lib error codes moved to errors.h and made X macros. this allows adding a corresponding text message, which is now output by debug_warn_err.

vfs_path, tex, tex_codec: small tweaks to error-related code.

This was SVN commit r3158.

source/lib/debug.cpp

@@ -571,7 +571,8 @@ ErrorReaction debug_warn_err(int err, const char* file, int line,
 
 	uint skip = 1; void* context = 0;
 	wchar_t buf[400];
-	swprintf(buf, ARRAY_SIZE(buf), L"Function call failed at %hs:%d (%hs): return value was %d", base_name, line, func, err);
+	char err_buf[200]; error_description_r(err, err_buf, ARRAY_SIZE(err_buf));
+	swprintf(buf, ARRAY_SIZE(buf), L"Function call failed at %hs:%d (%hs): return value was %d (%hs)", base_name, line, func, err, err_buf);
 	return display_error(buf, DE_ALLOW_SUPPRESS|DE_MANUAL_BREAK, skip, context, base_name, line);
 }
 

source/lib/errors.cpp

@@ -0,0 +1,75 @@
+#include "precompiled.h"
+
+#include "errors.h"
+#include "sysdep/sysdep.h"
+
+#include <string.h>
+#include <stdlib.h>	// abs
+
+
+static const char* lib_error_description(int err)
+{
+	// not in our range
+	if(!(ERR_MIN <= abs(err) && abs(err) < ERR_MAX))
+		return 0;
+
+	switch(err)
+	{
+#define ERR(err, id, str) case id: return str;
+#include "errors.h"
+	default: return "Unknown lib error";
+	}
+	UNREACHABLE;
+}
+
+
+void error_description_r(int err, char* buf, size_t max_chars)
+{
+	// lib error
+	const char* str = lib_error_description(err);
+	if(str)
+	{
+		// <err> was one of our error codes (chosen so as not to conflict
+		// with any others), so we're done.
+		strcpy_s(buf, max_chars, str);
+		return;
+	}
+
+	// Win32 GetLastError and errno both define values in [0,100).
+	// what we'll do is always try the OS-specific translation,
+	// add libc's interpretation if <err> is a valid errno, and
+	// output "Unknown" if none of the above succeeds.
+	const bool should_display_libc_err = (0 <= err && err < sys_nerr);
+	bool have_output = false;
+
+	// OS-specific error
+	if(sys_error_description_r(err, buf, max_chars) == 0)	// success
+	{
+		have_output = true;
+
+		// add a separator text before libc description
+		if(should_display_libc_err)
+			strcat_s(buf, max_chars, "; libc err=");
+	}
+
+	// libc error
+	if(should_display_libc_err)
+	{
+		strcat_s(buf, max_chars, strerror(err));
+		// note: we are sure to get meaningful output (not just "unknown")
+		// because err < sys_nerr.
+		have_output = true;
+	}
+
+	// fallback
+	if(!have_output)
+		snprintf(buf, max_chars, "Unknown error (%d, 0x%X)", err, err);
+}
+
+
+const char* error_description(int err)
+{
+	static char buf[200];
+	error_description_r(err, buf, ARRAY_SIZE(buf));
+	return buf;
+}

