1 files changed, 267 insertions, 0 deletions
diff --git a/src/kmk/load.c b/src/kmk/load.c
new file mode 100644
index 0000000..37e7b8e
--- /dev/null
+++ b/src/kmk/load.c
@@ -0,0 +1,267 @@
+/* Loading dynamic objects for GNU Make.
+Copyright (C) 2012-2016 Free Software Foundation, Inc.
+This file is part of GNU Make.
+
+GNU Make is free software; you can redistribute it and/or modify it under the
+terms of the GNU General Public License as published by the Free Software
+Foundation; either version 3 of the License, or (at your option) any later
+version.
+
+GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "makeint.h"
+
+#if MAKE_LOAD
+
+#include <string.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <dlfcn.h>
+#include <errno.h>
+
+#define SYMBOL_EXTENSION        "_gmk_setup"
+
+#include "debug.h"
+#include "filedef.h"
+#include "variable.h"
+
+/* Tru64 V4.0 does not have this flag */
+#ifndef RTLD_GLOBAL
+# define RTLD_GLOBAL 0
+#endif
+
+struct load_list
+  {
+    struct load_list *next;
+    const char *name;
+    void *dlp;
+  };
+
+static struct load_list *loaded_syms = NULL;
+
+static load_func_t
+load_object (const floc *flocp, int noerror, const char *ldname,
+             const char *symname)
+{
+  static void *global_dl = NULL;
+  load_func_t symp;
+
+  if (! global_dl)
+    {
+      global_dl = dlopen (NULL, RTLD_NOW|RTLD_GLOBAL);
+      if (! global_dl)
+        {
+          const char *err = dlerror ();
+          OS (fatal, flocp, _("Failed to open global symbol table: %s"), err);
+        }
+    }
+
+  symp = (load_func_t) dlsym (global_dl, symname);
+  if (! symp)
+    {
+      struct load_list *new;
+      void *dlp = NULL;
+
+    /* If the path has no "/", try the current directory first.  */
+      if (! strchr (ldname, '/')
+#ifdef HAVE_DOS_PATHS
+          && ! strchr (ldname, '\\')
+#endif
+         )
+        dlp = dlopen (concat (2, "./", ldname), RTLD_LAZY|RTLD_GLOBAL);
+
+      /* If we haven't opened it yet, try the default search path.  */
+      if (! dlp)
+        dlp = dlopen (ldname, RTLD_LAZY|RTLD_GLOBAL);
+
+      /* Still no?  Then fail.  */
+      if (! dlp)
+        {
+          const char *err = dlerror ();
+          if (noerror)
+            DB (DB_BASIC, ("%s", err));
+          else
+            OS (error, flocp, "%s", err);
+          return NULL;
+        }
+
+      /* Assert that the GPL license symbol is defined.  */
+      symp = (load_func_t) dlsym (dlp, "plugin_is_GPL_compatible");
+      if (! symp)
+        OS (fatal, flocp,
+             _("Loaded object %s is not declared to be GPL compatible"),
+             ldname);
+
+      symp = (load_func_t) dlsym (dlp, symname);
+      if (! symp)
+        {
+          const char *err = dlerror ();
+          OSSS (fatal, flocp, _("Failed to load symbol %s from %s: %s"),
+                symname, ldname, err);
+        }
+
+      /* Add this symbol to a trivial lookup table.  This is not efficient but
+         it's highly unlikely we'll be loading lots of objects, and we only
+         need it to look them up on unload, if we rebuild them.  */
+      new = xmalloc (sizeof (struct load_list));
+      new->name = xstrdup (ldname);
+      new->dlp = dlp;
+      new->next = loaded_syms;
+      loaded_syms = new;
+    }
+
+  return symp;
+}
+
+int
+load_file (const floc *flocp, const char **ldname, int noerror)
+{
+  int nmlen = strlen (*ldname);
+  char *new = alloca (nmlen + CSTRLEN (SYMBOL_EXTENSION) + 1);
+  char *symname = NULL;
+  char *loaded;
+  const char *fp;
+  int r;
