Make the code -Wall compliant on gcc 12.2 & 13.2 and clang 14.0.0

@kloczek writes:
> Just summary stats using gcc 13.x
>
> [tkloczko@pers-jacek SPECS]$ rpmbuild -ba ksh.spec  2>&1 |
>			grep -- \\[-W | sed 's/.*\[//; s/\]//' |
>			sort | uniq -c | sort -nr
>    2034 -Wunknown-pragmas
>    1226 -Wparentheses
>     283 -Wmissing-braces
>     179 -Wunused-value
>      25 -Wchar-subscripts
>      19 -Wlto-type-mismatch
>       9 -Wunused-variable
>       9 -Wunused-const-variable=
>       2 -Waddress
>       1 -Wuse-after-free
>       1 -Wunused-function
>       1 -Wunused-but-set-variable
>       1 -Wsequence-point
>       1 -Wdangling-pointer=

Cause: build system uses -Wall to turn on ALL the warnings.
Some users want a clean compile with -Wall, so here it is.

-Wunknown-pragmas was fixed by adding preprocessor directives that
hid them from inapplicable compilers. (AFAIK the standard says
unknown pragmas are ignored, so this was pretty obnoxious.)

-Wparentheses and -Wmissing-braces complain about perfectly valid
C90 syntax, and I am not going to change it. Instead, these
warnings have been disabled in src/lib/libast/features/common.

On my own gcc tests I also had a lot of -Wmaybe-unitialized
warnings. In most cases it was obvious from reading the code that
the variables will not be used uninitialised, so those warnings are
likely false positives. But a few of those did look like actual
problems, and the overhead of variable initialisers is negligible,
so this fixes them all.

The rest of the warnings were fixed with appropriate code tweaks,
too many to list here.

Resolves: #699

src/cmd/INIT/mamake.c

@@ -2,7 +2,7 @@
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1990-2013 AT&T Intellectual Property          *
-*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
+*          Copyright (c) 2020-2024 Contributors to ksh 93u+m           *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 2.0                  *
 *                                                                      *
@@ -15,7 +15,11 @@
 *            Johnothan King <[email protected]>             *
 *                                                                      *
 ***********************************************************************/
+#if __clang__
 #pragma clang diagnostic ignored "-Wparentheses"
+#elif __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
+#pragma GCC diagnostic ignored "-Wparentheses"
+#endif
 
 /*
  * mamake -- MAM make
@@ -36,7 +40,7 @@ static const char usage[] =
 "[-author?Glenn Fowler <[email protected]>]"
 "[-author?Contributors to https://github.com/ksh93/ksh]"
 "[-copyright?(c) 1994-2012 AT&T Intellectual Property]"
-"[-copyright?(c) 2020-2023 Contributors to ksh 93u+m]"
+"[-copyright?(c) 2020-2024 Contributors to ksh 93u+m]"
 "[-license?https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html]"
 "[+NAME?mamake - make abstract machine make]"
 "[+DESCRIPTION?\bmamake\b reads \amake abstract machine\a target and"
@@ -589,7 +593,10 @@ search(Dict_t* dict, char* name, void* value)
 	else if (value)
 	{
 		if (!(root = newof(0, Dict_item_t, 1, strlen(name))))
+		{
 			report(3, "out of memory [dictionary]", name, 0);
+			abort();
+		}
 		strcpy(root->name, name);
 	}
 	if (root)
@@ -727,7 +734,8 @@ view(void)
 	}
 	if ((s = (char*)search(state.vars, "VPATH", NULL)) && *s)
 	{
-		zp = 0;
+		p = NULL;
+		zp = NULL;
 		for (;;)
 		{
 			for (t = s; *t && *t != ':'; t++);
@@ -770,6 +778,8 @@ view(void)
 				}
 			}
 			n = strlen(s);
+			if(!p)
+				abort();
 			if (!(vp = newof(0, View_t, 1, strlen(p) + n + 1)))
 				report(3, "out of memory [view]", s, 0);
 			vp->node = n + 1;