source/lib/errors.h

@@ -0,0 +1,70 @@
+// X macros: error code, symbolic name in code, user-visible string.
+// error code is usually negative; positive denotes warnings.
+//   its absolute value must be within [ERR_MIN, ERR_MAX).
+#ifdef ERR
+
+// function arguments
+ERR(-100000, ERR_INVALID_PARAM, "Invalid function argument")
+ERR(-100001, ERR_INVALID_HANDLE, "Invalid Handle (argument)")
+ERR(-100002, ERR_BUF_SIZE, "Buffer argument too small")
+
+// system limitations
+ERR(-100020, ERR_NO_MEM, "Not enough memory")
+ERR(-100021, ERR_AGAIN, "Try again later")
+ERR(-100022, ERR_LIMIT, "Fixed limit exceeded")
+ERR(-100023, ERR_NO_SYS, "OS doesn't provide a required API")
+ERR(-100024, ERR_NOT_IMPLEMENTED, "Feature currently not implemented")
+ERR(-100025, ERR_NOT_SUPPORTED, "Feature isn't and won't be supported")
+
+ERR(-1060, ERR_TIMED_OUT, "Timed out")
+
+// file + vfs
+ERR(-100200, ERR_FILE_NOT_FOUND, "VFile not found")
+ERR(-100201, ERR_PATH_NOT_FOUND, "VDir not found")
+ERR(-100202, ERR_PATH_LENGTH, "Path exceeds VFS_MAX_PATH characters")
+ERR(-100203, ERR_PATH_INVALID, "Path is invalid")
+ERR(-100210, ERR_DIR_END, "End of directory reached (no more files)")
+ERR(-100220, ERR_NOT_FILE, "Not a file")
+ERR(-100230, ERR_FILE_ACCESS, "Insufficient access rights to open file")
+ERR(-100231, ERR_IO, "Error during IO")
+ERR(-100232, ERR_EOF, "Reading beyond end of file")
+
+// file format
+ERR(-100400, ERR_UNKNOWN_FORMAT, "Unknown file format")
+ERR(-100401, ERR_INCOMPLETE_HEADER, "File header not completely read")
+ERR(-100402, ERR_CORRUPTED, "File data is corrupted")
+
+// texture
+ERR(-100500, ERR_TEX_FMT_INVALID, "Invalid/unsupported texture format")
+ERR(-100501, ERR_TEX_INVALID_COLOR_TYPE, "Invalid color type")
+ERR(-100502, ERR_TEX_NOT_8BIT_PRECISION, "Not 8-bit channel precision")
+ERR(-100503, ERR_TEX_INVALID_LAYOUT, "Unsupported texel layout, e.g. right-to-left")
+ERR(-100504, ERR_TEX_COMPRESSED, "Unsupported texture compression")
+ERR(+100505, WARN_TEX_INVALID_DATA, "Warning: invalid texel data encountered")
+ERR(-100506, ERR_TEX_INVALID_SIZE, "Texture size is incorrect")
+
+ERR(-100600, ERR_CPU_FEATURE_MISSING, "This CPU doesn't support a required feature")
+
+// shaders
+ERR(-100700, ERR_SHDR_CREATE, "Shader creation failed")
+ERR(-100701, ERR_SHDR_COMPILE, "Shader compile failed")
+ERR(-100702, ERR_SHDR_NO_SHADER, "Invalid shader reference")
+ERR(-100703, ERR_SHDR_LINK, "Shader linking failed")
+ERR(-100704, ERR_SHDR_NO_PROGRAM, "Invalid shader program reference")
+
+#undef ERR
+#endif	// #ifdef ERR
+
+
+//-----------------------------------------------------------------------------
+
+#ifndef ERRORS_H__
+#define ERRORS_H__
+
+#define ERR_MIN 100000
+#define ERR_MAX 110000
+
+extern const char* error_description(int err);
+extern void error_description_r(int err, char* buf, size_t max_chars);
+
+#endif	// #ifndef ERRORS_H__

source/lib/lib.h

@@ -59,6 +59,10 @@ scope
 #include "config.h"
 #include "lib/types.h"
 
+// define error codes
+#define ERR(err, id, str) const int id = err;
+#include "lib/errors.h"
+
 #include "sysdep/sysdep.h"
 #include "sysdep/cpu.h"	// CAS
 
@@ -231,70 +235,6 @@ STMT(\
 )
 
 
-enum LibError
-{
-	// function arguments
-	ERR_INVALID_PARAM   = -1000,
-	ERR_INVALID_HANDLE  = -1001,
-	ERR_BUF_SIZE        = -1002,
-
-	// system limitations
-	// .. out of memory
-	ERR_NO_MEM           = -1020,
-	// .. try again later
-	ERR_AGAIN            = -1021,
-	// .. fixed limit exceeded
-	ERR_LIMIT            = -1022,
-	// .. the OS doesn't provide an API we need
-	ERR_NO_SYS           = -1023,
-	// .. feature not currently implemented (will probably change)
-	ERR_NOT_IMPLEMENTED  = -1024,
-	// .. feature won't be supported
-	ERR_NOT_SUPPORTED    = -1025,
-
-	ERR_TIMED_OUT         = -1060,
-
-	// file + vfs
-	ERR_FILE_NOT_FOUND  = -1200,
-	ERR_PATH_NOT_FOUND  = -1201,
-	ERR_PATH_LENGTH     = -1202,
-	ERR_PATH_INVALID    = -1203,
-	ERR_DIR_END         = -1210,
-	ERR_NOT_FILE        = -1220,
-	ERR_FILE_ACCESS     = -1230,
-	ERR_IO              = -1231,
-	ERR_EOF             = -1232,
-
-	// file format
-	ERR_UNKNOWN_FORMAT    = -1400,
-	ERR_INCOMPLETE_HEADER = -1401,
-	// .. data (e.g. in file) is obviously incorrect
-	ERR_CORRUPTED         = -1402,
-
-	// texture
-	ERR_TEX_FMT_INVALID         = -1500,
-	ERR_TEX_INVALID_COLOR_TYPE  = -1501,
-	ERR_TEX_NOT_8BIT_PRECISION  = -1502,
-	ERR_TEX_INVALID_LAYOUT      = -1503,
-	ERR_TEX_COMPRESSED          = -1504,
-	WARN_TEX_INVALID_DATA       = +1505,
-	ERR_TEX_INVALID_SIZE        = -1506,
-	ERR_TEX_HEADER_NOT_COMPLETE = -1507,
-
-	ERR_CPU_FEATURE_MISSING     = -1600,
-
-	// shaders
-	ERR_SHDR_CREATE             = -1700,
-	ERR_SHDR_COMPILE            = -1701,
-	ERR_SHDR_NO_SHADER          = -1702,
-	ERR_SHDR_LINK               = -1703,
-	ERR_SHDR_NO_PROGRAM         = -1704,
-
-	ERR_LAST
-};
-
-
-
 
