Undefined Behavior Study

A study of undefined behavior on various platforms, compilers, and tools. Some examples were inspired by https://www.nayuki.io/page/undefined-behavior-in-c-and-cplusplus-programs. There are some highlights in the video below.

Automated Results

Linux

Windows

1.Static Analysis

1.1.Compiler Warnings

Compiler	Undefined Behavior Type	Warning	Warning Opt	Name
clang	access after realloc	❌	❌	n/a
clang	array out of bounds	❌	❌	n/a
clang	automatic variable over stack	❌	❌	n/a
clang	bad alignment	❌	❌	n/a
clang	bad identifier name	❌	❌	n/a
clang	delete incomplete type	✔️	✔️	-Wdelete-incomplete
clang	dereferencing nullptr	❌	❌	n/a
clang	divide by zero	✔️	✔️	-Wdivision-by-zero
clang	initialize std string with nullptr	❌	❌	n/a
clang	large double to int	❌	❌	n/a
clang	malloc cast pod struct	❌	❌	n/a
clang	mutate const value	❌	❌	n/a
clang	non trivial destructor and global	❌	❌	n/a
clang	odr violation function	❌	❌	n/a
clang	odr violation function lib	❌	❌	n/a
clang	odr violation struct ret	❌	❌	n/a
clang	odr violation struct ret lib	❌	❌	n/a
clang	operator star on empty optional	❌	❌	n/a
clang	out of bounds pointer	❌	❌	n/a
clang	preincrement plus postincrement	✔️	✔️	-Wunsequenced
clang	preincrement plus value	✔️	✔️	-Wunsequenced
clang	read from old type	❌	❌	n/a
clang	reading uninitialized value add	✔️	✔️	-Wuninitialized
clang	reading uninitialized value cout	✔️	✔️	-Wuninitialized
clang	reading uninitialized value func arg	❌	❌	n/a
clang	reading uninitialized value if	✔️	✔️	-Wuninitialized
clang	reading uninitialized value lib call cref	✔️	✔️	-Wuninitialized-const-reference
clang	reading uninitialized value partial	❌	❌	n/a
clang	reading uninitialized value printf	✔️	✔️	-Wuninitialized
clang	reading uninitialized value return	✔️	✔️	-Wreturn-type
clang	reference out of scope	✔️	✔️	-Wreturn-stack-address
clang	reinterpret cast bad size	❌	❌	n/a
clang	reinterpret cast float to int32	❌	❌	n/a
clang	reinterpret cast int32 to float	❌	❌	n/a
clang	reinterpret cast int32 to uint32	❌	❌	n/a
clang	reinterpret cast uint32 to int32	❌	❌	n/a
clang	reinterpret cast unaligned bytes to uint32	❌	❌	n/a
clang	shifting more than width	✔️	✔️	-Wshift-count-overflow
clang	signed integer overflow	❌	❌	n/a
clang	sort comp reflexive	❌	❌	n/a
clang	stack overflow	✔️	✔️	-Winfinite-recursion
clang	std vector reserve set read	❌	❌	n/a
clang	strptime mktime unitialized	❌	❌	n/a
clang	virtual call in constructor	✔️	✔️	-Wcall-to-pure-virtual-from-ctor-dtor
clang	virtual call in constructor helper	❌	❌	n/a
clang	virtual call in constructor lib	❌	❌	n/a
clang	virtual call in constructor link	❌	❌	n/a
clang	virtual call in destructor	✔️	✔️	-Wcall-to-pure-virtual-from-ctor-dtor
clang	virtual call in destructor helper	❌	❌	n/a
clang	virtual call in destructor lib	❌	❌	n/a
clang	virtual call in destructor link	❌	❌	n/a
gcc	access after realloc	✔️	✔️	-Wuse-after-free
gcc	array out of bounds	❌	✔️	-Warray-bounds=
gcc	automatic variable over stack	❌	❌	n/a
gcc	bad alignment	❌	❌	n/a
gcc	bad identifier name	❌	❌	n/a
gcc	delete incomplete type	✔️	✔️	-Wdelete-incomplete
gcc	dereferencing nullptr	❌	❌	n/a
gcc	divide by zero	✔️	✔️	-Wdiv-by-zero
gcc	initialize std string with nullptr	❌	❌	n/a
gcc	large double to int	❌	❌	n/a
gcc	malloc cast pod struct	❌	❌	n/a
gcc	mutate const value	❌	❌	n/a
gcc	non trivial destructor and global	❌	❌	n/a
gcc	odr violation function	❌	❌	n/a
gcc	odr violation function lib	❌	❌	n/a
gcc	odr violation struct ret	❌	❌	n/a
gcc	odr violation struct ret lib	❌	❌	n/a
gcc	operator star on empty optional	❌	❌	n/a
gcc	out of bounds pointer	❌	✔️	-Warray-bounds=
gcc	preincrement plus postincrement	✔️	✔️	-Wsequence-point
gcc	preincrement plus value	✔️	✔️	-Wsequence-point
gcc	read from old type	❌	❌	n/a
gcc	reading uninitialized value add	✔️	✔️	-Wuninitialized
gcc	reading uninitialized value cout	✔️	✔️	-Wuninitialized
gcc	reading uninitialized value func arg	❌	✔️	-Wuninitialized
gcc	reading uninitialized value if	✔️	✔️	-Wuninitialized
gcc	reading uninitialized value lib call cref	✔️	✔️	-Wmaybe-uninitialized
gcc	reading uninitialized value partial	❌	❌	n/a
gcc	reading uninitialized value printf	✔️	✔️	-Wuninitialized
gcc	reading uninitialized value return	✔️	✔️	-Wreturn-type
gcc	reference out of scope	✔️	✔️	-Wreturn-local-addr
gcc	reinterpret cast bad size	✔️	✔️	-Wuninitialized,-Warray-bounds=
gcc	reinterpret cast float to int32	❌	✔️	-Wstrict-aliasing,-Wuninitialized
gcc	reinterpret cast int32 to float	❌	✔️	-Wstrict-aliasing,-Wuninitialized
gcc	reinterpret cast int32 to uint32	❌	❌	n/a
gcc	reinterpret cast uint32 to int32	❌	❌	n/a
gcc	reinterpret cast unaligned bytes to uint32	❌	❌	n/a
gcc	shifting more than width	✔️	✔️	-Wshift-count-overflow
gcc	signed integer overflow	❌	❌	n/a
gcc	sort comp reflexive	❌	❌	n/a
gcc	stack overflow	✔️	✔️	-Winfinite-recursion
gcc	std vector reserve set read	❌	❌	n/a
gcc	strptime mktime unitialized	❌	❌	n/a
gcc	virtual call in constructor	❌	❌	n/a
gcc	virtual call in constructor helper	❌	❌	n/a
gcc	virtual call in constructor lib	❌	❌	n/a
gcc	virtual call in constructor link	❌	❌	n/a
gcc	virtual call in destructor	❌	❌	n/a
gcc	virtual call in destructor helper	❌	❌	n/a
gcc	virtual call in destructor lib	❌	❌	n/a
gcc	virtual call in destructor link	❌	❌	n/a
msvc	access after realloc	❌	❌	n/a
msvc	array out of bounds	❌	❌	n/a
msvc	automatic variable over stack	❌	❌	n/a
msvc	bad alignment	❌	❌	n/a
msvc	bad identifier name	❌	❌	n/a
msvc	delete incomplete type	✔️	✔️	4150
msvc	dereferencing nullptr	❌	❌	n/a
msvc	divide by zero	✔️	✔️	4723
msvc	initialize std string with nullptr	❌	❌	n/a
msvc	large double to int	❌	❌	n/a
msvc	malloc cast pod struct	❌	❌	n/a
msvc	mutate const value	❌	❌	n/a
msvc	non trivial destructor and global	❌	❌	n/a
msvc	odr violation function	❌	❌	n/a
msvc	odr violation function lib	❌	❌	n/a
msvc	odr violation struct ret	❌	❌	n/a
msvc	odr violation struct ret lib	❌	❌	n/a
msvc	operator star on empty optional	❌	❌	n/a
msvc	out of bounds pointer	❌	❌	n/a
msvc	preincrement plus postincrement	❌	❌	n/a
msvc	preincrement plus value	❌	❌	n/a
msvc	read from old type	❌	❌	n/a
msvc	reading uninitialized value add	✔️	✔️	4700
msvc	reading uninitialized value cout	✔️	✔️	4700
msvc	reading uninitialized value func arg	❌	❌	n/a
msvc	reading uninitialized value if	✔️	✔️	4700
msvc	reading uninitialized value lib call cref	❌	❌	n/a
msvc	reading uninitialized value partial	❌	❌	n/a
msvc	reading uninitialized value printf	✔️	✔️	4700
msvc	reference out of scope	✔️	✔️	4172
msvc	reinterpret cast bad size	❌	❌	n/a
msvc	reinterpret cast float to int32	❌	❌	n/a
msvc	reinterpret cast int32 to float	❌	❌	n/a
msvc	reinterpret cast int32 to uint32	❌	❌	n/a
msvc	reinterpret cast uint32 to int32	❌	❌	n/a
msvc	reinterpret cast unaligned bytes to uint32	❌	❌	n/a
msvc	shifting more than width	✔️	✔️	4293
msvc	signed integer overflow	❌	❌	n/a
msvc	sort comp reflexive	❌	❌	n/a
msvc	stack overflow	✔️	✔️	4717
msvc	std vector reserve set read	❌	❌	n/a
msvc	virtual call in constructor	❌	❌	n/a
msvc	virtual call in constructor helper	❌	❌	n/a
msvc	virtual call in constructor lib	❌	❌	n/a
msvc	virtual call in constructor link	❌	❌	n/a
msvc	virtual call in destructor	❌	❌	n/a
msvc	virtual call in destructor helper	❌	❌	n/a
msvc	virtual call in destructor lib	❌	❌	n/a
msvc	virtual call in destructor link	❌	❌	n/a

