-INFO-DIR-ENTRY @ifinfo This file documents the GNU linker LD. -Copyright (C) 1991, 1992, 1993 Free Software Foundation, Inc. +Copyright (C) 1991, 1992, 1993, 1994 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice @@ -48,7 +48,7 @@ notice identical to this one except for the removal of this paragraph @subtitle The GNU linker @sp 1 @subtitle @code{ld} version 2 -@subtitle March 1993 +@subtitle January 1994 @author Steve Chamberlain and Roland Pesch @author Cygnus Support @page @@ -58,13 +58,14 @@ notice identical to this one except for the removal of this paragraph \hfill Cygnus Support\par \hfill steve\@cygnus.com, pesch\@cygnus.com\par \hfill {\it Using LD, the GNU linker}\par -\hfill Edited by Jeffrey Osier (jeffrey\@cygnus.com), March 1993.\par +\hfill Edited by Jeffrey Osier (jeffrey\@cygnus.com)\par +\hfill and Roland Pesch (pesch\@cygnus.com)\par } \global\parindent=0pt % Steve likes it this way. @end tex @vskip 0pt plus 1filll -Copyright @copyright{} 1991, 1992, 1993 Free Software Foundation, Inc. +Copyright @copyright{} 1991, 1992, 1993, 1994 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice @@ -129,8 +130,7 @@ This version of @code{ld} uses the general purpose BFD libraries to operate on object files. This allows @code{ld} to read, combine, and write object files in many different formats---for example, COFF or @code{a.out}. Different formats may be linked together to produce any -available kind of object file. @xref{BFD} for a list of formats -supported on various architectures. +available kind of object file. @xref{BFD}, for more information. @end ifclear Aside from its flexibility, the GNU linker is more helpful than other @@ -168,15 +168,15 @@ ld [ -o @var{output} ] @var{objfile}@dots{} [ -c @var{MRI-commandfile} ] [ -d | -dc | -dp ] [ -defsym @var{symbol}=@var{expression} ] [ -e @var{entry} ] [ -F ] [ -F @var{format} ] - [ -format @var{input-format} ] [ -g ] [ -G @var{size} ] [ --help ] [ -i ] - [ -l@var{archive} ] [ -L@var{searchdir} ] [ -M ] [ -Map @var{mapfile} ] - [ -m @var{emulation} ] [ -N | -n ] [ -noinhibit-exec ] - [ -oformat @var{output-format} ] [ -R @var{filename} ] [ -relax ] - [ -retain-symbols-file @var{filename} ] + [ -format @var{input-format} ] [ -g ] [ -G @var{size} ] [ -help ] + [ -i ] [ -l@var{archive} ] [ -L@var{searchdir} ] [ -M ] + [ -Map @var{mapfile} ] [ -m @var{emulation} ] [ -N | -n ] + [ -noinhibit-exec ] [ -oformat @var{output-format} ] + [ -R @var{filename} ] [ -relax ] [ -retain-symbols-file @var{filename} ] [ -r | -Ur ] [ -S ] [ -s ] [ -sort-common ] [ -stats ] [ -T @var{commandfile} ] [ -Ttext @var{org} ] [ -Tdata @var{org} ] - [ -Tbss @var{org} ] [ -t ] [ -u @var{symbol}] [-V] [-v] [ --version ] + [ -Tbss @var{org} ] [ -t ] [ -u @var{symbol}] [-V] [-v] [ -version ] [ -warn-common ] [ -y @var{symbol} ] [ -X ] [-x ] @end smallexample @@ -224,10 +224,20 @@ and the script command language. If @emph{no} binary input files at all are specified, the linker does not produce any output, and issues the message @samp{No input files}. -Option arguments must either follow the option letter without intervening +For options whose names are a single letter, +option arguments must either follow the option letter without intervening whitespace, or be given as separate arguments immediately following the option that requires them. +For options whose names are multiple letters, either one dash or two can +precede the option name; for example, @samp{--oformat} and +@samp{-oformat} are equivalent. Arguments to multiple-letter options +must either be separated from the option name by an equals sign, or be +given as separate arguments immediately following the option that +requires them. For example, @samp{--oformat srec} and +@samp{--oformat=srec} are equivalent. Unique abbreviations of the names +of multiple-letter options are accepted. + @table @code @ifset I960 @cindex architectures @@ -361,14 +371,11 @@ Ignored. Provided for compatibility with other tools. Set the maximum size of objects to be optimized using the GP register to @var{size} under MIPS ECOFF. Ignored for other object file formats. -@item --help -@kindex --help @cindex help @cindex usage +@kindex -help +@item -help