* Allow to use symbols as variables (prefixed with '@'). Now only tab completion

for variable names is missing B-}


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33723 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/elf.h

@@ -32,6 +32,7 @@ status_t elf_debug_lookup_symbol_address(addr_t address, addr_t *_baseAddress,
 status_t elf_debug_lookup_user_symbol_address(struct team* team, addr_t address,
 			addr_t *_baseAddress, const char **_symbolName,
 			const char **_imageName, bool *_exactMatch);
+addr_t elf_debug_lookup_symbol(const char* searchName);
 struct elf_image_info* elf_get_kernel_image();
 status_t elf_get_image_info_for_address(addr_t address, image_info* info);
 image_id elf_create_memory_image(const char* imageName, addr_t text,

src/system/kernel/debug/debug_parser.cpp

@@ -36,7 +36,7 @@
 	dereference	:= "*" [ "{" expression "}" ] unary
 	atom		:= variable | ( "(" expression ")" ) | ( "[" command "]" )
 	variable	:= identifier
-	identifier	:= ( "$" | "_" | "a" - "z" | "A" - "Z" )
+	identifier	:= ( "$" | "@" | "_" | "a" - "z" | "A" - "Z" )
 				   ( "_" | "a" - "z" | "A" - "Z" | "0" - "9" )*
 	commandPipe	:= command ( "|" command )*
 	command		:= identifier argument*
@@ -251,7 +251,7 @@ public:
 			fCurrentToken.value = strtoull(fCurrentToken.string, NULL, 0);
 
 		} else if (isalpha(*fCurrentChar) || *fCurrentChar == '_'
-				|| *fCurrentChar == '$') {
+				|| *fCurrentChar == '$' || *fCurrentChar == '@') {
 			// identifier
 			const char* begin = fCurrentChar;
 			fCurrentChar++;

src/system/kernel/debug/debug_variables.cpp

@@ -3,6 +3,7 @@
  * Distributed under the terms of the MIT License.
  */
 
+
 #include "debug_variables.h"
 
 #include <string.h>
@@ -11,6 +12,7 @@
 
 #include <arch/debug.h>
 #include <debug.h>
+#include <elf.h>
 #include <util/DoublyLinkedList.h>
 
 
@@ -18,6 +20,7 @@ static const int kVariableCount				= 64;
 static const int kTemporaryVariableCount	= 32;
 static const char kTemporaryVariablePrefix	= '_';
 static const char kArchSpecificVariablePrefix = '$';
+static const char kSymbolVariablePrefix = '@';
 static const char* const kCommandReturnValueVariable = "_";
 
 
@@ -70,6 +73,13 @@ is_arch_specific_variable(const char* variableName)
 }
 
 
+static inline bool
+is_symbol_variable(const char* variableName)
+{
+	return variableName[0] == kSymbolVariablePrefix;
+}
+
+
 static void
 dequeue_temporary_variable(TemporaryVariable* variable)
 {
@@ -239,6 +249,9 @@ is_debug_variable_defined(const char* variableName)
 	if (get_variable(variableName, false) != NULL)
 		return true;
 
+	if (is_symbol_variable(variableName))
+		return elf_debug_lookup_symbol(variableName + 1) != 0;
+
 	return is_arch_specific_variable(variableName)
 		&& arch_is_debug_variable_defined(variableName + 1);
 }
@@ -274,6 +287,12 @@ get_debug_variable(const char* variableName, uint64 defaultValue)
 		return value;
 	}
 
+	if (is_symbol_variable(variableName)) {
+		addr_t value = elf_debug_lookup_symbol(variableName + 1);
+		if (value != 0)
+			return value;
+	}
+
 	return defaultValue;
 }
 

src/system/kernel/elf.cpp

@@ -1695,6 +1695,47 @@ elf_debug_lookup_user_symbol_address(struct team* team, addr_t address,
 }
 
 
+/*!	Looks up a symbol in all kernel images. Note, this function is thought to
+	be used in the kernel debugger, and therefore doesn't perform any locking.
+*/
+addr_t
+elf_debug_lookup_symbol(const char* searchName)
+{
+	struct elf_image_info *image = NULL;
+	struct hash_iterator iterator;
+
+	hash_open(sImagesHash, &iterator);
+	while ((image = (elf_image_info *)hash_next(sImagesHash, &iterator))
+			!= NULL) {
+		if (image->num_debug_symbols > 0) {
+			// search extended debug symbol table (contains static symbols)
+			for (uint32 i = 0; i < image->num_debug_symbols; i++) {
+				struct Elf32_Sym *symbol = &image->debug_symbols[i];
+				const char *name = image->debug_string_table + symbol->st_name;
+
+				if (symbol->st_value > 0 && !strcmp(name, searchName))
+					return symbol->st_value + image->text_region.delta;
+			}
+		} else {
+			// search standard symbol lookup table
+			for (uint32 i = 0; i < HASHTABSIZE(image); i++) {
+				for (uint32 j = HASHBUCKETS(image)[i]; j != STN_UNDEF;
+						j = HASHCHAINS(image)[j]) {
+					struct Elf32_Sym *symbol = &image->syms[j];
+					const char *name = SYMNAME(image, symbol);
+
+					if (symbol->st_value > 0 && !strcmp(name, searchName))
+						return symbol->st_value + image->text_region.delta;
+				}
+			}
+		}
+	}
+	hash_close(sImagesHash, &iterator, false);
+
+	return 0;
+}
+
+
 status_t
 elf_load_user_image(const char *path, struct team *team, int flags,
 	addr_t *entry)