From 153558dff8a95dd89f3b5713838c22debe3b78e8 Mon Sep 17 00:00:00 2001
From: "Marc G. Fournier" <scrappy@hub.org>
Date: Fri, 19 Dec 1997 22:58:27 +0000
Subject: [PATCH] These files will get link'd to 'dynloader.[ch]', from
configure, which will then get link'd into SUBSYS.o
---
src/backend/port/dynloader/README.dlfcn.aix | 167 ++++++
src/backend/port/dynloader/aix.c | 603 ++++++++++++++++++++
src/backend/port/dynloader/aix.h | 56 ++
src/backend/port/dynloader/bsd.c | 107 ++++
4 files changed, 933 insertions(+)
create mode 100644 src/backend/port/dynloader/README.dlfcn.aix
create mode 100644 src/backend/port/dynloader/aix.c
create mode 100644 src/backend/port/dynloader/aix.h
create mode 100644 src/backend/port/dynloader/bsd.c
diff --git a/src/backend/port/dynloader/README.dlfcn.aix b/src/backend/port/dynloader/README.dlfcn.aix
new file mode 100644
index 00000000000..f64446d49b5
--- /dev/null
+++ b/src/backend/port/dynloader/README.dlfcn.aix
@@ -0,0 +1,167 @@
+Copyright (c) 1992,1993,1995, Jens-Uwe Mager, Helios Software GmbH
+Not derived from licensed software.
+
+Permission is granted to freely use, copy, modify, and redistribute
+this software, provided that no attempt is made to gain profit from it,
+the author is not construed to be liable for any results of using the
+software, alterations are clearly marked as such, and this notice is
+not modified.
+
+libdl.a
+-------
+
+This is an emulation library to emulate the SunOS/System V.4 functions
+to access the runtime linker. The functions are emulated by using the
+AIX load() function and by reading the .loader section of the loaded
+module to find the exports. The to be loaded module should be linked as
+follows (if using AIX 3):
+
+ cc -o module.so -bM:SRE -bE:module.exp -e _nostart $(OBJS)
+
+For AIX 4:
+
+ cc -o module.so -bM:SRE -bE:module.exp -bnoentry $(OBJS)
+
+The module export file contains the symbols to be exported. Because
+this library uses the loader section, the final module.so file can be
+stripped. C++ users should build their shared objects using the script
+makeC++SharedLib (part of the IBM C++ compiler), this will make sure
+that constructors and destructors for static and global objects will be
+called upon loading and unloading the module.
+
+Usage
+-----
+
+void *dlopen(const char *path, int mode);
+
+This routine loads the module pointed to by path and reads its export
+table. If the path does not contain a '/' character, dlopen will search
+for the module using the LIBPATH environment variable. It returns an
+opaque handle to the module or NULL on error. The mode parameter can be
+either RTLD_LAZY (for lazy function binding) or RTLD_NOW for immediate
+function binding. The AIX implementation currently does treat RTLD_NOW
+the same as RTLD_LAZY. The flag RTLD_GLOBAL might be or'ed into the
+mode parameter to allow loaded modules to bind to global variables or
+functions in other loaded modules loaded by dlopen(). If RTLD_GLOBAL is
+not specified, only globals from the main part of the executable or
+shared libraries are used to look for undefined symbols in loaded
+modules.
+
+
+void *dlsym(void *handle, const char *symbol);
+
+This routine searches for the symbol in the module referred to by
+handle and returns its address. If the symbol could not be found, the
+function returns NULL. The return value must be casted to a proper
+function pointer before it can be used. SunOS/System V.4 allow handle
+to be a NULL pointer to refer to the module the call is made from, this
+is not implemented.
+
+int dlclose(void *handle);
+
+This routine unloads the module referred to by the handle and disposes
+of any local storage. this function returns -1 on failure.
+
+char *dlerror(void);
+
+This routine can be used to retrieve a text message describing the most
+recent error that occured on on of the above routines. This function
+returns NULL if there is not error information.
