Adapt Windows cglobal() search for libjulia-internal

On Windows, we have a special list of libraries that we search for
default symbol resolution.  Now that we have symbols defined in
`libjulia` and then imported by `libjulia-internal`, we need to make
certain that we search `libjulia-internal` first (so that we find
non-trampoline functions first) and then `libjulia` (so that we do in
fact eventually find the symbols at all).

(cherry picked from commit 9489e64)

Author: staticfloat

src/ccall.cpp

@@ -22,11 +22,11 @@ static bool runtime_sym_gvs(jl_codegen_params_t &emission_context, const char *f
     GlobalVariable *libptrgv;
     jl_codegen_params_t::SymMapGV *symMap;
 #ifdef _OS_WINDOWS_
-    if ((intptr_t)f_lib == 1) {
+    if ((intptr_t)f_lib == (intptr_t)JL_EXE_LIBNAME) {
         libptrgv = prepare_global_in(M, jlexe_var);
         symMap = &emission_context.symMapExe;
     }
-    else if ((intptr_t)f_lib == 2) {
+    else if ((intptr_t)f_lib == (intptr_t)JL_LIBJULIA_INTERNAL_DL_LIBNAME) {
         libptrgv = prepare_global_in(M, jldll_var);
         symMap = &emission_context.symMapDl;
     }
@@ -1266,7 +1266,7 @@ static jl_cgval_t emit_ccall(jl_codectx_t &ctx, jl_value_t **args, size_t nargs)
     auto _is_libjulia_func = [&] (uintptr_t ptr, const char *name) {
         if ((uintptr_t)fptr == ptr)
             return true;
-        return (!f_lib || f_lib == JL_DL_LIBNAME) && f_name && !strcmp(f_name, name);
+        return (!f_lib || f_lib == JL_LIBJULIA_INTERNAL_DL_LIBNAME) && f_name && !strcmp(f_name, name);
     };
 #define is_libjulia_func(name) _is_libjulia_func((uintptr_t)&(name), #name)
 

src/codegen.cpp

@@ -397,7 +397,7 @@ static const auto jlexe_var = new JuliaVariable{
     [](LLVMContext &C) { return T_pint8; },
 };
 static const auto jldll_var = new JuliaVariable{
-    "jl_dl_handle",
+    "jl_libjulia_internal_handle",
     true,
     [](LLVMContext &C) { return T_pint8; },
 };
@@ -7531,7 +7531,7 @@ static void init_jit_functions(void)
     add_named_global(jlRTLD_DEFAULT_var, &jl_RTLD_DEFAULT_handle);
 #ifdef _OS_WINDOWS_
     add_named_global(jlexe_var, &jl_exe_handle);
-    add_named_global(jldll_var, &jl_dl_handle);
+    add_named_global(jldll_var, &jl_libjulia_internal_handle);
 #endif
     global_jlvalue_to_llvm(new JuliaVariable{"jl_true", true, get_pjlvalue}, &jl_true);
     global_jlvalue_to_llvm(new JuliaVariable{"jl_false", true, get_pjlvalue}, &jl_false);

src/dlload.c

@@ -308,8 +308,10 @@ const char *jl_dlfind_win32(const char *f_name)
     void * dummy;
     if (jl_dlsym(jl_exe_handle, f_name, &dummy, 0))
         return JL_EXE_LIBNAME;
-    if (jl_dlsym(jl_dl_handle, f_name, &dummy, 0))
-        return JL_DL_LIBNAME;
+    if (jl_dlsym(jl_libjulia_internal_handle, f_name, &dummy, 0))
+        return JL_LIBJULIA_INTERNAL_DL_LIBNAME;
+    if (jl_dlsym(jl_libjulia_handle, f_name, &dummy, 0))
+        return JL_LIBJULIA_DL_LIBNAME;
     if (jl_dlsym(jl_kernel32_handle, f_name, &dummy, 0))
         return "kernel32";
     if (jl_dlsym(jl_ntdll_handle, f_name, &dummy, 0))
@@ -334,8 +336,8 @@ const char *jl_dlfind_win32(const char *f_name)
     // explicit is preferred over implicit
     return NULL;
     // oops, we didn't find it. NULL defaults to searching jl_RTLD_DEFAULT_handle,
-    // which defaults to jl_dl_handle, where we won't find it, and will throw the
-    // appropriate error.
+    // which defaults to jl_libjulia_internal_handle, where we won't find it, and
+    // will throw the appropriate error.
 }
 #endif
 

src/init.c

@@ -293,7 +293,8 @@ JL_DLLEXPORT void jl_atexit_hook(int exitcode)
 
 static void post_boot_hooks(void);
 
