libbb: reduce the overhead of single parameter bb_error_msg() calls

Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by
Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower
overhead call to bb_perror_msg() when only a string was being printed
with no parameters. This saves space for some CPU architectures because
it avoids the overhead of a call to a variadic function. However there
has never been a simple version of bb_error_msg(), and since 2007 many
new calls to bb_perror_msg() have been added that only take a single
parameter and so could have been using bb_simple_perror_message().

This changeset introduces 'simple' versions of bb_info_msg(),
bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and
bb_herror_msg_and_die(), and replaces all calls that only take a
single parameter, or use something like ("%s", arg), with calls to the
corresponding 'simple' version.

Since it is likely that single parameter calls to the variadic functions
may be accidentally reintroduced in the future a new debugging config
option WARN_SIMPLE_MSG has been introduced. This uses some macro magic
which will cause any such calls to generate a warning, but this is
turned off by default to avoid use of the unpleasant macros in normal
circumstances.

This is a large changeset due to the number of calls that have been
replaced. The only files that contain changes other than simple
substitution of function calls are libbb.h, libbb/herror_msg.c,
libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c,
networking/udhcp/common.h and util-linux/mdev.c additonal macros have
been added for logging so that single parameter and multiple parameter
logging variants exist.

The amount of space saved varies considerably by architecture, and was
found to be as follows (for 'defconfig' using GCC 7.4):

Arm:     -92 bytes
MIPS:    -52 bytes
PPC:   -1836 bytes
x86_64: -938 bytes

Note that for the MIPS architecture only an exception had to be made
disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h)
because it made these files larger on MIPS.

Signed-off-by: James Byrne <james.byrne@origamienergy.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 17 insertions, 17 deletions

diff --git a/editors/ed.c b/editors/ed.c
index 1a36add39..d3ae8da92 100644
--- a/editors/ed.c
+++ b/editors/ed.c
@@ -165,7 +165,7 @@ static NOINLINE int searchLines(const char *str, int num1, int num2)
 
 	if (*str == '\0') {
 		if (searchString[0] == '\0') {
-			bb_error_msg("no previous search string");
+			bb_simple_error_msg("no previous search string");
 			return 0;
 		}
 		str = searchString;
@@ -228,7 +228,7 @@ static const char* getNum(const char *cp, smallint *retHaveNum, int *retNum)
 			case '\'':
 				cp++;
 				if ((unsigned)(*cp - 'a') >= 26) {
-					bb_error_msg("bad mark name");
+					bb_simple_error_msg("bad mark name");
 					return NULL;
 				}
 				haveNum = TRUE;
@@ -314,7 +314,7 @@ static int insertLine(int num, const char *data, int len)
 	LINE *newLp, *lp;
 
 	if ((num < 1) || (num > lastNum + 1)) {
-		bb_error_msg("inserting at bad line number");
+		bb_simple_error_msg("inserting at bad line number");
 		return FALSE;
 	}
 
@@ -384,7 +384,7 @@ static int readLines(const char *file, int num)
 	char *cp;
 
 	if ((num < 1) || (num > lastNum + 1)) {
-		bb_error_msg("bad line for read");
+		bb_simple_error_msg("bad line for read");
 		return FALSE;
 	}
 
@@ -629,7 +629,7 @@ static void subCommand(const char *cmd, int num1, int num2)
 	cp = buf;
 
 	if (isblank(*cp) || (*cp == '\0')) {
-		bb_error_msg("bad delimiter for substitute");
+		bb_simple_error_msg("bad delimiter for substitute");
 		return;
 	}
 
@@ -638,7 +638,7 @@ static void subCommand(const char *cmd, int num1, int num2)
 
 	cp = strchr(cp, delim);
 	if (cp == NULL) {
-		bb_error_msg("missing 2nd delimiter for substitute");
+		bb_simple_error_msg("missing 2nd delimiter for substitute");
 		return;
 	}
 
@@ -660,13 +660,13 @@ static void subCommand(const char *cmd, int num1, int num2)
 			printFlag = TRUE;
 			break;
 		default:
-			bb_error_msg("unknown option for substitute");
+			bb_simple_error_msg("unknown option for substitute");
 			return;
 	}
 
 	if (*oldStr == '\0') {
 		if (searchString[0] == '\0') {
-			bb_error_msg("no previous search string");
+			bb_simple_error_msg("no previous search string");
 			return;
 		}
 		oldStr = searchString;
@@ -846,7 +846,7 @@ static void doCommands(void)
 
 		case 'f':
 			if (*cp != '\0' && *cp != ' ') {
-				bb_error_msg("bad file command");
+				bb_simple_error_msg("bad file command");
 				break;
 			}
 			cp = skip_whitespace(cp);
@@ -870,7 +870,7 @@ static void doCommands(void)
 		case 'k':
 			cp = skip_whitespace(cp);
 			if ((unsigned)(*cp - 'a') >= 26 || cp[1]) {
-				bb_error_msg("bad mark name");
+				bb_simple_error_msg("bad mark name");
 				break;
 			}
 			marks[(unsigned)(*cp - 'a')] = num2;
@@ -887,7 +887,7 @@ static void doCommands(void)
 		case 'q':
 			cp = skip_whitespace(cp);
 			if (have1 || *cp) {
-				bb_error_msg("bad quit command");
+				bb_simple_error_msg("bad quit command");
 				break;
 			}
 			if (!dirty)
@@ -903,12 +903,12 @@ static void doCommands(void)
 
 		case 'r':
 			if (*cp != '\0' && *cp != ' ') {
-				bb_error_msg("bad read command");
+				bb_simple_error_msg("bad read command");
 				break;
 			}
 			cp = skip_whitespace(cp);
 			if (*cp == '\0') {
-				bb_error_msg("no file name");
+				bb_simple_error_msg("no file name");
 				break;
 			}
 			if (!have1)
@@ -925,14 +925,14 @@ static void doCommands(void)
 
 		case 'w':
 			if (*cp != '\0' && *cp != ' ') {
-				bb_error_msg("bad write command");
+				bb_simple_error_msg("bad write command");
 				break;
 			}
 			cp = skip_whitespace(cp);
 			if (*cp == '\0') {
 				cp = fileName;
 				if (!cp) {
-					bb_error_msg("no file name specified");
+					bb_simple_error_msg("no file name specified");
 					break;
 				}
 			}
@@ -960,7 +960,7 @@ static void doCommands(void)
 
 		case '.':
 			if (have1) {
-				bb_error_msg("no arguments allowed");
+				bb_simple_error_msg("no arguments allowed");
 				break;
 			}
 			printLines(curNum, curNum, FALSE);
@@ -984,7 +984,7 @@ static void doCommands(void)
 			break;
 
 		default:
-			bb_error_msg("unimplemented command");
+			bb_simple_error_msg("unimplemented command");
 			break;
 		}
 	}