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
I had forgotten that the same reachability code is used by both -Wreturn-type
and -Wunreachable-code, so the heuristics applied to the latter were indirectly
impacting the former.
To address this, the reachability code is more refactored so that whiled
the logic at its core is shared, the intention of the clients are better
captured and segregated in helper APIs.
Fixes PR19074, and also some false positives reported offline to me
by Nick Lewycky.
llvm-svn: 203209
This ports the last Sema tests over to use the frontend directly, and adds a
local lit substitution to disable inappropriate %clang usage under this
directory.
llvm-svn: 199348
non-constant value encountered. This allows the evaluator to deduce that
expressions like (x < 5 || true) is equal to true. Previously, it would visit
x and determined that the entire expression is could not evaluated to a
constant.
This fixes PR12318.
llvm-svn: 153226
several ways. We now warn for more of the return types, and correctly
locate the ignored ones. Also adds fix-it hints to remove the ignored
qualifiers. Fixes much of PR9058, although not all of it.
Patch by Hans Wennborg, a couple of minor style tweaks from me.
llvm-svn: 126321
The rationale behind this is that it is normal for callback functions to have a non-void return type
and it should still be possible to mark them noreturn. (JavaScriptCore is a good example of this).
llvm-svn: 112918
This flag and warning match GCC semantics. Also, move it to -Wextra as this is
a largely cosmetic issue and doesn't seem to mask problems. Subsequent fixes to
the tests which no longer by default emit the warning. Added explicit test
cases for both C and C++ behavior with the warning turned on.
llvm-svn: 108325
value. This is on by default, and controlled by -Wreturn-type (-Wmost
-Wall). I believe there should be very few false positives, though
the most interesting case would be:
int() { bar(); }
when bar does:
bar() { while (1) ; }
Here, we assume functions return, unless they are marked with the
noreturn attribute. I can envision a fixit note for functions that
never return normally that don't have a noreturn attribute to add a
noreturn attribute.
If anyone spots other false positives, let me know!
llvm-svn: 76821
This fixes <rdar://problem/6839489> 10A345: Clang does not warm about mismatched returns (void return from a bool function)
Will implement -Wreturn-type, -Wno-return-type in another commit.
llvm-svn: 70492
Dávid Bolvanský