1.2.Static Analyzers

Tool	Undefined Behavior Type	Warning	Name
clang-tidy	access after realloc	✔️	clang-analyzer-unix.Malloc
clang-tidy	array out of bounds	✔️	cppcoreguidelines-pro-bounds-constant-array-index
clang-tidy	automatic variable over stack	❌	n/a
clang-tidy	bad alignment	❌	n/a
clang-tidy	bad identifier name	✔️	bugprone-reserved-identifier,cert-dcl37-c,cert-dcl51-cpp
clang-tidy	delete incomplete type	✔️	clang-diagnostic-delete-incomplete
clang-tidy	dereferencing nullptr	✔️	clang-analyzer-core.NullDereference
clang-tidy	divide by zero	✔️	clang-analyzer-core.DivideZero,clang-diagnostic-division-by-zero
clang-tidy	initialize std string with nullptr	❌	n/a
clang-tidy	large double to int	❌	n/a
clang-tidy	malloc cast pod struct	❌	n/a
clang-tidy	mutate const value	✔️	cppcoreguidelines-pro-type-const-cast
clang-tidy	non trivial destructor and global	❌	n/a
clang-tidy	odr violation function	✔️	misc-include-cleaner
clang-tidy	odr violation function lib	❌	n/a
clang-tidy	odr violation struct ret	✔️	misc-include-cleaner
clang-tidy	odr violation struct ret lib	❌	n/a
clang-tidy	operator star on empty optional	✔️	bugprone-unchecked-optional-access
clang-tidy	out of bounds pointer	❌	n/a
clang-tidy	preincrement plus postincrement	✔️	clang-diagnostic-unsequenced
clang-tidy	preincrement plus value	✔️	clang-diagnostic-unsequenced
clang-tidy	read from old type	❌	n/a
clang-tidy	reading uninitialized value add	✔️	cppcoreguidelines-init-variables,clang-diagnostic-uninitialized,clang-analyzer-core.UndefinedBinaryOperatorResult
clang-tidy	reading uninitialized value cout	✔️	cppcoreguidelines-init-variables,clang-analyzer-core.CallAndMessage,clang-diagnostic-uninitialized
clang-tidy	reading uninitialized value func arg	✔️	cppcoreguidelines-init-variables,clang-analyzer-core.CallAndMessage
clang-tidy	reading uninitialized value if	✔️	cppcoreguidelines-init-variables,clang-analyzer-core.uninitialized.Branch,clang-diagnostic-uninitialized
clang-tidy	reading uninitialized value lib call cref	✔️	cppcoreguidelines-init-variables,clang-diagnostic-uninitialized-const-reference
clang-tidy	reading uninitialized value partial	✔️	cppcoreguidelines-init-variables,clang-analyzer-core.CallAndMessage
clang-tidy	reading uninitialized value printf	✔️	cppcoreguidelines-init-variables,clang-analyzer-core.CallAndMessage,clang-diagnostic-uninitialized
clang-tidy	reading uninitialized value return	✔️	clang-diagnostic-return-type
clang-tidy	reference out of scope	✔️	clang-analyzer-core.StackAddressEscape,clang-diagnostic-return-stack-address
clang-tidy	reinterpret cast bad size	❌	n/a
clang-tidy	reinterpret cast float to int32	❌	n/a
clang-tidy	reinterpret cast int32 to float	❌	n/a
clang-tidy	reinterpret cast int32 to uint32	❌	n/a
clang-tidy	reinterpret cast uint32 to int32	❌	n/a
clang-tidy	reinterpret cast unaligned bytes to uint32	❌	n/a
clang-tidy	shifting more than width	✔️	clang-analyzer-core.BitwiseShift,clang-diagnostic-shift-count-overflow,hicpp-signed-bitwise
clang-tidy	signed integer overflow	❌	n/a
clang-tidy	sort comp reflexive	❌	n/a
clang-tidy	stack overflow	✔️	misc-no-recursion,clang-diagnostic-infinite-recursion
clang-tidy	std vector reserve set read	❌	n/a
clang-tidy	strptime mktime unitialized	✔️	cppcoreguidelines-pro-type-member-init,hicpp-member-init
clang-tidy	virtual call in constructor	✔️	clang-analyzer-cplusplus.PureVirtualCall,clang-diagnostic-call-to-pure-virtual-from-ctor-dtor,misc-const-correctness
clang-tidy	virtual call in constructor helper	✔️	clang-analyzer-cplusplus.PureVirtualCall,misc-const-correctness
clang-tidy	virtual call in constructor lib	✔️	clang-analyzer-cplusplus.PureVirtualCall
clang-tidy	virtual call in constructor link	❌	n/a
clang-tidy	virtual call in destructor	✔️	clang-analyzer-cplusplus.PureVirtualCall,clang-diagnostic-call-to-pure-virtual-from-ctor-dtor
clang-tidy	virtual call in destructor helper	✔️	clang-analyzer-cplusplus.PureVirtualCall
clang-tidy	virtual call in destructor lib	✔️	clang-analyzer-cplusplus.PureVirtualCall
clang-tidy	virtual call in destructor link	❌	n/a
cppcheck	access after realloc	❌	n/a
cppcheck	array out of bounds	✔️	containerOutOfBounds,containerOutOfBoundsIndexExpression
cppcheck	automatic variable over stack	❌	n/a
cppcheck	bad alignment	❌	n/a
cppcheck	bad identifier name	❌	n/a
cppcheck	delete incomplete type	❌	n/a
cppcheck	dereferencing nullptr	✔️	nullPointer
cppcheck	divide by zero	✔️	zerodiv
cppcheck	initialize std string with nullptr	✔️	nullPointer
cppcheck	large double to int	❌	n/a
cppcheck	malloc cast pod struct	❌	n/a
cppcheck	mutate const value	❌	n/a
cppcheck	non trivial destructor and global	❌	n/a
cppcheck	odr violation function	❌	n/a
cppcheck	odr violation function lib	❌	n/a
cppcheck	odr violation struct ret	✔️	ctuOneDefinitionRuleViolation
cppcheck	odr violation struct ret lib	❌	n/a
cppcheck	operator star on empty optional	❌	n/a
cppcheck	out of bounds pointer	❌	n/a
cppcheck	preincrement plus postincrement	❌	n/a
cppcheck	preincrement plus value	❌	n/a
cppcheck	read from old type	❌	n/a
cppcheck	reading uninitialized value add	✔️	uninitvar
cppcheck	reading uninitialized value cout	✔️	uninitvar
cppcheck	reading uninitialized value func arg	❌	n/a
cppcheck	reading uninitialized value if	✔️	uninitvar
cppcheck	reading uninitialized value lib call cref	✔️	uninitvar
cppcheck	reading uninitialized value partial	✔️	uninitvar
cppcheck	reading uninitialized value printf	✔️	uninitvar
cppcheck	reading uninitialized value return	✔️	missingReturn
cppcheck	reference out of scope	✔️	returnReference
cppcheck	reinterpret cast bad size	❌	n/a
cppcheck	reinterpret cast float to int32	❌	n/a
cppcheck	reinterpret cast int32 to float	❌	n/a
cppcheck	reinterpret cast int32 to uint32	❌	n/a
cppcheck	reinterpret cast uint32 to int32	❌	n/a
cppcheck	reinterpret cast unaligned bytes to uint32	❌	n/a
cppcheck	shifting more than width	✔️	shiftTooManyBits
cppcheck	signed integer overflow	❌	n/a
cppcheck	sort comp reflexive	❌	n/a
cppcheck	stack overflow	❌	n/a
cppcheck	std vector reserve set read	✔️	containerOutOfBounds
cppcheck	strptime mktime unitialized	❌	n/a
cppcheck	virtual call in constructor	✔️	ctuOneDefinitionRuleViolation
cppcheck	virtual call in constructor helper	❌	n/a
cppcheck	virtual call in constructor lib	❌	n/a
cppcheck	virtual call in constructor link	❌	n/a
cppcheck	virtual call in destructor	❌	n/a
cppcheck	virtual call in destructor helper	❌	n/a
cppcheck	virtual call in destructor lib	❌	n/a
cppcheck	virtual call in destructor link	❌	n/a