+
+Initialization and termination handlers
+---------------------------------------
+
+The emulation provides for an initialization and a termination
+handler. The dlfcn.h file contains a structure declaration named
+dl_info with following members:
+
+ void (*init)(void);
+ void (*fini)(void);
+
+The init function is called upon first referencing the library. The
+fini function is called at dlclose() time or when the process exits.
+The module should declare a variable named dl_info that contains this
+structure which must be exported. These functions correspond to the
+documented _init() and _fini() functions of SunOS 4.x, but these are
+appearently not implemented in SunOS. When using SunOS 5.0, these
+correspond to #pragma init and #pragma fini respectively. At the same
+time any static or global C++ object's constructors or destructors will
+be called.
+
+Jens-Uwe Mager
+
+HELIOS Software GmbH
+Lavesstr. 80
+30159 Hannover
+Germany
+
+Phone: +49 511 36482-0
+FAX: +49 511 36482-69
+AppleLink: helios.de Attn: Jens-Uwe Mager
+Internet: jum@helios.de
+
+Revison History
+---------------
+
+SCCS/s.dlfcn.h:
+
+D 1.4 95/04/25 09:36:52 jum 4 3 00018/00004/00028
+MRs:
+COMMENTS:
+added RTLD_GLOBAL, include and C++ guards
+
+D 1.3 92/12/27 20:58:32 jum 3 2 00001/00001/00031
+MRs:
+COMMENTS:
+we always have prototypes on RS/6000
+
+D 1.2 92/08/16 17:45:11 jum 2 1 00009/00000/00023
+MRs:
+COMMENTS:
+added dl_info structure to implement initialize and terminate functions
+
+D 1.1 92/08/02 18:08:45 jum 1 0 00023/00000/00000
+MRs:
+COMMENTS:
+Erstellungsdatum und -uhrzeit 92/08/02 18:08:45 von jum
+
+SCCS/s.dlfcn.c:
+
+D 1.7 95/08/14 19:08:38 jum 8 6 00026/00004/00502
+MRs:
+COMMENTS:
+Integrated the fixes from Kirk Benell (kirk@rsinc.com) to allow loading of
+shared objects generated under AIX 4. Fixed bug that symbols with exactly
+8 characters would use garbage characters from the following symbol value.
+
+D 1.6 95/04/25 09:38:03 jum 6 5 00046/00006/00460
+MRs:
+COMMENTS:
+added handling of C++ static constructors and destructors, added RTLD_GLOBAL to bind against other loaded modules
+
+D 1.5 93/02/14 20:14:17 jum 5 4 00002/00000/00464
+MRs:
+COMMENTS:
+added path to dlopen error message to make clear where there error occured.
+
+D 1.4 93/01/03 19:13:56 jum 4 3 00061/00005/00403
+MRs:
+COMMENTS:
+to allow calling symbols in the main module call load with L_NOAUTODEFER and
+do a loadbind later with the main module.
+
+D 1.3 92/12/27 20:59:55 jum 3 2 00066/00008/00342
+MRs:
+COMMENTS:
+added search by L_GETINFO if module got loaded by LIBPATH
+
+D 1.2 92/08/16 17:45:43 jum 2 1 00074/00006/00276
+MRs:
+COMMENTS:
+implemented initialize and terminate functions, added reference counting to avoid multiple loads of the same library
+
+D 1.1 92/08/02 18:08:45 jum 1 0 00282/00000/00000
+MRs:
+COMMENTS:
+Erstellungsdatum und -uhrzeit 92/08/02 18:08:45 von jum
+
diff --git a/src/backend/port/dynloader/aix.c b/src/backend/port/dynloader/aix.c
new file mode 100644
index 00000000000..1c34186dc4b
--- /dev/null
+++ b/src/backend/port/dynloader/aix.c
@@ -0,0 +1,603 @@
+/*
+ * @(#)dlfcn.c 1.7 revision of 95/08/14 19:08:38
+ * This is an unpublished work copyright (c) 1992 HELIOS Software GmbH
+ * 30159 Hannover, Germany
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/ldr.h>
+#include <a.out.h>
+#include <ldfcn.h>
+#include "dlfcn.h"
+#include "c.h"
+
+/*
+ * We simulate dlopen() et al. through a call to load. Because AIX has
+ * no call to find an exported symbol we read the loader section of the
+ * loaded module and build a list of exported symbols and their virtual
+ * address.
