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Fixed #1539 (False positive: possible error Array index out of bounds)

This commit is contained in:
Robert Reif 2010-03-30 17:33:17 +02:00 committed by Daniel Marjamäki
parent c213227133
commit 32e597e343
2 changed files with 65 additions and 12 deletions
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16
lib/checkbufferoverrun.cpp
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@ -791,7 +791,7 @@ void CheckBufferOverrun::checkGlobalAndLocalVariable()
else if (tok->str() == "}") else if (tok->str() == "}")
--indentlevel; --indentlevel;
unsigned int size = 0; int size = 0;
std::string type; std::string type;
unsigned int varid = 0; unsigned int varid = 0;
int nextTok = 0; int nextTok = 0;
@ -842,28 +842,30 @@ void CheckBufferOverrun::checkGlobalAndLocalVariable()
else else
size = SHRT_MAX + 1; size = SHRT_MAX + 1;
} }
// checkScope assumes size is signed int so we limit the following sizes to INT_MAX
else if (index_type->str() == "int") else if (index_type->str() == "int")
{ {
if (index_type->isUnsigned()) if (index_type->isUnsigned())
size = UINT_MAX; // really UINT_MAX + 1; size = INT_MAX; // should be UINT_MAX + 1U;
else else
size = INT_MAX + 1U; size = INT_MAX; // should be INT_MAX + 1U;
} }
else if (index_type->str() == "long") else if (index_type->str() == "long")
{ {
if (index_type->isUnsigned()) if (index_type->isUnsigned())
{ {
if (index_type->isLong()) if (index_type->isLong())
size = ULONG_MAX; // really ULLONG_MAX + 1; size = INT_MAX; // should be ULLONG_MAX + 1ULL;
else else
size = ULONG_MAX; // really ULONG_MAX + 1; size = INT_MAX; // should be ULONG_MAX + 1UL;
} }
else else
{ {
if (index_type->isLong()) if (index_type->isLong())
size = ULONG_MAX; // really LLONG_MAX + 1; size = INT_MAX; // should be LLONG_MAX + 1LL;
else else
size = LONG_MAX + 1U; size = INT_MAX; // should be LONG_MAX + 1L;
} }
} }

61
test/testbufferoverrun.cpp
View File

@ -22,6 +22,7 @@
#include "testsuite.h" #include "testsuite.h"
#include <sstream> #include <sstream>
#include <climits>
extern std::ostringstream errout; extern std::ostringstream errout;
@ -93,7 +94,7 @@ private:
TEST_CASE(array_index_21); TEST_CASE(array_index_21);
TEST_CASE(array_index_22); TEST_CASE(array_index_22);
TEST_CASE(array_index_23); TEST_CASE(array_index_23);
TEST_CASE(array_index_24); // ticket #1492 TEST_CASE(array_index_24); // ticket #1492 and #1539
TEST_CASE(array_index_25); // ticket #1536 TEST_CASE(array_index_25); // ticket #1536
TEST_CASE(array_index_multidim); TEST_CASE(array_index_multidim);
TEST_CASE(array_index_switch_in_for); TEST_CASE(array_index_switch_in_for);
@ -761,19 +762,40 @@ private:
void array_index_24() void array_index_24()
{ {
// ticket #1492 // ticket #1492 and #1539
if (CHAR_MAX == SCHAR_MAX) // plain char is signed
{
check("void f(char n) {\n"
" int a[n];\n" // n <= CHAR_MAX
" a[-1] = 0;\n" // negative index
" a[128] = 0;\n" // 128 > CHAR_MAX
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (error) Array 'a[128]' index -1 out of bounds\n"
"[test.cpp:4]: (error) Array 'a[128]' index 128 out of bounds\n", errout.str());
}
else // plain char is unsigned
{
check("void f(char n) {\n"
" int a[n];\n" // n <= CHAR_MAX
" a[-1] = 0;\n" // negative index
" a[256] = 0;\n" // 256 > CHAR_MAX
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (error) Array 'a[256]' index -1 out of bounds\n"
"[test.cpp:4]: (error) Array 'a[256]' index 256 out of bounds\n", errout.str());
}
check("void f(signed char n) {\n" check("void f(signed char n) {\n"
" int a[n];\n" // n <= SCHAR_MAX " int a[n];\n" // n <= SCHAR_MAX
" a[-1] = 0;\n" // negative index " a[-1] = 0;\n" // negative index
" a[128] = 0;\n" // 128 > SCHAR_MAX " a[128] = 0;\n" // 128 > SCHAR_MAX
"}\n"); "}\n");
ASSERT_EQUALS("[test.cpp:3]: (error) Array 'a[128]' index -1 out of bounds\n" ASSERT_EQUALS("[test.cpp:3]: (error) Array 'a[128]' index -1 out of bounds\n"
"[test.cpp:4]: (error) Array 'a[128]' index 128 out of bounds\n", errout.str()); "[test.cpp:4]: (error) Array 'a[128]' index 128 out of bounds\n", errout.str());
check("void f(unsigned char n) {\n" check("void f(unsigned char n) {\n"
" int a[n];\n" // n <= UCHAR " int a[n];\n" // n <= UCHAR_MAX
" a[-1] = 0;\n" // negative index " a[-1] = 0;\n" // negative index
" a[256] = 0;\n" // 256 > UCHAR_MAX " a[256] = 0;\n" // 256 > UCHAR_MAX
"}\n"); "}\n");
ASSERT_EQUALS("[test.cpp:3]: (error) Array 'a[256]' index -1 out of bounds\n" ASSERT_EQUALS("[test.cpp:3]: (error) Array 'a[256]' index -1 out of bounds\n"
"[test.cpp:4]: (error) Array 'a[256]' index 256 out of bounds\n", errout.str()); "[test.cpp:4]: (error) Array 'a[256]' index 256 out of bounds\n", errout.str());
@ -793,6 +815,35 @@ private:
"}\n"); "}\n");
ASSERT_EQUALS("[test.cpp:3]: (error) Array 'a[65536]' index -1 out of bounds\n" ASSERT_EQUALS("[test.cpp:3]: (error) Array 'a[65536]' index -1 out of bounds\n"
"[test.cpp:4]: (error) Array 'a[65536]' index 65536 out of bounds\n", errout.str()); "[test.cpp:4]: (error) Array 'a[65536]' index 65536 out of bounds\n", errout.str());
check("void f(signed short n) {\n"
" int a[n];\n" // n <= SHRT_MAX
" a[-1] = 0;\n" // negative index
" a[32768] = 0;\n" // 32768 > SHRT_MAX
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (error) Array 'a[32768]' index -1 out of bounds\n"
"[test.cpp:4]: (error) Array 'a[32768]' index 32768 out of bounds\n", errout.str());
if (sizeof(int) == 4)
{
check("void f(int n) {\n"
" int a[n];\n" // n <= INT_MAX
" a[-1] = 0;\n" // negative index
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (error) Array 'a[2147483647]' index -1 out of bounds\n", errout.str());
check("void f(unsigned int n) {\n"
" int a[n];\n" // n <= UINT_MAX
" a[-1] = 0;\n" // negative index
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (error) Array 'a[2147483647]' index -1 out of bounds\n", errout.str());
check("void f(signed int n) {\n"
" int a[n];\n" // n <= INT_MAX
" a[-1] = 0;\n" // negative index
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (error) Array 'a[2147483647]' index -1 out of bounds\n", errout.str());
}
} }
void array_index_25() void array_index_25()