1.3.Static Analysis Summary

Debug (unoptimized) / RelWithDebInfo (optimized)

Undefined Behavior Type	clang	clang-tidy	cppcheck	gcc	msvc
access after realloc	❌	✔️	❌	✔️	❌
array out of bounds	❌	✔️	✔️	❌/✔️	❌
automatic variable over stack	❌	❌	❌	❌	❌
bad alignment	❌	❌	❌	❌	❌
bad identifier name	❌	✔️	❌	❌	❌
delete incomplete type	✔️	✔️	❌	✔️	✔️
dereferencing nullptr	❌	✔️	✔️	❌	❌
divide by zero	✔️	✔️	✔️	✔️	✔️
initialize std string with nullptr	❌	❌	✔️	❌	❌
large double to int	❌	❌	❌	❌	❌
malloc cast pod struct	❌	❌	❌	❌	❌
mutate const value	❌	✔️	❌	❌	❌
non trivial destructor and global	❌	❌	❌	❌	❌
odr violation function	❌	✔️	❌	❌	❌
odr violation function lib	❌	❌	❌	❌	❌
odr violation struct ret	❌	✔️	✔️	❌	❌
odr violation struct ret lib	❌	❌	❌	❌	❌
operator star on empty optional	❌	✔️	❌	❌	❌
out of bounds pointer	❌	❌	❌	❌/✔️	❌
preincrement plus postincrement	✔️	✔️	❌	✔️	❌
preincrement plus value	✔️	✔️	❌	✔️	❌
read from old type	❌	❌	❌	❌	❌
reading uninitialized value add	✔️	✔️	✔️	✔️	✔️
reading uninitialized value cout	✔️	✔️	✔️	✔️	✔️
reading uninitialized value func arg	❌	✔️	❌	❌/✔️	❌
reading uninitialized value if	✔️	✔️	✔️	✔️	✔️
reading uninitialized value lib call cref	✔️	✔️	✔️	✔️	❌
reading uninitialized value partial	❌	✔️	✔️	❌	❌
reading uninitialized value printf	✔️	✔️	✔️	✔️	✔️
reading uninitialized value return	✔️	✔️	✔️	✔️	n/a
reference out of scope	✔️	✔️	✔️	✔️	✔️
reinterpret cast bad size	❌	❌	❌	✔️	❌
reinterpret cast float to int32	❌	❌	❌	❌/✔️	❌
reinterpret cast int32 to float	❌	❌	❌	❌/✔️	❌
reinterpret cast int32 to uint32	❌	❌	❌	❌	❌
reinterpret cast uint32 to int32	❌	❌	❌	❌	❌
reinterpret cast unaligned bytes to uint32	❌	❌	❌	❌	❌
shifting more than width	✔️	✔️	✔️	✔️	✔️
signed integer overflow	❌	❌	❌	❌	❌
sort comp reflexive	❌	❌	❌	❌	❌
stack overflow	✔️	✔️	❌	✔️	✔️
std vector reserve set read	❌	❌	✔️	❌	❌
strptime mktime unitialized	❌	✔️	❌	❌	n/a
virtual call in constructor	✔️	✔️	✔️	❌	❌
virtual call in constructor helper	❌	✔️	❌	❌	❌
virtual call in constructor lib	❌	✔️	❌	❌	❌
virtual call in constructor link	❌	❌	❌	❌	❌
virtual call in destructor	✔️	✔️	❌	❌	❌
virtual call in destructor helper	❌	✔️	❌	❌	❌
virtual call in destructor lib	❌	✔️	❌	❌	❌
virtual call in destructor link	❌	❌	❌	❌	❌

