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Subsections
3.2 Command Line Options
3.2.1 Processor Selection Options
- [-mmcs51]Generate code for the Intel MCS51
family of processors. This is the default processor target.
- [-mds390]Generate code for the Dallas DS80C390
processor.
- [-mds400]Generate code for the Dallas DS80C400
processor.
- [-mz80]Generate code for the Zilog Z80
family of processors.
- [-mgbz80]Generate code for the GameBoy Z80
processor.
- [-mavr]Generate code for the Atmel AVR
processor (In development, not complete). AVR users should probably
have a look at avr-gcc http://savannah.nongnu.org/download/avr-libc/snapshots/.
- [-mpic14]Generate code for the Microchip
PIC 14-bit processors (p16f84 and variants).
- [-mpic16]Generate code for the Microchip
PIC 16-bit processors (p18f452 and variants).
- [-mtlcs900h]Generate code for the Toshiba TLCS-900H
processor (In development, not complete).
- [-mxa51]Generate code for the Phillips XA51
processor (In development, not complete).
3.2.2 Preprocessor Options
- [-I<path>]The additional location where
the pre processor will look for <..h> or ``..h'' files.
- [-D<macro[=value]>]Command
line definition of macros. Passed to the preprocessor.
- [-M]Tell the preprocessor to output a rule suitable
for make describing the dependencies of each object file. For each
source file, the preprocessor outputs one make-rule whose target is
the object file name for that source file and whose dependencies are
all the files `#include'd in it. This rule may be a single line or
may be continued with `\'-newline if it is long. The
list of rules is printed on standard output instead of the preprocessed
C program. `-M' implies `-E'.
- [-C]Tell the preprocessor not to discard comments.
Used with the `-E' option.
- [-MM]Like `-M' but the output mentions only
the user header files included with `#include ``file"'.
System header files included with `#include <file>' are omitted.
- [-Aquestion(answer)]Assert the
answer answer for question, in case it is tested with a preprocessor
conditional such as `#if #question(answer)'. `-A-' disables the
standard assertions that normally describe the target machine.
- [-Umacro]Undefine macro macro. `-U' options
are evaluated after all `-D' options, but before any `-include' and
`-imacros' options.
- [-dM]Tell the preprocessor to output only a
list of the macro definitions that are in effect at the end of preprocessing.
Used with the `-E' option.
- [-dD]Tell the preprocessor to pass all macro
definitions into the output, in their proper sequence in the rest
of the output.
- [-dN]Like `-dD' except that the macro arguments
and contents are omitted. Only `#define name' is included in the
output.
3.2.3 Linker Options
- [-L --lib-path]<absolute
path to additional libraries> This option is passed to the linkage
editor's additional libraries search path. The path
name must be absolute. Additional library files may be specified in
the command line. See section Compiling programs for more details.
- [--xram-loc<Value>]The start location
of the external ram, default value is 0. The value entered
can be in Hexadecimal or Decimal format, e.g.: --xram-loc 0x8000
or --xram-loc 32768.
- [--code-loc<Value>]The start location
of the code segment, default value 0. Note when this
option is used the interrupt vector table is also relocated to the
given address. The value entered can be in Hexadecimal or Decimal
format, e.g.: --code-loc 0x8000 or --code-loc 32768.
- [--stack-loc<Value>]By default
the stack is placed after the data segment. Using this
option the stack can be placed anywhere in the internal memory space
of the 8051. The value entered can be in Hexadecimal or Decimal format,
e.g. --stack-loc 0x20 or --stack-loc 32. Since the sp register
is incremented before a push or call, the initial sp will be set to
one byte prior the provided value. The provided value should not overlap
any other memory areas such as used register banks or the data segment
and with enough space for the current application.
- [--data-loc<Value>]The start location
of the internal ram data segment. The value entered can
be in Hexadecimal or Decimal format, eg. --data-loc 0x20 or --data-loc
32. (By default, the start location of the internal ram data segment
is set as low as possible in memory, taking into account the used
register banks and the bit segment at address 0x20. For example if
register banks 0 and 1 are used without bit variables, the data segment
will be set, if --data-loc is not used, to location 0x10.)
- [--idata-loc<Value>]The start location
of the indirectly addressable internal ram, default
value is 0x80. The value entered can be in Hexadecimal or Decimal
format, eg. --idata-loc 0x88 or --idata-loc 136.
- [--out-fmt-ihx]The linker output
(final object code) is in Intel Hex format.
(This is the default option).
- [--out-fmt-s19]The linker output
(final object code) is in Motorola S19 format.
3.2.4 MCS51 Options
- [--model-small]Generate code
for Small Model programs see section Memory Models for more details.
This is the default model.
