set JULIA_HOME to try point to the julia binary (#23525)

fix #14577

examples/embedding/LocalModule.jl

@@ -0,0 +1,13 @@
+__precompile__()
+module LocalModule
+
+export myapp
+
+function myapp()
+ p = addprocs(1)
+ @everywhere p println("Taking over the world...")
+ rmprocs(p)
+ nothing
+end
+
+end

examples/embedding/Makefile

@@ -38,7 +38,14 @@ $(BIN)/embedding$(EXE): $(SRCDIR)/embedding.c
 $(BIN)/embedding-debug$(EXE): $(SRCDIR)/embedding.c
  $(CC) $^ -o $@ $(CPPFLAGS_ADD) $(CPPFLAGS) $(CFLAGS_ADD) $(CFLAGS) $(LDFLAGS_ADD) $(LDFLAGS) $(DEBUGFLAGS)
 
-check: $(BIN)/embedding$(EXE)
+ifneq ($(abspath $(BIN)),$(abspath $(SRCDIR)))
+# for demonstration purposes, our demo code is also installed
+# in $BIN, although this would likely not be typical
+$(BIN)/LocalModule.jl: $(SRCDIR)/LocalModule.jl
+ cp $< $@
+endif
+
+check: $(BIN)/embedding$(EXE) $(BIN)/LocalModule.jl
  $(JULIA) $(SRCDIR)/embedding-test.jl $<
  @echo SUCCESS
 

examples/embedding/embedding-test.jl

@@ -20,8 +20,9 @@ end
  @test stderr == "MethodError: no method matching this_function_has_no_methods()\n"
  @test success(p)
  lines = wait(stdout_task)
- @test length(lines) == 9
+ @test length(lines) == 10
  @test parse(Float64, lines[1]) ≈ sqrt(2)
  @test lines[8] == "called bar"
  @test lines[9] == "calling new bar"
+ @test lines[10] == "\tFrom worker 2:\tTaking over the world..."
 end

examples/embedding/embedding.c

@@ -149,6 +149,25 @@ int main()
  bar();
  }
 
+ {
+ // Importing a Julia package
+
+ checked_eval_string("let d = dirname(unsafe_string(Base.JLOptions().julia_bin))\n"
+ // disable the package manager
+ " ENV[\"JULIA_PKGDIR\"] = joinpath(d, \"disabled\")\n"
+ // locate files relative to the "embedding" executable
+ " empty!(LOAD_PATH)\n"
+ " push!(LOAD_PATH, d)\n"
+ // this directory needs to be writable for the example,
+ // although in real code it usually wouldn't necessarily be used that way
+ " empty!(Base.LOAD_CACHE_PATH)\n"
+ " push!(Base.LOAD_CACHE_PATH, tempdir())\n"
+ "end");
+ checked_eval_string("import LocalModule");
+ checked_eval_string("LocalModule.myapp()");
+ }
+
+
  int ret = 0;
  jl_atexit_hook(ret);
  return ret;

src/jlapi.c

@@ -26,19 +26,24 @@ JL_DLLEXPORT char * __cdecl dirname(char *);
 #else
 #include <libgen.h>
 #endif
+#ifndef _OS_WINDOWS_
+#include <dlfcn.h>
+#endif
 
-JL_DLLEXPORT int jl_is_initialized(void) { return jl_main_module!=NULL; }
+JL_DLLEXPORT int jl_is_initialized(void)
+{
+ return jl_main_module != NULL;
+}
 
-// First argument is the usr/lib directory where libjulia is, or NULL to guess.
-// if that doesn't work, try the full path to the "lib" directory that
-// contains lib/julia/sys.ji
+// First argument is the usr/bin directory where the julia binary is, or NULL to guess.
 // Second argument is the path of a system image file (*.ji) relative to the
-// first argument path, or relative to the default julia home dir. The default
-// is something like ../lib/julia/sys.ji
+// first argument path, or relative to the default julia home dir.
+// The default is something like ../lib/julia/sys.ji
 JL_DLLEXPORT void jl_init_with_image(const char *julia_home_dir,
  const char *image_relative_path)
 {
- if (jl_is_initialized()) return;
+ if (jl_is_initialized())
+ return;
  libsupport_init();
  jl_options.julia_home = julia_home_dir;
  if (image_relative_path != NULL)
@@ -51,17 +56,30 @@ JL_DLLEXPORT void jl_init_with_image(const char *julia_home_dir,
 
 JL_DLLEXPORT void jl_init(void)
 {
- char *libjldir = NULL;
-
+ char *libbindir = NULL;
+#ifdef _OS_WINDOWS_
  void *hdl = (void*)jl_load_dynamic_library_e(NULL, JL_RTLD_DEFAULT);
- if (hdl)
- libjldir = dirname((char*)jl_pathname_for_handle(hdl));
- if (libjldir)
- jl_init_with_image(libjldir, jl_get_default_sysimg_path());
- else {
+ if (hdl) {
+ char *to_free = (char*)jl_pathname_for_handle(hdl);
+ if (to_free) {
+ libbindir = strdup(dirname(to_free));
+ free(to_free);
+ }
+ }
+#else
+ Dl_info dlinfo;
+ if (dladdr((void*)jl_init, &dlinfo) != 0 && dlinfo.dli_fname) {
+ char *to_free = strdup(dlinfo.dli_fname);
+ (void)asprintf(&libbindir, "%s" PATHSEPSTRING ".." PATHSEPSTRING "%s", dirname(to_free), "bin");
+ free(to_free);
+ }
+#endif
+ if (!libbindir) {
  printf("jl_init unable to find libjulia!\n");
  abort();
  }
+ jl_init_with_image(libbindir, jl_get_default_sysimg_path());
+ free(libbindir);
 }
 
 JL_DLLEXPORT jl_value_t *jl_eval_string(const char *str)