* Applied patch by Romain Picard: added support for the GNU extension dladdr(),

thanks!
* This closes ticket #2818.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28308 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/posix/dlfcn.h

@@ -1,8 +1,10 @@
+/*
+ * Copyright 2003-2008, Haiku Inc. All Rights Reserved.
+ * Distributed under the terms of the MIT License.
+ */
 #ifndef _DLFCN_H
 #define	_DLFCN_H
-/*
+
-** Distributed under the terms of the OpenBeOS License.
-*/
 
 #include <sys/types.h>
 
@@ -17,10 +19,19 @@
 extern "C" {
 #endif
 
+/* This is a gnu extension for the dladdr function */
+typedef struct {
+   const char *dli_fname;  /* Filename of defining object */
+   void *dli_fbase;        /* Load address of that object */
+   const char *dli_sname;  /* Name of nearest lower symbol */
+   void *dli_saddr;        /* Exact value of nearest symbol */
+} Dl_info;
+
 extern int	dlclose(void *image);
 extern char	*dlerror(void);
 extern void	*dlopen(const char *path, int mode);
 extern void *dlsym(void *image, const char *symbolName);
+extern int dladdr(void *addr, Dl_info *info);
 
 #ifdef __cplusplus
 }

src/system/libroot/posix/dlfcn.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2006, Axel Dörfler, [email protected]. All rights reserved.
+ * Copyright 2003-2008, Axel Dörfler, [email protected].
  * Distributed under the terms of the MIT License.
  *
  * Copyright 2002, Manuel J. Petit. All rights reserved.
@@ -72,6 +72,64 @@ dlerror(void)
 }
 
 
+int
+dladdr(void *addr, Dl_info *info)
+{
+	char curSymName[NAME_MAX];
+	static char symName[NAME_MAX];
+	static char imageName[MAXPATHLEN];
+	void *symLocation;
+	int32 cookie;
+	int32 symType, symNameLength;
+	uint32 symIndex;
+	image_info imageInfo;
+
+	if (info == NULL)
+		return 0;
+
+	imageName[0] = '\0';
+	symName[0] = '\0';
+	info->dli_fname = imageName;
+	info->dli_saddr = NULL;
+	info->dli_sname = symName;
+
+	cookie = 0;
+	while (get_next_image_info(0, &cookie, &imageInfo) == B_OK) {
+		// check if the image holds the symbol
+		if ((addr_t)addr >= (addr_t)imageInfo.text
+			&& (addr_t)addr < (addr_t)imageInfo.text + imageInfo.text_size)  {
+			strlcpy(imageName, imageInfo.name, MAXPATHLEN);
+			info->dli_fbase = imageInfo.text;
+			symIndex = 0;
+			symNameLength = NAME_MAX;
+
+			while (get_nth_image_symbol(imageInfo.id, symIndex, curSymName,
+					&symNameLength, &symType, &symLocation) == B_OK) {
+				// check if symbol is the nearest until now
+				if (symType == B_SYMBOL_TYPE_TEXT
+					&& symLocation <= addr
+					&& symLocation >= info->dli_saddr) {
+					strlcpy(symName, curSymName, NAME_MAX);
+					info->dli_saddr = symLocation;
+
+					// stop here if exact match
+					if (info->dli_saddr == addr)
+						return 1;
+				}
+				symIndex++;
+				symNameLength = NAME_MAX;
+			}
+			break;
+		}
+	}
+
+	if (info->dli_saddr != NULL)
+		return 1;
+
+	return 0;
+}
+
+
 // __libc_dl*** wrappers
 // We use a mixed glibc / bsd libc, and glibc wants these
 void *__libc_dlopen(const char *name);