code base: simplify checks against value returned from snprintf() via wrapper.

9 files changed, 172 insertions, 117 deletions

diff --git a/src/fallback/slbt_archive_import_mri.c b/src/fallback/slbt_archive_import_mri.c
index 76a4c06..fdcbf07 100644
--- a/src/fallback/slbt_archive_import_mri.c
+++ b/src/fallback/slbt_archive_import_mri.c
@@ -21,6 +21,7 @@
 #include "slibtool_dprintf_impl.h"
 #include "slibtool_symlink_impl.h"
 #include "slibtool_readlink_impl.h"
+#include "slibtool_snprintf_impl.h"
 #include "slibtool_errinfo_impl.h"
 
 #define PPRIX64 "%"PRIx64
@@ -46,8 +47,8 @@ static char * slbt_mri_argument(
 				mricwd,sizeof(mricwd)) < 0)
 			return 0;
 
-		if ((size_t)snprintf(dstbuf,sizeof(dstbuf),"%s/%s",
-				mricwd,arg) >= sizeof(dstbuf))
+		if (slbt_snprintf(dstbuf,sizeof(dstbuf),
+				"%s/%s",mricwd,arg) < 0)
 			return 0;
 
 		target = dstbuf;
@@ -123,9 +124,8 @@ int slbt_archive_import_mri(
 		return 0;
 
 	/* program */
-	if ((size_t)snprintf(program,sizeof(program),
-			"%s",dctx->cctx->host.ar)
-			>= sizeof(program))
+	if (slbt_snprintf(program,sizeof(program),
+			"%s",dctx->cctx->host.ar) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* fork */
diff --git a/src/helper/slbt_dump_machine.c b/src/helper/slbt_dump_machine.c
index 3d3a454..dfd32a4 100644
--- a/src/helper/slbt_dump_machine.c
+++ b/src/helper/slbt_dump_machine.c
@@ -15,6 +15,7 @@
 
 #include <slibtool/slibtool.h>
 #include "slibtool_spawn_impl.h"
+#include "slibtool_snprintf_impl.h"
 
 static void slbt_dump_machine_child(
 	char *	program,
@@ -61,8 +62,8 @@ int slbt_dump_machine(
 		return -1;
 	}
 
-	if ((size_t)snprintf(program,sizeof(program),"%s",
-			compiler) >= sizeof(program))
+	if (slbt_snprintf(program,sizeof(program),
+			"%s",compiler) < 0)
 		return -1;
 
 	/* fork */
diff --git a/src/internal/slibtool_snprintf_impl.c b/src/internal/slibtool_snprintf_impl.c
new file mode 100644
index 0000000..d883af6
--- /dev/null
+++ b/src/internal/slibtool_snprintf_impl.c
@@ -0,0 +1,39 @@
+/*******************************************************************/
+/*  slibtool: a skinny libtool implementation, written in C        */
+/*  Copyright (C) 2016--2021  SysDeer Technologies, LLC            */
+/*  Released under the Standard MIT License; see COPYING.SLIBTOOL. */
+/*******************************************************************/
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "slibtool_snprintf_impl.h"
+
+
+/*****************************************************************/
+/* snprintf() wrapper that simplifies usage via the following:  */
+/*                                                             */
+/* (1) fail (return a negative result) in case the buffer is  */
+/*     not sufficiently large for the formatted string plus  */
+/*     the terminating null character.                      */
+/*                                                         */
+/**********************************************************/
+
+
+int slbt_snprintf(char * buf, size_t buflen, const char * fmt, ...)
+{
+	va_list	ap;
+	size_t  nbytes;
+
+	va_start(ap,fmt);
+	nbytes = vsnprintf(buf,buflen,fmt,ap);
+	va_end(ap);
+
+	if (nbytes >= buflen)
+		return -1;
+
+	return nbytes;
+}
diff --git a/src/internal/slibtool_snprintf_impl.h b/src/internal/slibtool_snprintf_impl.h
new file mode 100644
index 0000000..87fa65a
--- /dev/null
+++ b/src/internal/slibtool_snprintf_impl.h
@@ -0,0 +1,6 @@
+#ifndef SLIBTOOL_SNPRINTF_IMPL_H
+#define SLIBTOOL_SNPRINTF_IMPL_H
+
+int slbt_snprintf(char * buf, size_t buflen, const char * fmt, ...);
+
+#endif
diff --git a/src/internal/slibtool_symlink_impl.c b/src/internal/slibtool_symlink_impl.c
index 27f8171..19ec8ee 100644
--- a/src/internal/slibtool_symlink_impl.c
+++ b/src/internal/slibtool_symlink_impl.c
@@ -13,6 +13,7 @@
 #include "slibtool_errinfo_impl.h"
 #include "slibtool_symlink_impl.h"
 #include "slibtool_readlink_impl.h"
+#include "slibtool_snprintf_impl.h"
 
