Handle llvm context error handler

[wsmoses]

parsing an opaque pointer bitcode with non opaque poitner context exit's julia rrather than throwing an error to be caught.

cc @giordano @vchuravy

https://github.com/llvm/llvm-project/blob/ccc416312ed72e92a885425d9cb9c01f9afa58eb/llvm/lib/IR/LLVMContext.cpp#L251

error: Opaque pointers are only supported in -opaque-pointers mode (Producer: 'LLVM15.0.7' Reader: 'LLVM 15.0.7jl')

#0  __GI_exit (status=1) at ./stdlib/exit.c:137
#1  0x00007aea4f36e126 in llvm::LLVMContext::diagnose(llvm::DiagnosticInfo const&) () from /home/wmoses/.julia/juliaup/julia-1.10.9+0.x64.linux.gnu/bin/../lib/julia/libLLVM-15jl.so
#2  0x00007aea4f36e24f in llvm::LLVMContext::emitError(llvm::Twine const&) () from /home/wmoses/.julia/juliaup/julia-1.10.9+0.x64.linux.gnu/bin/../lib/julia/libLLVM-15jl.so
#3  0x00007aea4fddc319 in llvm::errorToErrorCodeAndEmitErrors(llvm::LLVMContext&, llvm::Error) () from /home/wmoses/.julia/juliaup/julia-1.10.9+0.x64.linux.gnu/bin/../lib/julia/libLLVM-15jl.so
#4  0x00007aea4fdd0c2b in LLVMParseBitcodeInContext2 () from /home/wmoses/.julia/juliaup/julia-1.10.9+0.x64.linux.gnu/bin/../lib/julia/libLLVM-15jl.so
#5  0x00007aea0e88f89b in julia_LLVMParseBitcodeInContext2_31821 () at /home/wmoses/.julia/packages/LLVM/2JPxT/lib/15/libLLVM.jl:228
#6  0x00007aea0e8aa87f in jfptr_LLVMParseBitcodeInContext2_31822 () from /home/wmoses/.julia/compiled/v1.10/Enzyme/G1p5n_EYKCz.so
#7  0x00007aea5484706e in _jl_invoke (world=<optimized out>, mfunc=0x7aea4b002220, nargs=3, args=0x7fff765bff68, F=0x7aea2f5b43b0 <jl_system_image_data+1663600>) at /cache/build/builder-amdci5-6/julialang/julia-release-1-dot-10/src/gf.c:2895
#8  ijl_apply_generic (F=<optimized out>, args=0x7fff765bff68, nargs=<optimized out>) at /cache/build/builder-amdci5-6/julialang/julia-release-1-dot-10/src/gf.c:3077
#9  0x00007aea24341dee in julia_parse_17843 () at /home/wmoses/.julia/packages/LLVM/2JPxT/src/core/module.jl:223
#10 0x00007aea2423c03f in macro expansion () at /home/wmoses/.julia/packages/LLVM/2JPxT/src/core/module.jl:236
#11 macro expansion () at /home/wmoses/.julia/packages/LLVM/2JPxT/src/base.jl:97
#12 julia_parse_17288 () at /home/wmoses/.julia/packages/LLVM/2JPxT/src/core/module.jl:235
#13 0x00007aea24313528 in jfptr_parse_17289 () from /home/wmoses/.julia/compiled/v1.10/GPUCompiler/yPwef_EYKCz.so
#14 0x00007aea5484706e in _jl_invoke (world=<optimized out>, mfunc=0x7aea4b786e00, nargs=2, args=0x7fff765c02d0, F=0x7aea3f452920 <jl_system_image_data+274912>) at /cache/build/builder-amdci5-6/julialang/julia-release-1-dot-10/src/gf.c:2895
#15 ijl_apply_generic (F=<optimized out>

[wsmoses]

