[clang-tools-extra] r213156 - [clang-tidy] Also emit a warning for memset(x, 0, 0)
Benjamin Kramer
benny.kra at googlemail.com
Wed Jul 16 07:42:46 PDT 2014
Author: d0k
Date: Wed Jul 16 09:42:43 2014
New Revision: 213156
URL: http://llvm.org/viewvc/llvm-project?rev=213156&view=rev
Log:
[clang-tidy] Also emit a warning for memset(x, 0, 0)
It doesn't make sense to suggest swapping the arguments here but it's
still useless code
Modified:
clang-tools-extra/trunk/clang-tidy/google/MemsetZeroLengthCheck.cpp
clang-tools-extra/trunk/test/clang-tidy/google-memset-zero-length.cpp
Modified: clang-tools-extra/trunk/clang-tidy/google/MemsetZeroLengthCheck.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/google/MemsetZeroLengthCheck.cpp?rev=213156&r1=213155&r2=213156&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/google/MemsetZeroLengthCheck.cpp (original)
+++ clang-tools-extra/trunk/clang-tidy/google/MemsetZeroLengthCheck.cpp Wed Jul 16 09:42:43 2014
@@ -57,13 +57,17 @@ void MemsetZeroLengthCheck::check(const
const Expr *Arg2 = Call->getArg(2);
// Try to evaluate the second argument so we can also find values that are not
- // just literals. We don't emit a warning if the second argument also
- // evaluates to zero.
+ // just literals.
llvm::APSInt Value1, Value2;
- if (!Arg2->EvaluateAsInt(Value2, *Result.Context) || Value2 != 0 ||
- (Arg1->EvaluateAsInt(Value1, *Result.Context) && Value1 == 0))
+ if (!Arg2->EvaluateAsInt(Value2, *Result.Context) || Value2 != 0)
return;
+ // If both arguments evaluate to zero emit a warning without fix suggestions.
+ if (Arg1->EvaluateAsInt(Value1, *Result.Context) && Value1 == 0) {
+ diag(Call->getLocStart(), "memset of size zero");
+ return;
+ }
+
// Emit a warning and fix-its to swap the arguments.
auto D = diag(Call->getLocStart(),
"memset of size zero, potentially swapped arguments");
Modified: clang-tools-extra/trunk/test/clang-tidy/google-memset-zero-length.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/google-memset-zero-length.cpp?rev=213156&r1=213155&r2=213156&view=diff
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/google-memset-zero-length.cpp (original)
+++ clang-tools-extra/trunk/test/clang-tidy/google-memset-zero-length.cpp Wed Jul 16 09:42:43 2014
@@ -46,6 +46,8 @@ void foo(void *a, int xsize, int ysize)
memset(a, -1, sizeof(int));
memset(a, 0xcd, 1);
memset(a, v, 0);
+// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: memset of size zero
+// CHECK-FIXES: memset(a, v, 0);
memtmpl<0>();
}
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