 #define SLBT_DEV_NULL_FLAGS	(SLBT_DRIVER_ALL_STATIC      \
 				| SLBT_DRIVER_DISABLE_SHARED \
@@ -70,13 +71,14 @@ int slbt_create_symlink(
 	dotdot = fwrapper ? "../" : "";
 
 	/* atarget */
-	if ((size_t)snprintf(atarget,sizeof(atarget),"%s%s",
-			dotdot,slash) >= sizeof(atarget))
+	if (slbt_snprintf(atarget,sizeof(atarget),
+			"%s%s",dotdot,slash) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* tmplnk */
-	if ((size_t)snprintf(tmplnk,sizeof(tmplnk),"%s.symlink.tmp",
-			lnkname) >= sizeof(tmplnk))
+	if (slbt_snprintf(tmplnk,sizeof(tmplnk),
+			"%s.symlink.tmp",
+			lnkname) <0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* placeholder? */
diff --git a/src/logic/slbt_exec_execute.c b/src/logic/slbt_exec_execute.c
index 971ff3c..7b7ec97 100644
--- a/src/logic/slbt_exec_execute.c
+++ b/src/logic/slbt_exec_execute.c
@@ -13,6 +13,7 @@
 #include <slibtool/slibtool.h>
 #include "slibtool_spawn_impl.h"
 #include "slibtool_driver_impl.h"
+#include "slibtool_snprintf_impl.h"
 #include "slibtool_errinfo_impl.h"
 
 int  slbt_exec_execute(
@@ -60,10 +61,9 @@ int  slbt_exec_execute(
 		sprintf(mark,".libs/%s",base);
 
 		/* wrapper */
-		if ((size_t)snprintf(wrapper,sizeof(wrapper),
+		if (slbt_snprintf(wrapper,sizeof(wrapper),
 					"%s.exe.wrapper",
-					exeref)
-				>= sizeof(wrapper)) {
+					exeref) < 0) {
 			slbt_free_exec_ctx(actx);
 			return SLBT_BUFFER_ERROR(dctx);
 		}
diff --git a/src/logic/slbt_exec_install.c b/src/logic/slbt_exec_install.c
index 909b28f..a304d5a 100644
--- a/src/logic/slbt_exec_install.c
+++ b/src/logic/slbt_exec_install.c
@@ -20,6 +20,7 @@
 #include "slibtool_spawn_impl.h"
 #include "slibtool_symlink_impl.h"
 #include "slibtool_errinfo_impl.h"
+#include "slibtool_snprintf_impl.h"
 #include "argv/argv.h"
 
 static int slbt_install_usage(
@@ -81,8 +82,8 @@ static int slbt_exec_install_init_dstdir(
 		last = dest;
 
 	/* dstdir: initial string */
-	if ((size_t)snprintf(dstdir,PATH_MAX,"%s",
-			last->arg) >= PATH_MAX)
+	if (slbt_snprintf(dstdir,PATH_MAX,
+			"%s",last->arg) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* dstdir might end with a slash */
@@ -124,8 +125,8 @@ static int slbt_exec_install_import_libraries(
 	char	rev    [128];
 