2.Runtime Crashes

2.1.Runtime Crashes Return Codes

Compiler	Undefined Behavior Type	Debug	RelWithDebInfo
clang	access after realloc	0	0
clang	array out of bounds	0	0
clang	automatic variable over stack	139	0
clang	bad alignment	0	0
clang	bad identifier name	0	0
clang	delete incomplete type	0	0
clang	dereferencing nullptr	139	0
clang	divide by zero	0	0
clang	initialize std string with nullptr	134	134
clang	large double to int	0	0
clang	malloc cast pod struct	0	0
clang	mutate const value	0	0
clang	odr violation function	0	0
clang	odr violation struct ret	0	0
clang	operator star on empty optional	0	0
clang	out of bounds pointer	0	0
clang	preincrement plus postincrement	0	0
clang	preincrement plus value	0	0
clang	read from old type	0	0
clang	reading uninitialized value add	0	0
clang	reading uninitialized value cout	0	0
clang	reading uninitialized value func arg	0	139
clang	reading uninitialized value if	0	48
clang	reading uninitialized value lib call cref	0	0
clang	reading uninitialized value partial	0	0
clang	reading uninitialized value printf	0	0
clang	reading uninitialized value return	132	48
clang	reference out of scope	0	0
clang	reinterpret cast bad size	0	0
clang	reinterpret cast float to int32	0	0
clang	reinterpret cast int32 to float	0	0
clang	reinterpret cast int32 to uint32	0	0
clang	reinterpret cast uint32 to int32	0	0
clang	reinterpret cast unaligned bytes to uint32	0	0
clang	shifting more than width	0	0
clang	signed integer overflow	0	0
clang	sort comp reflexive	0	0
clang	stack overflow	139	48
clang	std vector reserve set read	0	0
clang	strptime mktime unitialized	0	0
clang	virtual call in constructor	134	134
clang	virtual call in constructor helper	134	134
clang	virtual call in constructor link	134	134
clang	virtual call in destructor	134	134
clang	virtual call in destructor helper	134	134
clang	virtual call in destructor link	134	134
gcc	access after realloc	0	0
gcc	array out of bounds	0	0
gcc	automatic variable over stack	139	0
gcc	bad alignment	0	0
gcc	bad identifier name	0	0
gcc	delete incomplete type	0	0
gcc	dereferencing nullptr	139	139
gcc	divide by zero	136	132
gcc	initialize std string with nullptr	134	134
gcc	large double to int	0	0
gcc	malloc cast pod struct	0	0
gcc	mutate const value	0	0
gcc	odr violation function	0	0
gcc	odr violation struct ret	0	0
gcc	operator star on empty optional	0	0
gcc	out of bounds pointer	0	0
gcc	preincrement plus postincrement	0	0
gcc	preincrement plus value	0	0
gcc	read from old type	0	0
gcc	reading uninitialized value add	0	0
gcc	reading uninitialized value cout	0	0
gcc	reading uninitialized value func arg	0	139
gcc	reading uninitialized value if	0	0
gcc	reading uninitialized value lib call cref	0	0
gcc	reading uninitialized value partial	0	0
gcc	reading uninitialized value printf	0	0
gcc	reading uninitialized value return	132	139
gcc	reference out of scope	139	139
gcc	reinterpret cast bad size	0	0
gcc	reinterpret cast float to int32	0	0
gcc	reinterpret cast int32 to float	0	0
gcc	reinterpret cast int32 to uint32	0	0
gcc	reinterpret cast uint32 to int32	0	0
gcc	reinterpret cast unaligned bytes to uint32	0	0
gcc	shifting more than width	0	0
gcc	signed integer overflow	0	0
gcc	sort comp reflexive	0	0
gcc	stack overflow	139	124
gcc	std vector reserve set read	0	0
gcc	strptime mktime unitialized	0	0
gcc	virtual call in constructor helper	134	134
gcc	virtual call in constructor link	134	134
gcc	virtual call in destructor helper	134	134
gcc	virtual call in destructor link	134	134
msvc	access after realloc	0	0
msvc	array out of bounds	-1	0
msvc	automatic variable over stack	-1073741571	0
msvc	bad alignment	0	0
msvc	bad identifier name	0	0
msvc	delete incomplete type	0	0
msvc	dereferencing nullptr	-1073741819	-1073741819
msvc	divide by zero	-1073741676	-1073741676
msvc	initialize std string with nullptr	-1073741819	-1073741819
msvc	large double to int	0	0
msvc	malloc cast pod struct	0	0
msvc	mutate const value	0	0
msvc	odr violation function	0	0
msvc	odr violation struct ret	0	0
msvc	operator star on empty optional	-1	0
msvc	out of bounds pointer	0	0
msvc	preincrement plus postincrement	0	0
msvc	preincrement plus value	0	0
msvc	read from old type	0	0
msvc	reading uninitialized value add	-1	0
msvc	reading uninitialized value cout	-1	0
msvc	reading uninitialized value func arg	-1073741819	-1073740791
msvc	reading uninitialized value if	-1	0
msvc	reading uninitialized value lib call cref	0	0
msvc	reading uninitialized value partial	-1	-1073740791
msvc	reading uninitialized value printf	-1	0
msvc	reference out of scope	0	0
msvc	reinterpret cast bad size	0	0
msvc	reinterpret cast float to int32	0	0
msvc	reinterpret cast int32 to float	0	0
msvc	reinterpret cast int32 to uint32	0	0
msvc	reinterpret cast uint32 to int32	0	0
msvc	reinterpret cast unaligned bytes to uint32	0	0
msvc	shifting more than width	0	0
msvc	signed integer overflow	0	0
msvc	sort comp reflexive	0	0
msvc	stack overflow	-1073741571	-1073741571
msvc	std vector reserve set read	-1	0
msvc	virtual call in constructor helper	-1	-1073740791
msvc	virtual call in constructor link	-1	-1073740791
msvc	virtual call in destructor helper	-1	-1073740791
msvc	virtual call in destructor link	-1	-1073740791

2.2.Runtime Crashes Summary

Debug (unoptimized) / RelWithDebInfo (optimized)

Undefined Behavior	clang	gcc	msvc
access after realloc	❌	❌	❌
array out of bounds	❌	❌	✔️/❌
automatic variable over stack	✔️/❌	✔️/❌	✔️/❌
bad alignment	❌	❌	❌
bad identifier name	❌	❌	❌
delete incomplete type	❌	❌	❌
dereferencing nullptr	✔️/❌	✔️	✔️
divide by zero	❌	✔️	✔️
initialize std string with nullptr	✔️	✔️	✔️
large double to int	❌	❌	❌
malloc cast pod struct	❌	❌	❌
mutate const value	❌	❌	❌
odr violation function	❌	❌	❌
odr violation struct ret	❌	❌	❌
operator star on empty optional	❌	❌	✔️/❌
out of bounds pointer	❌	❌	❌
preincrement plus postincrement	❌	❌	❌
preincrement plus value	❌	❌	❌
read from old type	❌	❌	❌
reading uninitialized value add	❌	❌	✔️/❌
reading uninitialized value cout	❌	❌	✔️/❌
reading uninitialized value func arg	❌/✔️	❌/✔️	✔️
reading uninitialized value if	❌/✔️	❌	✔️/❌
reading uninitialized value lib call cref	❌	❌	❌
reading uninitialized value partial	❌	❌	✔️
reading uninitialized value printf	❌	❌	✔️/❌
reading uninitialized value return	✔️	✔️	n/a
reference out of scope	❌	✔️	❌
reinterpret cast bad size	❌	❌	❌
reinterpret cast float to int32	❌	❌	❌
reinterpret cast int32 to float	❌	❌	❌
reinterpret cast int32 to uint32	❌	❌	❌
reinterpret cast uint32 to int32	❌	❌	❌
reinterpret cast unaligned bytes to uint32	❌	❌	❌
shifting more than width	❌	❌	❌
signed integer overflow	❌	❌	❌
sort comp reflexive	❌	❌	❌
stack overflow	✔️	✔️	✔️
std vector reserve set read	❌	❌	✔️/❌
strptime mktime unitialized	❌	❌	n/a
virtual call in constructor	✔️	n/a	n/a
virtual call in constructor helper	✔️	✔️	✔️
virtual call in constructor link	✔️	✔️	✔️
virtual call in destructor	✔️	n/a	n/a
virtual call in destructor helper	✔️	✔️	✔️
virtual call in destructor link	✔️	✔️	✔️