-JL_DLLEXPORT void *jl_dl_handle;
+JL_DLLEXPORT void *jl_libjulia_internal_handle;
+JL_DLLEXPORT void *jl_libjulia_handle;
 void *jl_RTLD_DEFAULT_handle;
 JL_DLLEXPORT void *jl_exe_handle;
 #ifdef _OS_WINDOWS_
@@ -657,7 +658,10 @@ void _julia_init(JL_IMAGE_SEARCH rel)
     jl_prep_sanitizers();
     void *stack_lo, *stack_hi;
     jl_init_stack_limits(1, &stack_lo, &stack_hi);
-    jl_dl_handle = jl_load_dynamic_library(NULL, JL_RTLD_DEFAULT, 1);
+
+    // Load libjulia-internal (which contains this function), and libjulia, explicitly.
+    jl_libjulia_internal_handle = jl_load_dynamic_library(NULL, JL_RTLD_DEFAULT, 1);
+    jl_libjulia_handle = jl_load_dynamic_library(JL_LIBJULIA_DL_LIBNAME, JL_RTLD_DEFAULT, 1);
 #ifdef _OS_WINDOWS_
     jl_ntdll_handle = jl_dlopen("ntdll.dll", 0); // bypass julia's pathchecking for system dlls
     jl_kernel32_handle = jl_dlopen("kernel32.dll", 0);

src/julia.h

@@ -1510,7 +1510,7 @@ JL_DLLEXPORT int jl_is_debugbuild(void) JL_NOTSAFEPOINT;
 JL_DLLEXPORT jl_sym_t *jl_get_UNAME(void) JL_NOTSAFEPOINT;
 JL_DLLEXPORT jl_sym_t *jl_get_ARCH(void) JL_NOTSAFEPOINT;
 JL_DLLEXPORT jl_value_t *jl_get_libllvm(void) JL_NOTSAFEPOINT;
-extern JL_DLLEXPORT int jl_n_threads;
+extern JL_DLLIMPORT int jl_n_threads;
 
 // environment entries
 JL_DLLEXPORT jl_value_t *jl_environ(int i);

src/julia_internal.h

@@ -990,7 +990,8 @@ STATIC_INLINE uint64_t cong(uint64_t max, uint64_t unbias, uint64_t *seed)
 }
 
 // libuv stuff:
-JL_DLLEXPORT extern void *jl_dl_handle;
+JL_DLLEXPORT extern void *jl_libjulia_handle;
+JL_DLLEXPORT extern void *jl_libjulia_internal_handle;
 JL_DLLEXPORT extern void *jl_RTLD_DEFAULT_handle;
 #if defined(_OS_WINDOWS_)
 JL_DLLEXPORT extern void *jl_exe_handle;
@@ -1012,8 +1013,13 @@ JL_DLLEXPORT jl_value_t *jl_get_cfunction_trampoline(
 
 
 // Windows only
-#define JL_EXE_LIBNAME ((const char*)1)
-#define JL_DL_LIBNAME ((const char*)2)
+#define JL_EXE_LIBNAME                  ((const char*)1)
+#define JL_LIBJULIA_INTERNAL_DL_LIBNAME ((const char*)2)
+#if defined(JL_DEBUG_BUILD)
+#define JL_LIBJULIA_DL_LIBNAME          "libjulia-debug"
+#else
+#define JL_LIBJULIA_DL_LIBNAME          "libjulia"
+#endif
 const char *jl_dlfind_win32(const char *name);
 
 // libuv wrappers:

src/runtime_ccall.cpp

@@ -33,8 +33,10 @@ void *jl_get_library_(const char *f_lib, int throw_err) JL_NOTSAFEPOINT
 #ifdef _OS_WINDOWS_
     if (f_lib == JL_EXE_LIBNAME)
         return jl_exe_handle;
-    if (f_lib == JL_DL_LIBNAME)
-        return jl_dl_handle;
+    if (f_lib == JL_LIBJULIA_INTERNAL_DL_LIBNAME)
+        return jl_libjulia_internal_handle;
+    if (f_lib == JL_LIBJULIA_DL_LIBNAME)
+        return jl_libjulia_handle;
 #endif
     if (f_lib == NULL)
         return jl_RTLD_DEFAULT_handle;