 	/* .libs/libfoo.so.x.y.z */
-	if ((size_t)snprintf(srcbuf,sizeof(srcbuf),"%s",
-			srcdso) >= sizeof(srcbuf))
+	if (slbt_snprintf(srcbuf,sizeof(srcbuf),
+			"%s",srcdso) <0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* (dso is under .libs) */
@@ -133,9 +134,11 @@ static int slbt_exec_install_import_libraries(
 		return SLBT_CUSTOM_ERROR(dctx,SLBT_ERR_INSTALL_FLOW);
 
 	/* libfoo.so.x.y.z */
-	if ((size_t)snprintf(implib,sizeof(implib),"%s",
-			++slash) >= sizeof(implib)
-				    - strlen(dctx->cctx->settings.impsuffix))
+	const char * impsuffix = dctx->cctx->settings.impsuffix;
+
+	if (slbt_snprintf(implib,
+			sizeof(implib) - strlen(impsuffix),
+			"%s",++slash) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* guard against an infinitely long version */
@@ -204,8 +207,8 @@ static int slbt_exec_install_import_libraries(
 	strcpy(implib,slash);
 	strcpy(dot,dctx->cctx->asettings.impsuffix);
 
-	if ((size_t)snprintf(hostlnk,sizeof(hostlnk),"%s/%s",
-			dstdir,slash) >= sizeof(hostlnk))
+	if (slbt_snprintf(hostlnk,sizeof(hostlnk),
+			"%s/%s",dstdir,slash) <0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	if (slbt_create_symlink(
@@ -242,13 +245,14 @@ static int slbt_exec_install_library_wrapper(
 		base = entry->arg;
 
 	/* /dstdir/libfoo.la */
-	if ((size_t)snprintf(instname,sizeof(instname),"%s/%s",
-			dstdir,base) >= sizeof(instname))
+	if (slbt_snprintf(instname,sizeof(instname),
+			"%s/%s",dstdir,base) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* libfoo.la.slibtool.install */
-	if ((size_t)snprintf(clainame,sizeof(clainame),"%s.slibtool.install",
-			entry->arg) >= sizeof(clainame))
+	if (slbt_snprintf(clainame,sizeof(clainame),
+			"%s.slibtool.install",
+			entry->arg) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* fdcwd */
@@ -356,9 +360,9 @@ static int slbt_exec_install_entry(
 	mark = &slnkname[base - entry->arg];
 	slen = sizeof(slnkname) - (mark - slnkname);
 
-	if ((size_t)snprintf(mark,slen,
+	if (slbt_snprintf(mark,slen,
 			".libs/%s.exe.wrapper",
-			base) >= slen)
+			base) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* fdcwd */
@@ -412,8 +416,8 @@ static int slbt_exec_install_entry(
 	strcpy(sobuf,dctx->cctx->settings.dsosuffix);
 	dsosuffix = sobuf;
 
-	if ((size_t)snprintf(slnkname,sizeof(slnkname),"%s.shrext",
-			srcfile) >= sizeof(slnkname))
+	if (slbt_snprintf(slnkname,sizeof(slnkname),
+			"%s.shrext",srcfile) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	if (!fstatat(fdcwd,slnkname,&st,0)) {
@@ -514,7 +518,7 @@ static int slbt_exec_install_entry(
 		if (slbt_readlinkat(fdcwd,dlnkname,hosttag,sizeof(hosttag)))
 			return SLBT_SYSTEM_ERROR(dctx,slnkname);
 	} else {
-		if ((size_t)snprintf(dot,slen,"%s.def.host",dsosuffix) >= slen)
+		if (slbt_snprintf(dot,slen,"%s.def.host",dsosuffix) < 0)
 			return SLBT_BUFFER_ERROR(dctx);
 
 		if (slbt_readlinkat(fdcwd,frelease ? dlnkname : slnkname,hosttag,sizeof(hosttag)))
@@ -573,8 +577,8 @@ static int slbt_exec_install_entry(
 			return SLBT_SYSTEM_ERROR(dctx,slnkname);
 