3.Extra Dynamic Analysis

3.1.Extra Dynamic Analysis Return Codes

Compiler	Tool	Undefined Behavior Type	Debug	RelWithDebInfo
clang	address	access after realloc	1	1
clang	address	array out of bounds	1	0
clang	address	automatic variable over stack	1	0
clang	address	bad alignment	0	0
clang	address	bad identifier name	0	0
clang	address	delete incomplete type	0	0
clang	address	dereferencing nullptr	1	0
clang	address	divide by zero	0	0
clang	address	initialize std string with nullptr	134	134
clang	address	large double to int	0	0
clang	address	malloc cast pod struct	0	0
clang	address	mutate const value	0	0
clang	address	odr violation function	0	0
clang	address	odr violation struct ret	0	0
clang	address	operator star on empty optional	0	0
clang	address	out of bounds pointer	0	0
clang	address	preincrement plus postincrement	0	0
clang	address	preincrement plus value	0	0
clang	address	read from old type	0	0
clang	address	reading uninitialized value add	0	0
clang	address	reading uninitialized value cout	0	0
clang	address	reading uninitialized value func arg	1	1
clang	address	reading uninitialized value if	0	48
clang	address	reading uninitialized value lib call cref	0	0
clang	address	reading uninitialized value partial	0	0
clang	address	reading uninitialized value printf	0	0
clang	address	reading uninitialized value return	132	48
clang	address	reference out of scope	1	0
clang	address	reinterpret cast bad size	1	0
clang	address	reinterpret cast float to int32	0	0
clang	address	reinterpret cast int32 to float	0	0
clang	address	reinterpret cast int32 to uint32	0	0
clang	address	reinterpret cast uint32 to int32	0	0
clang	address	reinterpret cast unaligned bytes to uint32	0	0
clang	address	shifting more than width	0	0
clang	address	signed integer overflow	0	0
clang	address	sort comp reflexive	0	0
clang	address	stack overflow	1	48
clang	address	std vector reserve set read	0	0
clang	address	strptime mktime unitialized	0	0
clang	address	virtual call in constructor	134	134
clang	address	virtual call in constructor helper	134	134
clang	address	virtual call in constructor link	134	134
clang	address	virtual call in destructor	134	134
clang	address	virtual call in destructor helper	134	134
clang	address	virtual call in destructor link	134	134
clang	address,undefined	access after realloc	1	1
clang	address,undefined	array out of bounds	1	1
clang	address,undefined	automatic variable over stack	1	1
clang	address,undefined	bad alignment	1	1
clang	address,undefined	bad identifier name	0	0
clang	address,undefined	delete incomplete type	0	0
clang	address,undefined	dereferencing nullptr	1	1
clang	address,undefined	divide by zero	1	1
clang	address,undefined	initialize std string with nullptr	134	134
clang	address,undefined	large double to int	1	1
clang	address,undefined	malloc cast pod struct	0	0
clang	address,undefined	mutate const value	0	0
clang	address,undefined	odr violation function	0	0
clang	address,undefined	odr violation struct ret	0	0
clang	address,undefined	operator star on empty optional	0	0
clang	address,undefined	out of bounds pointer	0	0
clang	address,undefined	preincrement plus postincrement	0	0
clang	address,undefined	preincrement plus value	0	0
clang	address,undefined	read from old type	1	1
clang	address,undefined	reading uninitialized value add	0	0
clang	address,undefined	reading uninitialized value cout	0	0
clang	address,undefined	reading uninitialized value func arg	1	1
clang	address,undefined	reading uninitialized value if	1	56
clang	address,undefined	reading uninitialized value lib call cref	0	0
clang	address,undefined	reading uninitialized value partial	0	0
clang	address,undefined	reading uninitialized value printf	0	0
clang	address,undefined	reading uninitialized value return	1	1
clang	address,undefined	reference out of scope	1	0
clang	address,undefined	reinterpret cast bad size	1	1
clang	address,undefined	reinterpret cast float to int32	0	0
clang	address,undefined	reinterpret cast int32 to float	0	0
clang	address,undefined	reinterpret cast int32 to uint32	0	0
clang	address,undefined	reinterpret cast uint32 to int32	0	0
clang	address,undefined	reinterpret cast unaligned bytes to uint32	0	0
clang	address,undefined	shifting more than width	1	1
clang	address,undefined	signed integer overflow	1	1
clang	address,undefined	sort comp reflexive	0	0
clang	address,undefined	stack overflow	1	1
clang	address,undefined	std vector reserve set read	0	0
clang	address,undefined	strptime mktime unitialized	0	0
clang	address,undefined	virtual call in constructor	134	134
clang	address,undefined	virtual call in constructor helper	134	134
clang	address,undefined	virtual call in constructor link	134	134
clang	address,undefined	virtual call in destructor	134	134
clang	address,undefined	virtual call in destructor helper	134	134
clang	address,undefined	virtual call in destructor link	134	134
clang	undefined	access after realloc	0	0
clang	undefined	array out of bounds	0	1
clang	undefined	automatic variable over stack	1	1
clang	undefined	bad alignment	0	1
clang	undefined	bad identifier name	0	0
clang	undefined	delete incomplete type	0	0
clang	undefined	dereferencing nullptr	1	1
clang	undefined	divide by zero	1	1
clang	undefined	initialize std string with nullptr	134	134
clang	undefined	large double to int	1	1
clang	undefined	malloc cast pod struct	0	0
clang	undefined	mutate const value	0	0
clang	undefined	odr violation function	0	0
clang	undefined	odr violation struct ret	0	0
clang	undefined	operator star on empty optional	0	0
clang	undefined	out of bounds pointer	0	0
clang	undefined	preincrement plus postincrement	0	0
clang	undefined	preincrement plus value	0	0
clang	undefined	read from old type	1	1
clang	undefined	reading uninitialized value add	0	0
clang	undefined	reading uninitialized value cout	0	0
clang	undefined	reading uninitialized value func arg	0	1
clang	undefined	reading uninitialized value if	1	1
clang	undefined	reading uninitialized value lib call cref	0	0
clang	undefined	reading uninitialized value partial	0	0
clang	undefined	reading uninitialized value printf	0	0
clang	undefined	reading uninitialized value return	1	1
clang	undefined	reference out of scope	0	0
clang	undefined	reinterpret cast bad size	0	1
clang	undefined	reinterpret cast float to int32	0	0
clang	undefined	reinterpret cast int32 to float	0	0
clang	undefined	reinterpret cast int32 to uint32	0	0
clang	undefined	reinterpret cast uint32 to int32	0	0
clang	undefined	reinterpret cast unaligned bytes to uint32	0	0
clang	undefined	shifting more than width	1	1
clang	undefined	signed integer overflow	1	1
clang	undefined	sort comp reflexive	0	0
clang	undefined	stack overflow	1	1
clang	undefined	std vector reserve set read	0	0
clang	undefined	strptime mktime unitialized	0	0
clang	undefined	virtual call in constructor	134	134
clang	undefined	virtual call in constructor helper	134	134
clang	undefined	virtual call in constructor link	134	134
clang	undefined	virtual call in destructor	134	134
clang	undefined	virtual call in destructor helper	134	134
clang	undefined	virtual call in destructor link	134	134
gcc	address	access after realloc	1	1
gcc	address	array out of bounds	1	1
gcc	address	automatic variable over stack	1	1
gcc	address	bad alignment	0	0
gcc	address	bad identifier name	0	0
gcc	address	delete incomplete type	0	0
gcc	address	dereferencing nullptr	1	1
gcc	address	divide by zero	1	132
gcc	address	initialize std string with nullptr	134	134
gcc	address	large double to int	0	0
gcc	address	malloc cast pod struct	0	0
gcc	address	mutate const value	0	0
gcc	address	odr violation function	0	0
gcc	address	odr violation struct ret	0	0
gcc	address	operator star on empty optional	0	0
gcc	address	out of bounds pointer	0	0
gcc	address	preincrement plus postincrement	0	0
gcc	address	preincrement plus value	0	0
gcc	address	read from old type	0	0
gcc	address	reading uninitialized value add	0	0
gcc	address	reading uninitialized value cout	0	0
gcc	address	reading uninitialized value func arg	1	1
gcc	address	reading uninitialized value if	0	0
gcc	address	reading uninitialized value lib call cref	0	0
gcc	address	reading uninitialized value partial	0	0
gcc	address	reading uninitialized value printf	0	0
gcc	address	reading uninitialized value return	132	132
gcc	address	reference out of scope	1	1
gcc	address	reinterpret cast bad size	1	1
gcc	address	reinterpret cast float to int32	0	0
gcc	address	reinterpret cast int32 to float	0	0
gcc	address	reinterpret cast int32 to uint32	0	0
gcc	address	reinterpret cast uint32 to int32	0	0
gcc	address	reinterpret cast unaligned bytes to uint32	0	0
gcc	address	shifting more than width	0	0
gcc	address	signed integer overflow	0	0
gcc	address	sort comp reflexive	0	0
gcc	address	stack overflow	1	124
gcc	address	std vector reserve set read	0	0
