espressif/binutils-gdb
1
0
Fork 0
mirror of https://github.com/espressif/binutils-gdb.git synced 2025-06-22 19:09:31 +08:00
Code Issues Packages Projects Releases Wiki Activity

error fixes and clarifications

Browse Source
This commit is contained in:
David MacKenzie
1993-08-05 22:49:26 +00:00
parent a9cad59194
commit 867a1b8a18
1 changed files with 89 additions and 84 deletions
Download Patch File Download Diff File Expand all files Collapse all files

173
ld/ld.texinfo
View File

@ -173,8 +173,8 @@ ld [ -o @var{output} ] @var{objfile}@dots{}
[ -m @var{emulation} ] [ -N | -n ] [ -noinhibit-exec ]
[ -oformat @var{output-format} ] [ -R @var{filename} ] [ -relax ]
[ -r | -Ur ] [ -S ] [ -s ] [ -sort-common ] [ -T @var{commandfile} ]
[ -Ttext @var{textorg} ] [ -Tdata @var{dataorg} ]
[ -Tbss @var{bssorg} ] [ -t ] [ -u @var{symbol}] [-V] [-v] [ --version ]
[ -Ttext @var{org} ] [ -Tdata @var{org} ]
[ -Tbss @var{org} ] [ -t ] [ -u @var{symbol}] [-V] [-v] [ --version ]
[ -warn-common ] [ -y@var{symbol} ] [ -X ] [-x ]
@end smallexample
@ -269,7 +269,7 @@ The default format is taken from the environment variable
@xref{Environment}.
@end ifset
You can also define the input
format from a script, using the command @code{TARGET}; see @ref{Other
format from a script, using the command @code{TARGET}; see @ref{Option
Commands}.
@end ifclear
@ -300,7 +300,7 @@ These three options are equivalent; multiple forms are supported for
compatibility with other linkers. They
assign space to common symbols even if a relocatable output file is
specified (with @samp{-r}). The script command
@code{FORCE_COMMON_ALLOCATION} has the same effect. @xref{Other
@code{FORCE_COMMON_ALLOCATION} has the same effect. @xref{Option
Commands}.
@cindex symbols, from command line
@ -333,11 +333,11 @@ entry point.
Ignored. Some older linkers used this option throughout a compilation
toolchain for specifying object-file format for both input and output
object files. The mechanisms @code{ld} uses for this purpose (the
@samp{-b} or @samp{-format} options for input files, the @code{TARGET}
command in linker scripts for output files, the @code{GNUTARGET}
environment variable) are more flexible, but @code{ld} accepts the
@samp{-F} option for compatibility with scripts written to call the old
linker.
@samp{-b} or @samp{-format} options for input files, @samp{-oformat}
option or the @code{TARGET} command in linker scripts for output files,
the @code{GNUTARGET} environment variable) are more flexible, but
@code{ld} accepts the @samp{-F} option for compatibility with scripts
written to call the old linker.
@kindex -format
@item -format @var{input-format}
@ -459,10 +459,10 @@ overrides it. @xref{BFD}.
@item -R @var{filename}
@kindex -R @var{file}
@cindex symbol-only input
On some platforms, this option performs global optimizations
that become possible when the linker resolves addressing in the
program, such as relaxing address modes and synthesizing new
instructions in the output object file.
Read symbol names and their addresses from @var{filename}, but do not
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
@ -496,7 +496,7 @@ If this option is not specified, an absolute file is produced. When
linking C++ programs, this option @emph{will not} resolve references to
constructors; to do that, use @samp{-Ur}.
This option does the same as @code{-i}.
This option does the same thing as @samp{-i}.
@item -S
@kindex -S
@ -514,12 +514,12 @@ appropriate output sections, it sorts them by size. First come all the
one byte symbols, then all the two bytes, then all the four bytes, and
then everything else. This option disables that sorting.
@item -Tbss @var{bssorg}
@kindex -Tbss @var{bssorg}
@itemx -Tdata @var{dataorg}
@kindex -Tdata @var{dataorg}
@itemx -Ttext @var{textorg}
@kindex -Ttext @var{textorg}
@item -Tbss @var{org}
@kindex -Tbss @var{org}
@itemx -Tdata @var{org}
@kindex -Tdata @var{org}
@itemx -Ttext @var{org}
@kindex -Ttext @var{org}
@cindex segment origins, cmd line
Use @var{org} as the starting address for---respectively---the
@code{bss}, @code{data}, or the @code{text} segment of the output file.
