DCHECK: Reference condition parameter in release builds

So that caller's won't get warnings about unused variables for
variables that are only used in calls to DCHECK, such as

  int x = ...
  DCHECK_EQ(x, 17);

R=andrew@webrtc.org

Previously committed: https://code.google.com/p/webrtc/source/detail?r=7858
and reverted: https://code.google.com/p/webrtc/source/detail?r=7859

Review URL: https://webrtc-codereview.appspot.com/31169004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7869 4adac7df-926f-26a2-2b94-8c16560cd09d
This commit is contained in:
kwiberg@webrtc.org 2014-12-11 08:32:30 +00:00
parent cd5b209d68
commit 55d42c32a4
2 changed files with 20 additions and 14 deletions

View File

@ -71,9 +71,14 @@ namespace rtc {
#define LAZY_STREAM(stream, condition) \
!(condition) ? static_cast<void>(0) : rtc::FatalMessageVoidify() & (stream)
// The actual stream used isn't important.
#define EAT_STREAM_PARAMETERS \
true ? static_cast<void>(0) \
// The actual stream used isn't important. We reference condition in the code
// but don't evaluate it; this is to avoid "unused variable" warnings (we do so
// in a particularly convoluted way with an extra ?: because that appears to be
// the simplest construct that keeps Visual Studio from complaining about
// condition being unused).
#define EAT_STREAM_PARAMETERS(condition) \
(true ? true : !(condition)) \
? static_cast<void>(0) \
: rtc::FatalMessageVoidify() & rtc::FatalMessage("", 0).stream()
// CHECK dies with a fatal error if condition is not true. It is *not*
@ -159,8 +164,9 @@ DEFINE_CHECK_OP_IMPL(GT, > )
#define CHECK_GE(val1, val2) CHECK_OP(GE, >=, val1, val2)
#define CHECK_GT(val1, val2) CHECK_OP(GT, > , val1, val2)
// The DCHECK macro is equivalent to CHECK except that it only generates code in
// debug builds.
// The DCHECK macro is equivalent to CHECK except that it only generates code
// in debug builds. It does reference the condition parameter in all cases,
// though, so callers won't risk getting warnings about unused variables.
#if (!defined(NDEBUG) || defined(DCHECK_ALWAYS_ON))
#define DCHECK(condition) CHECK(condition)
#define DCHECK_EQ(v1, v2) CHECK_EQ(v1, v2)
@ -170,13 +176,13 @@ DEFINE_CHECK_OP_IMPL(GT, > )
#define DCHECK_GE(v1, v2) CHECK_GE(v1, v2)
#define DCHECK_GT(v1, v2) CHECK_GT(v1, v2)
#else
#define DCHECK(condition) EAT_STREAM_PARAMETERS
#define DCHECK_EQ(v1, v2) EAT_STREAM_PARAMETERS
#define DCHECK_NE(v1, v2) EAT_STREAM_PARAMETERS
#define DCHECK_LE(v1, v2) EAT_STREAM_PARAMETERS
#define DCHECK_LT(v1, v2) EAT_STREAM_PARAMETERS
#define DCHECK_GE(v1, v2) EAT_STREAM_PARAMETERS
#define DCHECK_GT(v1, v2) EAT_STREAM_PARAMETERS
#define DCHECK(condition) EAT_STREAM_PARAMETERS(condition)
#define DCHECK_EQ(v1, v2) EAT_STREAM_PARAMETERS((v1) == (v2))
#define DCHECK_NE(v1, v2) EAT_STREAM_PARAMETERS((v1) != (v2))
#define DCHECK_LE(v1, v2) EAT_STREAM_PARAMETERS((v1) <= (v2))
#define DCHECK_LT(v1, v2) EAT_STREAM_PARAMETERS((v1) < (v2))
#define DCHECK_GE(v1, v2) EAT_STREAM_PARAMETERS((v1) >= (v2))
#define DCHECK_GT(v1, v2) EAT_STREAM_PARAMETERS((v1) > (v2))
#endif
// This is identical to LogMessageVoidify but in name.

View File

@ -60,7 +60,7 @@ bool AudioEncoderIlbc::EncodeInternal(uint32_t timestamp,
EncodedInfo* info) {
const size_t expected_output_len =
num_10ms_frames_per_packet_ == 2 ? 38 : 50;
CHECK_GE(max_encoded_bytes, expected_output_len);
DCHECK_GE(max_encoded_bytes, expected_output_len);
// Save timestamp if starting a new packet.
if (num_10ms_frames_buffered_ == 0)