The Exception Handling Proposal has been implemented in some environments, e.g. in binaryen. But has it been implemented in llvm yet? Will llvm based compilers (with wasm as a target) like clang or emscripten generate code with try-catch blocks? (And where can such updated information be found in general for other proposals and instruction types as well?)
Yes, the Wasm exception handling proposal is supported in the whole toolchain from llvm/clang, binaryen, and emscripten.
More info here: https://emscripten.org/docs/porting/exceptions.html
Related
NSDeprecated which tunnels through CF_Deprecated into the clang attribute availability only handles deprecation for MACOSX and IOS.
Are there any calls or series of macros that replicate this tool for third parties.
I am working on V2 of an SDK and there are certain calls we want to deprecate as well as EOL.
(Please note, this SDK is still in Objective-C; so Swift only solutions don't solve my issue)
The deprecation warnings and errors would be fantastic at compilation and code generation time; however, I fear this is something I'd need to spin on my own.
Any pointers or reference on this before I have to decide if I need to kill the time on this side project?
You can #define a macro in your SDK project to make a shorthand for the deprecation message. We did something similar in the Core Plot project.
There is a function attribute deprecated provided by GNU compiler.
The syntax to mark deprecated functions is:
void Foo() __attribute__( (deprecated("message", "replacement")) );
The first one is the message to display when emitting the warning; the second one enables the compiler to provide a Fix-It to replace the deprecated name with a new name.
More information on using function attributes can be found in GCC Attribute Syntax documentation or Attributes in Clang documentation
some handy macros are in the NSObjCRuntime.h from Apple.
NS_DEPRECATED_IOS(6.0,10.0)
works like a charm.
I'm confused about one aspect of LLVM:
For all the languages it supports, does it support compiling both to the intermediate code AND to straight binary?
For instance, if I write something in C, can LLVM (or Clang?) compile to either binary (like GCC) or intermediate code?
Or can only some languages be converted to intermediate? I guess it goes without saying that this intermediate requires some type of LLVM runtime? I never really hear bout the runtime, though.
LLVM is a framework for manipulating LLVM IR (the "bytecode" you're alluding to) and lowering it to target-specific binaries (for example x86 machine code). Clang is a front-end for C/C++ (and Objective C) that translates these source languages into LLVM IR.
With this in mind, answering your questions:
For all the languages it supports, does it support compiling both to
the intermediate code AND to straight binary?
LLVM can compile IR (intermediate code) to binary (or to assembly text).
For instance, if I write something in C, can LLVM (or Clang?) compile
to either binary (like GCC) or intermediate code?
Yes. Clang can compile your code to a binary directly (using LLVM as a backend), or just emit LLVM IR if you want that.
Or can only some languages be converted to intermediate? I guess it
goes without saying that this intermediate requires some type of LLVM
runtime?
Theoretically, once you have LLVM IR, the LLVM library can convert it to binary. Some languages require a runtime (say Java, or Python), so any compiler from these languages to LLVM IR will have to provide a runtime in one way or another. LLVM has some support for connecting to such runtimes (for example - GC hooks) but carries no "runtime of its own". The only "runtime" project related to LLVM is compiler-rt, which provides fast implementations of some language/compiler builtins and intrinsics. It's mainly used for C/C++/Objective C. It's not officially part of LLVM, though full toolchains based on Clang often use it.
If I create an Xcode project with the iOS Single View Application template and choose Swift for the language, will the compiler exclude from the release build (binary) functions that never get called?
I'm wondering because I want to include a third-party library that has a lot of superfluous classes & functions, and I want to keep my app small & fast.
While I agree with comments, it is unlikely to impact performance in any significant way even if it was included...
Xcode 6 uses Apple LLVM Compiler Version 6.1, depending on how closely related it is to LLVM Developer Group's version the optimization feature is available http://llvm.org/docs/Passes.html with options such as -dce: Dead Code Elimination, -adce: Aggressive Dead Code Elimination.
One way to know for sure what is included is checking the assembly output using -emit-assembly option in the swift compiler and review the output, or opening the binary in a disassembler such as Hopper ( http://www.hopperapp.com/download.html )
I couldn't manage to find an answear to this question. Is Swift just an Objective-C wrapper, where Swift code is turned into objective-c when the code compiles?
no, it is made into llvm bytecode or -as pointed out by delnan- as it called today llvm bitcode
"[The new term is used] partly to break association with bytecode as employed by traditional virtual machines (because LLVM IR is very much different from that)"
Why does the Dart2JS compiler not generate code that includes "use strict" at the top of each of the script files? If all generated Javascript code is valid ECMA5 code, then shouldn't the compiler automatically add the "use strict" command?
Update:
Apparently this is already being tracked by issue 1686.
To formally answer, this feature request can be found in issue 1686 in the Dart issue tracker.
As for why, there hasn't been much demand for it and the dart2js team has been focused on language conformance and performance.