Refactor dynamic linker API, fix system/dynlink example

1 files changed, 58 insertions, 43 deletions

diff --git a/libpsn00b/include/dlfcn.h b/libpsn00b/include/dlfcn.h
index b3a5cec..6874d06 100644
--- a/libpsn00b/include/dlfcn.h
+++ b/libpsn00b/include/dlfcn.h
@@ -21,39 +21,39 @@
 #define RTLD_DEFAULT ((DLL *) 0)
 
 typedef enum _DL_Error {
-	RTLD_E_NONE        =  0, // No error
-	RTLD_E_FILE_OPEN   =  1, // Unable to find or open file
-	RTLD_E_FILE_ALLOC  =  2, // Unable to allocate buffer to load file into
-	RTLD_E_FILE_READ   =  3, // Failed to read file
-	RTLD_E_NO_MAP      =  4, // No symbol map has been loaded yet
-	RTLD_E_MAP_ALLOC   =  5, // Unable to allocate symbol map structures
-	RTLD_E_NO_SYMBOLS  =  6, // No symbols found in symbol map
-	RTLD_E_DLL_NULL    =  7, // Unable to initialize DLL from null pointer
-	RTLD_E_DLL_ALLOC   =  8, // Unable to allocate DLL metadata structures
-	RTLD_E_DLL_FORMAT  =  9, // Unsupported DLL type or format
-	RTLD_E_NO_FILE_API = 10, // psxetc has been built without file support
-	RTLD_E_MAP_SYMBOL  = 11, // Symbol not found in symbol map
-	RTLD_E_DLL_SYMBOL  = 12, // Symbol not found in DLL
-	RTLD_E_HASH_LOOKUP = 13  // Hash table lookup failed due to internal error
+	RTLD_E_NONE			=  0, // No error
+	RTLD_E_FILE_OPEN	=  1, // Unable to find or open file
+	RTLD_E_FILE_ALLOC	=  2, // Unable to allocate buffer to load file into
+	RTLD_E_FILE_READ	=  3, // Failed to read file
+	RTLD_E_NO_MAP		=  4, // No symbol map has been loaded yet
+	RTLD_E_MAP_ALLOC	=  5, // Unable to allocate symbol map structures
+	RTLD_E_NO_SYMBOLS	=  6, // No symbols found in symbol map
+	RTLD_E_DLL_NULL		=  7, // Unable to initialize DLL from null pointer
+	RTLD_E_DLL_ALLOC	=  8, // Unable to allocate DLL metadata structures
+	RTLD_E_DLL_FORMAT	=  9, // Unsupported DLL type or format
+	RTLD_E_MAP_SYMBOL	= 10, // Symbol not found in symbol map
+	RTLD_E_DLL_SYMBOL	= 11, // Symbol not found in DLL
+	RTLD_E_HASH_LOOKUP	= 12  // Hash table lookup failed due to internal error
 } DL_Error;
 
 typedef enum _DL_ResolveMode {
-	RTLD_LAZY = 1, // Resolve functions when they are first called (default)
-	RTLD_NOW  = 2  // Resolve all symbols immediately on load
+	RTLD_LAZY				= 1, // Resolve functions when they are first called (default)
+	RTLD_NOW				= 2, // Resolve all symbols immediately on load
+	RTLD_FREE_ON_DESTROY	= 4  // Automatically free DLL buffer when closing DLL
 } DL_ResolveMode;
 
 // Members of this struct should not be accessed directly in most cases, but
 // they are intentionally exposed for easier expandability.
 typedef struct _DLL {
-	void           *ptr;
-	void           *malloc_ptr;
-	size_t         size;
-	const uint32_t *hash;
-	uint32_t       *got;
-	Elf32_Sym      *symtab;
-	const char     *strtab;
-	uint16_t       symbol_count;
-	uint16_t       got_length;
+	void			*ptr;
+	void			*malloc_ptr;
+	size_t			size;
+	const uint32_t	*hash;
+	uint32_t		*got;
+	Elf32_Sym		*symtab;
+	const char		*strtab;
+	uint16_t		symbol_count;
+	uint16_t		got_length;
 } DLL;
 