@ -717,7 +717,7 @@ input files
@item
file formats
@item
output file format
output file layout
@item
addresses of sections
@item
@ -727,8 +727,7 @@ placement of common blocks
You may supply a command file (also known as a link script) to the
linker either explicitly through the @samp{-T} option, or implicitly as
an ordinary file. If the linker opens a file which it cannot recognize
as a supported object or archive format, it tries to interpret the file
as a command file.
as a supported object or archive format, it reports an error.
@menu
* Scripts:: Linker Scripts
@ -736,7 +735,7 @@ as a command file.
* MEMORY:: MEMORY Command
* SECTIONS:: SECTIONS Command
* Entry Point:: The Entry Point
* Other Commands:: Other Commands
* Option Commands:: Option Commands
@end menu
@node Scripts
@ -795,7 +794,7 @@ You may call special purpose built-in functions.
* Operators:: Operators
* Evaluation:: Evaluation
* Assignment:: Assignment: Defining Symbols
* Built-ins:: Built-In Functions
* Arithmetic Functions:: Built-In Functions
@end menu
@node Integers
@ -1043,7 +1042,7 @@ relative to a particular section (@pxref{SECTIONS}).
When a linker expression is evaluated and assigned to a variable, it is
given either an absolute or a relocatable type. An absolute expression
type is one in which the symbol contains the value that it will have in
the output file, a relocatable expression type is one in which the
the output file; a relocatable expression type is one in which the
value is expressed as a fixed offset from the base of a section.
The type of the expression is controlled by its position in the script
@ -1086,8 +1085,8 @@ SECTIONS @{ @dots{}
will cause the error message ``@code{Non constant expression for initial
address}''.
@node Built-ins
@subsection Built-In Functions
@node Arithmetic Functions
@subsection Arithmetic Functions
@cindex functions in expression language
The command language includes a number of built-in
functions for use in link script expressions.
@ -1211,7 +1210,7 @@ paging.
@end table
@node MEMORY
@section MEMORY Command
@section Memory Layout
@kindex MEMORY
@cindex regions of memory
@cindex discontinuous memory
@ -1225,7 +1224,7 @@ must avoid. The linker does not shuffle sections to fit into the
available regions, but does move the requested sections into the correct
regions and issue errors when the regions become too full.
The command files may contain at most one use of the @code{MEMORY}
A command file may contain at most one use of the @code{MEMORY}
command; however, you can define as many blocks of memory within it as
you wish. The syntax is:
@ -1257,7 +1256,7 @@ omit the parentheses around it as well.
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}.
abbreviated to @code{org} or @code{o} (but not, for example, @samp{ORG}).
@item @var{len}
@kindex LENGTH =
@kindex len =
@ -1285,13 +1284,13 @@ Options}). If the combined output sections directed to a region are too
big for the region, the linker will issue an error message.
@node SECTIONS
@section SECTIONS Command
@section Specifying Output Sections
@kindex SECTIONS
The @code{SECTIONS} command controls exactly where input sections are
placed into output sections, their order and to which output sections
they are allocated.
placed into output sections, their order in the output file, and to
which output sections they are allocated.
You may use at most one @code{SECTIONS} command in a commands file,
You may use at most one @code{SECTIONS} command in a script file,
but you can have as many statements within it as you wish. Statements
within the @code{SECTIONS} command can do one of three things:
@itemize @bullet
@ -1300,27 +1299,27 @@ define the entry point;
@item
assign a value to a symbol;
@item
describe the placement of a named output section, and what input
sections make it up.
describe the placement of a named output section, and which input
sections go into it.
@end itemize
The first two possibilities---defining the entry point, and defining
The first two operations---defining the entry point and defining
symbols---can also be done outside the @code{SECTIONS} command:
@pxref{Entry Point}, @pxref{Assignment}. They are permitted here as
well for your convenience in reading the script, so that symbols or the
@pxref{Entry Point}, and @pxref{Assignment}. They are permitted here as
well for your convenience in reading the script, so that symbols and the
entry point can be defined at meaningful points in your output-file
layout.
When no @code{SECTIONS} command is specified, the default action
of the linker is to place each input section into an identically named
output section in the order that the sections are first encountered in
the input files; if all input sections are present in the first file,
for example, the order of sections in the output file will match the
order in the first input file.
