--- name: "nescc" section: "1" platform: "linux" package: "nescc" version: "1.3.5-1.1" release: "Debian 12 (Bookworm)" platforms: ["linux"] url: "https://new.carta.tech/nescc" --- # nescc(1) nesC compiler ## NAME 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)](/gcc/1.md), 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.