nescc [-gcc=gcc-name] [-fnesc-gcc=gcc-name] [-fnesc-mingw-gcc]
[-fnesc-topdir=dir] [-fnesc-docs-use-graphviz] [-fnesc-is-app]
[-conly] [-fnesc-cfile=file] [-fnesc-gccize]
[--version] [-fnesc-include=file] [-fnesc-verbose] [-Wnesc-...]
[any gcc option] files...
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.
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...).
- 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.
- 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.
- Generate documentation for the compiled component in directory dir.
- Specify directory paths that should be stripped from the source file names when generating "package names" for the documentation files.
- 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.
- Tell nescc that the source being compiled is an application, and to generate an app description page for the entire application.
- 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.
- 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).
- 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.
- 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.
- 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.
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
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.
- Disabled the automatic inlining of all small functions, and of all functions with a single call site.
- Optimize atomic statements [EXPERIMENTAL]: reduce or remove the overhead of atomic statements in simple cases (e.g., single-byte reads).
- Print the version of nescc and of the selected gcc compiler (see -gcc).
- Include the specified file before compiling a nesC component. Behaves as if includes header-file; was included at the start of that component.
- Output information on the compiled programs structure, and in particular its user-specified attributes. For more details, see the separate nesC dump documentation.
- Where to output the information requested by -fnesc-dump. Defaults to stdout.
- Be more verbose than -v.
By default, nesC compiles uses of task void taskname() ... to
void taskname(), and post taskname() to
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").
- Add colon separated directories to the nescc search path.
- Remove the functions dbg(), dbg_clear(), dbg_active() from the source code.
- Compile with the deputy compiler.
- Do not use the deputy compiler. This is the default.
- Make modules default to having the @safe() attribute. Has no effect if -fnesc-deputy is not set.
- 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):
- Warn when function pointers are used (use of function pointers is deprecated in nesC and leads to inaccurate data race detection).
- Warn when interrupt handlers call commands or events not annotated with async.
- Warn about potential data races.
- Warn when configuration wiring leads to "fan-out" and the function return type does not have a combining function defined.
- Warn when unexpected documentation strings (starting with /**) are seen.
- Warn when implicit connections between components are used.
- Turns on -Wnesc-fnptr, -Wnesc-async, -Wnesc-combine and-Wnesc-data-race.
- 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.
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
nescc defines the following preprocessor symbol:
- NESC (since v1.1)
- set to XYZ where x.yz is the nesC version
- A colon separated list of additional search directories for nesC components.
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.