part of shnell – a source to source compiler enhancement tool
© Jens Gustedt, 2017-2019
the list of valid shnell extensions
This file list all shnell extensions that are accepted. They are usually invoked by a pragma inside the C source. For example a pragma
would unroll the code between the two pragma 5 times and replace the occurence of ${I} by the current number. (See regVar for meta-variables.)
Corresponding scripts are run as they are listed here. Arguments to the directive are passed through the environment variable CMOD_EXTENSION_ARGUMENTS, but are better handled through the arguments module.
The identifier for an extension must follow the same rules as for C identifiers and should generally not be reserved.
Simple directives for demonstrative purposes
the simplest “extension”, copy the source over, ignore all the arguments
copy=cat
copy the source over and echo all arguments of the directive to stderr
hello = ${EXEDIR}/hello.sh
comment all the source in the directive
comment=sed s+^+//+
ignore all the source in the directive
ignore = ${EXEDIR}/ignore.sh
an invalid extension because there remains a $
invalid = EXEDIR/hello
Unrolling
specialize code for a list of values that an identifier takes
specialize = ${EXEDIR}/specialize.sh
specialize code for a list of ranges of values that an identifier takes
ranges = ${EXEDIR}/ranges.sh
foreach code for a list of values
foreach = ${EXEDIR}/foreach.sh
do loop for a specified number of values
do = ${EXEDIR}/do.sh
Binding
evaluate an expression
let = ${EXEDIR}/let.sh
bind variables to values
bind = ${EXEDIR}/bind.sh
Meta directives to organize shnell dialects
add short cuts to avoid the amend meta directive
dialect = ${EXEDIR}/dialect.sh
re-valuate a whole source blob
eval = ${EXEDIR}/evaluation.sh
load text snippets from files load = ${EXEDIR}/load.sh
generate mangled names, experimental
module = ${EXEDIR}/module.sh
generate internal names, experimental
intern = ${EXEDIR}/intern.sh
import names from other modules, experimental
using = ${EXEDIR}/using.sh
create shortcut for module name, experimental
rename = ${EXEDIR}/rename.sh
Targeted source replacement
factor all decimal integers, toy
factor = ${EXEDIR}/factor.sh
compute simple constant expressions, semi-toy
compute = ${EXEDIR}/compute.sh
compute expressions by using the POSIX bc tool
bc = ${EXEDIR}/bc.sh
Environment and configuration
add POSIX configuration variables
getconf = ${EXEDIR}/getconf.sh
evaluate environment variables
env = ${EXEDIR}/env.sh
obtain the bytes of the git hash of the source file
gitID = ${EXEDIR}/gitID.sh
C language specific tools
add enum configuration variables
enum = ${EXEDIR}/enum.sh
Implement C and C++ attributes by translating them to compiler specifics
attribute = ${EXEDIR}/attribute.sh
Put all code onto a single physical line, use this to construct #define
oneline = ${EXEDIR}/oneline.sh
Put all code onto a single logical line, use this to construct #define
logicalline = ${EXEDIR}/logicalline.sh
Trade: simple naming naming enforcement for im- and export
The TRADE dialect and the trade commandline interface use export and implicit directives to ensure that each TU /exports/ properly named identifiers and is able to import from other TU by simple implicit naming conventions.
introduce prefix naming conventions
export = ${EXEDIR}/export.sh
make names private, can only be used with export
private = ${EXEDIR}/private.sh
introduce short names for other TU, can only be used with export
alias = ${EXEDIR}/alias.sh
import headers from other TU implicitly
implicit = ${EXEDIR}/implicit.sh
introduce short names for legacy TU, can only be used with implicit
legacy = ${EXEDIR}/legacy.sh
establich startup handlers, can only be used with implicit
startup = ${EXEDIR}/startup.sh
establish atexit handlers, can only be used with implicit
atexit = ${EXEDIR}/atexit.sh
establish local handlers, can only be used with implicit
local = ${EXEDIR}/local.sh
Other directives
bring generic selection to C++
generic_selection = ${EXEDIR}/generic_selection.sh
translate C++ lambda to gcc’s nested functions
lambda = ${EXEDIR}/lambda.sh
normalize C code such that all control constructs use compound statements
normalize = ${EXEDIR}/normalize.sh
define a holdback for a lambda expression
holdback = ${EXEDIR}/holdback.sh
tentatively define a preprocessor macro
define = ${EXEDIR}/define.sh
run the depending code through the C preprocessor
preprocess = ${EXEDIR}/preprocess.sh
run the depending code through the C preprocessor
preprocess = ${EXEDIR}/preprocess.sh