- [--model-large]Generate code
for Large model programs see section Memory Models for more details.
If this option is used all source files in the project should be compiled
with this option.
- [--xstack]Uses a pseudo stack in the
first 256 bytes in the external ram for allocating variables and passing
parameters. See section on external stack for more details.
- [--iram-size<Value>]Causes
the linker to check if the internal ram usage is within limits of
the given value.
- [--xram-size<Value>]Causes
the linker to check if the external ram usage is within limits of
the given value.
- [--code-size<Value>]Causes the linker
to check if the code memory usage is within limits of the given value.
3.2.5 DS390 Options
- [--model-flat24]Generate 24-bit
flat mode code. This is the one and only that the ds390 code generator
supports right now and is default when using -mds390. See section
Memory Models for more details.
- [--stack-10bit]Generate code
for the 10 bit stack mode of the Dallas DS80C390 part. This is the
one and only that the ds390 code generator supports right now and
is default when using -mds390. In this mode, the stack is located
in the lower 1K of the internal RAM, which is mapped to 0x400000.
Note that the support is incomplete, since it still uses a single
byte as the stack pointer. This means that only the lower 256 bytes
of the potential 1K stack space will actually be used. However, this
does allow you to reclaim the precious 256 bytes of low RAM for use
for the DATA and IDATA segments. The compiler will not generate any
code to put the processor into 10 bit stack mode. It is important
to ensure that the processor is in this mode before calling any re-entrant
functions compiled with this option. In principle, this should work
with the --stack-auto option, but
that has not been tested. It is incompatible with the --xstack
option. It also only makes sense if the processor is in 24 bit contiguous
addressing mode (see the --model-flat24 option).
3.2.6 Z80 Options
- [--callee-saves-bc]Force
a called function to always save BC.
- [--no-std-crt0]When linking,
skip the standard crt0.o object file. You must provide your own crt0.o
for your system when linking.
3.2.7 Optimization Options
- [--nogcse]Will not do global subexpression
elimination, this option may be used when the compiler creates undesirably
large stack/data spaces to store compiler temporaries. A warning message
will be generated when this happens and the compiler will indicate
the number of extra bytes it allocated. It recommended that this option
NOT be used, #pragma NOGCSE can be used
to turn off global subexpression elimination
for a given function only.
- [--noinvariant]Will not do loop
invariant optimizations, this may be turned off for reasons explained
for the previous option. For more details of loop optimizations performed
see section Loop Invariants.It recommended that this option NOT be
used, #pragma NOINVARIANT can be used
to turn off invariant optimizations for a given function only.
- [--noinduction]Will not do loop
induction optimizations, see section strength reduction for more details.It
is recommended that this option is NOT used, #pragma NOINDUCTION
can be used to turn off induction optimizations for a given function
only.
- [--nojtbound] Will not generate
boundary condition check when switch statements
are implemented using jump-tables. See section Switch Statements for
more details. It is recommended that this option is NOT used, #pragma NOJTBOUND
can be used to turn off boundary checking for jump tables for a given
function only.
- [--noloopreverse]Will not do
loop reversal optimization.
- [--nolabelopt]Will not optimize
labels (makes the dumpfiles more readable).
- [--no-xinit-opt]Will not memcpy
initialized data from code space into xdata space. This saves a few
bytes in code space if you don't have initialized data.
3.2.8 Other Options
- [-c --compile-only]will
compile and assemble the source, but will not call the linkage editor.
- [--c1mode]reads the preprocessed
source from standard input and compiles it. The file name for the
assembler output must be specified using the -o option.
- [-E]Run only the C preprocessor. Preprocess all
the C source files specified and output the results to standard output.
- [-o <path/file>]The output path
resp. file where everything will be placed. If the parameter is a
path, it must have a trailing slash (or backslash for the Windows
binaries) to be recognized as a path.
- [--stack-auto]All functions in
the source file will be compiled as reentrant,
i.e. the parameters and local variables will be allocated on the stack.
see section Parameters and Local Variables for more details. If this
option is used all source files in the project should be compiled
with this option.
- [--callee-saves]function1[,function2][,function3]....
The compiler by default uses a caller saves convention for register
saving across function calls, however this can cause unnecessary register
pushing & popping when calling small functions from larger functions.
This option can be used to switch the register saving convention for
the function names specified. The compiler will not save registers
when calling these functions, no extra code will be generated at the
entry & exit (function prologue
& epilogue) for these functions
to save & restore the registers used by these functions, this can
SUBSTANTIALLY reduce code & improve run time performance of the generated
code. In the future the compiler (with inter procedural analysis)
will be able to determine the appropriate scheme to use for each function
call. DO NOT use this option for built-in functions such as _mulint...,
if this option is used for a library function the appropriate library
function needs to be recompiled with the same option. If the project
consists of multiple source files then all the source file should
be compiled with the same --callee-saves option string. Also see
#pragma CALLEE-SAVES.