 		/* dstfile */
-		if ((size_t)snprintf(dstfile,sizeof(dstfile),"%s/%s",
-				dstdir,base) >= sizeof(dstfile))
+		if (slbt_snprintf(dstfile,sizeof(dstfile),
+				"%s/%s",dstdir,base) < 0)
 			return SLBT_BUFFER_ERROR(dctx);
 
 		/* single spawn, no symlinks */
@@ -603,8 +607,8 @@ static int slbt_exec_install_entry(
 
 	/* dstfile */
 	if (!dest)
-		if ((size_t)snprintf(dstfile,sizeof(dstfile),"%s/%s",
-				dstdir,target) >= sizeof(dstfile))
+		if (slbt_snprintf(dstfile,sizeof(dstfile),
+				"%s/%s",dstdir,target) < 0)
 			return SLBT_BUFFER_ERROR(dctx);
 
 	/* spawn */
@@ -625,8 +629,8 @@ static int slbt_exec_install_entry(
 	}
 
 	/* destination symlink: dstdir/libfoo.so */
-	if ((size_t)snprintf(dlnkname,sizeof(dlnkname),"%s/%s",
-			dstdir,base) >= sizeof(dlnkname))
+	if (slbt_snprintf(dlnkname,sizeof(dlnkname),
+			"%s/%s",dstdir,base) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* create symlink: libfoo.so --> libfoo.so.x.y.z */
@@ -672,8 +676,8 @@ static int slbt_exec_install_entry(
 	}
 
 	/* destination symlink: dstdir/libfoo.so.x */
-	if ((size_t)snprintf(dlnkname,sizeof(dlnkname),"%s/%s",
-			dstdir,slnkname) >= sizeof(dlnkname))
+	if (slbt_snprintf(dlnkname,sizeof(dlnkname),
+			"%s/%s",dstdir,slnkname) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	if (fpe) {
diff --git a/src/logic/slbt_exec_link.c b/src/logic/slbt_exec_link.c
index 84d3933..6eb9e8d 100644
--- a/src/logic/slbt_exec_link.c
+++ b/src/logic/slbt_exec_link.c
@@ -22,6 +22,7 @@
 #include "slibtool_mapfile_impl.h"
 #include "slibtool_metafile_impl.h"
 #include "slibtool_readlink_impl.h"
+#include "slibtool_snprintf_impl.h"
 #include "slibtool_symlink_impl.h"
 
 struct slbt_deps_meta {
@@ -101,10 +102,9 @@ static int slbt_get_deps_meta(
 	fdcwd = slbt_driver_fdcwd(dctx);
 
 	/* -rpath */
-	if ((size_t)snprintf(depfile,sizeof(depfile),
+	if (slbt_snprintf(depfile,sizeof(depfile),
 				"%s.slibtool.rpath",
-				libfilename)
-			>= sizeof(depfile))
+				libfilename) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* -Wl,%s */
@@ -114,10 +114,9 @@ static int slbt_get_deps_meta(
 	}
 
 	/* .deps */
-	if ((size_t)snprintf(depfile,sizeof(depfile),
+	if (slbt_snprintf(depfile,sizeof(depfile),
 				"%s.slibtool.deps",
-				libfilename)
-			>= sizeof(depfile))
+				libfilename) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* mapinfo */
@@ -188,8 +187,8 @@ static bool slbt_adjust_object_argument(
 	else
 		slash = arg;
 
-	if ((size_t)snprintf(base,sizeof(base),"%s",
-			slash) >= sizeof(base))
+	if (slbt_snprintf(base,sizeof(base),
+			"%s",slash) < 0)
 		return false;
 
 	sprintf(slash,".libs/%s",base);
@@ -239,8 +238,8 @@ static bool slbt_adjust_wrapper_argument(
 		else
 			slash = arg;
 
