[llvm-dev] Help with LLVM exceptions

[Justin Mann via llvm-dev]

I am trying to use LLVM 3.9 exceptions in my language. I have modeled the
IL using C++ as the reference. My IL works correctly when the exception is
thrown in the same function catching the exception, but fails when it needs
to unwind. I am running the code using JIT.

Is there a doc, that explains this is in more detail. I have already read
through:
http://llvm.org/docs/ExceptionHandling.html
http://blog.llvm.org/2011/11/llvm-30-exception-handling-redesign.html
https://llvm.org/svn/llvm-project/llvm/trunk/examples/ExceptionDemo/ExceptionDemo.cpp

Here is my IL:
; ModuleID = 'sj'
source_filename = "sj"
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"

@sjExceptionType = constant { i32 } { i32 999 }
@_ZTIPv = external constant i8*
@0 = private unnamed_addr constant [24 x i8] c"CAUGHT EXCEPTION global\00"

; Function Attrs: nounwind readnone
declare i32 @llvm.eh.typeid.for(i8*) #0

define void @global() personality i8* bitcast (i32 (...)*
@__gxx_personality_v0 to i8*) {
entry:
  br label %body

body:                                             ; preds = %entry
  invoke void @foo()
          to label %0 unwind label %catch

; <label>:0:                                      ; preds = %body
  ret void

catch:                                            ; preds = %body
  %1 = landingpad { i8*, i32 }
          catch i8* bitcast (i8** @_ZTIPv to i8*)
  %2 = extractvalue { i8*, i32 } %1, 0
  %3 = extractvalue { i8*, i32 } %1, 1
  %4 = call i8* @__cxa_begin_catch(i8* %2)
  %5 = sext i32 %3 to i64
  call void @debugFunction(i8* getelementptr inbounds ([24 x i8], [24 x
i8]* @0, i32 0, i32 0), i8* %4, i64 %5)
  call void @throwException()
  call void @__cxa_end_catch()
  ret void
}

declare i32 @__gxx_personality_v0(...)

define private void @foo() {
entry:
  br label %body

body:                                             ; preds = %entry
  call void @raiseException(i64 1)
  ret void
}

; Function Attrs: noreturn
declare void @raiseException(i64) #1

declare i8* @__cxa_begin_catch(i8*)

declare void @debugFunction(i8*, i8*, i64)

declare void @throwException()

declare void @__cxa_end_catch()

attributes #0 = { nounwind readnone }
attributes #1 = { noreturn }


---
throwException is being linked from C, here is the code:
extern "C" void raiseException(int64_t type) {
    auto t = new SJException();
    throw (void*)t;
}
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