Red Hat ENTERPRISE LINUX 4 Manual page 83

Chapter 4. GCC Command Options
This option does not suppress the preprocessor's debug output, such as
debug output with the dependency rules you should explicitly specify the dependency output file
with , or use an environment variable like
-MF
ment Variables Affecting GCC). Debug output will still be sent to the regular output stream as
normal.
Passing to the driver implies
-M
-MM
Like but do not mention header files that are found in system header directories, nor header
-M
files that are included, directly or indirectly, from such a header.
This implies that the choice of angle brackets or double quotes in an
not in itself determine whether that header will appear in
change in semantics from GCC versions 3.0 and earlier.
-MF
file
When used with
the preprocessor sends the rules to the same place it would have sent preprocessed output.
When used with the driver options
file.
-MG
In conjunction with an option such as
ing header files are generated files and adds them to the dependency list without raising an error.
The dependency filename is taken directly from the
path. also suppresses preprocessed output, as a missing header file renders this useless.
-MG
This feature is used in automatic updating of makefiles.
-MP
This option instructs CPP to add a phony target for each dependency other than the main file,
causing each to depend on nothing. These dummy rules work around errors
remove header files without updating the
This is typical output:
test.o: test.c test.h
test.h:
-MT
target
Change the target of the rule emitted by dependency generation. By default CPP takes the name
of the main input file, including any path, deletes any file suffix such as
platform's usual object suffix. The result is the target.
An option will set the target to be exactly the string you specify. If you want multiple targets,
-MT
you can specify them as a single argument to
For example,
-MT '$(objpfx)foo.o'
$(objpfx)foo.o: foo.c
-MQ
target
Same as , but it quotes any characters which are special to Make.
-MT
gives
$$(objpfx)foo.o: foo.c
, and suppresses warnings with an implicit
-E
or , specifies a file to write the dependencies to. If no
-M -MM
-MD
DEPENDENCIES_OUTPUT
-MM
or , overrides the default dependency output
-MMD -MF
requesting dependency generation,
-M
#include
to match.
Makefile
, or use multiple
-MT
might give
. To avoid mixing such
-dM
(Section 4.19 Environ-
.
-w
directive does
#include
dependency output. This is a slight
switch is given
-MF
assumes miss-
-MG
directive without prepending any
make
, and appends the
.c
options.
-MT
-MQ '$(objpfx)foo.o'
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gives if you