fix: duplicate global constants

src/compiler/orcv2.jl

@@ -46,7 +46,35 @@ function absolute_symbol_materialization(name, ptr)
     return LLVM.absolute_symbols(Ref(gv))
 end
 
-const hnd_string_map = Dict{String, Ref{Ptr{Cvoid}}}()
+const hnd_string_map = Dict{String,Ref{Ptr{Cvoid}}}()
+
+# These are special (external or private) global
+# constants that should not be incremented (renamed)
+const global_var_prefixes = ("ejl_enz_", "ejl_jl_", "enz_exception", "_j_const_", "jl_", "_j_str")
+
+# store non-special external global constants
+# They will be incremented to produce new names
+const glob_vars_maps = Dict{String,Int}()
+
+# TODO: may not be necessary once the core
+# issue is found regarding linkage type of
+# private constants is change to external
+# when ccall is used.
+function rename_global!(glob_var)
+    _name = LLVM.name(glob_var)
+    if any(startswith.(_name, global_var_prefixes))
+    else
+        if haskey(glob_vars_maps, _name)
+            glob_vars_maps[_name] += 1
+            _new_name = _name * ".$(glob_vars_maps[_name])"
+            LLVM.name!(glob_var, _new_name)
+            glob_vars_maps[_new_name] = 1
+        else
+            glob_vars_maps[_name] = 1
+        end
+
+    end
+end
 
 function fix_ptr_lookup(name)
     if startswith(name, "ejlstr\$") || startswith(name, "ejlptr\$")
@@ -258,6 +286,13 @@ function add!(mod)
         replace_uses!(f, ptr)
         Compiler.eraseInst(mod, f)
     end
+
+    # rename non-special global constants that
+    # have external linkage (modified by the ccall
+    # execution path)
+    for glob_var in collect(globals(mod))
+        rename_global!(glob_var)
+    end
     lljit = jit[].jit
     jd = LLVM.JITDylib(lljit)
     tsm = move_to_threadsafe(mod)

test/Project.toml

@@ -2,6 +2,7 @@
 BFloat16s = "ab4f0b2a-ad5b-11e8-123f-65d77653426b"
 ChainRules = "082447d4-558c-5d27-93f4-14fc19e9eca2"
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"
+Clang_jll = "0ee61d77-7f21-5576-8119-9fcc46b10100"
 Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 Enzyme = "7da242da-08ed-463a-9acd-ee780be4f1d9"
 EnzymeTestUtils = "12d8515a-0907-448a-8884-5fe00fdf1c5a"
@@ -12,6 +13,7 @@ InlineStrings = "842dd82b-1e85-43dc-bf29-5d0ee9dffc48"
 JLArrays = "27aeb0d3-9eb9-45fb-866b-73c2ecf80fcb"
 LLVM = "929cbde3-209d-540e-8aea-75f648917ca0"
 LLVM_jll = "86de99a1-58d6-5da7-8064-bd56ce2e322c"
+Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 LogExpFunctions = "2ab3a3ac-af41-5b50-aa03-7779005ae688"
 ParallelTestRunner = "d3525ed8-44d0-4b2c-a655-542cee43accc"

test/global_constants.jl

@@ -0,0 +1,72 @@
+using Enzyme
+using Libdl
+using Test
+
+const LLVM_IR = raw"""
+; ModuleID = '<stdin>'
+source_filename = "<string>"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-conda-linux-gnu"
+
+
+@A = private unnamed_addr constant [3 x double] [double 1.000000e+00, double 2.000000e+00, double 3.000000e+00], align 8
+
+define double @func(double %x, double %y, i64 %n) {
+entry:
+  %ptr  = getelementptr inbounds [3 x double], [3 x double]* @A, i64 0, i64 %n
+  %aval = load double, double* %ptr, align 8
+  %prod = fmul double %x, %aval
+  %sum  = fadd double %prod, %y
+  ret double %sum
+}
+"""
+
+tmp_dir = tempdir()
+tmp_so_file = joinpath(tmp_dir, "func.so")
+
+run(
+    pipeline(
+        `clang -x ir - -Xclang -no-opaque-pointers -O3 -fPIC -fembed-bitcode -shared -o $(tmp_so_file)`;
+        stdin=IOBuffer(LLVM_IR)
+    )
+);
+lib = Libdl.dlopen(tmp_so_file);
+const fptr = Libdl.dlsym(lib, :func);
+
+
+function func_llvm(x::Float64, y::Float64, n::Int)
+    n >= 0 && n <= 2 || throw("0 ≤ n ≤ 2")
+    Base.llvmcall((LLVM_IR, "func"), Cdouble,
+        Tuple{Cdouble,Cdouble,Clong},
+        x, y, n
+    )
+end;
+
+
+function func_ccall(x::Float64, y::Float64, n::Int)
+    n >= 0 && n <= 2 || throw("0 ≤ n ≤ 2")
+    ccall(fptr, Cdouble,
+        (Cdouble, Cdouble, Clong),
+        x, y, n
+    )
+end;
+
+@testset "Rename external global constants ccall" begin
+
+    x = 2.0
+    y = 1.0
+    n = 2
+    A = [1.0, 2.0, 3.0]
+
+    @test func_llvm(x, y, n) == func_ccall(x, y, n)
+    @test func_llvm(x, y, n) == x * A[n+1] + y
+    @test func_ccall(x, y, n) == x * A[n+1] + y
+
+
+
+    @test gradient(Reverse, func_llvm, Const(x), y, Const(n)) == (nothing, 1.0, nothing)
+    @test gradient(Reverse, func_llvm, x, Const(y), Const(n)) == (3.0, nothing, nothing)
+
+    @test gradient(Reverse, func_ccall, Const(x), y, Const(n)) == (nothing, 1.0, nothing)
+    @test gradient(Reverse, func_ccall, x, Const(y), Const(n)) == (3.0, nothing, nothing)
+end