nescc man page

nescc — nesC compiler

Synopsis

nescc [-gcc=gcc-name] [-fnesc-gcc=gcc-name] [-fnesc-mingw-gcc]
[-fnesc-target=architecture] [-fnesc-docdir=dir]
[-fnesc-topdir=dir] [-fnesc-docs-use-graphviz] [-fnesc-is-app]
[-fnesc-simulate]
[-fnesc-nido-tosnodes=n] [-fnesc-nido-motenumber=expression]
[-conly] [-fnesc-cfile=file] [-fnesc-gccize]
[-fnesc-cppdir=directory] [-fnesc-separator=separator]
[-fnesc-no-inline] [-fnesc-optimize-atomic]
[--version] [-fnesc-include=file] [-fnesc-verbose] [-Wnesc-...]
[-fnesc-dump=specification] [-fnesc-dumpfile=file]
[-fnesc-scheduler=specification] [-fnesc-path=path]
[-fnesc-no-debug]
[-fnesc-deputy] [-fnesc-no-deputy]
[-fnesc-default-safe] [-fnesc-default-unsafe]
[any gcc option] files...

Description

nescc is an extension to gcc that knows how to compile nesC applications. If invoked on regular C files, it behaves exactly like gcc. When invoked on a nesC component or interface (.nc extension) file it compiles and links (except if the -c, -S, -conly, -E or -fsyntax-only options are used) that component with the other files specified on the command line.

Options

nescc accepts all gcc options, and some additional nesC specific options:

-gcc=gcc-name -fnesc-gcc=gcc-name
Specify which gcc compiler to use to compile and link any C files, either explicitly specified, or generated as the output of the nesC-to-C compiler. This option supports cross-compilation of nesC code (the usual mode of operation...).
-fnesc-mingw-gcc
Pass this option if the gcc version specified with -gcc=... was compiled for Window's mingw environment, and hence expects Windows-style rather than Unix-style paths.
-fnesc-target=architecture
Specify the target architecture to compile for. Currently supported platforms are avr (the Atmel AVR family), msp430 (the TI MSP430 family) and self (the machine the nesC compiler is running on). If you use the env target, the architecture details are read from the NESC_MACHINE environment variable. See the separate env target documentation for details.
-fnesc-docdir=dir
Generate documentation for the compiled component in directory dir.
-fnesc-topdir=dir
Specify directory paths that should be stripped from the source file names when generating "package names" for the documentation files.
-fnesc-docs-use-graphviz
Explicitly enable or disable the use of the graphviz tool in the generated documentation. Without this option, graphviz is enabled iff the dot program is found in the current path. Use of graphviz requires dot. The documentation generation tool checks the version of dot, and enables client-side image maps, if supported.
-fnesc-is-app
Tell nescc that the source being compiled is an application, and to generate an app description page for the entire application.
-fnesc-simulate
Compile for a simulation environment.
-fnesc-nido-tosnodes=n, -fnesc-nido-motenumber=expression
When -fnesc-simulate is specified, the nesC program is compiled for a simulation environment, where a single executable will simulate n nodes. Specifically, in the generated code, each global variable becomes an n element array, and all accesses to global variables are indexed with expression.
-conly
Just compile to C, leaving the generated source code for top-level-component comp.nc in C file comp.c (except if the -fnesc-cfile option is specified).
-fnesc-cfile=file
Specify a file in which to save the C code generated when compiling a component. Note: if you specify two components on the command line, then the C code from the second one will overwrite the C code from the first.
-fnesc-gccize
Output target-specific extensions as gcc-style attributes rather than using the target's original syntax. Can help if using -conly and sending the nesC output from some other tool that understands gcc attributes but not the target-specific extensions.
-fnesc-cppdir=directory
Save all preprocessing results in directory. The directory is created if it doesn't exist. This can be helpful to track down preprocessor-related compilation problems. You probably want to ensure that directory is empty when you call nescc, to make it obvious which files where preprocessed as part of the current compilation.
-fnesc-separator=separator

Set separator used to create symbol names in the generated C code (default $). The compiler needs to generate unique names to denote, e.g., a module variable. It does this by concatenating various symbol names to ensure that it generates unique names. For instance, variable bar in module Maz becomes a global C variable Maz$bar in the compiler output. Some C compilers do not like $ in symbol names, so you can specify a different separator, e.g., __ (leading to generated symbols like Maz__bar).

