When comparing if the shift is large enough to make the result zero, use
an unsigned long long to make sure the result fits. Also, a check that
avoids setting the value if the shift is equal to or larger than the
number of bits in the operand (this is undefined behaviour). Finally,
add a check to make sure the calculated value is not too large to store.
Add test cases to cover this.
This was detected by an MSVC warning.
valueflow.cpp(1350): warning C4334: '<<' : result of 32-bit shift implicitly
converted to 64 bits (was 64-bit shift intended?)
* use already cached name token rather than recalculating it
multiple times
* cache end of template parameters token and use it rather than
recalculating it multiple times
* remove unnecessary end of template token and name token checks
* remove function parameter that is already contained in another
parameter
* valueflow: remove unused variable known
since e4677ae640 will trigger :
lib/valueflow.cpp:506:20: warning: unused variable 'known' [-Wunused-variable]
const bool known = (parent->astOperand1()->hasKnownValue() ||
* templatesimplifier: cleanup
since 48c960f56c showing:
lib/templatesimplifier.h:279:16: warning: private field 'mTokenizer' is not used
[-Wunused-private-field]
Tokenizer *mTokenizer;
* split CheckNullPointer::arithmeticError() into
* CheckNullPointer::pointerArithmeticError() and
* CheckNullPointer::redundantConditionWarning()
* Additional errorlist entry:
```XML
<error id="nullPointerArithmeticRedundantCheck"
severity="warning"
msg="Either the condition is redundant or there is pointer arithmetic with NULL pointer."
verbose="Either the condition is redundant or there is pointer arithmetic with NULL pointer." cwe="682"/>
```
This fixes issue in:
```cpp
void f()
{
char stack[512];
RGNDATA *data;
if (data_size > sizeof (stack))
data = malloc (data_size);
else
data = (RGNDATA *)stack;
if ((char *)data != stack)
free (data); // <- data is not stack
}
```
It seems the `ProgramMemory` can't handle two known values(such as int and tok) together. So instead `ValueFlowAfterAssign` runs `ValueFlowForward` with tok values and then runs it with the other values.
* Code changes for Token::mImpl optimisation
* Added new TokenImpl optimisation
Moving members to the TokenImpl struct reduces the size of the Token class, which is a fairly significant optimisation. In my testing on Windows with 32-bit Release-PCRE, this change reduced the size of the Token class from 108 bits to 52 bits and reduced run-time of my test case by around 20%.
* Several optimisations
Deleted some code that ran very slowly and did nothing, as there is no need to change a Token's string to null if you are about to delete it.
Added a frontToken to simplifyCalculations to reduce the amount of work it has to do on already-simplified calculations.
Moved template removal to the end of the list as this reduces redundant iteration and saves time.
* Added tok argument to simplifyCalculations
This means callers can avoid unnecessary work if they know which tokens have already been simplified. Passing nullptr indicates the original behaviour (starting from the front of the list).
* Removed mention of member from another change
* Re-added and optimised some code deleted in error
Changing mTemplateInstantiations to a vector avoids the high cost of doing repeated linear searches. Changing how the code iterates through the array was necessary because the vector can be resized at several points during the loop, which breaks existing references and iterators.
* Changed mTemplateInstantiations to a vector
This is an optimisation that makes repeated linear searches of this collection significantly faster.
Also added a copy constructor to TokenAndName so code can make copies of these objects to keep a reference if a vector gets resized.
* A cleaner optimisation to removing template tokens
This reverts the previous change to made mInstantiatedTemplates a vector and the iterator changes to support this, and makes mTypesUsedInTemplateInstantiation so the eraseTokens logic can be unified.
* Reverted vector to list
Also made mTypesUsedInTemplateInstantiation a vector of TokenAndName objects so it can share the same logic as the other members.
* Added member for template simplifier pointer
This can be used more efficiently than marking Tokens with a flag and then searching through all templates to find the one that matches.
* Turned loop inside out
This means we only have to iterate through the std::list once. std::list is very expensive to iterate through.
* Latest code from danmar and fixed optimisations
In particular I have optimised simplifying template instantiation names as this was incredibly slow because of the number of times it had to iterate through the template instantiation list. Previous optimisations to this weren't very effective and broke some edge cases.
* Added changes from danmar
Made mExplicitInstantiationsToDelete a vector of TokenAndName to be consistent with the rest of the members, which are cleaned up very efficiently.
* Tokens can have many templateSimplifierPointers
* templateSimplifierPointers must be kept in sync
This makes arrays non-null in valueflow, so it can catch comparisons against null that is always true:
```cpp
void f(void) {
int buf[42];
if( buf != 0) {;} // << always true
}
```
Add a check for function arguments that can be constant:
```cpp
extern void bar(int);
void f(int x) {
bar((x & 0x01) >> 7); // function 'bar' is always called with a '0'-argument
}
```
Daniel Marjamäki
amai2012
IOBYTE
rikardfalkeborn
amai2012
Carlo Marcelo Arenas Belón
ivangalkin
Paul Fultz II
Oliver Schode
Sebastian
rebnridgway
PKEuS