src/cmd/ksh93/bltins/print.c

@@ -2,7 +2,7 @@
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1982-2014 AT&T Intellectual Property          *
-*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
+*          Copyright (c) 2020-2024 Contributors to ksh 93u+m           *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 2.0                  *
 *                                                                      *
@@ -178,7 +178,6 @@ int    b_print(int argc, char *argv[], Shbltin_t *context)
 	exitval = 0;
 	disc.version = OPT_VERSION;
 	disc.infof = infof;
-	opt_info.disc = &disc;
 	if(argc>0)
 	{
 		options = sh_optprint;
@@ -197,6 +196,7 @@ int    b_print(int argc, char *argv[], Shbltin_t *context)
 			goto skip;
 		}
 	}
+	opt_info.disc = &disc;
 	while((n = optget(argv,options))) switch(n)
 	{
 		case 'n':
@@ -215,6 +215,7 @@ int    b_print(int argc, char *argv[], Shbltin_t *context)
 			/* print to history file */
 			if(!sh_histinit())
 			{
+				opt_info.disc = NULL;
 				errormsg(SH_DICT,ERROR_system(1),e_history);
 				UNREACHABLE();
 			}
@@ -251,6 +252,7 @@ int    b_print(int argc, char *argv[], Shbltin_t *context)
 				vname = nv_open(opt_info.arg, sh.var_tree, NV_VARNAME);
 				if(!vname)
 				{
+					opt_info.disc = NULL;
 					errormsg(SH_DICT, ERROR_exit(2), e_create, opt_info.arg);
 					UNREACHABLE();
 				}
@@ -284,9 +286,11 @@ int    b_print(int argc, char *argv[], Shbltin_t *context)
 				errormsg(SH_DICT,2, "%s", opt_info.arg);
 			break;
 		case '?':
+			opt_info.disc = NULL;
 			errormsg(SH_DICT,ERROR_usage(2), "%s", opt_info.arg);
 			UNREACHABLE();
 	}
+	opt_info.disc = NULL;
 	argv += opt_info.index;
 	if(error_info.errors || (argc<0 && !(format = *argv++)))
 	{
@@ -1099,7 +1103,6 @@ static int extend(Sfio_t* sp, void* v, Sffmt_t* fe)
  */
 static int reload(int argn, char fmt, void* v, Sffmt_t* fe)
 {
-	union types_t*	value = (union types_t*)v;
 	struct printf*	pp = (struct printf*)fe;
 	int		r;
 	int		n;

src/cmd/ksh93/bltins/typeset.c

@@ -2,7 +2,7 @@
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1982-2012 AT&T Intellectual Property          *
-*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
+*          Copyright (c) 2020-2024 Contributors to ksh 93u+m           *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 2.0                  *
 *                                                                      *
@@ -647,8 +647,8 @@ static int     setall(char **argv,int flag,Dt_t *troot,struct tdata *tp)
 	char *last = 0;
 	int nvflags=(flag&(NV_ARRAY|NV_NOARRAY|NV_VARNAME|NV_IDENT|NV_ASSIGN|NV_STATIC|NV_MOVE));
 	int r=0, ref=0, comvar=(flag&NV_COMVAR),iarray=(flag&NV_IARRAY);
-	Dt_t *save_vartree;
-	Namval_t *save_namespace;
+	Dt_t *save_vartree = NULL;
+	Namval_t *save_namespace = NULL;
 	if(flag&NV_GLOBAL)
 	{
 		save_vartree = sh.var_tree;
@@ -1474,7 +1474,6 @@ static int print_namval(Sfio_t *file,Namval_t *np,int flag, struct tdata *tp)
 	}
 	if(isfun)
 	{
-		Sfio_t *iop=0;
 		char *fname=0;
 		if(nv_isattr(np,NV_NOFREE))
 			return 0;

src/cmd/ksh93/bltins/ulimit.c

@@ -2,7 +2,7 @@
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1982-2012 AT&T Intellectual Property          *
-*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
+*          Copyright (c) 2020-2024 Contributors to ksh 93u+m           *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 2.0                  *
 *                                                                      *
@@ -74,7 +74,7 @@ int	b_ulimit(int argc,char *argv[],Shbltin_t *context)
 	const Limit_t* tp;
 	char* conf;
 	int label, unit, nosupport, ret=0;
-	rlim_t i;
+	rlim_t i=0;
 	char tmp[41];
         Optdisc_t disc;
         NOT_USED(context);

