Fix stringop-overflow errors from gcc 10 in iconv.

On s390x, I've recognize various -Werror=stringop-overflow messages
in iconv/loop.c and iconv/skeleton.c if build with gcc10 -O3.

With this commit gcc knows the size and do not raise those errors anymore.

diff --git a/iconv/loop.c b/iconv/loop.c
index 9f7570d591564f4b22043cd075ebe0f5dcc4cf63..b032fcd9ac037bbb50e70423109cee31882b474f 100644 (file)
--- a/iconv/loop.c
+++ b/iconv/loop.c
@@ -420,8 +420,10 @@ SINGLE(LOOPFCT) (struct __gconv_step *step,
 #  else
       /* We don't have enough input for another complete input
         character.  */
-      while (inptr < inend)
-       state->__value.__wchb[inlen++] = *inptr++;
+      size_t inlen_after = inlen + (inend - inptr);
+      assert (inlen_after <= sizeof (state->__value.__wchb));
+      for (; inlen < inlen_after; inlen++)
+       state->__value.__wchb[inlen] = *inptr++;
 #  endif
 
       return __GCONV_INCOMPLETE_INPUT;
@@ -483,11 +485,11 @@ SINGLE(LOOPFCT) (struct __gconv_step *step,
       /* We don't have enough input for another complete input
         character.  */
       assert (inend - inptr > (state->__count & ~7));
-      assert (inend - inptr <= sizeof (state->__value));
+      assert (inend - inptr <= sizeof (state->__value.__wchb));
       state->__count = (state->__count & ~7) | (inend - inptr);
-      inlen = 0;
-      while (inptr < inend)
-       state->__value.__wchb[inlen++] = *inptr++;
+      for (inlen = 0; inlen < inend - inptr; inlen++)
+       state->__value.__wchb[inlen] = inptr[inlen];
+      inptr = inend;
 #  endif
     }
 

diff --git a/iconv/skeleton.c b/iconv/skeleton.c
index 1dc642e2fc97b30fb11902edc0e43838f2375296..1a38b51a5af752bb31d55116278c6301206708a8 100644 (file)
--- a/iconv/skeleton.c
+++ b/iconv/skeleton.c
@@ -795,11 +795,13 @@ FUNCTION_NAME (struct __gconv_step *step, struct __gconv_step_data *data,
 # else
          /* Make sure the remaining bytes fit into the state objects
             buffer.  */
-         assert (inend - *inptrp < 4);
+         size_t cnt_after = inend - *inptrp;
+         assert (cnt_after <= sizeof (data->__statep->__value.__wchb));
 
          size_t cnt;
-         for (cnt = 0; *inptrp < inend; ++cnt)
-           data->__statep->__value.__wchb[cnt] = *(*inptrp)++;
+         for (cnt = 0; cnt < cnt_after; ++cnt)
+           data->__statep->__value.__wchb[cnt] = (*inptrp)[cnt];
+         *inptrp = inend;
          data->__statep->__count &= ~7;
          data->__statep->__count |= cnt;
 # endif