-		if ((size_t)snprintf(base,sizeof(base),"%s",
-				slash) >= sizeof(base))
+		if (slbt_snprintf(base,sizeof(base),
+				"%s",slash) < 0)
 			return false;
 
 		sprintf(slash,".libs/%s",base);
@@ -289,8 +288,8 @@ static int slbt_adjust_linker_argument(
 		else
 			slash = arg;
 
-		if ((size_t)snprintf(base,sizeof(base),"%s",
-				slash) >= sizeof(base))
+		if (slbt_snprintf(base,sizeof(base),
+				"%s",slash) < 0)
 			return 0;
 
 		sprintf(slash,".libs/%s",base);
@@ -560,9 +559,9 @@ static int slbt_exec_link_adjust_argument_vector(
 			sprintf(lib,"%s.slibtool.deps",*carg);
 
 			/* account for {'-','L','-','l'} */
-			if ((size_t)snprintf(arg,sizeof(arg),
-						"%s",*carg)
-					>= (sizeof(arg) - 4))
+			if (slbt_snprintf(arg,
+					sizeof(arg) - 4,
+					"%s",*carg) < 0)
 				return slbt_exec_link_exit(
 					depsmeta,
 					SLBT_BUFFER_ERROR(dctx));
@@ -905,6 +904,7 @@ static int slbt_exec_link_create_dep_file(
 {
 	int			ret;
 	int			deps;
+	int			slen;
 	int			fdcwd;
 	char **			parg;
 	char *			popt;
@@ -913,7 +913,6 @@ static int slbt_exec_link_create_dep_file(
 	char *			mark;
 	char *			base;
 	size_t			size;
-	size_t			slen;
 	char			deplib [PATH_MAX];
 	bool			is_reladir;
 	char			reladir[PATH_MAX];
@@ -927,11 +926,9 @@ static int slbt_exec_link_create_dep_file(
 	fdcwd = slbt_driver_fdcwd(dctx);
 
 	/* depfile */
-	slen = snprintf(depfile,sizeof(depfile),
-		"%s.slibtool.deps",
-		libfilename);
-
-	if (slen >= sizeof(depfile))
+	if (slbt_snprintf(depfile,sizeof(depfile),
+			"%s.slibtool.deps",
+			libfilename) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* deps */
@@ -965,10 +962,12 @@ static int slbt_exec_link_create_dep_file(
 
 			/* [relative .la directory] */
 			if (base > *parg) {
-				slen = snprintf(reladir,sizeof(reladir),
+				slen = slbt_snprintf(
+					reladir,
+					sizeof(reladir),
 					"%s",*parg);
 
-				if (slen >= sizeof(reladir)) {
+				if (slen < 0) {
 					close(deps);
 					return SLBT_BUFFER_ERROR(dctx);
 				}
@@ -986,9 +985,9 @@ static int slbt_exec_link_create_dep_file(
 			strcpy(depfile,*parg);
 			mark = depfile + (base - *parg);
 			size = sizeof(depfile) - (base - *parg);
-			slen = snprintf(mark,size,".libs/%s",base);
+			slen = slbt_snprintf(mark,size,".libs/%s",base);
 
-			if (slen >= size) {
+			if (slen < 0) {
 				close(deps);
 				return SLBT_BUFFER_ERROR(dctx);
 			}
@@ -1038,9 +1037,9 @@ static int slbt_exec_link_create_dep_file(
 			strcpy(depfile,*parg);
 			mark = depfile + (base - *parg);
 			size = sizeof(depfile) - (base - *parg);
-			slen = snprintf(mark,size,".libs/%s",base);
+			slen = slbt_snprintf(mark,size,".libs/%s",base);
 
-			if (slen >= size) {
+			if (slen < 0) {
 				close(deps);
 				return SLBT_BUFFER_ERROR(dctx);
 			}
@@ -1051,11 +1050,11 @@ static int slbt_exec_link_create_dep_file(
 			size = sizeof(depfile) - (mark - depfile);
 
 			if (!farchive) {
-				slen = snprintf(mark,size,
+				slen = slbt_snprintf(mark,size,
 					"%s.slibtool.deps",
 					dctx->cctx->settings.dsosuffix);
 