+ */
+
+typedef struct
+{
+ char *name; /* the symbols's name */
+ void *addr; /* its relocated virtual address */
+} Export, *ExportPtr;
+
+/*
+ * xlC uses the following structure to list its constructors and
+ * destructors. This is gleaned from the output of munch.
+ */
+typedef struct
+{
+ void (*init) (void); /* call static constructors */
+ void (*term) (void); /* call static destructors */
+} Cdtor, *CdtorPtr;
+
+/*
+ * The void * handle returned from dlopen is actually a ModulePtr.
+ */
+typedef struct Module
+{
+ struct Module *next;
+ char *name; /* module name for refcounting */
+ int refCnt; /* the number of references */
+ void *entry; /* entry point from load */
+ struct dl_info *info; /* optional init/terminate functions */
+ CdtorPtr cdtors; /* optional C++ constructors */
+ int nExports; /* the number of exports found */
+ ExportPtr exports; /* the array of exports */
+} Module, *ModulePtr;
+
+/*
+ * We keep a list of all loaded modules to be able to call the fini
+ * handlers and destructors at atexit() time.
+ */
+static ModulePtr modList;
+
+/*
+ * The last error from one of the dl* routines is kept in static
+ * variables here. Each error is returned only once to the caller.
+ */
+static char errbuf[BUFSIZ];
+static int errvalid;
+
+extern char *strdup(const char *);
+static void caterr(char *);
+static int readExports(ModulePtr);
+static void terminate(void);
+static void *findMain(void);
+
+void *
+dlopen(const char *path, int mode)
+{
+ register ModulePtr mp;
+ static void *mainModule;
+
+ /*
+ * Upon the first call register a terminate handler that will close
+ * all libraries. Also get a reference to the main module for use with
+ * loadbind.
+ */
+ if (!mainModule)
+ {
+ if ((mainModule = findMain()) == NULL)
+ return NULL;
+ atexit(terminate);
+ }
+
+ /*
+ * Scan the list of modules if we have the module already loaded.
+ */
+ for (mp = modList; mp; mp = mp->next)
+ if (strcmp(mp->name, path) == 0)
+ {
+ mp->refCnt++;
+ return mp;
+ }
+ if ((mp = (ModulePtr) calloc(1, sizeof(*mp))) == NULL)
+ {
+ errvalid++;
+ strcpy(errbuf, "calloc: ");
+ strcat(errbuf, strerror(errno));
+ return NULL;
+ }
+ if ((mp->name = strdup(path)) == NULL)
+ {
+ errvalid++;
+ strcpy(errbuf, "strdup: ");
+ strcat(errbuf, strerror(errno));
+ free(mp);
+ return NULL;
+ }
+
+ /*
+ * load should be declared load(const char *...). Thus we cast the
+ * path to a normal char *. Ugly.
+ */
+ if ((mp->entry = (void *) load((char *) path, L_NOAUTODEFER, NULL)) == NULL)
+ {
+ free(mp->name);
+ free(mp);
+ errvalid++;
+ strcpy(errbuf, "dlopen: ");
+ strcat(errbuf, path);
+ strcat(errbuf, ": ");
+
+ /*
+ * If AIX says the file is not executable, the error can be
+ * further described by querying the loader about the last error.
+ */
+ if (errno == ENOEXEC)
+ {
+ char *tmp[BUFSIZ / sizeof(char *)];
+
+ if (loadquery(L_GETMESSAGES, tmp, sizeof(tmp)) == -1)
+ strcpy(errbuf, strerror(errno));
+ else
+ {
+ char **p;
+
+ for (p = tmp; *p; p++)
+ caterr(*p);
+ }
+ }
+ else
+ strcat(errbuf, strerror(errno));
+ return NULL;
+ }
+ mp->refCnt = 1;
+ mp->next = modList;
+ modList = mp;
+ if (loadbind(0, mainModule, mp->entry) == -1)
+ {
+ dlclose(mp);
+ errvalid++;
+ strcpy(errbuf, "loadbind: ");
+ strcat(errbuf, strerror(errno));
+ return NULL;
+ }
+
+ /*
+ * If the user wants global binding, loadbind against all other loaded
+ * modules.
