A better answer is to actually get rid of strcpy() / strcat() / sprintf()
because there will always be compilers complaining about them.
Here's a patch that does that for freetype2-demos, please take a look.
Le jeu. 23 juil. 2020 à 13:16, Werner LEMBERG a écrit :
> > There seems to be a new warning in 2.10.2 (compared to 2.10.1) when
> > compiling for 32-bit: [...]
>
> Fixed in git, thanks.
>
> > Also have had a bunch of strncat related warning (probably gcc 1
> specific, or some compiler switch specific) in ft2-demos, for a while:
> >
> > ===
> > inlined from 'RunIns' at src/ttdebug.c:2105:11:
> > /usr/include/bits/string_fortified.h:136:10: warning:
> > '__builtin___strncat_chk' output may be truncated copying 31 bytes
> > from a string of length 31 [-Wstringop-truncation]
>
> (The problematic calls of strncat are in function `Cur_U_Line'.)
>
> Hmm. The answer to
>
>
> https://stackoverflow.com/questions/50198319/gcc-8-wstringop-truncation-what-is-the-good-practice
>
> recommends to switch off the warning if the code does exactly ...
>
>
> Werner
>
>
From dc5dae42212453f9a7850f201ad82c39e041e698 Mon Sep 17 00:00:00 2001
From: David Turner
Date: Sun, 17 May 2020 21:37:09 +0200
Subject: [build] Remove strncat / strcpy() / sprintf() from sources.
This removes all uses of these potentially unsafe functions from
the sources, mostly to avoid dealing with overzealous
compiler warnings, and preventing buffer overflow issues.
This is done through several steps:
+ common.h: Add ft_strdup() to implement a proper strdup()
function that also works on Windows.
+ strbuf.h: New header and associated source file, providing
a trivial data type and functions to safely perform formatted
string concatenation on a fixed-size buffer, while ensuring
the result is always properly zero-terminated.
Usage is pretty simple, and documented in the header.
+ Update the other sources to use ft_debug(), stdbuf_xxx()
and snprintf() instead of sprintf() in order to get rid of
any potential for buffer overflow / unterminated strings.
---
Makefile | 2 +
src/common.c | 22 +++-
src/common.h | 9 +++-
src/ftbench.c | 32 ++--
src/ftcommon.c | 133 +++---
src/ftcommon.h | 34
src/ftdiff.c | 22
src/ftdump.c | 4 +-
src/ftgamma.c | 4 +-
src/ftgrid.c | 39 --
src/ftmulti.c | 68
src/ftsbit.c | 2 +-
src/ftstring.c | 9 ++--
src/ftview.c | 88 +++
src/strbuf.c | 139 +
src/strbuf.h | 117 +
src/ttdebug.c | 131 ++
17 files changed, 600 insertions(+), 255 deletions(-)
create mode 100644 src/strbuf.c
create mode 100644 src/strbuf.h
diff --git a/Makefile b/Makefile
index e6ad0af..851c4f7 100644
--- a/Makefile
+++ b/Makefile
@@ -333,9 +333,11 @@ else
# Rules for compiling object files for text-only demos.
#
$(OBJ_DIR_2)/common.$(SO): $(SRC_DIR)/common.c
+ $(OBJ_DIR_2)/strbuf.$(SO): $(SRC_DIR)/strbuf.c
$(OBJ_DIR_2)/output.$(SO): $(SRC_DIR)/output.c
$(OBJ_DIR_2)/mlgetopt.$(SO): $(SRC_DIR)/mlgetopt.c
COMMON_OBJ := $(OBJ_DIR_2)/common.$(SO) \
+$(OBJ_DIR_2)/strbuf.$(SO) \
$(OBJ_DIR_2)/output.$(SO) \
$(OBJ_DIR_2)/mlgetopt.$(SO)
diff --git a/src/common.c b/src/common.c
index 1960165..3eed8ef 100644
--- a/src/common.c
+++ b/src/common.c
@@ -5,7 +5,7 @@
#include
#include
#include
-
+#include
char*
ft_basename( const char* name )
@@ -36,6 +36,25 @@
}
+ char*
+ ft_strdup( const char* str )
+ {
+char* result;
+size_t len;
+
+
+if ( !str )
+ return NULL;
+
+len= strlen( str );
+result = (char*)malloc( len + 1 );
+if (result)
+ memcpy( result, str, len + 1);
+
+return result;
+ }
+
+
void
Panic( const char* fmt,
... )
@@ -105,5 +124,4 @@
return -1;
}
-
/* End */
diff --git a/src/common.h b/src/common.h
index afa5f70..0cf4fea 100644
--- a/src/common.h
+++ b/src/common.h
@@ -1,7 +1,6 @@
#ifndef COMMON_H_
#define COMMON_H_
-
#ifdef __cplusplus
extern "C" {
#endif
@@ -26,6 +25,14 @@
utf8_next( const char** pcursor,
const char* end );
+ /*
+ * Implement strdup() which is POSIX, but not C89 or even C11, and
+ * Microsoft insists on renaming it _strdup() instead. Platform
+ * auto-detection is complicated, so just provide a re-implementation.
+ */
+ extern char*
+ ft_strdup( const char* name );
+
#ifdef __cplusplus
}
#endif
diff --git a/src/ftbench.c b/src/ftbench.c
index 58a7741..28b3d70 100644
--- a/src/ftbench.c
+++ b/src/ftbench.c
@@ -835,27 +835,27 @@
/* we expect that at least one interpreter version is available */
if ( num_tt_interpreter_versions == 2 )
-