Print a summary of the command-line options on the standard output and exit. -This option and @samp{--version} begin with two dashes instead of one -for compatibility with other GNU programs. The other options start with -only one dash for compatibility with other linkers. @kindex -i @cindex incremental link @@ -430,10 +437,10 @@ Set the text and data sections to be readable and writable. Also, do not page-align the data segment. If the output format supports Unix style magic numbers, mark the output as @code{OMAGIC}. -@item -n @kindex -n @cindex read-only text @kindex NMAGIC +@item -n Set the text segment to be read only, and mark the output as @code{NMAGIC} if possible. @@ -476,10 +483,10 @@ relocate it or include it in the output. This allows your output file to refer symbolically to absolute locations of memory defined in other programs. -@item -relax @kindex -relax @cindex synthesizing linker @cindex relaxing addressing modes +@item -relax An option with machine dependent effects. @ifset GENERIC Currently this option is only supported on the H8/300 and the Intel 960. @@ -520,10 +527,10 @@ or symbols needed for relocations. You may only specify @samp{-retain-symbols-file} once in the command line. It overrides @samp{-s} and @samp{-S}. -@item -r @cindex partial link @cindex relocatable output @kindex -r +@item -r Generate relocatable output---i.e., generate an output file that can in turn serve as input to @code{ld}. This is often called @dfn{partial linking}. As a side effect, in environments that support standard Unix @@ -536,14 +543,14 @@ constructors; to do that, use @samp{-Ur}. This option does the same thing as @samp{-i}. -@item -S @kindex -S @cindex strip debugger symbols +@item -S Omit debugger symbol information (but not all symbols) from the output file. -@item -s @kindex -s @cindex strip all symbols +@item -s Omit all symbol information from the output file. @item -sort-common @@ -581,10 +588,10 @@ the target format. @xref{Commands}. If @var{commandfile} does not exist, @code{ld} looks for it in the directories specified by any preceding @samp{-L} options. Multiple @samp{-T} options accumulate. -@item -t @kindex -t @cindex verbose @cindex input files, displaying +@item -t Print the names of the input files as @code{ld} processes them. @item -u @var{symbol} @@ -597,9 +604,9 @@ arguments to enter additional undefined symbols. @c Nice idea, but no such command: This option is equivalent @c to the @code{EXTERN} linker command. -@item -Ur @kindex -Ur @cindex constructors +@item -Ur For anything other than C++ programs, this option is equivalent to @samp{-r}: it generates relocatable output---i.e., an output file that can in turn serve as input to @code{ld}. When linking C++ programs, @samp{-Ur} @@ -609,19 +616,19 @@ with @samp{-Ur}; once the constructor table has been built, it cannot be added to. Use @samp{-Ur} only for the last partial link, and @samp{-r} for the others. -@item -V @kindex -V @cindex version +@item -V Display the version number for @code{ld} and list the linker emulations supported. Display which input files can and cannot be opened. -@item -v @kindex -v @cindex version +@item -v Display the version number for @code{ld}. -@item --version -@kindex --version +@item -version +@kindex -version Display the version number for @code{ld} and exit. @item -warn-common @@ -709,16 +716,16 @@ encountered in a different order. @end smallexample @end enumerate -@item -X @kindex -X @cindex local symbols, deleting @cindex L, deleting symbols beginning +@item -X If @samp{-s} or @samp{-S} is also specified, delete only local symbols beginning with @samp{L}. -@item -x @kindex -x @cindex deleting local symbols +@item -x If @samp{-s} or @samp{-S} is also specified, delete all local symbols, not just those beginning with @samp{L}. @@ -944,14 +951,14 @@ counter may never be moved backwards. @example SECTIONS @{ - output : - @{ - file1(.text) - . = . + 1000; - file2(.text) - . += 1000; - file3(.text) - @} = 0x1234; + output : + @{ + file1(.text) + . = . + 1000; + file2(.text) + . += 1000; + file3(.text) + @} = 0x1234; @} @end example @noindent @@ -961,6 +968,11 @@ appears, also with a 1000 byte gap following before @code{file3} is loaded. The notation @samp{= 0x1234} specifies what data to write in the gaps (@pxref{Section Options}). +@iftex +@vfill +@end iftex + +@need 5000 @node Operators @subsection Operators @cindex Operators for arithmetic @@ -1112,11 +1124,11 @@ section definition by using the absolute assignment function is the last byte of an output section named @code{.data}: @example SECTIONS@{ @dots{} -.data : - @{ - *(.data) - _edata = ABSOLUTE(.) ; - @} + .data : + @{ + *(.data) + _edata = ABSOLUTE(.) ; + @} @dots{} @} @end example @@ -1130,9 +1142,9 @@ result of an expression is required, but the value is not available, then an error results. For example, a script like the following @example SECTIONS @{ @dots{} - text 9+this_isnt_constant : - @{ @dots{} - @} + text 9+this_isnt_constant : + @{ @dots{} + @} @dots{} @} @end example @kindex Non constant expression @@ -1163,16 +1175,16 @@ example, @code{symbol_1} and @code{symbol_2} are assigned identical values: @example SECTIONS@{ @dots{} - .output1 : - @{ - start_of_output_1 = ABSOLUTE(.); - @dots{} - @} - .output : - @{ - symbol_1 = ADDR(.output1); - symbol_2 = start_of_output_1; - @} + .output1 : + @{ + start_of_output_1 = ABSOLUTE(.); + @dots{} + @} + .output : + @{ + symbol_1 = ADDR(.output1); + symbol_2 = start_of_output_1; + @} @dots{} @} @end example @@ -1193,10 +1205,10 @@ section and to set a variable within the section to the next @code{0x8000} boundary after the input sections: @example SECTIONS@{ @dots{} - .data ALIGN(0x2000): @{ - *(.data) - variable = ALIGN(0x8000); - @} + .data ALIGN(0x2000): @{ + *(.data) + variable = ALIGN(0x8000); + @} @dots{} @} @end example @noindent @@ -1216,12 +1228,13 @@ values for symbols. For example, the following command-file fragment shows how to set a global symbol @code{begin} to the first location in the @code{.text} section---but if a symbol called @code{begin} already existed, its value is preserved: + @smallexample SECTIONS@{ @dots{} - .text : @{ - begin = DEFINED(begin) ? begin : . ; - @dots{} - @} + .text : @{ + begin = DEFINED(begin) ? begin : . ; + @dots{} + @} @dots{} @} @end smallexample @@ -1242,13 +1255,13 @@ been allocated. In the following example, @code{symbol_1} and @c What does it return if the section hasn't been allocated? 0? @example SECTIONS@{ @dots{} - .output @{ - .start = . ; - @dots{} - .end = . ; - @} - symbol_1 = .end - .start ; - symbol_2 = SIZEOF(.output); + .output @{ + .start = . ; + @dots{} + .end = . ; + @} + symbol_1 = .end - .start ; + symbol_2 = SIZEOF(.output); @dots{} @} @end example @@ -1285,37 +1298,40 @@ you wish. The syntax is: @example MEMORY - @{ - @var{name} (@var{attr}) : ORIGIN = @var{origin}, LENGTH = @var{len} - @dots{} - @} + @{ + @var{name} (@var{attr}) : ORIGIN = @var{origin}, LENGTH = @var{len} + @dots{} + @} @end example @table @code -@item @var{name} @cindex naming memory regions +@item @var{name} is a name used internally by the linker to refer to the region. Any symbol name may be used. The region names are stored in a separate name space, and will not conflict with symbols, file names or section names. Use distinct names to specify multiple regions. -@item (@var{attr}) + @cindex memory region attributes +@item (@var{attr}) is an optional list of attributes, permitted for compatibility with the AT&T linker but not used by @code{ld} beyond checking that the attribute list is valid. Valid attribute lists must be made up of the characters ``@code{LIRWX}''. If you omit the attribute list, you may omit the parentheses around it as well. -@item @var{origin} + @kindex ORIGIN = @kindex o = @kindex org = +@item @var{origin} is the start address of the region in physical memory. It is an expression that must evaluate to a constant before memory allocation is performed. The keyword @code{ORIGIN} may be abbreviated to @code{org} or @code{o} (but not, for example, @samp{ORG}). -@item @var{len} + @kindex LENGTH = @kindex len = @kindex l = +@item @var{len} is the size in bytes of the region (an expression). The keyword @code{LENGTH} may be abbreviated to @code{len} or @code{l}. @end table @@ -1326,10 +1342,10 @@ starting at @code{0x40000000} for four megabytes: @example MEMORY - @{ - rom : ORIGIN = 0, LENGTH = 256K - ram : org = 0x40000000, l = 4M - @} + @{ + rom : ORIGIN = 0, LENGTH = 256K + ram : org = 0x40000000, l = 4M + @} @end example Once you have defined a region of memory named @var{mem}, you can direct @@ -1392,9 +1408,9 @@ these specifications are optional; the simplest form of a section definition is @example SECTIONS @{ @dots{} -@var{secname} : @{ - @var{contents} - @} + @var{secname} : @{ + @var{contents} + @} @dots{} @} @end example @cindex naming output sections @@ -1432,10 +1448,10 @@ like in a single section definition, separated from one another by whitespace. @table @code -@item @var{filename} @kindex @var{filename} @cindex input files, section defn @cindex files, including in output sections +@item @var{filename} You may simply name a particular input file to be placed in the current output section; @emph{all} sections from that file are placed in the current section definition. If the file name has already been mentioned @@ -1451,21 +1467,21 @@ The example also illustrates that multiple statements can be included in the contents of a section definition, since each file name is a separate statement. +@kindex @var{filename}(@var{section}) +@cindex files and sections, section defn @item @var{filename}( @var{section} ) @itemx @var{filename}( @var{section}, @var{section}, @dots{} ) @itemx @var{filename}( @var{section} @var{section} @dots{} ) -@kindex @var{filename}(@var{section}) -@cindex files and sections, section defn You can name one or more sections from your input files, for insertion in the current output section. If you wish to specify a list of input-file sections inside the parentheses, you may separate the section names by either commas or whitespace. +@cindex input sections to output section +@kindex *(@var{section}) @item * (@var{section}) @itemx * (@var{section}, @var{section}, @dots{}) @itemx * (@var{section} @var{section} @dots{}) -@cindex input sections to output section -@kindex *(@var{section}) Instead of explicitly naming particular input files in a link control script, you can refer to @emph{all} files from the @code{ld} command line: use @samp{*} instead of a particular file name before the @@ -1480,26 +1496,27 @@ into the @code{.text} section of an @code{a.out} file, and sections @code{13} and @code{14} into the @code{.data} section: @example SECTIONS @{ - .text :@{ - *("1" "2" "3" "4") - @} - - .data :@{ - *("13" "14") - @} + .text :@{ + *("1" "2" "3" "4") + @} + + .data :@{ + *("13" "14") + @} @} @end example +@cindex @code{[@var{section}@dots{}]}, not supported @samp{[ @var{section} @dots{} ]} used to be accepted as an alternate way to specify named sections from all unallocated input files. Because some operating systems (VMS) allow brackets in file names, that notation is no longer supported. -@item @var{filename}@code{( COMMON )} -@itemx *( COMMON ) -@kindex *( COMMON ) @cindex uninitialized data @cindex commons in output +@kindex *( COMMON ) +@item @var{filename}@code{( COMMON )} +@itemx *( COMMON ) Specify where in your output file to place uninitialized data with this notation. @code{*(COMMON)} by itself refers to all uninitialized data from all input files (so far as it is not yet @@ -1515,6 +1532,7 @@ For example, the following command script arranges the output file into three consecutive sections, named @code{.text}, @code{.data}, and @code{.bss}, taking the input for each from the correspondingly named sections of all the input files: + @example SECTIONS @{ .text : @{ *(.text) @} @@ -1534,21 +1552,21 @@ files are written to output section @code{outputc}. @example SECTIONS @{ - outputa 0x10000 : - @{ - all.o - foo.o (.input1) - @} - outputb : - @{ - foo.o (.input2) - foo1.o (.input1) - @} - outputc : - @{ - *(.input1) - *(.input2) - @} + outputa 0x10000 : + @{ + all.o + foo.o (.input1) + @} + outputb : + @{ + foo.o (.input2) + foo1.o (.input1) + @} + outputc : + @{ + *(.input1) + *(.input2) + @} @} @end example @@ -1566,10 +1584,10 @@ command; you can intermix them freely with any of the statements we've just described. @table @code -@item CREATE_OBJECT_SYMBOLS -@kindex CREATE_OBJECT_SYMBOLS @cindex input filename symbols @cindex filename symbols +@kindex CREATE_OBJECT_SYMBOLS +@item CREATE_OBJECT_SYMBOLS Create a symbol for each input file in the current section, set to the address of the first byte of data written from that input file. For instance, with @code{a.out} @@ -1577,13 +1595,13 @@ files it is conventional to have a symbol for each input file. You can accomplish this by defining the output @code{.text} section as follows: @example SECTIONS @{ - .text 0x2020 : - @{ - CREATE_OBJECT_SYMBOLS - *(.text) - _etext = ALIGN(0x2000); - @} - @dots{} + .text 0x2020 : + @{ + CREATE_OBJECT_SYMBOLS + *(.text) + _etext = ALIGN(0x2000); + @} + @dots{} @} @end example @@ -1624,10 +1642,10 @@ containing symbols matching the object file names: 00002068 t d.o @end example -@item @var{symbol} = @var{expression} ; @kindex @var{symbol} = @var{expression} ; -@itemx @var{symbol} @var{f}= @var{expression} ; @kindex @var{symbol} @var{f}= @var{expression} ; +@item @var{symbol} = @var{expression} ; +@itemx @var{symbol} @var{f}= @var{expression} ; @var{symbol} is any symbol name (@pxref{Symbols}). ``@var{f}='' refers to any of the operators @code{&= += -= *= /=} which combine arithmetic and assignment. @@ -1636,6 +1654,7 @@ arithmetic and assignment. When you assign a value to a symbol within a particular section definition, the value is relative to the beginning of the section (@pxref{Assignment}). If you write + @example SECTIONS @{ abs = 14 ; @@ -1645,20 +1664,21 @@ SECTIONS @{ @dots{} @} @end example + @c FIXME: Try above example! @noindent @code{abs} and @code{rel} do not have the same value; @code{rel} has the same value as @code{abs2}. -@item BYTE(@var{expression}) @kindex BYTE(@var{expression}) -@itemx SHORT(@var{expression}) @kindex SHORT(@var{expression}) -@itemx LONG(@var{expression}) @kindex LONG(@var{expression}) -@itemx QUAD(@var{expression}) @kindex QUAD(@var{expression}) @cindex direct output +@item BYTE(@var{expression}) +@itemx SHORT(@var{expression}) +@itemx LONG(@var{expression}) +@itemx QUAD(@var{expression}) By including one of these four statements in a section definition, you can explicitly place one, two, four, or eight bytes (respectively) at the current address of that section. @code{QUAD} is only supported when @@ -1693,7 +1713,7 @@ optional portions: SECTIONS @{ @dots{} @var{secname} @var{start} BLOCK(@var{align}) (NOLOAD) : AT ( @var{ldadr} ) - @{ @var{contents} @} =@var{fill} >@var{region} + @{ @var{contents} @} =@var{fill} >@var{region} @dots{} @} @end smallexample @@ -1705,29 +1725,30 @@ Definition}, and @pxref{Section Placement} for details on @code{=@var{fill}}, and @code{>@var{region}}---are all optional. @table @code -@item @var{start} @cindex start address, section @cindex section start @cindex section address +@item @var{start} You can force the output section to be loaded at a specified address by specifying @var{start} immediately following the section name. @var{start} can be represented as any expression. The following example generates section @var{output} at location @code{0x40000000}: + @example SECTIONS @{ - @dots{} - output 0x40000000: @{ - @dots{} - @} - @dots{} + @dots{} + output 0x40000000: @{ + @dots{} + @} + @dots{} @} @end example -@item BLOCK(@var{align}) @kindex BLOCK(@var{align}) @cindex section alignment @cindex aligning sections +@item BLOCK(@var{align}) You can include @code{BLOCK()} specification to advance the location counter @code{.} prior to the beginning of the section, so that the section will begin at the specified alignment. @var{align} is @@ -1744,8 +1765,8 @@ need to be loaded into each object file: @example SECTIONS @{ - ROM 0 (NOLOAD) : @{ @dots{} @} - @dots{} + ROM 0 (NOLOAD) : @{ @dots{} @} + @dots{} @} @end example @@ -1795,24 +1816,22 @@ for (dst = _bstart; dst< _bend; dst++) *dst = 0; @end smallexample -@item =@var{fill} @kindex =@var{fill} @cindex section fill pattern @cindex fill pattern, entire section -Including -@code{=@var{fill}} in a section definition specifies the initial fill -value for that section. -You may use any expression to specify @var{fill}. -Any unallocated holes in the current output -section when written to the output file will be filled with the two -least significant bytes of the