+ */
+ if (mode & RTLD_GLOBAL)
+ {
+ register ModulePtr mp1;
+
+ for (mp1 = mp->next; mp1; mp1 = mp1->next)
+ if (loadbind(0, mp1->entry, mp->entry) == -1)
+ {
+ dlclose(mp);
+ errvalid++;
+ strcpy(errbuf, "loadbind: ");
+ strcat(errbuf, strerror(errno));
+ return NULL;
+ }
+ }
+ if (readExports(mp) == -1)
+ {
+ dlclose(mp);
+ return NULL;
+ }
+
+ /*
+ * If there is a dl_info structure, call the init function.
+ */
+ if (mp->info = (struct dl_info *) dlsym(mp, "dl_info"))
+ {
+ if (mp->info->init)
+ (*mp->info->init) ();
+ }
+ else
+ errvalid = 0;
+
+ /*
+ * If the shared object was compiled using xlC we will need to call
+ * static constructors (and later on dlclose destructors).
+ */
+ if (mp->cdtors = (CdtorPtr) dlsym(mp, "__cdtors"))
+ {
+ while (mp->cdtors->init)
+ {
+ (*mp->cdtors->init) ();
+ mp->cdtors++;
+ }
+ }
+ else
+ errvalid = 0;
+ return mp;
+}
+
+/*
+ * Attempt to decipher an AIX loader error message and append it
+ * to our static error message buffer.
+ */
+static void
+caterr(char *s)
+{
+ register char *p = s;
+
+ while (*p >= '0' && *p <= '9')
+ p++;
+ switch (atoi(s))
+ {
+ case L_ERROR_TOOMANY:
+ strcat(errbuf, "to many errors");
+ break;
+ case L_ERROR_NOLIB:
+ strcat(errbuf, "can't load library");
+ strcat(errbuf, p);
+ break;
+ case L_ERROR_UNDEF:
+ strcat(errbuf, "can't find symbol");
+ strcat(errbuf, p);
+ break;
+ case L_ERROR_RLDBAD:
+ strcat(errbuf, "bad RLD");
+ strcat(errbuf, p);
+ break;
+ case L_ERROR_FORMAT:
+ strcat(errbuf, "bad exec format in");
+ strcat(errbuf, p);
+ break;
+ case L_ERROR_ERRNO:
+ strcat(errbuf, strerror(atoi(++p)));
+ break;
+ default:
+ strcat(errbuf, s);
+ break;
+ }
+}
+
+void *
+dlsym(void *handle, const char *symbol)
+{
+ register ModulePtr mp = (ModulePtr) handle;
+ register ExportPtr ep;
+ register int i;
+
+ /*
+ * Could speed up the search, but I assume that one assigns the result
+ * to function pointers anyways.
+ */
+ for (ep = mp->exports, i = mp->nExports; i; i--, ep++)
+ if (strcmp(ep->name, symbol) == 0)
+ return ep->addr;
+ errvalid++;
+ strcpy(errbuf, "dlsym: undefined symbol ");
+ strcat(errbuf, symbol);
+ return NULL;
+}
+
+char *
+dlerror(void)
+{
+ if (errvalid)
+ {
+ errvalid = 0;
+ return errbuf;
+ }
+ return NULL;
+}
+
+int
+dlclose(void *handle)
+{
+ register ModulePtr mp = (ModulePtr) handle;
+ int result;
+ register ModulePtr mp1;
+
+ if (--mp->refCnt > 0)
+ return 0;
+ if (mp->info && mp->info->fini)
+ (*mp->info->fini) ();
+ if (mp->cdtors)
+ while (mp->cdtors->term)
+ {
+ (*mp->cdtors->term) ();
+ mp->cdtors++;
+ }
+ result = unload(mp->entry);
+ if (result == -1)
+ {
+ errvalid++;
+ strcpy(errbuf, strerror(errno));
+ }
+ if (mp->exports)
+ {
+ register ExportPtr ep;
+ register int i;
+
+ for (ep = mp->exports, i = mp->nExports; i; i--, ep++)
+ if (ep->name)
+ free(ep->name);
+ free(mp->exports);
+ }
+ if (mp == modList)
+ modList = mp->next;
+ else
+ {
+ for (mp1 = modList; mp1; mp1 = mp1->next)
+ if (mp1->next == mp)
+ {
+ mp1->next = mp->next;
+ break;
+ }
+ }
+ free(mp->name);
+ free(mp);
+ return result;
+}
+
+static void
+terminate(void)
+{
+ while (modList)
+ dlclose(modList);
+}
+
+/*
+ * Build the export table from the XCOFF .loader section.