-				if (slen >= size) {
+				if (slen < 0) {
 					close(deps);
 					return SLBT_BUFFER_ERROR(dctx);
 				}
@@ -1071,10 +1070,10 @@ static int slbt_exec_link_create_dep_file(
 			}
 
 			if (!mapinfo) {
-				slen = snprintf(mark,size,
+				slen = slbt_snprintf(mark,size,
 					".a.slibtool.deps");
 
-				if (slen >= size) {
+				if (slen < 0) {
 					close(deps);
 					return SLBT_BUFFER_ERROR(dctx);
 				}
@@ -1148,13 +1147,17 @@ static int slbt_exec_link_create_host_tag(
 	char	hostlnk[PATH_MAX];
 
 	/* libfoo.so.def.{flavor} */
-	if ((size_t)snprintf(hosttag,sizeof(hosttag),"%s.%s",
+	if (slbt_snprintf(hosttag,
+			sizeof(hosttag),
+			"%s.%s",
 			deffilename,
-			dctx->cctx->host.flavor) >= sizeof(hosttag))
+			dctx->cctx->host.flavor) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
-	if ((size_t)snprintf(hostlnk,sizeof(hostlnk),"%s.host",
-			deffilename) >= sizeof(hostlnk))
+	if (slbt_snprintf(hostlnk,
+			sizeof(hostlnk),
+			"%s.host",
+			deffilename) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* libfoo.so.def is under .libs/ */
@@ -1208,8 +1211,8 @@ static int slbt_exec_link_create_import_library(
 
 	/* eargv */
 	if (fmdso) {
-		if ((size_t)snprintf(program,sizeof(program),"%s",
-				dctx->cctx->host.mdso) >= sizeof(program))
+		if (slbt_snprintf(program,sizeof(program),
+				"%s",dctx->cctx->host.mdso) < 0)
 			return SLBT_BUFFER_ERROR(dctx);
 
 		eargv[0] = program;
@@ -1220,8 +1223,8 @@ static int slbt_exec_link_create_import_library(
 		eargv[5] = deffilename;
 		eargv[6] = 0;
 	} else {
-		if ((size_t)snprintf(program,sizeof(program),"%s",
-				dctx->cctx->host.dlltool) >= sizeof(program))
+		if (slbt_snprintf(program,sizeof(program),
+				"%s",dctx->cctx->host.dlltool) < 0)
 			return SLBT_BUFFER_ERROR(dctx);
 
 		eargv[0] = program;
@@ -1313,13 +1316,13 @@ static int slbt_exec_link_create_archive(
 	ectx->program = program;
 
 	/* output */
-	if ((size_t)snprintf(output,sizeof(output),"%s",
-			arfilename) >= sizeof(output))
+	if (slbt_snprintf(output,sizeof(output),
+			"%s",arfilename) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	/* ar alternate argument vector */
-	if ((size_t)snprintf(program,sizeof(program),"%s",
-			dctx->cctx->host.ar) >= sizeof(program))
+	if (slbt_snprintf(program,sizeof(program),
+			"%s",dctx->cctx->host.ar) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 
@@ -1437,59 +1440,58 @@ static int slbt_exec_link_create_library(
 		(void)0;
 
 	} else if (!laout && (dctx->cctx->drvflags & SLBT_DRIVER_MODULE)) {
-		if ((size_t)snprintf(soname,sizeof(soname),"-Wl,%s",
-					dctx->cctx->output)
-				>= sizeof(soname))
+		if (slbt_snprintf(soname,sizeof(soname),
+				"-Wl,%s",dctx->cctx->output) < 0)
 			return SLBT_BUFFER_ERROR(dctx);
 
 		*ectx->soname  = "-Wl,-soname";
 		*ectx->lsoname = soname;
 