value, repeated as necessary. You can -also change the fill value with a @code{FILL} statement in the -@var{contents} of a section definition. +@item =@var{fill} +Including @code{=@var{fill}} in a section definition specifies the +initial fill value for that section. You may use any expression to +specify @var{fill}. Any unallocated holes in the current output section +when written to the output file will be filled with the two least +significant bytes of the value, repeated as necessary. You can also +change the fill value with a @code{FILL} statement in the @var{contents} +of a section definition. -@item >@var{region} @kindex >@var{region} @cindex section, assigning to memory region @cindex memory regions and sections +@item >@var{region} Assign this section to a previously defined region of memory. @xref{MEMORY}. @@ -1858,6 +1877,7 @@ For example, you can use these rules to generate an entry point with an assignment statement: if no symbol @code{start} is defined within your input files, you can simply define it, assigning it an appropriate value--- + @example start = 0x2020; @end example @@ -1867,6 +1887,7 @@ The example shows an absolute address, but you can use any expression. For example, if your input object files use some other symbol-name convention for the entry point, you can just assign the value of whatever symbol contains the start address to @code{start}: + @example start = other_symbol ; @end example @@ -1895,6 +1916,7 @@ must arrange to actually run this code; GNU C++ calls constructors from a subroutine @code{__main}, which it inserts automatically into the startup code for @code{main}, and destructors from @code{_exit}.) +@need 1000 @kindex FLOAT @kindex NOFLOAT @item FLOAT @@ -2110,113 +2132,17 @@ not itself call any subroutines). @cindex back end @cindex object file management +@cindex object formats available +@kindex objdump -i The linker accesses object and archive files using the BFD libraries. These libraries allow the linker to use the same routines to operate on object files whatever the object file format. A different object file format can be supported simply by creating a new BFD back end and adding -it to the library. You can use @code{objdump -i} +it to the library. To conserve runtime memory, however, the linker and +associated tools are usually configured to support only a subset of the +object file formats available. You can use @code{objdump -i} (@pxref{objdump,,objdump,binutils.info,The GNU Binary Utilities}) to -list all the formats available for each architecture under BFD. This -was the list of formats, and of architectures supported for each format, -as of the time this manual was prepared: -@cindex formats available -@cindex architectures available -@example -BFD header file version 0.18 -a.out-i386 - (header big endian, data big endian) - m68k:68020 - a29k - sparc - i386 -a.out-sunos-big - (header big endian, data big endian) - m68k:68020 - a29k - sparc - i386 -b.out.big - (header big endian, data little endian) - i960:core -b.out.little - (header little endian, data little endian) - i960:core -coff-a29k-big - (header big endian, data big endian) - a29k -coff-h8300 - (header big endian, data big endian) - H8/300 -coff-i386 - (header little endian, data little endian) - i386 -coff-Intel-big - (header big endian, data little endian) - i960:core -coff-Intel-little - (header little endian, data little endian) - i960:core -coff-m68k - (header big endian, data big endian) - m68k:68020 -coff-m88kbcs - (header big endian, data big endian) - m88k:88100 -ecoff-bigmips - (header big endian, data big endian) - mips -ecoff-littlemips - (header little endian, data little endian) - mips -elf-big - (header big endian, data big endian) - m68k:68020 - vax - i960:core - a29k - sparc - mips - i386 - m88k:88100 - H8/300 - rs6000:6000 -elf-little - (header little endian, data little endian) - m68k:68020 - vax - i960:core - a29k - sparc - mips - i386 - m88k:88100 - H8/300 - rs6000:6000 -ieee - (header big endian, data big endian) - m68k:68020 - vax - i960:core - a29k - sparc - mips - i386 - m88k:88100 - H8/300 - rs6000:6000 -srec - (header big endian, data big endian) - m68k:68020 - vax - i960:core - a29k - sparc - mips - i386 - m88k:88100 - H8/300 - rs6000:6000 -@end example +list all the formats available for your configuration. @cindex BFD requirements @cindex requirements for BFD @@ -2274,9 +2200,9 @@ lower case; for example, @samp{chip} is the same as @samp{CHIP}. The following list shows only the upper-case form of each command. @table @code +@cindex @code{ABSOLUTE} (MRI) @item ABSOLUTE @var{secname} @item ABSOLUTE @var{secname}, @var{secname}, @dots{} @var{secname} -@cindex @code{ABSOLUTE} (MRI) Normally, @code{ld} includes in the output file all sections from all the input files. However, in an MRI-compatible script, you can use the @code{ABSOLUTE} command to restrict the sections that will be present in @@ -2286,31 +2212,32 @@ commands will appear in the linker output. You can still use other input sections (whatever you select on the command line, or using @code{LOAD}) to resolve addresses in the output file. -@item ALIAS @var{out-secname}, @var{in-secname} @cindex @code{ALIAS} (MRI) +@item ALIAS @var{out-secname}, @var{in-secname} Use this command to place the data from input section @var{in-secname} in a section called @var{out-secname} in the linker output file. @var{in-secname} may be an integer. -@item BASE @var{expression} @cindex @code{BASE} (MRI) +@item BASE @var{expression} Use the value of @var{expression} as the lowest address (other than absolute addresses) in the output file. +@cindex @code{CHIP} (MRI) @item CHIP @var{expression} @itemx CHIP @var{expression}, @var{expression} -@cindex @code{CHIP} (MRI) This command does nothing; it is accepted only for compatibility. -@item END @cindex @code{END} (MRI) +@item END This command does nothing whatever; it's only accepted for compatibility. -@item FORMAT @var{output-format} @cindex @code{FORMAT} (MRI) +@item FORMAT @var{output-format} Similar to the @code{OUTPUT_FORMAT} command in the more general linker language, but restricted to one of these output formats: + @enumerate @item S-records, if @var{output-format} is @samp{S} @@ -2323,47 +2250,47 @@ COFF (the @samp{coff-m68k} variant in BFD), if @var{output-format} is @samp{COFF} @end enumerate -@item LIST @var{anything}@dots{} @cindex @code{LIST} (MRI) +@item LIST @var{anything}@dots{} Print (to the standard output file) a link map, as produced by the @code{ld} command-line option @samp{-M}. The keyword @code{LIST} may be followed by anything on the same line, with no change in its effect. +@cindex @code{LOAD} (MRI) @item LOAD @var{filename} @item LOAD @var{filename}, @var{filename}, @dots{} @var{filename} -@cindex @code{LOAD} (MRI) Include one or more object file @var{filename} in the link; this has the same effect as specifying @var{filename} directly on the @code{ld} command line. -@item NAME @var{output-name} @cindex @code{NAME} (MRI) +@item NAME @var{output-name} @var{output-name} is the name for the program produced by @code{ld}; the MRI-compatible command @code{NAME} is equivalent to the command-line option @samp{-o} or the general script language command @code{OUTPUT}. +@cindex @code{ORDER} (MRI) @item ORDER @var{secname}, @var{secname}, @dots{} @var{secname} @itemx ORDER @var{secname} @var{secname} @var{secname} -@cindex @code{ORDER} (MRI) Normally, @code{ld} orders the sections in its output file in the order in which they first appear in the input files. In an MRI-compatible script, you can override this ordering with the @code{ORDER} command. The sections you list with @code{ORDER} will appear first in your output file, in the order specified. +@cindex @code{PUBLIC} (MRI) @item PUBLIC @var{name}=@var{expression} @itemx PUBLIC @var{name},@var{expression} @itemx PUBLIC @var{name} @var{expression} -@cindex @code{PUBLIC} (MRI) Supply a value (@var{expression}) for external symbol @var{name} used in the linker input files. +@cindex @code{SECT} (MRI) @item SECT @var{secname}, @var{expression} @itemx SECT @var{secname}=@var{expression} @itemx SECT @var{secname} @var{expression} -@cindex @code{SECT} (MRI) You can use any of these three forms of the @code{SECT} command to specify the start address (@var{expression}) for section @var{secname}. If you have more than one @code{SECT} statement for the same |