src/cmd/ksh93/edit/completion.c

@@ -2,7 +2,7 @@
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1982-2012 AT&T Intellectual Property          *
-*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
+*          Copyright (c) 2020-2024 Contributors to ksh 93u+m           *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 2.0                  *
 *                                                                      *
@@ -36,7 +36,7 @@
 static char *fmtx(const char *string)
 {
 	const char	*cp = string;
-	int	 	n,c;
+	int	 	n = 0, c;
 	int		pos = 0;
 	unsigned char 	*state = (unsigned char*)sh_lexstates[2];
 	int		offset = stktell(sh.stk);

src/cmd/ksh93/edit/edit.c

@@ -2,7 +2,7 @@
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1982-2014 AT&T Intellectual Property          *
-*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
+*          Copyright (c) 2020-2024 Contributors to ksh 93u+m           *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 2.0                  *
 *                                                                      *
@@ -924,7 +924,7 @@ static int putstack(Edit_t *ep,char string[], int nbyte, int type)
  */
 int ed_getchar(Edit_t *ep,int mode)
 {
-	int n, c;
+	int n = 0, c;
 	char readin[LOOKAHEAD+1];
 	if(!ep->e_lookahead)
 	{

src/cmd/ksh93/edit/history.c

@@ -556,7 +556,7 @@ void hist_eof(History_t *hp)
 	char *cp,*first,*endbuff;
 	int incmd = 0;
 	off_t count = hp->histcnt;
-	int oldind,n,skip=0;
+	int oldind=0,n,skip=0;
 	off_t last = sfseek(hp->histfp,0,SEEK_END);
 	if(last < count)
 	{

src/cmd/ksh93/edit/vi.c

@@ -2,7 +2,7 @@
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1982-2012 AT&T Intellectual Property          *
-*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
+*          Copyright (c) 2020-2024 Contributors to ksh 93u+m           *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 2.0                  *
 *                                                                      *
@@ -182,7 +182,6 @@ static void	getline(Vi_t*,int);
 static int	getrchar(Vi_t*);
 static int	mvcursor(Vi_t*,int);
 static void	pr_string(Vi_t*,const char*);
-static void	putstring(Vi_t*,int, int);
 static void	refresh(Vi_t*,int);
 static void	replace(Vi_t*,int, int);
 static void	restore_v(Vi_t*);
@@ -206,17 +205,14 @@ static int	textmod(Vi_t*,int,int);
 int ed_viread(void *context, int fd, char *shbuf, int nchar, int reedit)
 {
 	Edit_t *ed = (Edit_t*)context;
-	int i;			/* general variable */
-	int term_char=0;	/* read() termination character */
+	int i;				/* general variable */
 	Vi_t *vp = ed->e_vi;
 	char prompt[PRSIZE+2];		/* prompt */
 	genchar Physical[2*MAXLINE];	/* physical image */
-	genchar Ubuf[MAXLINE];	/* used for U command */
-	genchar ubuf[MAXLINE];	/* used for u command */
+	genchar Ubuf[MAXLINE];		/* used for U command */
+	genchar ubuf[MAXLINE];		/* used for u command */
 	genchar Window[MAXLINE];	/* window image */
 	int Globals[9];			/* local global variables */
-	int esc_or_hang=0;		/* <ESC> or hangup */
-	char cntl_char=0;		/* TRUE if control character present */
 	if(!vp)
 	{
 		ed->e_vi = vp = sh_newof(0,Vi_t,1,0);
@@ -1658,20 +1654,6 @@ static void pr_string(Vi_t *vp, const char *sp)
 	return;
 }
 
-/*{	PUTSTRING( column, nchars )
- *
- *	Put nchars starting at column of physical into the workspace
- * to be printed.
- *
-}*/
-
-static void putstring(Vi_t *vp,int col, int nchars)
-{
-	while( nchars-- )
-		putchar(physical[col++]);
-	return;
-}
-
 /*{	VI_REDRAW( )
  *
  *	Print the prompt and force a total refresh.

