Change Windows CRT func to be considered as libjulia func (JuliaLang#…

…39636)

This prefers crtdll over ntdll.
This supports the specialization of `memcpy` ccall on Windows.

src/ccall.cpp

@@ -5,6 +5,10 @@
 #include <llvm/Bitcode/BitcodeReader.h>
 #include <llvm/Linker/Linker.h>
 
+#ifdef _OS_WINDOWS_
+extern const char jl_crtdll_basename[];
+#endif
+
 // somewhat unusual variable, in that aotcompile wants to get the address of this for a sanity check
 GlobalVariable *jl_emit_RTLD_DEFAULT_var(Module *M)
 {
@@ -1266,7 +1270,20 @@ 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_LIBJULIA_INTERNAL_DL_LIBNAME) && f_name && !strcmp(f_name, name);
+        if (f_lib) {
+#ifdef _OS_WINDOWS_
+            if ((f_lib == JL_EXE_LIBNAME) || // preventing invalid pointer access
+                (f_lib == JL_LIBJULIA_INTERNAL_DL_LIBNAME) ||
+                (!strcmp(f_lib, jl_crtdll_basename))) {
+                // libjulia-like
+            }
+            else
+                return false;
+#else
+            return false;
+#endif
+        }
+        return f_name && !strcmp(f_name, name);
     };
 #define is_libjulia_func(name) _is_libjulia_func((uintptr_t)&(name), #name)
 

src/dlload.c

@@ -57,6 +57,25 @@ static int endswith_extension(const char *path) JL_NOTSAFEPOINT
     return 0;
 }
 
+#ifdef _OS_WINDOWS_
+#ifdef _MSC_VER
+#if (_MSC_VER >= 1930) || (_MSC_VER < 1800)
+#error This version of MSVC has not been tested.
+#elif _MSC_VER >= 1900 // VC++ 2015 / 2017 / 2019
+#define CRTDLL_BASENAME "vcruntime140"
+#elif _MSC_VER >= 1800 // VC++ 2013
+#define CRTDLL_BASENAME "msvcr120"
+#endif
+#else
+#define CRTDLL_BASENAME "msvcrt"
+#endif
+
+const char jl_crtdll_basename[] = CRTDLL_BASENAME;
+const char jl_crtdll_name[] = CRTDLL_BASENAME ".dll";
+
+#undef CRTDLL_BASENAME
+#endif
+
 #define PATHBUF 4096
 
 #define JL_RTLD(flags, FLAG) (flags & JL_RTLD_ ## FLAG ? RTLD_ ## FLAG : 0)
@@ -314,18 +333,10 @@ const char *jl_dlfind_win32(const char *f_name)
         return JL_LIBJULIA_DL_LIBNAME;
     if (jl_dlsym(jl_kernel32_handle, f_name, &dummy, 0))
         return "kernel32";
+    if (jl_dlsym(jl_crtdll_handle, f_name, &dummy, 0)) // Prefer crtdll over ntdll
+        return jl_crtdll_basename;
     if (jl_dlsym(jl_ntdll_handle, f_name, &dummy, 0))
         return "ntdll";
-    if (jl_dlsym(jl_crtdll_handle, f_name, &dummy, 0))
-#if defined(_MSC_VER)
-#if _MSC_VER == 1800
-        return "msvcr120";
-#else
-#error This version of MSVC has not been tested.
-#endif
-#else
-        return "msvcrt";
-#endif
     if (jl_dlsym(jl_winsock_handle, f_name, &dummy, 0))
         return "ws2_32";
     // additional common libraries (libc?) could be added here, but in general,

src/init.c

@@ -302,6 +302,7 @@ void *jl_ntdll_handle;
 void *jl_kernel32_handle;
 void *jl_crtdll_handle;
 void *jl_winsock_handle;
+extern const char jl_crtdll_name[];
 #endif
 
 uv_loop_t *jl_io_loop;
@@ -665,11 +666,7 @@ void _julia_init(JL_IMAGE_SEARCH rel)
 #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);
-#if defined(_MSC_VER) && _MSC_VER == 1800
-    jl_crtdll_handle = jl_dlopen("msvcr120.dll", 0);
-#else
-    jl_crtdll_handle = jl_dlopen("msvcrt.dll", 0);
-#endif
+    jl_crtdll_handle = jl_dlopen(jl_crtdll_name, 0);
     jl_winsock_handle = jl_dlopen("ws2_32.dll", 0);
     jl_exe_handle = GetModuleHandleA(NULL);
     JL_MUTEX_INIT(&jl_in_stackwalk);

test/ccall.jl

@@ -1579,6 +1579,19 @@ let
     @test arr[1] == '0'
 end
 
+# issue #38751
+let
+    function f38751!(dest::Vector{UInt8}, src::Vector{UInt8}, n::UInt)
+        d, s = pointer(dest), pointer(src)
+        GC.@preserve dest src ccall(:memcpy, Cvoid, (Ptr{UInt8}, Ptr{UInt8}, Csize_t), d, s, n)
+        return dest
+    end
+    dest = zeros(UInt8, 8)
+    @test f38751!(dest, collect(0x1:0x8), UInt(8)) == 0x1:0x8
+    llvm = sprint(code_llvm, f38751!, (Vector{UInt8}, Vector{UInt8}, UInt))
+    @test !occursin("call void inttoptr", llvm)
+end
+
 # issue #34061
 let o_file = tempname(), err = Base.PipeEndpoint()
     run(pipeline(Cmd(`$(Base.julia_cmd()) --color=no --output-o=$o_file -e '