Introduce a new "swift" build configuration that guards declarations
and statements with a language version - if the current language version
of the compiler is at least that version, the block will parse as normal.
For inactive blocks, the code will not be parsed an no diagnostics will
be emitted there.
Example:
#if swift(>=2.2)
print("Active")
#else
this code will not parse or emit diagnostics
#endif
https://github.com/apple/swift-evolution/blob/master/proposals/0020-if-swift-version.md
rdar://problem/19823607
This is a WIP to make CompilerVersion more general.
- Rename CompilerVersion to just "Version"
- Make version comparison general and put _compiler_version special logic
with its second version component in a specialized parsing function
- Add a generic version parsing function
Swift SVN r32726
This configuration clause will suppress lex diagnostics and skip parsing
altogether if the code under the clause isn't active - the compiler must
have a repository version greater than or equal to the version given to
_compiler_version.
This option is only meant to be used sparingly and not to track the
Swift *language* version.
Example, if using a compiler versioned 700.0.28:
#if _compiler_version("700.0.23")
print("This code will compile for versions 700.0.23 and later.")
#else
This + code + will + not + be + parsed
#endif
Included are new diagnostics for checking that the version is formatted
correctly and isn't empty.
New tests:
- Compiler version comparison unit tests
- Build configuration diagnostics
- Skipping parsing of code under inactive clauses
rdar://problem/22730282
Swift SVN r32195