 	} else if (relfilename && dctx->cctx->verinfo.verinfo) {
-		if ((size_t)snprintf(soname,sizeof(soname),"-Wl,%s%s-%s%s.%d%s",
+		if (slbt_snprintf(soname,sizeof(soname),
+					"-Wl,%s%s-%s%s.%d%s",
 					ectx->sonameprefix,
 					dctx->cctx->libname,
 					dctx->cctx->release,
 					dctx->cctx->settings.osdsuffix,
 					dctx->cctx->verinfo.major,
-					dctx->cctx->settings.osdfussix)
-				>= sizeof(soname))
+					dctx->cctx->settings.osdfussix) < 0)
 			return SLBT_BUFFER_ERROR(dctx);
 
 		*ectx->soname  = "-Wl,-soname";
 		*ectx->lsoname = soname;
 
 	} else if (relfilename) {
-		if ((size_t)snprintf(soname,sizeof(soname),"-Wl,%s%s-%s%s",
+		if (slbt_snprintf(soname,sizeof(soname),
+					"-Wl,%s%s-%s%s",
 					ectx->sonameprefix,
 					dctx->cctx->libname,
 					dctx->cctx->release,
-					dctx->cctx->settings.dsosuffix)
-				>= sizeof(soname))
+					dctx->cctx->settings.dsosuffix) < 0)
 			return SLBT_BUFFER_ERROR(dctx);
 
 		*ectx->soname  = "-Wl,-soname";
 		*ectx->lsoname = soname;
 
 	} else if (dctx->cctx->drvflags & SLBT_DRIVER_AVOID_VERSION) {
-		if ((size_t)snprintf(soname,sizeof(soname),"-Wl,%s%s%s",
+		if (slbt_snprintf(soname,sizeof(soname),
+					"-Wl,%s%s%s",
 					ectx->sonameprefix,
 					dctx->cctx->libname,
-					dctx->cctx->settings.dsosuffix)
-				>= sizeof(soname))
+					dctx->cctx->settings.dsosuffix) < 0)
 			return SLBT_BUFFER_ERROR(dctx);
 
 		*ectx->soname  = "-Wl,-soname";
 		*ectx->lsoname = soname;
 
 	} else {
-		if ((size_t)snprintf(soname,sizeof(soname),"-Wl,%s%s%s.%d%s",
+		if (slbt_snprintf(soname,sizeof(soname),
+					"-Wl,%s%s%s.%d%s",
 					ectx->sonameprefix,
 					dctx->cctx->libname,
 					dctx->cctx->settings.osdsuffix,
 					dctx->cctx->verinfo.major,
-					dctx->cctx->settings.osdfussix)
-				>= sizeof(soname))
+					dctx->cctx->settings.osdfussix) < 0)
 			return SLBT_BUFFER_ERROR(dctx);
 
 		*ectx->soname  = "-Wl,-soname";
@@ -1498,9 +1500,9 @@ static int slbt_exec_link_create_library(
 
 	/* PE: --output-def */
 	if (dctx->cctx->drvflags & SLBT_DRIVER_IMAGE_PE) {
-		if ((size_t)snprintf(symfile,sizeof(symfile),"-Wl,%s",
-					ectx->deffilename)
-				>= sizeof(output))
+		if (slbt_snprintf(symfile,sizeof(symfile),
+					"-Wl,%s",
+					ectx->deffilename) < 0)
 			return SLBT_BUFFER_ERROR(dctx);
 
 		*ectx->symdefs = "-Wl,--output-def";
@@ -1525,14 +1527,14 @@ static int slbt_exec_link_create_library(
 	} else if (dctx->cctx->drvflags & SLBT_DRIVER_AVOID_VERSION) {
 		strcpy(output,dsofilename);
 	} else {
-		if ((size_t)snprintf(output,sizeof(output),"%s%s.%d.%d.%d%s",
+		if (slbt_snprintf(output,sizeof(output),
+					"%s%s.%d.%d.%d%s",
 					dsobasename,
 					dctx->cctx->settings.osdsuffix,
 					dctx->cctx->verinfo.major,
 					dctx->cctx->verinfo.minor,
 					dctx->cctx->verinfo.revision,
-					dctx->cctx->settings.osdfussix)
-				>= sizeof(output))
+					dctx->cctx->settings.osdfussix) < 0)
 			return SLBT_BUFFER_ERROR(dctx);
 	}
 