+ */
+static int
+readExports(ModulePtr mp)
+{
+ LDFILE *ldp = NULL;
+ SCNHDR sh,
+ shdata;
+ LDHDR *lhp;
+ char *ldbuf;
+ LDSYM *ls;
+ int i;
+ ExportPtr ep;
+
+ if ((ldp = ldopen(mp->name, ldp)) == NULL)
+ {
+ struct ld_info *lp;
+ char *buf;
+ int size = 4 * 1024;
+
+ if (errno != ENOENT)
+ {
+ errvalid++;
+ strcpy(errbuf, "readExports: ");
+ strcat(errbuf, strerror(errno));
+ return -1;
+ }
+
+ /*
+ * The module might be loaded due to the LIBPATH environment
+ * variable. Search for the loaded module using L_GETINFO.
+ */
+ if ((buf = malloc(size)) == NULL)
+ {
+ errvalid++;
+ strcpy(errbuf, "readExports: ");
+ strcat(errbuf, strerror(errno));
+ return -1;
+ }
+ while ((i = loadquery(L_GETINFO, buf, size)) == -1 && errno == ENOMEM)
+ {
+ free(buf);
+ size += 4 * 1024;
+ if ((buf = malloc(size)) == NULL)
+ {
+ errvalid++;
+ strcpy(errbuf, "readExports: ");
+ strcat(errbuf, strerror(errno));
+ return -1;
+ }
+ }
+ if (i == -1)
+ {
+ errvalid++;
+ strcpy(errbuf, "readExports: ");
+ strcat(errbuf, strerror(errno));
+ free(buf);
+ return -1;
+ }
+
+ /*
+ * Traverse the list of loaded modules. The entry point returned
+ * by load() does actually point to the data segment origin.
+ */
+ lp = (struct ld_info *) buf;
+ while (lp)
+ {
+ if (lp->ldinfo_dataorg == mp->entry)
+ {
+ ldp = ldopen(lp->ldinfo_filename, ldp);
+ break;
+ }
+ if (lp->ldinfo_next == 0)
+ lp = NULL;
+ else
+ lp = (struct ld_info *) ((char *) lp + lp->ldinfo_next);
+ }
+ free(buf);
+ if (!ldp)
+ {
+ errvalid++;
+ strcpy(errbuf, "readExports: ");
+ strcat(errbuf, strerror(errno));
+ return -1;
+ }
+ }
+ if (TYPE(ldp) != U802TOCMAGIC)
+ {
+ errvalid++;
+ strcpy(errbuf, "readExports: bad magic");
+ while (ldclose(ldp) == FAILURE)
+ ;
+ return -1;
+ }
+
+ /*
+ * Get the padding for the data section. This is needed for AIX 4.1
+ * compilers. This is used when building the final function pointer to
+ * the exported symbol.
+ */
+ if (ldnshread(ldp, _DATA, &shdata) != SUCCESS)
+ {
+ errvalid++;
+ strcpy(errbuf, "readExports: cannot read data section header");
+ while (ldclose(ldp) == FAILURE)
+ ;
+ return -1;
+ }
+ if (ldnshread(ldp, _LOADER, &sh) != SUCCESS)
+ {
+ errvalid++;
+ strcpy(errbuf, "readExports: cannot read loader section header");
+ while (ldclose(ldp) == FAILURE)
+ ;
+ return -1;
+ }
+
+ /*
+ * We read the complete loader section in one chunk, this makes
+ * finding long symbol names residing in the string table easier.