You will get a compile-time warning if any symbol in the program being compiled contains the separator you specify (the presence of the separator in a symbol could lead to the generation of incorrect code). The separator can however start or end a symbol.

-fnesc-no-inline
Disabled the automatic inlining of all small functions, and of all functions with a single call site.
-fnesc-optimize-atomic
Optimize atomic statements [EXPERIMENTAL]: reduce or remove the overhead of atomic statements in simple cases (e.g., single-byte reads).
--version
Print the version of nescc and of the selected gcc compiler (see -gcc).
-fnesc-include=header-file
Include the specified file before compiling a nesC component. Behaves as if includes header-file; was included at the start of that component.
-fnesc-dump=specification
Output information on the compiled programs structure, and in particular its user-specified attributes. For more details, see the separate nesC dump documentation.
-fnesc-dumpfile=file
Where to output the information requested by -fnesc-dump. Defaults to stdout.
-fnesc-verbose
Be more verbose than -v.
-fnesc-scheduler=component,unique-string,interface-name,interface-definition,run-event,post-command

By default, nesC compiles uses of task void taskname() ... to void taskname(), and post taskname() to TOS_post(taskname).

With this option, each task gets its own interface-definition interface, the task implementation is transformed into a run-event event and posts becomes a call to the post-command command. This per-task interface is automatically connected to the parameterised interface-name interface of scheduler component component. The parameter id for the connection is chosen with unique("unique-string").

-fnesc-path=path
Add colon separated directories to the nescc search path.
-fnesc-no-debug
Remove the functions dbg(), dbg_clear(), dbg_active() from the source code.
-fnesc-deputy
Compile with the deputy compiler.
-fnesc-no-deputy
Do not use the deputy compiler. This is the default.
-fnesc-default-safe
Make modules default to having the @safe() attribute. Has no effect if -fnesc-deputy is not set.
-fnesc-default-unsafe
Make modules default to having the @unsafe() attribute. Has no effect if -fnesc-deputy is not set.

There are a number of warnings specific to nesC, specified with -Wnesc- (all these warnings are off by default):

-Wnesc-fnptr
Warn when function pointers are used (use of function pointers is deprecated in nesC and leads to inaccurate data race detection).
-Wnesc-async
Warn when interrupt handlers call commands or events not annotated with async.
-Wnesc-data-race
Warn about potential data races.
-Wnesc-combine
Warn when configuration wiring leads to "fan-out" and the function return type does not have a combining function defined.
-Wnesc-docstring
Warn when unexpected documentation strings (starting with /**) are seen.
-Wnesc-implicit-conn
Warn when implicit connections between components are used.
-Wnesc-all
Turns on -Wnesc-fnptr, -Wnesc-async, -Wnesc-combine and-Wnesc-data-race.
-Wnesc-error
Turns the -Wnesc-fnptr, -Wnesc-async, -Wnesc-combine and -Wnesc-data-race warnings into errors.

When compiling a nesC component, the nesC compiler recognizes the gcc C language (-f...) and warning (-W...) options. The -S, -c and -o options work as usual, the -x option accepts nesc. The -v option causes the nesC compiler to print out the paths of all components and interfaces that are loaded. Directories can be added to nesCs search path with -I.

Examples

If you wish to compile a component Bar.nc to a C file, you can do:

nescc -c -o /dev/null -fnesc-cfile=Bar.c Bar.nc

Preprocessor Symbols

nescc defines the following preprocessor symbol:

NESC (since v1.1)
set to XYZ where x.yz is the nesC version

Environment Variables

NESCPATH
A colon separated list of additional search directories for nesC components.

See Also

gcc(1), platform-specific gcc

Notes

The warnings for the new nesC 1.1 features (see -Wnesc-all) are off by default to increase compatibility with nesC 1.0 code. To match the language specification in the nesC 1.1 reference manual, you should compile with -Wnesc-all and -Wnesc-error. These options will become the default in future releases.

Referenced By

nescc-mig(1), nescc-ncg(1), nescc-wiring(1).

May 22, 2013