@@ -1647,10 +1649,9 @@ static int slbt_exec_link_create_executable(
 		*ectx->noundef = "-Wl,--no-undefined";
 
 	/* executable wrapper: create */
-	if ((size_t)snprintf(wrapper,sizeof(wrapper),
+	if (slbt_snprintf(wrapper,sizeof(wrapper),
 				"%s.wrapper.tmp",
-				dctx->cctx->output)
-			>= sizeof(wrapper))
+				dctx->cctx->output) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	if ((fdwrap = openat(fdcwd,wrapper,O_RDWR|O_CREAT|O_TRUNC,0644)) < 0)
@@ -1694,9 +1695,8 @@ static int slbt_exec_link_create_executable(
 		return SLBT_SYSTEM_ERROR(dctx,0);
 
 	/* output */
-	if ((size_t)snprintf(output,sizeof(output),"%s",
-				exefilename)
-			>= sizeof(output))
+	if (slbt_snprintf(output,sizeof(output),
+			"%s",exefilename) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	*ectx->lout[0] = "-o";
@@ -1717,8 +1717,9 @@ static int slbt_exec_link_create_executable(
 	ectx->program = ccwrap ? ccwrap : depsmeta.altv[0];
 
 	/* executable wrapper symlink */
-	if ((size_t)snprintf(wraplnk,sizeof(wraplnk),"%s.exe.wrapper",
-			exefilename) >= sizeof(wraplnk))
+	if (slbt_snprintf(wraplnk,sizeof(wraplnk),
+			"%s.exe.wrapper",
+			exefilename) < 0)
 		return slbt_exec_link_exit(
 			&depsmeta,
 			SLBT_BUFFER_ERROR(dctx));
@@ -1896,7 +1897,8 @@ int slbt_exec_link(
 		actx = ectx;
 
 	/* libfoo.so.x.y.z */
-	if ((size_t)snprintf(soxyz,sizeof(soxyz),"%s%s%s%s%s.%d.%d.%d%s",
+	if (slbt_snprintf(soxyz,sizeof(soxyz),
+				"%s%s%s%s%s.%d.%d.%d%s",
 				ectx->sonameprefix,
 				dctx->cctx->libname,
 				dctx->cctx->release ? "-" : "",
@@ -1905,8 +1907,7 @@ int slbt_exec_link(
 				dctx->cctx->verinfo.major,
 				dctx->cctx->verinfo.minor,
 				dctx->cctx->verinfo.revision,
-				dctx->cctx->settings.osdfussix)
-			>= sizeof(soxyz)) {
+				dctx->cctx->settings.osdfussix) < 0) {
 		slbt_free_exec_ctx(actx);
 		return SLBT_BUFFER_ERROR(dctx);
 	}
diff --git a/src/logic/slbt_exec_uninstall.c b/src/logic/slbt_exec_uninstall.c
index 9ffed87..c50c8dd 100644
--- a/src/logic/slbt_exec_uninstall.c
+++ b/src/logic/slbt_exec_uninstall.c
@@ -15,6 +15,7 @@
 #include "slibtool_driver_impl.h"
 #include "slibtool_uninstall_impl.h"
 #include "slibtool_readlink_impl.h"
+#include "slibtool_snprintf_impl.h"
 #include "slibtool_errinfo_impl.h"
 #include "argv/argv.h"
 
@@ -170,8 +171,9 @@ static int slbt_exec_uninstall_entry(
 	char		path [PATH_MAX];
 	char		lpath[PATH_MAX];
 
-	if ((size_t)snprintf(path,PATH_MAX,"%s",
-			entry->arg) >= PATH_MAX-8)
+	if (slbt_snprintf(path,
+			PATH_MAX - 8,
+			"%s",entry->arg) < 0)
 		return SLBT_BUFFER_ERROR(dctx);
 
 	*parg = (char *)entry->arg;