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   as    ( 1 )

портативный ассемблер GNU (the portable GNU assembler.)

Имя (Name)

AS - the portable GNU assembler.


Синопсис (Synopsis)

as [-a[cdghlns][=file]] [--alternate] [-D] [--compress-debug-sections] [--nocompress-debug-sections] [--debug-prefix-map old=new] [--defsym sym=val] [-f] [-g] [--gstabs] [--gstabs+] [--gdwarf-<N>] [--gdwarf-sections] [--gdwarf-cie-version=VERSION] [--help] [-I dir] [-J] [-K] [-L] [--listing-lhs-width=NUM] [--listing-lhs-width2=NUM] [--listing-rhs-width=NUM] [--listing-cont-lines=NUM] [--keep-locals] [--no-pad-sections] [-o objfile] [-R] [--statistics] [-v] [-version] [--version] [-W] [--warn] [--fatal-warnings] [-w] [-x] [-Z] [@FILE] [--sectname-subst] [--size-check=[error|warning]] [--elf-stt-common=[no|yes]] [--generate-missing-build-notes=[no|yes]] [--target-help] [target-options] [--|files ...]


Описание (Description)

GNU as is really a family of assemblers. If you use (or have used) the GNU assembler on one architecture, you should find a fairly similar environment when you use it on another architecture. Each version has much in common with the others, including object file formats, most assembler directives (often called pseudo-ops) and assembler syntax.

as is primarily intended to assemble the output of the GNU C compiler "gcc" for use by the linker "ld". Nevertheless, we've tried to make as assemble correctly everything that other assemblers for the same machine would assemble. Any exceptions are documented explicitly. This doesn't mean as always uses the same syntax as another assembler for the same architecture; for example, we know of several incompatible versions of 680x0 assembly language syntax.

Each time you run as it assembles exactly one source program. The source program is made up of one or more files. (The standard input is also a file.)

You give as a command line that has zero or more input file names. The input files are read (from left file name to right). A command-line argument (in any position) that has no special meaning is taken to be an input file name.

If you give as no file names it attempts to read one input file from the as standard input, which is normally your terminal. You may have to type ctl-D to tell as there is no more program to assemble.

Use -- if you need to explicitly name the standard input file in your command line.

If the source is empty, as produces a small, empty object file.

as may write warnings and error messages to the standard error file (usually your terminal). This should not happen when a compiler runs as automatically. Warnings report an assumption made so that as could keep assembling a flawed program; errors report a grave problem that stops the assembly.

If you are invoking as via the GNU C compiler, you can use the -Wa option to pass arguments through to the assembler. The assembler arguments must be separated from each other (and the -Wa) by commas. For example:

gcc -c -g -O -Wa,-alh,-L file.c

This passes two options to the assembler: -alh (emit a listing to standard output with high-level and assembly source) and -L (retain local symbols in the symbol table).

Usually you do not need to use this -Wa mechanism, since many compiler command-line options are automatically passed to the assembler by the compiler. (You can call the GNU compiler driver with the -v option to see precisely what options it passes to each compilation pass, including the assembler.)