more experiments on load_dyld.c

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@604 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

C/load_dyld.c

@@ -0,0 +1,187 @@
+/*************************************************************************
+*									 *
+*	 YAP Prolog 							 *
+*									 *
+*	Yap Prolog was developed at NCCUP - Universidade do Porto	 *
+*									 *
+* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997	 *
+*									 *
+**************************************************************************
+*									 *
+* File:		load_dl.c						 *
+* comments:	dl based dynamic loaderr of external routines		 *
+*               tested on i486-linuxelf					 *
+*************************************************************************/
+
+#include "Yap.h"
+#include "Yatom.h"
+#include "Heap.h"
+#include "yapio.h"
+#include "Foreign.h"
+
+#if LOAD_DYDL
+
+#include <string.h>
+
+/* This code is originally from Rex A. Dieter posting in comp.sys.next.programmer */
+#import <mach-o/dyld.h>
+
+enum dyldErrorSource
+{
+    OFImage,
+};
+
+#define NUM_OFI_ERRORS (sizeof(OFIErrorStrings) /  sizeof(OFIErrorStrings[0]))
+
+static char *
+mydlerror(int dl_errno)
+{
+  char *errString;
+  switch(dl_errno) {
+  default:
+  case NSObjectFileImageFailure:
+  case NSObjectFileImageFormat:
+    /* for these a message is printed on stderr by dyld */
+    errString = "Can't create object file image";
+    break;
+  case NSObjectFileImageSuccess:
+    errString = NULL;
+    break;
+  case NSObjectFileImageInappropriateFile:
+    errString = "Inappropriate file type for dynamic loading";
+    break;
+  case NSObjectFileImageArch:
+    errString = "Wrong CPU type in object file";
+    break;
+  case NSObjectFileImageAccess:
+    errString = "Can't read object file (no access)";
+    break;
+  }
+  return(errString);
+}
+
+
+static void *
+mydlopen(char *path)
+{
+    int dyld_result;
+    NSObjectFileImage ofile;
+    NSModule handle = NULL;
+    dyld_result = NSCreateObjectFileImageFromFile(path, &ofile);
+    if (dyld_result != NSObjectFileImageSuccess) {
+      dl_errno = dyld_result;
+    } else {
+      /* NSLinkModule will cause the run to abort on any link error's */
+      /* not very friendly but the error recovery functionality is limited */
+        handle = NSLinkModule(ofile, path, TRUE);
+    } return handle;
+}
+
+static void *
+mydlsym(char *symbol)
+{
+    void *addr;
+    if (NSIsSymbolNameDefined(symbol))
+        addr = NSAddressOfSymbol(NSLookupAndBindSymbol(symbol));
+    else
+        addr = NULL;
+    return addr;
+} 
+
+static void
+mydlclose(void *handle)
+{
+  NSUnLinkModule(handle, NSUNLINKMODULE_OPTION_NONE);
+} 
+
+/*
+ * LoadForeign(ofiles,libs,proc_name,init_proc) dynamically loads foreign
+ * code files and libraries and locates an initialization routine
+*/
+Int
+LoadForeign(StringList ofiles, StringList libs,
+	       char *proc_name,	YapInitProc *init_proc)
+{
+
+  while (ofiles) {
+    void *handle;
+
+    /* mydlopen wants to follow the LD_CONFIG_PATH */
+    if (!TrueFileName(ofiles->s, FileNameBuf, TRUE)) {
+      strcpy(LoadMsg, "[ Trying to open unexisting file in LoadForeign ]");
+      return LOAD_FAILLED;
+    }
+    if((handle=mydlopen(FileNameBuf)) == 0)
+    {
+      fprintf(stderr,"calling dlopen with error %s\n", mydlerror());
+/*      strcpy(LoadMsg,dlerror());*/
+      return LOAD_FAILLED;
+    }
+
+    ofiles->handle = handle;
+
+    ofiles = ofiles->next;
+  }
+  /* load libraries first so that their symbols are available to
+     other routines */
+  while (libs) {
+
+    if (libs->s[0] == '-') {
+      strcpy(FileNameBuf,"lib");
+      strcat(FileNameBuf,libs->s+2);
+      strcat(FileNameBuf,".so");
+    } else {
+      strcpy(FileNameBuf,libs->s);
+    }
+
+    if((libs->handle=mydlopen(FileNameBuf)) == NULL)
+    {
+      strcpy(LoadMsg,mydlerror());
+      return LOAD_FAILLED;
+    }
+    libs = libs->next;
+  }
+
+  *init_proc = (YapInitProc) mydlsym(proc_name);
+
+  if(! *init_proc) {
+    strcpy(LoadMsg,"Could not locate initialization routine");
+    return LOAD_FAILLED;
+  }
+
+  return LOAD_SUCCEEDED;
+}
+
+void 
+ShutdownLoadForeign(void)
+{
+  ForeignObj *f_code;
+
+  f_code = ForeignCodeLoaded;
+  while (f_code != NULL) {
+    StringList objs, libs;
+
+    objs = f_code->objs;
+    while (objs != NULL) {
+      if (mydlclose(objs->handle) != 0)
+	return; /* ERROR */
+      objs = objs->next;
+    }
+    libs = f_code->libs;
+    while (libs != NULL) {
+      if (mydlclose(libs->handle) != 0)
+	return; /* ERROR */
+      objs = libs->next;
+    }
+    f_code = f_code->next;
+  }
+}
+
+Int
+ReLoadForeign(StringList ofiles, StringList libs,
+	       char *proc_name,	YapInitProc *init_proc)
+{
+  return(LoadForeign(ofiles,libs, proc_name, init_proc));
+}
+
+#endif