[PATCH] D63082: [Diagnostics] Added support for -Wint-in-bool-context

[Dávid Bolvanský via Phabricator via cfe-commits]

xbolva00 marked 4 inline comments as done and an inline comment as not done.
xbolva00 added inline comments.


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Comment at: test/Sema/warn-int-in-bool-context.c:26
+  r = a << 7;   // expected-warning {{'<<' in boolean context; did you mean '<'?}}
+  r = ONE << b; // expected-warning {{'<<' in boolean context; did you mean '<'?}}
+
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jfb wrote:
> xbolva00 wrote:
> > jfb wrote:
> > > I'm not sure the "did you mean" part is helpful. Do we have data showing that this is what people actually mean?
> > No, no data, just what GCC suggests.
> I would drop it without knowing that it's actually what people usually mean.
Leave just “<<' in boolean context“ seems not ideal for me as a diag message. 

Or is it ok for you?


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Comment at: test/Sema/warn-int-in-bool-context.c:33
+  r = a ? 3 : -2;
+  r = a ? 0 : TWO; // expected-warning {{'?:' with integer constants in boolean context}}
+  r = a ? 3 : ONE; // expected-warning {{'?:' with integer constants in boolean context, the expression will always evaluate to 'true'}}
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jfb wrote:
> xbolva00 wrote:
> > jfb wrote:
> > > Why does this one warn? It doesn't always yield the same result.
> > GCC warns here..
> Our goal isn't to achieve GCC warning parity. I like warnings that fire when it's extremely likely a bug. Here the diagnostic seems to be inconsistent with other instances of this diagnostic. Maybe this should warn, but then other cases should as well (such as `a?3:-2` above). Or maybe it shouldn't warn at all.
I will drop it and leave only “warn_integer_constants_in_conditional_always_true” diag.


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Comment at: test/Sema/warn-unreachable.c:147
+  // expected-warning at +1 {{'*' in boolean context, the expression will always evaluate to 'false'}}
   if (0 * x) calledFun(); // expected-warning {{will never be executed}}
 }
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jfb wrote:
> xbolva00 wrote:
> > jfb wrote:
> > > It seems like here the "will never be executed" warning is more useful. Do we want to emit both?
> > Useful but -Wunreachable-code is disabled by default (not part of -Wall).
> I don't think we want two diagnostics when one will do.
I will drop mul handling then..


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Comment at: test/SemaCXX/warn-int-in-bool-context.cpp:96
+
+  if (f == apple || orange) // expected-warning {{enum constant in boolean context}}
+    return a;
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xbolva00 wrote:
> @aaron.ballman : In C (but not in C++ ugh?) mode we have: 'use of logical '||' with constant operand' here..
> 
> /home/xbolva00/LLVM/llvm/tools/clang/test/SemaCXX/warn-int-in-bool-context.cpp:106:18: warning: use of logical '||' with constant operand
>   if (f == apple || orange) // expected-warning {{enum constant in boolean context}}
>                  ^  ~~~~~~
> /home/xbolva00/LLVM/llvm/tools/clang/test/SemaCXX/warn-int-in-bool-context.cpp:106:18: note: use '|' for a bitwise operation
>   if (f == apple || orange) // expected-warning {{enum constant in boolean context}}
>                  ^~
>                  |
> /home/xbolva00/LLVM/llvm/tools/clang/test/SemaCXX/warn-int-in-bool-context.cpp:106:21: warning: enum constant in boolean context
>   if (f == apple || orange) // expected-warning {{enum constant in boolean context}}
> 
> 
> 
> 
What is your opinion here (^^) , @jfb ?

Thanks.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D63082/new/

https://reviews.llvm.org/D63082