- [--debug]When this option is used the
compiler will generate debug information, that can be used with the
SDCDB. The debug information is collected in a file with .cdb extension.
For more information see documentation for SDCDB.
- [-S]Stop after the stage of compilation proper;
do not assemble. The output is an assembler code file for the input
file specified.
- [-Wa_asmOption[,asmOption]...]Pass
the asmOption to the assembler.
- [-Wl_linkOption[,linkOption]...]Pass
the linkOption to the linker.
- [--int-long-reent]Integer
(16 bit) and long (32 bit) libraries have been compiled as reentrant.
Note by default these libraries are compiled as non-reentrant. See
section Installation for more details.
- [--cyclomatic]This option will
cause the compiler to generate an information message for each function
in the source file. The message contains some important information
about the function. The number of edges and nodes the compiler detected
in the control flow graph of the function, and most importantly the
cyclomatic complexity see section
on Cyclomatic Complexity for more details.
- [--float-reent] Floating point
library is compiled as reentrant. See section Installation
for more details.
- [--nooverlay] The compiler will
not overlay parameters and local variables of any function, see section
Parameters and local variables for more details.
- [--main-return]This option can
be used when the code generated is called by a monitor program. The
compiler will generate a 'ret' upon return from the 'main'
function. The default option is to lock up i.e. generate a 'ljmp
.'.
- [--peep-file<filename>]This option
can be used to use additional rules to be used by the peep hole optimizer.
See section Peep Hole optimizations for details on how to write these
rules.
- [--no-peep] Disable peep-hole optimization.
- [--peep-asm] Pass the inline assembler
code through the peep hole optimizer. This can cause unexpected changes
to inline assembler code, please go through the peephole optimizer
rules defined in the source file tree '<target>/peeph.def' before
using this option.
- [--nostdincl]This will prevent
the compiler from passing on the default include path to the preprocessor.
- [--nostdlib]This will prevent the
compiler from passing on the default library path
to the linker.
- [--verbose]Shows the various actions
the compiler is performing.
- [-V]Shows the actual commands the compiler is
executing.
- [--no-c-code-in-asm]Hides
your ugly and inefficient c-code from the asm file, so you can always
blame the compiler :).
- [--i-code-in-asm]Include i-codes
in the asm file. Sounds like noise but is most helpful for debugging
the compiler itself.
- [--less-pedantic]Disable some
of the more pedantic warnings (jwk burps: please be more specific
here, please!)
- [--print-search-dirs]Display
the directories in the compiler's search path
- [--vc]Display errors and warnings using
MSVC style, so you can use SDCC with visual studio.
- [--use-stdout]Send errors and
warnings to stdout instead of stderr.
3.2.9 Intermediate Dump Options
The following options are provided for the purpose of retargetting
and debugging the compiler. These provided a means to dump the intermediate
code (iCode) generated by the compiler in human readable
form at various stages of the compilation process.
- [--dumpraw]This option will cause
the compiler to dump the intermediate code into a file of named <source
filename>.dumpraw just after the intermediate code has been generated
for a function, i.e. before any optimizations are done. The basic
blocks at this stage ordered in the depth first
number, so they may not be in sequence of execution.
- [--dumpgcse]Will create a dump of
iCode's, after global subexpression elimination,
into a file named <source filename>.dumpgcse.
- [--dumpdeadcode]Will create
a dump of iCode's, after deadcode elimination,
into a file named <source filename>.dumpdeadcode.
- [--dumploop]Will create a dump of
iCode's, after loop optimizations, into
a file named <source filename>.dumploop.
- [--dumprange]Will create a dump
of iCode's, after live range analysis,
into a file named <source filename>.dumprange.
- [--dumlrange]Will dump the life
ranges for all symbols.
- [--dumpregassign]Will create
a dump of iCode's, after register assignment,
into a file named <source filename>.dumprassgn.
- [--dumplrange]Will create a dump
of the live ranges of iTemp's
- [--dumpall]Will cause all the above
mentioned dumps to be created.
By default SDCC writes it's error messages to ''standard error''.
To force all messages to ''standard output'' use --use-stdout.
Aditionaly, if you happen to have visual studio installed in your
windows machine, you can use it to compile your sources using a custom
build and the SDCC --vc option. Something
like this should work:
c:\sdcc\bin\sdcc.exe
--vc --model-large -c $(InputPath)
Next: 3.3 Environment variables
Up: 3 Using SDCC
Previous: 3.1 Compiling
  Contents
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Bernhard Held
2003-08-29