src/cmd/ksh93/features/math.sh

@@ -2,7 +2,7 @@
 #                                                                      #
 #               This software is part of the ast package               #
 #          Copyright (c) 1982-2013 AT&T Intellectual Property          #
-#          Copyright (c) 2020-2023 Contributors to ksh 93u+m           #
+#          Copyright (c) 2020-2024 Contributors to ksh 93u+m           #
 #                      and is licensed under the                       #
 #                 Eclipse Public License, Version 2.0                  #
 #                                                                      #
@@ -122,7 +122,9 @@ eval `iffe $iffeflags -c "$cc" - dat,npt,mac $lib $iffehdrs $iffelibs 2>&$stderr
 eval `iffe $iffeflags -c "$cc" - num $nums $iffehdrs $iffelibs 2>&$stderr`
 
 cat <<!
+#if __clang__
 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
+#endif
 
 /* : : generated by $command from $table : : */
 

src/cmd/ksh93/mamstate.c

@@ -2,7 +2,7 @@
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1982-2011 AT&T Intellectual Property          *
-*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
+*          Copyright (c) 2020-2024 Contributors to ksh 93u+m           *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 2.0                  *
 *                                                                      *
@@ -14,7 +14,11 @@
 *                  Martijn Dekker <[email protected]>                   *
 *                                                                      *
 ***********************************************************************/
+#if __clang__
 #pragma clang diagnostic ignored "-Wparentheses"
+#elif __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
+#pragma GCC diagnostic ignored "-Wparentheses"
+#endif
 /*
  * AT&T Bell Laboratories
  * make abstract machine file state support

src/cmd/ksh93/sh/deparse.c

@@ -2,7 +2,7 @@
 *                                                                      *
 *               This software is part of the ast package               *
 *          Copyright (c) 1982-2011 AT&T Intellectual Property          *
-*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
+*          Copyright (c) 2020-2024 Contributors to ksh 93u+m           *
 *                      and is licensed under the                       *
 *                 Eclipse Public License, Version 2.0                  *
 *                                                                      *
@@ -458,7 +458,7 @@ static void p_arg(const struct argnod *arg,int endchar,int opts)
 static void p_redirect(const struct ionod *iop)
 {
 	char *cp;
-	int iof,iof2;
+	int iof, endc, endc2 = -1;
 	for(;iop;iop=iop->ionxt)
 	{
 		iof=iop->iofile;
@@ -505,34 +505,34 @@ static void p_redirect(const struct ionod *iop)
 		}
 		sfputr(outfile,cp,-1);
 		if(iop->ionxt)
-			iof = ' ';
+			endc = ' ';
 		else
 		{
-			if((iof=end_line)=='\n')
+			if((endc=end_line)=='\n')
 				begin_line = 1;
 		}
 		if((iof&IOLSEEK) && (iof&IOARITH))
-			iof2 = iof, iof = ' ';
-		if((iop->iofile & IOPROCSUB) && !(iop->iofile & IOLSEEK))
+			endc2 = endc, endc = ' ';
+		if((iof&IOPROCSUB) && !(iof&IOLSEEK))
 		{
 			/* process substitution as argument to redirection */
-			sfprintf(outfile," %c(", (iop->iofile & IOPUT) ? '>' : '<');
+			sfprintf(outfile," %c(", (iof&IOPUT) ? '>' : '<');
 			begin_line = 0;
 			p_tree((Shnode_t*)iop->ioname,PROC_SUBST);
-			sfputc(outfile,iof);
+			sfputc(outfile,endc);
 		}
 		else if(iop->iodelim)
 		{
-			if(!(iop->iofile&IODOC))
+			if(!(iof&IODOC))
 				sfwrite(outfile,"''",2);
-			sfputr(outfile,sh_fmtq(iop->iodelim),iof);
+			sfputr(outfile,sh_fmtq(iop->iodelim),endc);
 		}
-		else if(iop->iofile&IORAW)
-			sfputr(outfile,sh_fmtq(iop->ioname),iof);
+		else if(iof&IORAW)
+			sfputr(outfile,sh_fmtq(iop->ioname),endc);
 		else
 			sfputr(outfile,iop->ioname,iof);
 		if((iof&IOLSEEK) && (iof&IOARITH))
-			sfputr(outfile, "))", iof2);
+			sfputr(outfile, "))", endc2);
 	}
 	return;
 }