+ */
+ if ((ldbuf = (char *) malloc(sh.s_size)) == NULL)
+ {
+ errvalid++;
+ strcpy(errbuf, "readExports: ");
+ strcat(errbuf, strerror(errno));
+ while (ldclose(ldp) == FAILURE)
+ ;
+ return -1;
+ }
+ if (FSEEK(ldp, sh.s_scnptr, BEGINNING) != OKFSEEK)
+ {
+ errvalid++;
+ strcpy(errbuf, "readExports: cannot seek to loader section");
+ free(ldbuf);
+ while (ldclose(ldp) == FAILURE)
+ ;
+ return -1;
+ }
+ if (FREAD(ldbuf, sh.s_size, 1, ldp) != 1)
+ {
+ errvalid++;
+ strcpy(errbuf, "readExports: cannot read loader section");
+ free(ldbuf);
+ while (ldclose(ldp) == FAILURE)
+ ;
+ return -1;
+ }
+ lhp = (LDHDR *) ldbuf;
+ ls = (LDSYM *) (ldbuf + LDHDRSZ);
+
+ /*
+ * Count the number of exports to include in our export table.
+ */
+ for (i = lhp->l_nsyms; i; i--, ls++)
+ {
+ if (!LDR_EXPORT(*ls))
+ continue;
+ mp->nExports++;
+ }
+ if ((mp->exports = (ExportPtr) calloc(mp->nExports, sizeof(*mp->exports))) == NULL)
+ {
+ errvalid++;
+ strcpy(errbuf, "readExports: ");
+ strcat(errbuf, strerror(errno));
+ free(ldbuf);
+ while (ldclose(ldp) == FAILURE)
+ ;
+ return -1;
+ }
+
+ /*
+ * Fill in the export table. All entries are relative to the entry
+ * point we got from load.
+ */
+ ep = mp->exports;
+ ls = (LDSYM *) (ldbuf + LDHDRSZ);
+ for (i = lhp->l_nsyms; i; i--, ls++)
+ {
+ char *symname;
+ char tmpsym[SYMNMLEN + 1];
+
+ if (!LDR_EXPORT(*ls))
+ continue;
+ if (ls->l_zeroes == 0)
+ symname = ls->l_offset + lhp->l_stoff + ldbuf;
+ else
+ {
+
+ /*
+ * The l_name member is not zero terminated, we must copy the
+ * first SYMNMLEN chars and make sure we have a zero byte at
+ * the end.
+ */
+ StrNCpy(tmpsym, ls->l_name, SYMNMLEN+1);
+ symname = tmpsym;
+ }
+ ep->name = strdup(symname);
+ ep->addr = (void *) ((unsigned long) mp->entry +
+ ls->l_value - shdata.s_vaddr);
+ ep++;
+ }
+ free(ldbuf);
+ while (ldclose(ldp) == FAILURE)
+ ;
+ return 0;
+}
+
+/*
+ * Find the main modules entry point. This is used as export pointer
+ * for loadbind() to be able to resolve references to the main part.
+ */
+static void *
+findMain(void)
+{
+ struct ld_info *lp;
+ char *buf;
+ int size = 4 * 1024;
+ int i;
+ void *ret;
+
+ if ((buf = malloc(size)) == NULL)
+ {
+ errvalid++;
+ strcpy(errbuf, "findMain: ");
+ strcat(errbuf, strerror(errno));
+ return NULL;
+ }
+ while ((i = loadquery(L_GETINFO, buf, size)) == -1 && errno == ENOMEM)
+ {
+ free(buf);
+ size += 4 * 1024;
+ if ((buf = malloc(size)) == NULL)
+ {
+ errvalid++;
+ strcpy(errbuf, "findMain: ");
+ strcat(errbuf, strerror(errno));
+ return NULL;
+ }
+ }
+ if (i == -1)
+ {
+ errvalid++;
+ strcpy(errbuf, "findMain: ");
+ strcat(errbuf, strerror(errno));
+ free(buf);
+ return NULL;
+ }
+
+ /*
+ * The first entry is the main module. The entry point returned by
+ * load() does actually point to the data segment origin.