gcc	address	strptime mktime unitialized	0	0
gcc	address	virtual call in constructor helper	134	134
gcc	address	virtual call in constructor link	134	134
gcc	address	virtual call in destructor helper	134	134
gcc	address	virtual call in destructor link	134	134
gcc	address,leak,undefined	access after realloc	1	1
gcc	address,leak,undefined	array out of bounds	1	1
gcc	address,leak,undefined	automatic variable over stack	1	1
gcc	address,leak,undefined	bad alignment	1	1
gcc	address,leak,undefined	bad identifier name	0	0
gcc	address,leak,undefined	delete incomplete type	0	0
gcc	address,leak,undefined	dereferencing nullptr	1	1
gcc	address,leak,undefined	divide by zero	1	1
gcc	address,leak,undefined	initialize std string with nullptr	134	134
gcc	address,leak,undefined	large double to int	0	0
gcc	address,leak,undefined	malloc cast pod struct	0	0
gcc	address,leak,undefined	mutate const value	0	0
gcc	address,leak,undefined	odr violation function	0	0
gcc	address,leak,undefined	odr violation struct ret	0	0
gcc	address,leak,undefined	operator star on empty optional	0	0
gcc	address,leak,undefined	out of bounds pointer	0	0
gcc	address,leak,undefined	preincrement plus postincrement	0	0
gcc	address,leak,undefined	preincrement plus value	0	0
gcc	address,leak,undefined	read from old type	1	1
gcc	address,leak,undefined	reading uninitialized value add	0	0
gcc	address,leak,undefined	reading uninitialized value cout	0	0
gcc	address,leak,undefined	reading uninitialized value func arg	1	1
gcc	address,leak,undefined	reading uninitialized value if	0	0
gcc	address,leak,undefined	reading uninitialized value lib call cref	0	0
gcc	address,leak,undefined	reading uninitialized value partial	0	0
gcc	address,leak,undefined	reading uninitialized value printf	0	0
gcc	address,leak,undefined	reading uninitialized value return	1	1
gcc	address,leak,undefined	reference out of scope	1	1
gcc	address,leak,undefined	reinterpret cast bad size	1	1
gcc	address,leak,undefined	reinterpret cast float to int32	0	0
gcc	address,leak,undefined	reinterpret cast int32 to float	0	0
gcc	address,leak,undefined	reinterpret cast int32 to uint32	0	0
gcc	address,leak,undefined	reinterpret cast uint32 to int32	0	0
gcc	address,leak,undefined	reinterpret cast unaligned bytes to uint32	0	0
gcc	address,leak,undefined	shifting more than width	1	1
gcc	address,leak,undefined	signed integer overflow	1	1
gcc	address,leak,undefined	sort comp reflexive	0	0
gcc	address,leak,undefined	stack overflow	1	124
gcc	address,leak,undefined	std vector reserve set read	0	0
gcc	address,leak,undefined	strptime mktime unitialized	0	0
gcc	address,leak,undefined	virtual call in constructor helper	134	134
gcc	address,leak,undefined	virtual call in constructor link	134	134
gcc	address,leak,undefined	virtual call in destructor helper	134	134
gcc	address,leak,undefined	virtual call in destructor link	134	134
gcc	leak	access after realloc	0	0
gcc	leak	array out of bounds	0	0
gcc	leak	automatic variable over stack	23	0
gcc	leak	bad alignment	0	0
gcc	leak	bad identifier name	0	0
gcc	leak	delete incomplete type	0	0
gcc	leak	dereferencing nullptr	23	23
gcc	leak	divide by zero	23	132
gcc	leak	initialize std string with nullptr	134	134
gcc	leak	large double to int	0	0
gcc	leak	malloc cast pod struct	0	0
gcc	leak	mutate const value	0	0
gcc	leak	odr violation function	0	0
gcc	leak	odr violation struct ret	0	0
gcc	leak	operator star on empty optional	0	0
gcc	leak	out of bounds pointer	0	0
gcc	leak	preincrement plus postincrement	0	0
gcc	leak	preincrement plus value	0	0
gcc	leak	read from old type	0	0
gcc	leak	reading uninitialized value add	0	0
gcc	leak	reading uninitialized value cout	0	0
gcc	leak	reading uninitialized value func arg	0	23
gcc	leak	reading uninitialized value if	0	0
gcc	leak	reading uninitialized value lib call cref	0	0
gcc	leak	reading uninitialized value partial	0	0
gcc	leak	reading uninitialized value printf	0	0
gcc	leak	reading uninitialized value return	132	23
gcc	leak	reference out of scope	23	23
gcc	leak	reinterpret cast bad size	0	0
gcc	leak	reinterpret cast float to int32	0	0
gcc	leak	reinterpret cast int32 to float	0	0
gcc	leak	reinterpret cast int32 to uint32	0	0
gcc	leak	reinterpret cast uint32 to int32	0	0
gcc	leak	reinterpret cast unaligned bytes to uint32	0	0
gcc	leak	shifting more than width	0	0
gcc	leak	signed integer overflow	0	0
gcc	leak	sort comp reflexive	0	0
gcc	leak	stack overflow	23	124
gcc	leak	std vector reserve set read	0	0
gcc	leak	strptime mktime unitialized	0	0
gcc	leak	virtual call in constructor helper	134	134
gcc	leak	virtual call in constructor link	134	134
gcc	leak	virtual call in destructor helper	134	134
gcc	leak	virtual call in destructor link	134	134
gcc	undefined	access after realloc	0	0
gcc	undefined	array out of bounds	0	1
gcc	undefined	automatic variable over stack	139	139
gcc	undefined	bad alignment	0	0
gcc	undefined	bad identifier name	0	0
gcc	undefined	delete incomplete type	0	0
gcc	undefined	dereferencing nullptr	1	1
gcc	undefined	divide by zero	1	1
gcc	undefined	initialize std string with nullptr	134	134
gcc	undefined	large double to int	0	0
gcc	undefined	malloc cast pod struct	0	0
gcc	undefined	mutate const value	0	0
gcc	undefined	odr violation function	0	0
gcc	undefined	odr violation struct ret	0	0
gcc	undefined	operator star on empty optional	0	0
gcc	undefined	out of bounds pointer	0	0
gcc	undefined	preincrement plus postincrement	0	0
gcc	undefined	preincrement plus value	0	0
gcc	undefined	read from old type	1	1
gcc	undefined	reading uninitialized value add	0	0
gcc	undefined	reading uninitialized value cout	0	0
gcc	undefined	reading uninitialized value func arg	0	1
gcc	undefined	reading uninitialized value if	0	0
gcc	undefined	reading uninitialized value lib call cref	0	0
gcc	undefined	reading uninitialized value partial	0	0
gcc	undefined	reading uninitialized value printf	0	0
gcc	undefined	reading uninitialized value return	1	1
gcc	undefined	reference out of scope	1	1
gcc	undefined	reinterpret cast bad size	1	1
gcc	undefined	reinterpret cast float to int32	0	0
gcc	undefined	reinterpret cast int32 to float	0	0
gcc	undefined	reinterpret cast int32 to uint32	0	0
gcc	undefined	reinterpret cast uint32 to int32	0	0
gcc	undefined	reinterpret cast unaligned bytes to uint32	0	0
gcc	undefined	shifting more than width	1	1
gcc	undefined	signed integer overflow	1	1
gcc	undefined	sort comp reflexive	0	0
gcc	undefined	stack overflow	139	124
gcc	undefined	std vector reserve set read	0	0
gcc	undefined	strptime mktime unitialized	0	0
gcc	undefined	virtual call in constructor helper	134	134
gcc	undefined	virtual call in constructor link	134	134
gcc	undefined	virtual call in destructor helper	134	134
gcc	undefined	virtual call in destructor link	134	134
gcc	valgrind	access after realloc	1	1
gcc	valgrind	array out of bounds	0	0
gcc	valgrind	automatic variable over stack	139	0
gcc	valgrind	bad alignment	0	0
gcc	valgrind	bad identifier name	0	0
gcc	valgrind	delete incomplete type	0	0
gcc	valgrind	dereferencing nullptr	139	139
gcc	valgrind	divide by zero	136	132
gcc	valgrind	initialize std string with nullptr	134	134
gcc	valgrind	large double to int	0	0
gcc	valgrind	malloc cast pod struct	0	0
gcc	valgrind	mutate const value	0	0
gcc	valgrind	odr violation function	0	0
gcc	valgrind	odr violation struct ret	0	0
gcc	valgrind	operator star on empty optional	0	0
gcc	valgrind	out of bounds pointer	0	0
gcc	valgrind	preincrement plus postincrement	0	0
gcc	valgrind	preincrement plus value	0	0
gcc	valgrind	read from old type	0	0
gcc	valgrind	reading uninitialized value add	1	0
gcc	valgrind	reading uninitialized value cout	1	0
gcc	valgrind	reading uninitialized value func arg	1	139
gcc	valgrind	reading uninitialized value if	1	0
gcc	valgrind	reading uninitialized value lib call cref	1	1
gcc	valgrind	reading uninitialized value partial	1	0
gcc	valgrind	reading uninitialized value printf	1	0
gcc	valgrind	reading uninitialized value return	132	139
gcc	valgrind	reference out of scope	139	139
gcc	valgrind	reinterpret cast bad size	0	1
gcc	valgrind	reinterpret cast float to int32	0	0
gcc	valgrind	reinterpret cast int32 to float	0	0
gcc	valgrind	reinterpret cast int32 to uint32	0	0
gcc	valgrind	reinterpret cast uint32 to int32	0	0
gcc	valgrind	reinterpret cast unaligned bytes to uint32	0	0
gcc	valgrind	shifting more than width	0	0
gcc	valgrind	signed integer overflow	0	0
gcc	valgrind	sort comp reflexive	0	0
gcc	valgrind	stack overflow	139	124
gcc	valgrind	std vector reserve set read	0	0
gcc	valgrind	strptime mktime unitialized	1	1
gcc	valgrind	virtual call in constructor helper	134	134
gcc	valgrind	virtual call in constructor link	134	134
gcc	valgrind	virtual call in destructor helper	134	134
gcc	valgrind	virtual call in destructor link	134	134

