Fix an incorrectly aligned result when converting between pointer types (#457)

fix alignment issue of idlist
This commit is contained in:
Tom M 2018-11-10 08:07:30 +01:00 committed by GitHub
parent edc59ee3b5
commit 06bcf8db9f
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@ -77,9 +77,31 @@ enum
SM24_ID
};
static const char idlist[] = {"RIFFLISTsfbkINFOsdtapdtaifilisngINAMiromiverICRDIENGIPRD"
"ICOPICMTISFTsnamsmplphdrpbagpmodpgeninstibagimodigenshdrsm24"
};
/*
* This declares a char array containing the SF2 chunk identifiers. This
* array is being accessed like an uint32 below to simplify id comparison.
* To make sure it is suitably aligned for uint32 access, we must wrap it
* inside a union along with a uint32 telling the compiler to align it
* for integer access and avoiding undefined behaviour.
* This basically is the C89 equivalent to what is written in C11 as:
* alignas(uint32_t) static const char idlist[] = {};
*
* See: EXP36-C. Do not cast pointers into more strictly aligned pointer
* types - SEI CERT C Coding Standard
*/
static const union fluid_idlist
{
/*
* Cannot be char c[ ], because in C89, arrays wraped in unions
* must have a fixed size. Otherwise the size of the union would depend
* on the initialization of its first member, which results in
* different sizes for different instances of the same union type.
*/
char c[116];
uint32_t i;
} idlist = {"RIFFLISTsfbkINFOsdtapdtaifilisngINAMiromiverICRDIENGIPRD"
"ICOPICMTISFTsnamsmplphdrpbagpmodpgeninstibagimodigenshdrsm24"
};
/* generator types */
@ -183,7 +205,7 @@ static const unsigned short invalid_preset_gen[] =
};
#define CHNKIDSTR(id) &idlist[(id - 1) * 4]
#define CHNKIDSTR(id) &idlist.c[(id - 1) * 4]
/* sfont file chunk sizes */
#define SF_PHDR_SIZE (38)
@ -284,7 +306,7 @@ static int load_shdr(SFData *sf, unsigned int size);
static int fixup_pgen(SFData *sf);
static int fixup_igen(SFData *sf);
static int chunkid(unsigned int id);
static int chunkid(uint32_t id);
static int read_listchunk(SFData *sf, SFChunk *chunk);
static int pdtahelper(SFData *sf, unsigned int expid, unsigned int reclen, SFChunk *chunk, int *size);
static int preset_compare_func(void *a, void *b);
@ -486,14 +508,12 @@ void fluid_sffile_close(SFData *sf)
*/
/* sound font file load functions */
static int chunkid(unsigned int id)
static int chunkid(uint32_t id)
{
unsigned int i;
const unsigned int *p;
const uint32_t *p = &idlist.i;
p = (const unsigned int *)&idlist;
for(i = 0; i < sizeof(idlist) / sizeof(int); i++, p += 1)
for(i = 0; i < sizeof(idlist) / sizeof(idlist.i); i++, p += 1)
{
if(*p == id)
{
@ -987,6 +1007,7 @@ static int load_phdr(SFData *sf, int size)
FLUID_LOG(FLUID_ERR, "Out of memory");
return FALSE;
}
sf->preset = fluid_list_append(sf->preset, preset);
preset->zone = NULL; /* In case of failure, fluid_sffile_close can cleanup */
READSTR(sf, &preset->name); /* possible read failure ^ */
@ -1078,6 +1099,7 @@ static int load_pbag(SFData *sf, int size)
FLUID_LOG(FLUID_ERR, "Out of memory");
return FALSE;
}
p2->data = z;
z->gen = NULL; /* Init gen and mod before possible failure, */
z->mod = NULL; /* to ensure proper cleanup (fluid_sffile_close) */
@ -1211,6 +1233,7 @@ static int load_pmod(SFData *sf, int size)
FLUID_LOG(FLUID_ERR, "Out of memory");
return FALSE;
}
p3->data = m;
READW(sf, m->src);
READW(sf, m->dest);
@ -1367,6 +1390,7 @@ static int load_pgen(SFData *sf, int size)
FLUID_LOG(FLUID_ERR, "Out of memory");
return FALSE;
}
p3->data = g;
g->id = genid;
}
@ -1508,6 +1532,7 @@ static int load_ihdr(SFData *sf, int size)
FLUID_LOG(FLUID_ERR, "Out of memory");
return FALSE;
}
sf->inst = fluid_list_append(sf->inst, p);
p->zone = NULL; /* For proper cleanup if fail (fluid_sffile_close) */
p->idx = i;
@ -1593,6 +1618,7 @@ static int load_ibag(SFData *sf, int size)
FLUID_LOG(FLUID_ERR, "Out of memory");
return FALSE;
}
p2->data = z;
z->gen = NULL; /* In case of failure, */
z->mod = NULL; /* fluid_sffile_close can clean up */
@ -1727,6 +1753,7 @@ static int load_imod(SFData *sf, int size)
FLUID_LOG(FLUID_ERR, "Out of memory");
return FALSE;
}
p3->data = m;
READW(sf, m->src);
READW(sf, m->dest);
@ -1872,6 +1899,7 @@ static int load_igen(SFData *sf, int size)
FLUID_LOG(FLUID_ERR, "Out of memory");
return FALSE;
}
p3->data = g;
g->id = genid;
}
@ -2011,6 +2039,7 @@ static int load_shdr(SFData *sf, unsigned int size)
FLUID_LOG(FLUID_ERR, "Out of memory");
return FALSE;
}
sf->sample = fluid_list_append(sf->sample, p);
READSTR(sf, &p->name);
READD(sf, p->start);