Due to statement expressions supported as GCC extension, it is possible
to put 'break' or 'continue' into a loop/switch statement but outside
its body, for example:
for ( ; ({ if (first) { first = 0; continue; } 0; }); )
This code is rejected by GCC if compiled in C mode but is accepted in C++
code. GCC bug 44715 tracks this discrepancy. Clang used code generation
that differs from GCC in both modes: only statement of the third
expression of 'for' behaves as if it was inside loop body.
This change makes code generation more close to GCC, considering 'break'
or 'continue' statement in condition and increment expressions of a
loop as it was inside the loop body. It also adds error for the cases
when 'break'/'continue' appear outside loop due to this syntax. If
code generation differ from GCC, warning is issued.
Differential Revision: http://llvm-reviews.chandlerc.com/D2518
llvm-svn: 199897
This checker has not been updated to work with interprocedural analysis,
and actually contains both logical correctness issues but also
memory bugs. We can resuscitate it from version control once there
is focused interest in making it a real viable checker again.
llvm-svn: 198476
This patch wasn't reviewed, and isn't correctly preserving the behaviors
relied upon by QT. I don't have a direct example of fallout, but it
should go through the standard code review process. For example, it
should never have removed the QT test case that was added when fixing
those users.
llvm-svn: 193174
Due to statement expressions supported as GCC extension, it is possible
to put 'break' or 'continue' into a loop/switch statement but outside its
body, for example:
for ( ; ({ if (first) { first = 0; continue; } 0; }); )
Such usage must be diagnosed as an error, GCC rejects it. To recognize
this and similar patterns the flags BreakScope and ContinueScope are
temporarily turned off while parsing condition expression.
Differential Revision: http://llvm-reviews.chandlerc.com/D1762
llvm-svn: 193073
As part of this change, I discovered that a few of our tests were not testing
the RangeConstraintManager. Luckily all of those passed when I moved them
over to use that constraint manager.
llvm-svn: 162384
dead stores within nested assignments. I have
never seen an actual bug found by this specific
warning, and it can lead to many false positives.
llvm-svn: 123394
The end result is now we eagarly constant-fold symbols in the analyzer that are perfectly constrained
to be a constant value. This allows us to recover some path-sensitivity in some cases by lowering
the required level of reasoning power needed to evaluate some expressions.
The net win from this change is that the false positive in PR 8015 is fixed, and we also
find more idempotent operations bugs.
We do, however, regress with the BugReporterVisitors, which need to be modified to understand
this constant folding (and look past it). This causes some diagnostic regressions in plist-output.m
which will get addressed in a future patch. plist-output.m is now marked XFAIL, while
plist-output-alternate.m now tests that the plist output is working, but with the suboptimal
diagnostics. This second test file will eventually be removed.
llvm-svn: 113477
- Added wasReferenced function to PseudoConstantAnalysis to determine if a variable was ever referenced in a function (outside of a self-assignment)
- BlockDeclRefExpr referenced variables are now explicitly added to the non-constant list
- Remove unnecessary ignore of implicit casts
- Generalized parameter self-assign detection to detect deliberate self-assigns of variables to avoid unused variable warnings
- Updated test cases with deliberate self-assignments
- Fixed bug with C++ references and pseudoconstants
- Added test case for C++ references and pseudoconstants
llvm-svn: 111965
- Unfinished analysis may still report valid warnings if the path was completely analyzed
- New 'CanVary' heuristic to recursively determine if a subexpression has a varying element
- Updated test cases, including one known bug
- Exposed GRCoreEngine through GRExprEngine
llvm-svn: 110970
- Added checks for static local variables, self assigned parameters, and truncating/extending self assignments
- Removed command line option (now default with --analyze)
- Updated test cases to pass with idempotent operation warnings
llvm-svn: 108550
As a bonus, fix the warning for || and && operators; it was emitted even if one of the operands had side effects, e.g:
x || test_logical_foo1();
emitted a bogus "expression result unused" for 'x'.
llvm-svn: 107274
a scalar variable with a scalar parameter. This is a
form of defensive programming. If the variable is unused,
it will be caused by -Wunused-variable.
llvm-svn: 98795
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
Stephan Bergmann