#59 0x0000710865ccdc28 in julia_abstract_call_gf_by_type_34114 (interp=<error reading variable: Cannot access memory at address 0x7b26>, f=0x71087d2a7fd0 <jl_system_image_data+102928>, arginfo=..., 
--Type <RET> for more, q to quit, c to continue without paging--q
Quit
(rr) f 1
#1  0x0000710875f98100 in llvm::LLVMContext::diagnose (this=0x56fc0a31e720, DI=...) at /home/wmoses/git/julia10/deps/srccache/llvm-julia-15.0.7-10/llvm/lib/IR/LLVMContext.cpp:263
263	    exit(1);
(rr) l
258	  DiagnosticPrinterRawOStream DP(errs());
259	  errs() << getDiagnosticMessagePrefix(DI.getSeverity()) << ": ";
260	  DI.print(DP);
261	  errs() << "\n";
262	  if (DI.getSeverity() == DS_Error)
263	    exit(1);
264	}
265	
266	void LLVMContext::emitError(uint64_t LocCookie, const Twine &ErrorStr) {
267	  diagnose(DiagnosticInfoInlineAsm(LocCookie, ErrorStr));
(rr) p pImpl->DiagHandler
$1 = std::unique_ptr<llvm::DiagnosticHandler> = {get() = 0x56fc0a665ac0}
(rr) b LLVMContext::diagnose
Breakpoint 2 at 0x710875f97f60: file /home/wmoses/git/julia10/deps/srccache/llvm-julia-15.0.7-10/llvm/lib/IR/LLVMContext.cpp, line 243.
(rr) rc
Continuing.

Thread 1 hit Breakpoint 2, llvm::LLVMContext::diagnose (this=0x56fc0a31e720, DI=...) at /home/wmoses/git/julia10/deps/srccache/llvm-julia-15.0.7-10/llvm/lib/IR/LLVMContext.cpp:243
243	void LLVMContext::diagnose(const DiagnosticInfo &DI) {
(rr) n
245	    if (LLVMRemarkStreamer *RS = getLLVMRemarkStreamer())
(rr) 
244	  if (auto *OptDiagBase = dyn_cast<DiagnosticInfoOptimizationBase>(&DI))
(rr) 
250	      (!pImpl->RespectDiagnosticFilters || isDiagnosticEnabled(DI)) &&
(rr) 
199	      pointer    _M_ptr() const noexcept { return std::get<0>(_M_t); }
(rr) 
258	  DiagnosticPrinterRawOStream DP(errs());
(rr) 
259	  errs() << getDiagnosticMessagePrefix(DI.getSeverity()) << ": ";
(rr) 
error: 260	  DI.print(DP);
(rr) 
Opaque pointers are only supported in -opaque-pointers mode (Producer: 'LLVM15.0.7' Reader: 'LLVM 15.0.7jl')261	  errs() << "\n";
(rr) p !pImpl->RespectDiagnosticFilters || isDiagnosticEnabled(DI)
$2 = true
(rr) b handleDiagnostics
Breakpoint 3 at 0x710875f23120: handleDiagnostics. (4 locations)
(rr) rc
Continuing.

Thread 1 hit Breakpoint 3.2, llvm::DiagnosticHandler::handleDiagnostics (DI=..., this=0x56fc0a665ac0) at /home/wmoses/git/julia10/deps/srccache/llvm-julia-15.0.7-10/llvm/include/llvm/IR/DiagnosticHandler.h:43
43	    if (DiagHandlerCallback) {
(rr) n
llvm::LLVMContext::diagnose (this=0x56fc0a31e720, DI=...) at /home/wmoses/git/julia10/deps/srccache/llvm-julia-15.0.7-10/llvm/lib/IR/LLVMContext.cpp:254
254	  if (!isDiagnosticEnabled(DI))
(rr) rc
Continuing.

Thread 1 hit Breakpoint 3.2, llvm::DiagnosticHandler::handleDiagnostics (DI=..., this=0x56fc0a665ac0) at /home/wmoses/git/julia10/deps/srccache/llvm-julia-15.0.7-10/llvm/include/llvm/IR/DiagnosticHandler.h:43
43	    if (DiagHandlerCallback) {
(rr) l
38	  /// Override handleDiagnostics to provide custom implementation.
39	  /// Return true if it handles diagnostics reporting properly otherwise
40	  /// return false to make LLVMContext::diagnose() to print the message
41	  /// with a prefix based on the severity.
42	  virtual bool handleDiagnostics(const DiagnosticInfo &DI) {
43	    if (DiagHandlerCallback) {
44	      DiagHandlerCallback(DI, DiagnosticContext);
45	      return true;
46	    }
47	    return false;
(rr) p DiagHandlerCallback
$3 = (llvm::DiagnosticHandler::DiagnosticHandlerTy) 0x0

yeah the problem is misisng the diaghandlercallback from https://github.com/JuliaLLVM/LLVM.jl/blob/326f833f770cbfa83968e75f59ec0e3a85b8fa4b/src/core/context.jl#L187C26-L187C43

