:: commit 5c3674c8047f1523ed16ec12c16b1e56662521ba

Petr Pisar <ppisar@redhat.com> — 2023-04-05 11:02

parents: 0aa6ed2734

Const warnings (#98)

* Fix a warning lzp_upcast() discarding a const qualifier

GCC 13 warns:

src/libbz3.c:111:45: warning: passing argument 1 of 'lzp_upcast' discards 'const' qualifier from pointe
r target type [-Wdiscarded-qualifiers]
  111 |                 if (heur > in && lzp_upcast(heur) != lzp_upcast(ref + (heur - in))) goto not_fo
und;
      |                                             ^~~~
src/libbz3.c:83:28: note: expected 'u8 *' {aka 'unsigned char *'} but argument is of type 'const u8 *'
{aka 'const unsigned char *'}
   83 | static u32 lzp_upcast(u8 * ptr) {
      |                       ~~~~~^~~

lzp_upcast() obviously does not modify the pointerd memory, hence this
patch fixes it by changing an lzp_upcast() prototype.

* Fix a const discard warning in lzp_decode_block()

GCC 13 warned:

src/libbz3.c:190:38: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
  190 |                 if (oe > out_end) oe = out_end;
      |                                      ^

oe pointer is never dereferenced, hence this patch makes oe a pointer
to a constant data.

diff --git a/src/libbz3.c b/src/libbz3.c
index fcb9996..d61f328 100644
--- a/src/libbz3.c
+++ b/src/libbz3.c
@@ -80,7 +80,7 @@ static u32 crc32sum(u32 crc, u8 * RESTRICT buf, size_t size) {
 
 #define MATCH 0xf2
 
-static u32 lzp_upcast(u8 * ptr) {
+static u32 lzp_upcast(const u8 * ptr) {
     // val = *(u32 *)ptr; - written this way to avoid UB
     u32 val;
     memcpy(&val, ptr, sizeof(val));
@@ -186,7 +186,7 @@ static s32 lzp_decode_block(const u8 * RESTRICT in, const u8 * in_end, s32 * RES
                 }
 
                 const u8 * ref = outs + val;
-                u8 * oe = out + len;
+                const u8 * oe = out + len;
                 if (oe > out_end) oe = out_end;
 
                 while (out < oe) *out++ = *ref++;