 #ifndef MIN
 #define MIN(a, b) (((a) < (b))? (a) : (b))

source/lib/res/file/vfs_path.cpp

@@ -31,7 +31,6 @@ int path_validate(const uint line, const char* path)
 	size_t path_len = 0;	// counted as we go; checked against max.
 
 	const char* msg = 0;	// error occurred <==> != 0
-	int err = -1;			// what we pass to caller
 
 	int c = 0, last_c;		// used for ./ detection
 
@@ -78,12 +77,10 @@ int path_validate(const uint line, const char* path)
 			goto ok;
 	}
 
-	// failed somewhere - err is the error code,
-	// or -1 if not set specifically above.
 fail:
-	debug_printf("%s called from line %d failed: %s (error code %d)\n", __func__, line, msg, err);
+	debug_printf("%s called from line %d failed: %s\n", __func__, line, msg);
 	debug_warn("failed");
-	return err;
+	return -1;
 
 ok:
 	return 0;

source/lib/res/graphics/tex.cpp

@@ -416,10 +416,10 @@ static int tex_load_impl(void* file_, size_t file_size, Tex* t)
 	// make sure the entire header has been read
 	const size_t min_hdr_size = c->hdr_size(0);
 	if(file_size < min_hdr_size)
-		return ERR_TEX_HEADER_NOT_COMPLETE;
+		return ERR_INCOMPLETE_HEADER;
 	const size_t hdr_size = c->hdr_size(file);
 	if(file_size < hdr_size)
-		return ERR_TEX_HEADER_NOT_COMPLETE;
+		return ERR_INCOMPLETE_HEADER;
 	t->ofs = hdr_size;
 
 	DynArray da;

source/lib/res/graphics/tex_codec.cpp

@@ -48,7 +48,7 @@ int tex_codec_for_header(const u8* file, size_t file_size, const TexCodecVTbl**
 {
 	// we guarantee at least 4 bytes for is_hdr to look at
 	if(file_size < 4)
-		return ERR_TEX_HEADER_NOT_COMPLETE;
+		return ERR_INCOMPLETE_HEADER;
 
 	for(*c = codecs; *c; *c = (*c)->next)
 	{

source/lib/sysdep/sysdep.h

@@ -212,6 +212,8 @@ extern int sys_cursor_free(void* cursor);
 
 
 
+extern int sys_error_description_r(int err, char* buf, size_t max_chars);
+
 extern int get_executable_name(char* n_path, size_t buf_size);
 
 // return filename of the module which contains address <addr>,

source/lib/sysdep/win/win.cpp

@@ -37,7 +37,6 @@ char win_sys_dir[MAX_PATH+1];
 char win_exe_dir[MAX_PATH+1];
 
 
-
 // we need to know the app's main window for the error dialog, so that
 // it is modal and actually stops the app. if it keeps running while
 // we're reporting an error, it'll probably crash and take down the
@@ -634,6 +633,27 @@ int sys_cursor_free(void* cursor)
 }
 
 
+//-----------------------------------------------------------------------------
+
+
+int sys_error_description_r(int err, char* buf, size_t max_chars)
+{
+	// not in our range (Win32 error numbers are positive)
+	if(err < 0)
+		return -1;
+
+	const LPCVOID source = 0;	// ignored (we're not using FROM_HMODULE etc.)
+	const DWORD lang_id = 0;	// look for neutral, then current locale
+	va_list* args = 0;			// we don't care about "inserts"
+	DWORD ret = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, source, (DWORD)err,
+		lang_id, buf, (DWORD)max_chars, args);
+	if(!ret)
+		return -1;
+	debug_assert(ret < max_chars);	// ret = #chars output
+	return 0;
+}
+
+
 ///////////////////////////////////////////////////////////////////////////////
 //
 // module init and shutdown mechanism