Merge pull request #208 from maleadt/vc/orc_resolver

[ORC] Implement a reasonable default resolver and throw errors on undefinded symbols

Author: vchuravy

COVERAGE.md

@@ -1154,7 +1154,7 @@ ORC JIT
 Support
 -------
 
-- [ ] LLVMLoadLibraryPermanently
-- [ ] LLVMParseCommandLineOptions
-- [ ] LLVMSearchForAddressOfSymbol
-- [ ] LLVMAddSymbol
+- [x] LLVMLoadLibraryPermanently
+- [x] LLVMParseCommandLineOptions
+- [x] LLVMSearchForAddressOfSymbol
+- [x] LLVMAddSymbol

src/orc.jl

@@ -11,6 +11,9 @@ export JITTargetMachine
 end
 
 Base.unsafe_convert(::Type{API.LLVMOrcJITStackRef}, orc::OrcJIT) = orc.ref
+Base.unsafe_convert(::Type{Ptr{Cvoid}}, orc::OrcJIT) = Base.unsafe_convert(Ptr{Cvoid}, orc.ref)
+
+OrcJIT(ref::Ptr{Cvoid}) = OrcJIT(Base.unsafe_convert(API.LLVMOrcJITStackRef, ref))
 
 """
     OrcJIT(::TargetMachine)
@@ -28,6 +31,15 @@ function dispose(orc::OrcJIT)
     API.LLVMOrcDisposeInstance(orc)
 end
 
+function OrcJIT(f::Core.Function, tm::TargetMachine)
+    orc = OrcJIT(tm)
+    try
+        f(orc)
+    finally
+        dispose(orc)
+    end
+end
+
 function errormsg(orc::OrcJIT)
     # The error message is owned by `orc`, and will
     # be disposed along-side the OrcJIT. 
@@ -39,12 +51,52 @@ struct OrcModule
 end
 Base.convert(::Type{API.LLVMOrcModuleHandle}, mod::OrcModule) = mod.handle
 
-function compile!(orc::OrcJIT, mod::Module, resolver = C_NULL, ctx = C_NULL; lazy=false)
+"""
+   resolver(name, ctx)
+
+Lookup the symbol `name`. Iff `ctx` is passed to this function it should be a
+pointer to the OrcJIT we are compiling for.
+"""
+function resolver(name, ctx)
+    name = unsafe_string(name)
+    ## Step 0: Should have already resolved it iff it was in the
+    ##         same module
+    ## Step 1: See if it's something known to the execution engine
+    ptr = C_NULL
+    if ctx != C_NULL
+        orc = OrcJIT(ctx)
+        ptr = pointer(address(orc, name))
+    end
+
+    ## Step 2: Search the program symbols
+    if ptr == C_NULL
+        #
+        # SearchForAddressOfSymbol expects an unmangled 'C' symbol name.
+        # Iff we are on Darwin, strip the leading '_' off.
+        @static if Sys.isapple()
+            if name[1] == '_'
+                name = name[2:end]
+            end
+        end
+        ptr = LLVM.find_symbol(name)
+    end
+
+    ## Step 4: Lookup in libatomic
+    # TODO: Do we need to do this?
+
+    if ptr == C_NULL
+        error("OrcJIT: Symbol `$name` lookup failed. Aborting!")
+    end
+
+    return UInt64(reinterpret(UInt, ptr))
+end
+
+function compile!(orc::OrcJIT, mod::Module, resolver = @cfunction(resolver, UInt64, (Cstring, Ptr{Cvoid})), resolver_ctx = orc; lazy=false)
     r_mod = Ref{API.LLVMOrcModuleHandle}()
     if lazy
-        API.LLVMOrcAddLazilyCompiledIR(orc, r_mod, mod, resolver, ctx)
+        API.LLVMOrcAddLazilyCompiledIR(orc, r_mod, mod, resolver, resolver_ctx)
     else
-        API.LLVMOrcAddEagerlyCompiledIR(orc, r_mod, mod, resolver, ctx)
+        API.LLVMOrcAddEagerlyCompiledIR(orc, r_mod, mod, resolver, resolver_ctx)
     end
     OrcModule(r_mod[])
 end
@@ -53,9 +105,9 @@ function Base.delete!(orc::OrcJIT, mod::OrcModule)
     LLVM.API.LLVMOrcRemoveModule(orc, mod)
 end
 
-function add!(orc::OrcJIT, obj::MemoryBuffer, resolver = C_NULL, ctx = C_NULL)
+function add!(orc::OrcJIT, obj::MemoryBuffer, resolver = @cfunction(resolver, UInt64, (Cstring, Ptr{Cvoid})), resolver_ctx = orc)
     r_mod = Ref{API.LLVMOrcModuleHandle}()
-    API.LLVMOrcAddObjectFile(orc, r_mod, obj, resolver, ctx)
+    API.LLVMOrcAddObjectFile(orc, r_mod, obj, resolver, resolver_ctx)
     return OrcModule(r_mod[])
 end
 
@@ -98,7 +150,7 @@ end
 
 function callback!(orc::OrcJIT, callback, ctx)
     r_address = Ref{API.LLVMOrcTargetAddress}()
-    LLVM.API.LLVMOrcLazyCompileCallback(orc, r_address, callback, ctx)
+    API.LLVMOrcCreateLazyCompileCallback(orc, r_address, callback, ctx)
     return OrcTargetAddress(r_address[])
 end
 

src/support.jl

@@ -4,3 +4,26 @@ function clopts(opts...)
     args = ["", opts...]
     API.LLVMParseCommandLineOptions(length(args), args, C_NULL)
 end
+
+"""
+    add_symbol(name, ptr)
+
+Permanently add the symbol `name` with the value `ptr`. These symbols are searched
+before any libraries.
+"""
+add_symbol(name, ptr) = LLVM.API.LLVMAddSymbol(name, ptr)
+
+"""
+    load_library_permantly(path)
+
+This function permanently loads the dynamic library at the given path.
+It is safe to call this function multiple times for the same library.
+"""
+load_library_permantly(path) = LLVM.API.LLVMLoadLibraryPermanently(path)
+
+"""
+    find_symbol(name)
+
+Search the global symbols for `name` and return the pointer to it.
+"""
+find_symbol(name) = LLVM.API.LLVMSearchForAddressOfSymbol(name)