When no @code{SECTIONS} command is given, the linker places each input
section into an identically named output section in the order that the
sections are first encountered in the input files. If all input sections
are present in the first file, for example, the order of sections in the
output file will match the order in the first input file.
@menu
* Section Definition:: Section Definitions
* Section Contents:: Section Contents
* Section Placement:: Section Placement
* Section Data Expressions:: Section Data Expressions
* Section Options:: Optional Section Attributes
@end menu
@ -1328,7 +1327,7 @@ order in the first input file.
@subsection Section Definitions
@cindex section definition
The most frequently used statement in the @code{SECTIONS} command is
the @dfn{section definition}, which you can use to specify the
the @dfn{section definition}, which specifies the
properties of an output section: its location, alignment, contents,
fill pattern, and target memory region. Most of
these specifications are optional; the simplest form of a section
@ -1344,9 +1343,9 @@ SECTIONS @{ @dots{}
@noindent
@var{secname} is the name of the output section, and @var{contents} a
specification of what goes there---for example, a list of input files or
sections of input files. As you might assume, the whitespace shown is
optional. You do need the colon @samp{:} and the braces @samp{@{@}},
however.
sections of input files (@pxref{Section Placement}). As you might
assume, the whitespace shown is optional. You do need the colon
@samp{:} and the braces @samp{@{@}}, however.
@var{secname} must meet the constraints of your output format. In
formats which only support a limited number of sections, such as
@ -1355,15 +1354,15 @@ formats which only support a limited number of sections, such as
@code{.bss}). If the output format supports any number of sections, but
with numbers and not names (as is the case for Oasys), the name should be
supplied as a quoted numeric string. A section name may consist of any
sequence characters, but any name which does not conform to the standard
sequence of characters, but any name which does not conform to the standard
@code{ld} symbol name syntax must be quoted.
@xref{Symbols, , Symbol Names}.
@node Section Contents
@subsection Section Contents
@node Section Placement
@subsection Section Placement
@cindex contents of a section
In a section definition, you can specify the contents of an output section by
listing particular object files, by listing particular input-file
listing particular input files, by listing particular input-file
sections, or by a combination of the two. You can also place arbitrary
data in the section, and define symbols relative to the beginning of the
section.
@ -1380,8 +1379,11 @@ whitespace.
@cindex files, including in output sections
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. To specify a list of particular files by
name:
current section definition. If the file name has already been mentioned
in another section definition, with an explicit section name list, then
only those sections which have not yet been allocated are used.
To specify a list of particular files by name:
@example
.data : @{ afile.o bfile.o cfile.o @}
@end example
@ -1390,10 +1392,6 @@ 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.
If the file name has already been mentioned in another section
definition, with an explicit section name list, then only those sections
which have not yet been allocated are used.
@item @var{filename}( @var{section} )
@itemx @var{filename}( @var{section}, @var{section}, @dots{} )
@itemx @var{filename}( @var{section} @var{section} @dots{} )
@ -1414,6 +1412,10 @@ script, you can refer to @emph{all} files from the @code{ld} command
line: use @samp{*} instead of a particular file name before the
parenthesized input-file section list.
If you have already explicitly included some files by name, @samp{*}
refers to all @emph{remaining} files---those whose places in the output
file have not yet been defined.
For example, to copy sections @code{1} through @code{4} from an Oasys file
into the @code{.text} section of an @code{a.out} file, and sections @code{13}
and @code{14} into the @code{.data} section:
@ -1429,10 +1431,6 @@ SECTIONS @{
@}
@end example
If you have already explicitly included some files by name, @samp{*}
refers to all @emph{remaining} files---those whose places in the output
file have not yet been defined.
@item [ @var{section} ]
@itemx [ @var{section}, @var{section}, @dots{} ]
@itemx [ @var{section} @var{section} @dots{} ]
@ -1498,8 +1496,10 @@ SECTIONS @{
@}
@end example
There are still more kinds of statements permitted in the contents of
output section definitions. The foregoing statements permitted you to
@node Section Data Expressions
@subsection Section Data Expressions
@cindex expressions in a section
The foregoing statements
arrange, in your output file, data originating from your input files.
You can also place data directly in an output section from the link
command script. Most of these additional statements involve
@ -1515,7 +1515,7 @@ intermix them freely with any of the statements we've just described.
