Allow this warning to detect a larger number of constant values, including
negative numbers, and handle non-int types better.
Differential Revision: https://reviews.llvm.org/D66044
llvm-svn: 372448
We're building the CFG from bottom to top, so when the return-value expression
has a non-trivial CFG on its own, we need to continue building from the entry
to the return-value expression CFG rather than from the block to which
we've just appended the return statement.
Fixes a false positive warning "control may reach end of non-void function".
llvm-svn: 370406
Respect C++17 copy elision; previously it would generate destructor calls
for elided temporaries, including in initialization and return statements.
Don't generate duplicate destructor calls for statement expressions.
Fix destructors in initialization lists and comma operators.
Improve printing of implicit destructors.
Patch by Nicholas Allegra!
Differential Revision: https://reviews.llvm.org/D66404
llvm-svn: 370247
Add a defensive check against an invalid destructor in the CFG.
Unions with fields with destructors have their own destructor implicitly
deleted. Due to a bug in the CFG we're still trying to evaluate them
at the end of the object's lifetime and crash because we are unable
to find the destructor's declaration.
rdar://problem/47362608
Differential Revision: https://reviews.llvm.org/D56899
llvm-svn: 351610
Despite the fact that cast expressions return rvalues, GCC still
handles such outputs as lvalues when compiling inline assembler.
In this commit, we are treating it by removing LValueToRValue
casts inside GCCAsmStmt outputs.
Differential Revision: https://reviews.llvm.org/D45416
llvm-svn: 344864
Constructors of simple variables now can be queried to discover that they're
constructing into simple variables.
Differential Revision: https://reviews.llvm.org/D42699
llvm-svn: 324794
This patch adds a new CFGStmt sub-class, CFGConstructor, which replaces
the regular CFGStmt with CXXConstructExpr in it whenever the CFG has additional
information to provide regarding what sort of object is being constructed.
It is useful for figuring out what memory is initialized in client of the
CFG such as the Static Analyzer, which do not operate by recursive AST
traversal, but instead rely on the CFG to provide all the information when they
need it. Otherwise, the statement that triggers the construction and defines
what memory is being initialized would normally occur after the
construct-expression, and the client would need to peek to the next CFG element
or use statement parent map to understand the necessary facts about
the construct-expression.
As a proof of concept, CFGConstructors are added for new-expressions
and the respective test cases are provided to demonstrate how it works.
For now, the only additional data contained in the CFGConstructor element is
the "trigger statement", such as new-expression, which is the parent of the
constructor. It will be significantly expanded in later commits. The additional
data is organized as an auxiliary structure - the "construction context",
which is allocated separately from the CFGElement.
Differential Revision: https://reviews.llvm.org/D42672
llvm-svn: 324668
Output generated by option -ast-print looks like C/C++ code, and it
really is for plain C. For C++ the produced output was not valid C++
code, but the differences were small. With this change the output
is fixed and can be compiled. Tests are changed so that output produced
by -ast-print is compiled again with the same flags and both outputs are
compared.
Option -ast-print is extensively used in clang tests but it itself
was tested poorly, existing tests only checked that compiler did not
crash. There are unit tests in file DeclPrinterTest.cpp, but they test
only terse output mode.
Differential Revision: https://reviews.llvm.org/D26452
llvm-svn: 286439
new expression, distinguish between the case of a constant and non-constant
initializer. In the former case, if the bound is erroneous (too many
initializer elements, bound is negative, or allocated size overflows), reject,
and take the bound into account when determining whether we need to
default-construct any elements. In the remanining cases, move the logic to
check for default-constructibility of trailing elements into the initialization
code rather than inventing a bogus array bound, to cope with cases where the
number of initialized elements is not the same as the number of initializer
list elements (this can happen due to string literal initialization or brace
elision).
This also fixes rejects-valid and crash-on-valid errors when initializing a
new'd array of character type from a braced string literal.
llvm-svn: 283406
MaterializeTemporaryExpr already contains information about the lifetime
of the temporary; if the lifetime is not the full statement, we do not
want to emit a destructor at the end of the full statement for it.
llvm-svn: 214292
For namespaces, this is consistent with mangling and GCC's debug info
behavior. For structs, GCC uses <anonymous struct> but we prefer
consistency between all anonymous entities but don't want to confuse
them with template arguments, etc, so we'll just go with parens in all
cases.
llvm-svn: 205398
In an expression like "new (a, b) Foo(x, y)", two things happen:
- Memory is allocated by calling a function named 'operator new'.
- The memory is initialized using the constructor for 'Foo'.
Currently the analyzer only models the second event, though it has special
cases for both the default and placement forms of operator new. This patch
is the first step towards properly modeling both events: it changes the CFG
so that the above expression now generates the following elements.
1. a
2. b
3. (CFGNewAllocator)
4. x
5. y
6. Foo::Foo
The analyzer currently ignores the CFGNewAllocator element, but the next
step is to treat that as a call like any other.
The CFGNewAllocator element is not added to the CFG for analysis-based
warnings, since none of them take advantage of it yet.
llvm-svn: 199123
Summary:
If a noreturn destructor is executed while returning a value from a function,
the resulting CFG has had two edges to the exit block. This crashed the analyzer,
because it expects that blocks with no terminators have only one outgoing edge.
I added code to avoid creating the second edge in this case.
PS: The crashes did not manifest themselves always, as usually the
NoReturnFunctionChecker would stop program evaluation before the analyzer hit
the assertion, but in the case of lifetime extended temporaries, the checker
failed to do that (which is a separate bug in itself).
Reviewers: jordan_rose
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1513
llvm-svn: 190125
This paves the way for adding support for modeling the destructor of a
region before it is deleted. The statement "delete <expr>" now generates
this series of CFG elements:
1. <expr>
2. [B1.1]->~Foo() (Implicit destructor)
3. delete [B1.1]
Patch by Karthik Bhat!
llvm-svn: 189828
This builtin does not actually evaluate its arguments for side effects,
so we shouldn't include them in the CFG. In the analyzer, rely on the
constant expression evaluator to get the proper semantics, at least for
now. (In the future, we could get ambitious and try to provide path-
sensitive size values.)
In theory, this does pose a problem for liveness analysis: a variable can
be used within the __builtin_object_size argument expression but not show
up as live. However, it is very unlikely that such a value would be used
to compute the object size and not used to access the object in some way.
<rdar://problem/14760817>
llvm-svn: 188679
Consider the case where a SwitchStmt satisfied isAllEnumCasesCovered()
as well as having no cases at all (i.e. the enum it covers has no
enumerators).
In this case, we should add a successor to repair the CFG.
This fixes PR16212.
llvm-svn: 183237
Neither the compiler nor the analyzer are doing anything with non-VarDecl
decls in the CFG, and having them there creates extra nodes in the
analyzer's path diagnostics. Simplify the CFG (and the path edges) by
simply leaving them out. We can always add interesting decls back in when
they become relevant.
Note that this only affects decls declared in a DeclStmt, and then only
those that appear within a function body.
llvm-svn: 183157
First check only wrapped with i==8, second wrapped at i==2,8,18,28,...
This fix restores the intended behavior: i==8,18,28,...
Found with -fsanitize=integer.
llvm-svn: 171718
Richard Trieu