 /* API */
@@ -62,8 +62,6 @@ typedef struct _DLL {
 extern "C" {
 #endif
 
-// TODO: rewrite these javadoc comments into proper documentation
-
 /**
  * @brief Reads the symbol table from the provided string buffer (which may or
  * may not be null-terminated), parses it and stores the parsed entries into a
@@ -80,13 +78,14 @@ extern "C" {
  * file in the appropriate format after building the executable, by using this
  * command:
  *
- *   mipsel-unknown-elf-nm -f posix -l -n executable.elf >executable.map
+ *   mipsel-none-elf-nm -f posix -l -n executable.elf >executable.map
  *
  * @param ptr
  * @param size
  * @return -1 or number of entries parsed
  */
 int32_t DL_ParseSymbolMap(const char *ptr, size_t size);
+
 /**
  * @brief File wrapper around DL_ParseSymbolMap(). Allocates a temporary buffer
  * then loads the specified map file into it (using BIOS APIs) and calls
@@ -96,14 +95,16 @@ int32_t DL_ParseSymbolMap(const char *ptr, size_t size);
  * @param filename Must always contain device name, e.g. "cdrom:MODULE.DLL;1"
  * @return -1 or number of entries parsed
  */
-int32_t DL_LoadSymbolMap(const char *filename);
+//int32_t DL_LoadSymbolMapFromFile(const char *filename);
+
 /**
  * @brief Frees internal buffers containing the currently loaded symbol map.
  * This is automatically done before loading a new symbol map so there is no
  * need to call this function in most cases, however it can still be useful to
  * free up space on the heap once the symbol map is no longer needed.
  */
-void    DL_UnloadSymbolMap(void);
+void DL_UnloadSymbolMap(void);
+
 /**
  * @brief Queries the currently loaded symbol map for the symbol with the given
  * name and returns a pointer to it, which can then be used to directly access
@@ -112,7 +113,8 @@ void    DL_UnloadSymbolMap(void);
  * @param name
  * @return NULL or pointer to symbol (any type)
  */
-void    *DL_GetSymbolByName(const char *name);
+void *DL_GetSymbolByName(const char *name);
+
 /**
  * @brief Sets a custom function to be called for resolving symbols in DLLs.
  * The function will be given a pointer to the current DLL and the unresolved
@@ -123,7 +125,7 @@ void    *DL_GetSymbolByName(const char *name);
  * 
  * @param callback NULL or pointer to callback function
  */
-void    DL_SetResolveCallback(void *(*callback)(DLL *, const char *));
+void DL_SetResolveCallback(void *(*callback)(DLL *, const char *));
 
 /**
  * @brief Initializes a buffer holding the contents of a dynamically-loaded
@@ -131,8 +133,8 @@ void    DL_SetResolveCallback(void *(*callback)(DLL *, const char *));
  * binary) *in-place*. A new DLL struct is allocated to store metadata but,
  * unlike DL_ParseSymbolMap(), the DLL's actual code, data and tables are
  * referenced directly from the provided buffer. The buffer must not be moved
- * or deallocated, at least not before calling dlclose() on the DLL struct
- * returned by this function.
+ * or deallocated, at least not before calling DL_DestroyDLL() on the DLL
+ * struct returned by this function.
  *
  * The third argument specifies when symbols in the DLL should be resolved.
  * Setting it to RTLD_LAZY defers resolution of undefined functions to when
@@ -145,7 +147,8 @@ void    DL_SetResolveCallback(void *(*callback)(DLL *, const char *));
  * @param mode RTLD_LAZY or RTLD_NOW
  * @return NULL or pointer to a new DLL struct
  */
-DLL  *dlinit(void *ptr, size_t size, DL_ResolveMode mode);
+DLL *DL_CreateDLL(void *ptr, size_t size, DL_ResolveMode mode);
+
 /**
  * @brief File wrapper around dlinit(). Allocates a new buffer, loads the
  * specified file into it (using BIOS APIs) and calls dlinit() on that. When
@@ -153,19 +156,22 @@ DLL  *dlinit(void *ptr, size_t size, DL_ResolveMode mode);
  * automatically destroyed.
  *
  * @param filename Must always contain device name, e.g. "cdrom:MODULE.DLL;1"
- * @param mode RTLD_LAZY or RTLD_NOW
+ * @param mode RTLD_LAZY or RTLD_NOW + optionally RTLD_FREE_ON_DESTROY
  * @return NULL or pointer to a new DLL struct
  */
-DLL  *dlopen(const char *filename, DL_ResolveMode mode);
+//DLL *DL_LoadDLLFromFile(const char *filename, DL_ResolveMode mode);
+
 /**
  * @brief Destroys a loaded DLL by calling its global destructors and freeing
- * the buffer it's loaded in. Any pointer passed to dlclose() should no longer
- * be used after the call. If the DLL was initialized in-place using dlinit(),
- * dlclose() will *NOT* free the buffer initially passed to dlinit().
+ * the buffer it's loaded in. Any pointer passed to DL_DestroyDLL() should no
+ * longer be used after the call. If the DLL was initialized in-place using
+ * DL_CreateDLL(), DL_DestroyDLL() will only free the buffer initially passed
+ * to DL_CreateDLL() if RTLD_FREE_ON_DESTROY was used.
  *
  * @param dll
  */
-void dlclose(DLL *dll);
+void DL_DestroyDLL(DLL *dll);
+
 /**
  * @brief Returns a pointer to the DLL symbol with the given name, or null if
  * it can't be found. If null or RTLD_DEFAULT is passed as first argument, the
@@ -176,7 +182,8 @@ void dlclose(DLL *dll);
  * @param name
  * @return NULL or pointer to symbol (any type)
  */
-void *dlsym(DLL *dll, const char *name);
+void *DL_GetDLLSymbol(const DLL *dll, const char *name);
+
 /**
  * @brief Returns a code describing the last error that occurred, or DL_E_NONE
  * if no error has occurred since the last call to dlerror() (i.e. calling this
@@ -184,7 +191,15 @@ void *dlsym(DLL *dll, const char *name);
  *
  * @return NULL or member of DL_Error enum
  */
-DL_Error dlerror(void);
+DL_Error DL_GetLastError(void);
+
+/* POSIX "compatibility" macros */
+
+#define dlinit(ptr, size, mode)	DL_CreateDLL(ptr, size, mode)
+//#define dlopen(filename, mode)	DL_LoadDLLFromFile(filename, mode)
+#define dlsym(dll, name)		DL_GetDLLSymbol(dll, name)
+#define dlclose(dll)			DL_DestroyDLL(dll)
+#define dlerror()				DL_GetLastError()
 
 #ifdef __cplusplus
 }