@cindex filename symbols
Create a symbol for each input file
in the current section, set to the address of the first byte of
data written from the input file. For instance, with @code{a.out}
data written from that input file. For instance, with @code{a.out}
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
@ -1530,7 +1530,7 @@ SECTIONS @{
@}
@end example
If @code{objsym} is a file containing this script, and @code{a.o},
If @code{sample.ld} is a file containing this script, and @code{a.o},
@code{b.o}, @code{c.o}, and @code{d.o} are four input files with
contents like the following---
@example
@ -1542,7 +1542,7 @@ int abss;
@end example
@noindent
@samp{ld -M sample a.o b.o c.o d.o} would create a map like this,
@samp{ld -M -T sample.ld a.o b.o c.o d.o} would create a map like this,
containing symbols matching the object file names:
@example
00000000 A __DYNAMIC
@ -1613,7 +1613,7 @@ appropriate for the output file format (@pxref{BFD}).
@kindex FILL(@var{expression})
@cindex holes, filling
@cindex unspecified memory
Specifies the ``fill pattern'' for the current section. Any otherwise
Specify the ``fill pattern'' for the current section. Any otherwise
unspecified regions of memory within the section (for example, regions
you skip over by assigning a new value to the location counter @samp{.})
are filled with the two least significant bytes from the
@ -1638,7 +1638,7 @@ SECTIONS @{
@end smallexample
@var{secname} and @var{contents} are required. @xref{Section
Definition}, and @pxref{Section Contents} for details on @var{contents}.
Definition}, and @pxref{Section Placement} for details on @var{contents}.
The remaining elements---@var{start}, @code{BLOCK(@var{align)}},
@code{(NOLOAD)} @code{=@var{fill}}, and @code{>@var{region}}---are all
optional.
@ -1762,8 +1762,8 @@ whatever symbol contains the start address to @code{start}:
start = other_symbol ;
@end example
@node Other Commands
@section Other Commands
@node Option Commands
@section Option Commands
The command language includes a number of other commands that you can
use for specialized purposes. They are similar in purpose to
command-line options.
@ -1808,10 +1808,10 @@ way are treated identically to object files listed on the command line.
@cindex naming the output file
Use this command to name the link output file @var{filename}. The
effect of @code{OUTPUT(@var{filename})} is identical to the effect of
@w{@samp{-o @var{filename}}}, and whichever is encountered last will
control the name actually used to name the output file. In particular,
you can use this command to supply a default output-file name other than
@code{a.out}.
@w{@samp{-o @var{filename}}}, and whichever is encountered last
(@samp{-T} or @samp{-o} will control the name actually used to name the
output file. In particular, you can use this command to supply a
default output-file name other than @code{a.out}.
@ifclear SingleFormat
@item OUTPUT_ARCH ( @var{bfdname} )
@ -1827,7 +1827,9 @@ command.
@kindex OUTPUT_FORMAT ( @var{bfdname} )
@cindex format, output file
Specify a particular output format, with one of the names used by the
BFD back-end routines (@pxref{BFD}). This selection will only affect
BFD back-end routines (@pxref{BFD}). The effect is identical to the
effect of the @samp{-oformat} command-line option.
This selection will only affect
the output file; the related command @code{TARGET} affects primarily
input files.
@end ifclear
@ -1852,11 +1854,10 @@ process.
@kindex TARGET ( @var{format} )
Change the input-file object code format (like the command-line option
@samp{-b} or its synonym @samp{-format}). The argument @var{format} is
one of the strings used by BFD to name binary formats. In the current
@code{ld} implementation, if @code{TARGET} is specified but
@code{OUTPUT_FORMAT} is not, the last @code{TARGET} argument is also
used as the default format for the @code{ld} output file.
@xref{BFD}.
one of the strings used by BFD to name binary formats. If @code{TARGET}
is specified but @code{OUTPUT_FORMAT} is not, the last @code{TARGET}
argument is also used as the default format for the @code{ld} output
file. @xref{BFD}.
@kindex GNUTARGET
If you don't use the @code{TARGET} command, @code{ld} uses the value of
@ -2109,6 +2110,10 @@ scripts have a much simpler command set than the scripting language
otherwise used with @code{ld}. @sc{gnu} @code{ld} supports the most
commonly used MRI linker commands; these commands are described here.
In general, MRI scripts aren't of much use with the @code{a.out} object
file format, since it only has three sections and MRI scripts lack some
features to make use of them.
You can specify a file containing an MRI-compatible script using the
@samp{-c} command-line option.