3.2.1.Extra Dynamic Analysis Summary Clang

Debug (unoptimized) / RelWithDebInfo (optimized)

Undefined Behavior Type	address	address,undefined	undefined
access after realloc	✔️	✔️	❌
array out of bounds	✔️/❌	✔️	❌/✔️
automatic variable over stack	✔️/❌	✔️	✔️
bad alignment	❌	✔️	❌/✔️
bad identifier name	❌	❌	❌
delete incomplete type	❌	❌	❌
dereferencing nullptr	✔️/❌	✔️	✔️
divide by zero	❌	✔️	✔️
initialize std string with nullptr	✔️	✔️	✔️
large double to int	❌	✔️	✔️
malloc cast pod struct	❌	❌	❌
mutate const value	❌	❌	❌
odr violation function	❌	❌	❌
odr violation struct ret	❌	❌	❌
operator star on empty optional	❌	❌	❌
out of bounds pointer	❌	❌	❌
preincrement plus postincrement	❌	❌	❌
preincrement plus value	❌	❌	❌
read from old type	❌	✔️	✔️
reading uninitialized value add	❌	❌	❌
reading uninitialized value cout	❌	❌	❌
reading uninitialized value func arg	✔️	✔️	❌/✔️
reading uninitialized value if	❌/✔️	✔️	✔️
reading uninitialized value lib call cref	❌	❌	❌
reading uninitialized value partial	❌	❌	❌
reading uninitialized value printf	❌	❌	❌
reading uninitialized value return	✔️	✔️	✔️
reference out of scope	✔️/❌	✔️/❌	❌
reinterpret cast bad size	✔️/❌	✔️	❌/✔️
reinterpret cast float to int32	❌	❌	❌
reinterpret cast int32 to float	❌	❌	❌
reinterpret cast int32 to uint32	❌	❌	❌
reinterpret cast uint32 to int32	❌	❌	❌
reinterpret cast unaligned bytes to uint32	❌	❌	❌
shifting more than width	❌	✔️	✔️
signed integer overflow	❌	✔️	✔️
sort comp reflexive	❌	❌	❌
stack overflow	✔️	✔️	✔️
std vector reserve set read	❌	❌	❌
strptime mktime unitialized	❌	❌	❌
virtual call in constructor	✔️	✔️	✔️
virtual call in constructor helper	✔️	✔️	✔️
virtual call in constructor link	✔️	✔️	✔️
virtual call in destructor	✔️	✔️	✔️
virtual call in destructor helper	✔️	✔️	✔️
virtual call in destructor link	✔️	✔️	✔️

3.2.2.Extra Dynamic Analysis Summary Gcc

Debug (unoptimized) / RelWithDebInfo (optimized)

Undefined Behavior Type	address	address,leak,undefined	leak	undefined	valgrind
access after realloc	✔️	✔️	❌	❌	✔️
array out of bounds	✔️	✔️	❌	❌/✔️	❌
automatic variable over stack	✔️	✔️	✔️/❌	✔️	✔️/❌
bad alignment	❌	✔️	❌	❌	❌
bad identifier name	❌	❌	❌	❌	❌
delete incomplete type	❌	❌	❌	❌	❌
dereferencing nullptr	✔️	✔️	✔️	✔️	✔️
divide by zero	✔️	✔️	✔️	✔️	✔️
initialize std string with nullptr	✔️	✔️	✔️	✔️	✔️
large double to int	❌	❌	❌	❌	❌
malloc cast pod struct	❌	❌	❌	❌	❌
mutate const value	❌	❌	❌	❌	❌
odr violation function	❌	❌	❌	❌	❌
odr violation struct ret	❌	❌	❌	❌	❌
operator star on empty optional	❌	❌	❌	❌	❌
out of bounds pointer	❌	❌	❌	❌	❌
preincrement plus postincrement	❌	❌	❌	❌	❌
preincrement plus value	❌	❌	❌	❌	❌
read from old type	❌	✔️	❌	✔️	❌
reading uninitialized value add	❌	❌	❌	❌	✔️/❌
reading uninitialized value cout	❌	❌	❌	❌	✔️/❌
reading uninitialized value func arg	✔️	✔️	❌/✔️	❌/✔️	✔️
reading uninitialized value if	❌	❌	❌	❌	✔️/❌
reading uninitialized value lib call cref	❌	❌	❌	❌	✔️
reading uninitialized value partial	❌	❌	❌	❌	✔️/❌
reading uninitialized value printf	❌	❌	❌	❌	✔️/❌
reading uninitialized value return	✔️	✔️	✔️	✔️	✔️
reference out of scope	✔️	✔️	✔️	✔️	✔️
reinterpret cast bad size	✔️	✔️	❌	✔️	❌/✔️
reinterpret cast float to int32	❌	❌	❌	❌	❌
reinterpret cast int32 to float	❌	❌	❌	❌	❌
reinterpret cast int32 to uint32	❌	❌	❌	❌	❌
reinterpret cast uint32 to int32	❌	❌	❌	❌	❌
reinterpret cast unaligned bytes to uint32	❌	❌	❌	❌	❌
shifting more than width	❌	✔️	❌	✔️	❌
signed integer overflow	❌	✔️	❌	✔️	❌
sort comp reflexive	❌	❌	❌	❌	❌
stack overflow	✔️	✔️	✔️	✔️	✔️
std vector reserve set read	❌	❌	❌	❌	❌
strptime mktime unitialized	❌	❌	❌	❌	✔️
virtual call in constructor	n/a	n/a	n/a	n/a	n/a
virtual call in constructor helper	✔️	✔️	✔️	✔️	✔️
virtual call in constructor link	✔️	✔️	✔️	✔️	✔️
virtual call in destructor	n/a	n/a	n/a	n/a	n/a
virtual call in destructor helper	✔️	✔️	✔️	✔️	✔️
virtual call in destructor link	✔️	✔️	✔️	✔️	✔️

