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The sources of the Free Pascal compiler, RTL, packages and utilities.
See https://www.freepascal.org/ for more info.
bd09b88a5b
o blocks are implemented as a variation of procedure variables
o declaration of a block variable: "test: procedure(c: char) is block;"
(C equivalent: (void)(^test)(char c) )
o the compiler automatically converts procedures/functions whose address
is passed to a block parameter or assigned to a block variable into
a "block". This consists of
1) generating a block descriptor (containing the size of the "block
literal" (see below) and the signature of the invocation function
encoded as an Objective-C selector)
2) generating a wrapper function around the original funcion (with C
calling convention), that has an extra first hidden parameter
(marked as vo_is_parentfp in the compiler) whose type is a pointer
to the describing "block literal"
3) generating the "block literal", which contains a pointer to an
external variable indicating whether this block captures context or
not, some flags (see compiler/blockutl.get_block_literal_flags for
info), a pointer to the wrapper function and a pointer to the
descriptor. In the future, it will also contain captured variables.
o right now, only global procedures/functions can be converted to blocks
(because they don't require state capturing). The next steps are (Object
Pascal) methods (not Objective-C methods, because Objective-C method
procvars don't exist) and finally nested functions
o on Mac OS X, the functionality will only work on Mac OS X 10.7 and later,
because we have to use the so-called "ABI.2010.3.16" to ensure that
our blocks aren't called as variadic functions by the runtime (which
came out after the Mac OS X 10.6 release)
o while the currently implemented functionality does not require any
library support at all, there's no use enabling it on other platforms
because unless it has been confirmed to work with a blocks runtime,
there's no point in using blocks (they're just somewhat bulky procvars
right now). Enabling it on other platforms (in combination with the
GNUStep Objective-C run time), should simply be a matter of adding
the right {$linklib xxx} statement to rtl/inc/blockrtl.pp file, adding
that file to Makefile.fpc for that platform and adding that platform
to the compiler/systems.systems_blocks_supported set
git-svn-id: branches/blocks@28232 -
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| compiler | ||
| ide | ||
| installer | ||
| packages | ||
| rtl | ||
| tests | ||
| utils | ||
| .gitattributes | ||
| .gitignore | ||
| fpmake_add1.inc | ||
| fpmake_proc1.inc | ||
| fpmake.pp | ||
| Makefile | ||
| Makefile.fpc | ||