[wsmoses]

somehow it isn't registered, doing this fixes it:

(LLVM.context(), LLVM.API.LLVMContextGetDiagnosticHandler(LLVM.context())) = (LLVM.Context(0x0000000000bc8e50, typed ptrs), Ptr{Nothing} @0x0000000000000000)
e2 = LLVM.LLVMException("Opaque pointers are only supported in -opaque-pointers mode (Producer: 'LLVM15.0.7' Reader: 'LLVM 16.0.6jl')")
ERROR: LoadError: 
No reverse pass found for ejlstr$square$./libsquare.dylib
 at context:   %3 = call double @"ejlstr$square$./libsquare.dylib"(double %0) #5, !dbg !14

Stacktrace:
 [1] csquare
   @ ~/git/Enzyme.jl/ba.jl:12


Stacktrace:
 [1] csquare
   @ ~/git/Enzyme.jl/ba.jl:12 [inlined]
 [2] diffejulia_csquare_368wrap
   @ ~/git/Enzyme.jl/ba.jl:0
 [3] macro expansion
   @ ~/git/Enzyme.jl/src/compiler.jl:5491 [inlined]
 [4] enzyme_call
   @ ~/git/Enzyme.jl/src/compiler.jl:5025 [inlined]
 [5] CombinedAdjointThunk
   @ ~/git/Enzyme.jl/src/compiler.jl:4900 [inlined]
 [6] autodiff
   @ ~/git/Enzyme.jl/src/Enzyme.jl:515 [inlined]
 [7] autodiff(mode::ReverseMode{false, false, false, FFIABI, false, false}, f::typeof(csquare), ::Type{Active}, args::Active{Float64})
   @ Enzyme ~/git/Enzyme.jl/src/Enzyme.jl:536
 [8] macro expansion
   @ show.jl:1232 [inlined]
 [9] top-level scope
   @ ~/git/Enzyme.jl/ba.jl:14
in expression starting at /home/wmoses/git/Enzyme.jl/ba.jl:14
(base) wmoses@hydra:~/git/Enzyme.jl$ git push -fgi^C
(base) wmoses@hydra:~/git/Enzyme.jl$ git diff HEAD~!
fatal: ambiguous argument 'HEAD~!': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
(base) wmoses@hydra:~/git/Enzyme.jl$ git diff HEAD~1
diff --git a/src/compiler/validation.jl b/src/compiler/validation.jl
index 6992069c..f5e7a1e0 100644
--- a/src/compiler/validation.jl
+++ b/src/compiler/validation.jl
@@ -519,10 +519,15 @@ function try_import_llvmbc(mod::LLVM.Module, flib::String, fname::String, import
         end
 
         if data !== nothing
+           @show LLVM.context(), LLVM.API.LLVMContextGetDiagnosticHandler(LLVM.context())
+           if LLVM.API.LLVMContextGetDiagnosticHandler(LLVM.context()) == C_NULL
+               LLVM._install_handlers(LLVM.context())
+           end
             try
                 inmod = parse(LLVM.Module, data)
                 found = haskey(functions(inmod), fname)
             catch e2
+               @show e2
             end
         end
     catch e

[maleadt]

We already install the handler for every context created by LLVM:

LLVM.jl/src/core/context.jl

Line 35 in 326f833

_install_handlers(ctx)

I guess this is with a non-LLVM.jl managed context?

[wsmoses]

i guess -- but as this is from enzyme the only contexts we get come from gpucompiler

[maleadt]

Ah, I guess we also need to apply this to ORC's TSCtx:

LLVM.jl/src/executionengine/ts_module.jl

Lines 21 to 28 in 326f833

	function ThreadSafeContext(; opaque_pointers=nothing)
	ts_ctx = ThreadSafeContext(API.LLVMOrcCreateNewThreadSafeContext())
	if opaque_pointers !== nothing
	opaque_pointers!(context(ts_ctx), opaque_pointers)
	end
	activate(ts_ctx)
	ts_ctx
	end

Can you try adding a call to _install_handlers(context(ts_ctx)) or so to the ctor?