4.Overall Summary

Undefined Behavior Type	Compiler Warning	Standalone Static Analysis	Runtime Crash	Extra Dynamic Analsyis
access after realloc	✔️	✔️	❌	✔️
array out of bounds	✔️	✔️	✔️	✔️
automatic variable over stack	❌	❌	✔️	✔️
bad alignment	❌	❌	❌	✔️
bad identifier name	❌	✔️	❌	❌
delete incomplete type	✔️	✔️	❌	❌
dereferencing nullptr	❌	✔️	✔️	✔️
divide by zero	✔️	✔️	✔️	✔️
initialize std string with nullptr	❌	✔️	✔️	✔️
large double to int	❌	❌	❌	✔️
malloc cast pod struct	❌	❌	❌	❌
mutate const value	❌	✔️	❌	❌
non trivial destructor and global	❌	❌	n/a	n/a
odr violation function	❌	✔️	❌	❌
odr violation function lib	❌	❌	n/a	n/a
odr violation struct ret	❌	✔️	❌	❌
odr violation struct ret lib	❌	❌	n/a	n/a
operator star on empty optional	❌	✔️	✔️	❌
out of bounds pointer	✔️	❌	❌	❌
preincrement plus postincrement	✔️	✔️	❌	❌
preincrement plus value	✔️	✔️	❌	❌
read from old type	❌	❌	❌	✔️
reading uninitialized value add	✔️	✔️	✔️	✔️
reading uninitialized value cout	✔️	✔️	✔️	✔️
reading uninitialized value func arg	✔️	✔️	✔️	✔️
reading uninitialized value if	✔️	✔️	✔️	✔️
reading uninitialized value lib call cref	✔️	✔️	❌	✔️
reading uninitialized value partial	❌	✔️	✔️	✔️
reading uninitialized value printf	✔️	✔️	✔️	✔️
reading uninitialized value return	✔️	✔️	✔️	✔️
reference out of scope	✔️	✔️	✔️	✔️
reinterpret cast bad size	✔️	❌	❌	✔️
reinterpret cast float to int32	✔️	❌	❌	❌
reinterpret cast int32 to float	✔️	❌	❌	❌
reinterpret cast int32 to uint32	❌	❌	❌	❌
reinterpret cast uint32 to int32	❌	❌	❌	❌
reinterpret cast unaligned bytes to uint32	❌	❌	❌	❌
shifting more than width	✔️	✔️	❌	✔️
signed integer overflow	❌	❌	❌	✔️
sort comp reflexive	❌	❌	❌	❌
stack overflow	✔️	✔️	✔️	✔️
std vector reserve set read	❌	✔️	✔️	❌
strptime mktime unitialized	❌	✔️	❌	✔️
virtual call in constructor	✔️	✔️	✔️	✔️
virtual call in constructor helper	❌	✔️	✔️	✔️
virtual call in constructor lib	❌	✔️	n/a	n/a
virtual call in constructor link	❌	❌	✔️	✔️
virtual call in destructor	✔️	✔️	✔️	✔️
virtual call in destructor helper	❌	✔️	✔️	✔️
virtual call in destructor lib	❌	✔️	n/a	n/a
virtual call in destructor link	❌	❌	✔️	✔️

Versions

• Linux 1b21937069a7 6.5.0-41-generic #41~22.04.2-Ubuntu SMP PREEMPT_DYNAMIC Mon Jun 3 11:32:55 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
• Ubuntu clang version 18.1.3 (1ubuntu1)
• clang-tidy: 18.1.3
• Cppcheck 2.13.0
• gcc (Ubuntu 13.2.0-23ubuntu4) 13.2.0
• GNU bash, version 5.2.21(1)-release (x86_64-pc-linux-gnu)
• GNU parallel 20231122
• MSVC: 2022 MSVC 19.40.33811.0
• Python 3.12.3
• valgrind-3.22.0
• Windows SDK version 10.0.22621.0 to target Windows 10.0.17763.

Reference Warning Classes

Compiler	Name	Code	Class
clang	divide by zero	division-by-zero	default
clang	infinite recursion	infinite-recursion	Most
clang	most	Most	all
clang	shift count overflow	shift-count-overflow	default
clang	uninitialized	uninitialized	Most
clang	return type	return-type	Most
gcc	delete incomplete	delete-incomplete	default
gcc	divide by zero	div-by-zero	default
gcc	shift count overflow	shift-count-overflow	extra
gcc	strict aliasing	strict-aliasing	all
gcc	return type	return-type	all
gcc	uninitialized	uninitialized	all
MSVC	divide by zero	4723	W3
MSVC	uninitialized	4700	W1
MSVC	stack overflow	4717	W1
MSVC	shift count overflow	4293	W1
MSVC	truncation of constant value	4309	W2

Notes

Valgrind was run on GCC compiled binaries. msan, asan, and ubsan are all different flags into clang's "fsanatize" parameter.

Passing means the process halted with a non zero error code. Tests were on intel x86_64. MSVC was tested on Windows 10 and the rest was tested on Ubuntu 20.04. Debug mode and RelWithDebInfo is in reference to CMake's build types.

There is only one case of each type. It's expected that slightly different implementations of the same types of undefined behavior may yield different results. Multiple runs were not performed consistently for statistical purposes.

There were a few other static analyzers, but they didn't seem appropriate for these problems. I tried OCLint version 0.13.1, but it didn't provide any additional insights besides compiler warnings in regards to undefined behavior. It did warn about short variable names. I also tried cppclean 0.12. It wasn't able to identify undefined behavior issues. It was able to find static data, which is in the stack overflow code by design.

It's recommended for clang-tidy to have a compile database. If it doesn't it will not detect certain errors. For example, it wouldn't detect the stack overflow error.

Analysis

When in debug mode, MSVC halted on the most undefined behavior. Clang and GCC both benefited with the additional "-Wall" flag to catch undefined behavior as warnings. No extra flags made MSVC catch more undefined behavior.

Valgrind caught a few more cases of undefined behavior over running the programs directly. The additional cases were reading uninitialized values and dereferencing an array out of its bounds. It did provide more actionable messages than just "seg fault." Clang with "-fsanitize=undefined" performed much better in RelWithDebInfo mode over just Debug mode. It caught all types but reading from an uninitialized value and out of bounds pointer.

asan was able to identify the array out of bounds error over the undefined option, but didn't detect other use cases. Once the optimizer works, the address sanitizer is not effective at detecting undefined behavior. Pairing it with ubsan combined the best of both tools.

msan was similar to asan, except it didn't identify any new cases. It also benefited from pairing up with ubsan, but ubsan by itself was good enough.

Reading from an uninitialized value is a very common mistake for beginners and experts. Compilers sometimes catch it as warnings. Valgrind can detect it, but clang with fsantize can often miss it.

Updates

2022/07/25

clang 10->14

undefined behavior	new check
reading uninitialized value lib call cref	-Wuninitialized-const-reference

gcc 9.3->11.2

undefined behavior	new check
array out of bounds	-Warray-bounds
out of bound pointer	-Warray-bounds
reading uninitialized value lib call cref	-Wmaybe-uninitialized
type pun cast same line	-Wuninitialized
type pun cast two lines	-Wuninitialized

clang-tidy 10->14

undefined behavior	new check
bad identifier name	bugprone-reserved-identifier
reading uninitialized value lib call cref	clang-diagnostic-uninitialized-const-reference

cppcheck 1.9->2.7

undefined behavior	new check
odr violation struct ret	ctuOneDefinitionRuleViolation
reading uninitialized value return	missingReturn
std vector reserve set read	containerOutOfBounds

2024/07/06

gcc 11.2.0->13.2.0

undefined behavior	new check
access after realloc	-Wuse-after-free
stack overflow	-Winfinite-recursion

clang-tidy 14.0 -> 18.1.3

undefined behavior	new check
odr violation function	misc-include-cleaner*
odr violation struct ret	misc-include-cleaner*
operator star on empty optional	bugprone-unchecked-optional-access

*misc-include-cleaner doesn't really call out the ODR violation, but it is a strong indicator.

Clang's memory sanitizer removed. Its results were similar to address. Also, the results were questionable, since it didn't work with a memory compiled standard library.

The type pun examples were changed to reinterpret cast ones. There are more examples to stress that the standard has strict requirements on reinterpret cast. Still most of them aren't checked.

Variability

Valgrind seems to have different results over time. This may be due to version upgrades from 3.11 to 1.13 or the very nature of undefined behavior itself. It was observed that array out of bounds was undetected by valgrind during the upgrade. Not detecting uninitialized memory in release with debug info went undetected at some point later.