Merge pull request #31403 from JuliaLang/tb/llvmcall_extern

Allow ccall(..., llvmcall, ...) to external functions.
JuliaLang · Mar 21, 2019 · 54fe55b · 54fe55b
2 parents f611b46 + b437e61
commit 54fe55b
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Showing 2 changed files with 16 additions and 2 deletions.
diff --git a/src/ccall.cpp b/src/ccall.cpp
@@ -1949,8 +1949,14 @@ jl_cgval_t function_sig_t::emit_a_ccall(
         }
         else {
             assert(symarg.f_name != NULL);
-            llvmf = jl_Module->getOrInsertFunction(symarg.f_name, functype);
-            if (!isa<Function>(llvmf) || cast<Function>(llvmf)->getIntrinsicID() == Intrinsic::not_intrinsic)
+            const char* f_name = symarg.f_name;
+            bool f_extern = (strncmp(f_name, "extern ", 7) == 0);
+            if (f_extern)
+                f_name += 7;
+            llvmf = jl_Module->getOrInsertFunction(f_name, functype);
+            if (!f_extern &&
+                (!isa<Function>(llvmf) ||
+                 cast<Function>(llvmf)->getIntrinsicID() == Intrinsic::not_intrinsic))
                 jl_error("llvmcall only supports intrinsic calls");
         }
     }

diff --git a/test/llvmcall.jl b/test/llvmcall.jl
@@ -229,3 +229,11 @@ module LLVMCallFunctionTest
         @test really_complicated_identity(x) === x
     end
 end
+
+# support for calling external functions
+let
+    f() = ccall("time", llvmcall, Cvoid, (Ptr{Cvoid},), C_NULL)
+    @test_throws ErrorException f()
+    f() = ccall("extern time", llvmcall, Cvoid, (Ptr{Cvoid},), C_NULL)
+    f()
+end