WIP/RFC: Add intrinsics for querying the debug level

src/ccall.cpp

@@ -1871,6 +1871,13 @@ static jl_cgval_t emit_ccall(jl_codectx_t &ctx, jl_value_t **args, size_t nargs)
             return mark_or_box_ccall_result(ctx, ret, retboxed, rt, unionall, static_rt);
         }
     }
+    else if (is_libjulia_func(jl_debug_level)) {
+        assert(lrt == getInt32Ty(ctx.builder.getContext()));
+        assert(!isVa && !llvmcall && nccallargs == 0);
+        JL_GC_POP();
+        auto level = ConstantInt::get(getInt32Ty(ctx.builder.getContext()), jl_options.debug_level);
+        return mark_or_box_ccall_result(ctx, level, retboxed, rt, unionall, static_rt);
+    }
 
     jl_cgval_t retval = sig.emit_a_ccall(
             ctx,

src/jl_exported_funcs.inc

@@ -112,6 +112,7 @@
     XX(jl_declare_constant) \
     XX(jl_defines_or_exports_p) \
     XX(jl_deprecate_binding) \
+    XX(jl_debug_level) \
     XX(jl_dlclose) \
     XX(jl_dlopen) \
     XX(jl_dlsym) \

src/julia_internal.h

@@ -1291,6 +1291,8 @@ JL_DLLEXPORT jl_array_t *jl_array_copy(jl_array_t *ary);
 JL_DLLEXPORT uintptr_t jl_object_id_(jl_value_t *tv, jl_value_t *v) JL_NOTSAFEPOINT;
 JL_DLLEXPORT void jl_set_next_task(jl_task_t *task) JL_NOTSAFEPOINT;
 
+JL_DLLEXPORT int jl_debug_level(void);
+
 // -- synchronization utilities -- //
 
 extern jl_mutex_t typecache_lock;

src/llvm-cpufeatures.cpp

@@ -90,6 +90,11 @@ void lowerHaveFMA(Function &intr, Function &caller, CallInst *I) {
     return;
 }
 
+void lowerDebugLevel(Function &intr, Function &caller, CallInst *I) {
+    I->replaceAllUsesWith(ConstantInt::get(I->getType(), jl_options.debug_level));
+    return;
+}
+
 bool lowerCPUFeatures(Module &M)
 {
     SmallVector<Instruction*,6> Materialized;
@@ -104,6 +109,13 @@ bool lowerCPUFeatures(Module &M)
                 lowerHaveFMA(F, *I->getParent()->getParent(), I);
                 Materialized.push_back(I);
             }
+        } else if (FN == "julia.debug_level") {
+            for (Use &U: F.uses()) {
+                User *RU = U.getUser();
+                CallInst *I = cast<CallInst>(RU);
+                lowerDebugLevel(F, *I->getParent()->getParent(), I);
+                Materialized.push_back(I);
+            }
         }
     }
 

src/runtime_intrinsics.c

@@ -1460,3 +1460,8 @@ JL_DLLEXPORT jl_value_t *jl_have_fma(jl_value_t *typ)
     // TODO: run-time feature check?
     return jl_false;
 }
+
+JL_DLLEXPORT int jl_debug_level()
+{
+    return jl_options.debug_level;
+}