Enable dynamic extensions for MinGW.

4 files changed, 110 insertions, 2 deletions

diff --git a/pc/ChangeLog b/pc/ChangeLog
index 15ce56ec..e7378b5f 100644
--- a/pc/ChangeLog
+++ b/pc/ChangeLog
@@ -1,3 +1,17 @@
+2013-02-09  Eli Zaretskii  <eliz@gnu.org>
+
+	* gawkmisc.pc (dlopen, dlerror, dlclose, dlsym) [DYNAMIC]: New
+	functions for _WIN32 build.
+
+	* dlfcn.h: New file.
+
+	* Makefile (pkgextensiondir, DEFLIBPATH, SHLIBEXT): New variables.
+	(AWKOBJS4): New sub-list of object files; add gawkapi$O.
+	(ALLOBJS): Include AWKOBJS4.
+	(CFLAGS): Add -DDEFLIBPATH=$(DEFLIBPATH) -DSHLIBEXT=$(SHLIBEXT).
+
+	* config.sed (DYNAMIC): Define for _WIN32 build.
+
 2013-02-07   Scott Deifik  <scottd.mail@sbcglobal.net>
 
 	* Makefile.tst: Sync with mainline.
diff --git a/pc/Makefile b/pc/Makefile
index 52354f34..71197c53 100644
--- a/pc/Makefile
+++ b/pc/Makefile
@@ -68,6 +68,9 @@ MAK = $(MAKE) $(MAKEFILE)
 #prefix =
 prefix = c:/gnu
 pkgdatadir = $(prefix)/lib/awk
+pkgextensiondir = $(prefix)/lib/gawk
+DEFLIBPATH = "\"$(pkgextensiondir)\""
+SHLIBEXT = "\"dll\""
 #
 # Define the install method. Method 1 is Unix-like (and requires cat
 # and cp); method 2 uses gawk and batch files.
@@ -183,13 +186,14 @@ BIND = EMPTY
 PBIND = EMPTY
 EMPTY=
 
-CFLAGS = $(CF) -DGAWK -I. -DHAVE_CONFIG_H
+CFLAGS = $(CF) -DGAWK -I. -DHAVE_CONFIG_H -DDEFLIBPATH=$(DEFLIBPATH) -DSHLIBEXT=$(SHLIBEXT)
 
 # object files
 AWKOBJS1  = array$O builtin$O eval$O field$O floatcomp$O gawkmisc$O io$O main$O
 AWKOBJS2  = ext$O msg$O node$O profile$O re$O replace$O version$O symbol$O
 AWKOBJS3  = debug$O cint_array$O int_array$O mpfr$O str_array$O command$O
-AWKOBJS = $(AWKOBJS1) $(AWKOBJS2) $(AWKOBJS3)
+AWKOBJS4  = gawkapi$O
+AWKOBJS = $(AWKOBJS1) $(AWKOBJS2) $(AWKOBJS3) $(AWKOBJS4)
 
 ALLOBJS = $(AWKOBJS) awkgram$O getid$O $(OBJ)
 
diff --git a/pc/config.sed b/pc/config.sed
index 5e57e82b..6f76f43e 100644
--- a/pc/config.sed
+++ b/pc/config.sed
@@ -26,6 +26,10 @@
 /configh\.in/a\
 /* pc/config.h.  Generated automatically by pc/config.sed.  */
 
+/^#undef DYNAMIC$\c
+#ifdef _WIN32\
+#define DYNAMIC 1\
+#endif
 s/^#undef GETPGRP_VOID *$/#define GETPGRP_VOID 1/
 s/^#undef GETGROUPS_T *$/#define GETGROUPS_T gid_t/
 /^#undef GETPGRP_VOID$/c\
diff --git a/pc/gawkmisc.pc b/pc/gawkmisc.pc
index e44191cd..5e412d71 100644
--- a/pc/gawkmisc.pc
+++ b/pc/gawkmisc.pc
@@ -609,6 +609,92 @@ int execvp(const char *file, const char *const *argv)
 
 	return -1;
 }
+
+#ifdef DYNAMIC
+
+#include <dlfcn.h>
+
+static DWORD last_err;
+
+void *
+dlopen (const char *file, int mode)
+{
+  char dllfn[MAX_PATH], *p;
+  HANDLE dllhandle;
+
+  if (mode != RTLD_LAZY)
+    {
+      errno = EINVAL;
+      last_err = ERROR_INVALID_PARAMETER;
+      return NULL;
+    }
+
+  /* MSDN says to be sure to use backslashes in the DLL file name.  */
+  strcpy (dllfn, file);
+  for (p = dllfn; *p; p++)
+    if (*p == '/')
+      *p = '\\';
+
+  dllhandle = LoadLibrary (dllfn);
+  if (!dllhandle)
+    last_err = GetLastError ();
+
+  return dllhandle;
+}
+
+char *
+dlerror (void)
+{
+  static char errbuf[1024];
+  DWORD ret;
+
+  if (!last_err)
+    return NULL;
+
+  ret = FormatMessage (FORMAT_MESSAGE_FROM_SYSTEM
+		       | FORMAT_MESSAGE_IGNORE_INSERTS,
+		       NULL, last_err, 0, errbuf, sizeof (errbuf), NULL);
+  while (ret > 0 && (errbuf[ret - 1] == '\n' || errbuf[ret - 1] == '\r'))
+    --ret;
+
+  errbuf[ret] = '\0';
+  if (!ret)
+    sprintf (errbuf, "Error code %lu", last_err);
+
+  last_err = 0;
+  return errbuf;
+}
+
+int
+dlclose (void *handle)
+{
+  if (!handle || handle == INVALID_HANDLE_VALUE)
+    return -1;
+  if (!FreeLibrary (handle))
+    return -1;
+
+  return 0;
+}
+
+void *
+dlsym (void *handle, const char *name)
+{
+  FARPROC addr = NULL;
+
+  if (!handle || handle == INVALID_HANDLE_VALUE)
+    {
+      last_err = ERROR_INVALID_PARAMETER;
+      return NULL;
+    }
+
+  addr = GetProcAddress (handle, name);
+  if (!addr)
+    last_err = GetLastError ();
+
+  return (void *)addr;
+}
+#endif
+
 #endif	/* __MINGW32__ */
 
 #ifdef __DJGPP__