+ */
+ lp = (struct ld_info *) buf;
+ ret = lp->ldinfo_dataorg;
+ free(buf);
+ return ret;
+}
diff --git a/src/backend/port/dynloader/aix.h b/src/backend/port/dynloader/aix.h
new file mode 100644
index 00000000000..7310aee5998
--- /dev/null
+++ b/src/backend/port/dynloader/aix.h
@@ -0,0 +1,56 @@
+/*
+ * $Id: aix.h,v 1.1 1997/12/19 22:58:26 scrappy Exp $
+ *
+ * @(#)dlfcn.h 1.4 revision of 95/04/25 09:36:52
+ * This is an unpublished work copyright (c) 1992 HELIOS Software GmbH
+ * 30159 Hannover, Germany
+ */
+
+#ifndef __dlfcn_h__
+#define __dlfcn_h__
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+/*
+ * Mode flags for the dlopen routine.
+ */
+#define RTLD_LAZY 1 /* lazy function call binding */
+#define RTLD_NOW 2 /* immediate function call binding */
+#define RTLD_GLOBAL 0x100 /* allow symbols to be global */
+
+/*
+ * To be able to intialize, a library may provide a dl_info structure
+ * that contains functions to be called to initialize and terminate.
+ */
+ struct dl_info
+ {
+ void (*init) (void);
+ void (*fini) (void);
+ };
+
+#if __STDC__ || defined(_IBMR2)
+ void *dlopen(const char *path, int mode);
+ void *dlsym(void *handle, const char *symbol);
+ char *dlerror(void);
+ int dlclose(void *handle);
+#else
+ void *dlopen();
+ void *dlsym();
+ char *dlerror();
+ int dlclose();
+#endif
+
+#ifdef __cplusplus
+}
+
+#endif
+
+#define pg_dlopen(f) dlopen(filename, RTLD_LAZY)
+#define pg_dlsym(h,f) dlsym(h, f)
+#define pg_dlclose(h) dlclose(h)
+#define pg_dlerror() dlerror()
+
+#endif /* __dlfcn_h__ */
diff --git a/src/backend/port/dynloader/bsd.c b/src/backend/port/dynloader/bsd.c
new file mode 100644
index 00000000000..42d15d840f3
--- /dev/null
+++ b/src/backend/port/dynloader/bsd.c
@@ -0,0 +1,107 @@
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)dl.c 5.4 (Berkeley) 2/23/91";
+
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <nlist.h>
+#include <link.h>
+#include <dlfcn.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "port-protos.h"
+
+static char error_message[BUFSIZ];
+
+char *
+BSD44_derived_dlerror(void)
+{
+ static char ret[BUFSIZ];
+
+ strcpy(ret, error_message);
+ error_message[0] = 0;
+ return ((ret[0] == 0) ? (char *) NULL : ret);
+}
+
+void *
+BSD44_derived_dlopen(const char *file, int num)
+{
+#ifdef __mips__
+ sprintf(error_message, "dlopen (%s) not supported", file);
+ return NULL;
+#else
+ void *vp;
+
+ if ((vp = dlopen((char *) file, num)) == (void *) NULL)
+ {
+ sprintf(error_message, "dlopen (%s) failed", file);
+ }
+ return (vp);
+#endif
+}
+
+void *
+BSD44_derived_dlsym(void *handle, const char *name)
+{
+#ifdef __mips__
+ sprintf(error_message, "dlsym (%s) failed", name);
+ return NULL;
+#else
+ void *vp;
+ char buf[BUFSIZ];
+
+ if (*name != '_')
+ {
+ sprintf(buf, "_%s", name);
+ name = buf;
+ }
+ if ((vp = dlsym(handle, (char *) name)) == (void *) NULL)
+ {
+ sprintf(error_message, "dlsym (%s) failed", name);
+ }
+ return (vp);
+#endif
+}
+
+void
+BSD44_derived_dlclose(void *handle)
+{
+#ifndef __mips__
+ dlclose(handle);
+#endif
+}
--
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