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src/file_mkv.c: improve Frama-C annotations

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This commit is contained in:
Christophe Grenier 2023-10-08 14:40:58 +02:00
parent 8582846b9b
commit 2327c1f304
1 changed files with 10 additions and 3 deletions
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13
src/file_mkv.c
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@ -55,6 +55,7 @@ const file_hint_t file_hint_mkv= {
/*@
@ requires \valid_read(p + (0 .. p_size-1));
@ requires \initialized(p + (0 .. p_size-1));
@ requires \valid(uint64);
@ requires \separated(p + (..), uint64);
@ ensures -1 == \result || (1 <= \result <= 8);
@ -66,14 +67,16 @@ static int EBML_read_unsigned(const unsigned char *p, const unsigned int p_size,
{
unsigned char test_bit = 0x80;
unsigned int i, bytes = 1;
/*@ assert \valid_read(p); */
const unsigned char c=*p;
uint64_t val;
if(p_size==0 || c== 0x00)
return -1;
/*@ assert c != 0; */
/*@ assert 0 < c < 0x100; */
/*@
@ loop invariant test_bit > 0;
@ loop invariant test_bit == (0x100 >> bytes);
@ loop invariant 1 <= bytes <= 8;
@ loop assigns test_bit, bytes;
@ loop unroll 8;
@*/
@ -85,11 +88,12 @@ static int EBML_read_unsigned(const unsigned char *p, const unsigned int p_size,
}
/*@ assert (c & test_bit) == test_bit; */
/*@ assert 1 <= bytes <= 8; */
/*@ assert c >= test_bit; */
if(p_size < bytes)
return -1;
/*@ assert bytes <= p_size; */
val = c - test_bit; //eliminate first bit, val < 0x80
// val = c & !test_bit; //eliminate first bit, val < 0x80
/*@ assert test_bit > 0; */
val = c & ~test_bit;
/*@ assert val <= 0xfe; */
/*@
@ loop assigns i, val;
@ -108,8 +112,10 @@ static int EBML_read_unsigned(const unsigned char *p, const unsigned int p_size,
/*@
@ requires EBML_size > 0;
@ requires \initialized(buffer + (0 .. buffer_size-1));
@ requires \valid_read(buffer + (0 .. buffer_size-1));
@ requires \valid_read(EBML_Header + (0 .. EBML_size-1));
@ requires \initialized(EBML_Header + (0 .. EBML_size-1));
@ assigns \result;
@*/
static int EBML_find(const unsigned char *buffer, const unsigned int buffer_size, const unsigned char *EBML_Header, const unsigned int EBML_size)
@ -146,6 +152,7 @@ static int EBML_find(const unsigned char *buffer, const unsigned int buffer_size
/*@
@ requires \valid_read(p + (0 .. p_size-1));
@ requires \initialized(p + (0 .. p_size-1));
@ requires \valid(strlength);
@ requires \separated(p + (..), strlength);
@ ensures -1 == \result || (1 <= \result <= 8);