+  load_func_t symp;
+
+  /* Break the input into an object file name and a symbol name.  If no symbol
+     name was provided, compute one from the object file name.  */
+  fp = strchr (*ldname, '(');
+  if (fp)
+    {
+      const char *ep;
+
+      /* There's an open paren, so see if there's a close paren: if so use
+         that as the symbol name.  We can't have whitespace: it would have
+         been chopped up before this function is called.  */
+      ep = strchr (fp+1, ')');
+      if (ep && ep[1] == '\0')
+        {
+          int l = fp - *ldname;;
+
+          ++fp;
+          if (fp == ep)
+            OS (fatal, flocp, _("Empty symbol name for load: %s"), *ldname);
+
+          /* Make a copy of the ldname part.  */
+          memcpy (new, *ldname, l);
+          new[l] = '\0';
+          *ldname = new;
+          nmlen = l;
+
+          /* Make a copy of the symbol name part.  */
+          symname = new + l + 1;
+          memcpy (symname, fp, ep - fp);
+          symname[ep - fp] = '\0';
+        }
+    }
+
+  /* Add this name to the string cache so it can be reused later.  */
+  *ldname = strcache_add (*ldname);
+
+  /* If this object has been loaded, we're done.  */
+  loaded = allocated_variable_expand ("$(.LOADED)");
+  fp = strstr (loaded, *ldname);
+  r = fp && (fp==loaded || fp[-1]==' ') && (fp[nmlen]=='\0' || fp[nmlen]==' ');
+  if (r)
+    goto exit;
+
+  /* If we didn't find a symbol name yet, construct it from the ldname.  */
+  if (! symname)
+    {
+      char *p = new;
+
+      fp = strrchr (*ldname, '/');
+#ifdef HAVE_DOS_PATHS
+      if (fp)
+        {
+          const char *fp2 = strchr (fp, '\\');
+
+          if (fp2 > fp)
+            fp = fp2;
+        }
+      else
+        fp = strrchr (*ldname, '\\');
+      /* The (improbable) case of d:foo.  */
+      if (fp && *fp && fp[1] == ':')
+        fp++;
+#endif
+      if (!fp)
+        fp = *ldname;
+      else
+        ++fp;
+      while (isalnum (*fp) || *fp == '_')
+        *(p++) = *(fp++);
+      strcpy (p, SYMBOL_EXTENSION);
+      symname = new;
+    }
+
+  DB (DB_VERBOSE, (_("Loading symbol %s from %s\n"), symname, *ldname));
+
+  /* Load it!  */
+  symp = load_object (flocp, noerror, *ldname, symname);
+  if (! symp)
+    return 0;
+
+  /* Invoke the symbol.  */
+  r = (*symp) (flocp);
+
+  /* If it succeeded, add the load file to the loaded variable.  */
+  if (r > 0)
+    {
+      size_t loadlen = strlen (loaded);
+      char *newval = alloca (loadlen + strlen (*ldname) + 2);
+      /* Don't add a space if it's empty.  */
+      if (loadlen)
+        {
+          memcpy (newval, loaded, loadlen);
+          newval[loadlen++] = ' ';
+        }
+      strcpy (&newval[loadlen], *ldname);
+      do_variable_definition (flocp, ".LOADED", newval, o_default, f_simple, 0);
+    }
+
+ exit:
+  free (loaded);
+  return r;
+}
+
+void
+unload_file (const char *name)
+{
+  struct load_list *d;
+
+  for (d = loaded_syms; d != NULL; d = d->next)
+    if (streq (d->name, name) && d->dlp)
+      {
+        if (dlclose (d->dlp))
+          perror_with_name ("dlclose", d->name);
+        d->dlp = NULL;
+        break;
+      }
+}
+
+#else
+
+int
+load_file (const floc *flocp, const char **ldname UNUSED, int noerror)
+{
+  if (! noerror)
+    O (fatal, flocp,
+       _("The 'load' operation is not supported on this platform."));
+
+  return 0;
+}
+
+void
+unload_file (const char *name UNUSED)
+{
+  O (fatal, NILF, "INTERNAL: Cannot unload when load is not supported!");
+}
+
+#endif  /* MAKE_LOAD */