From 5915ea929c43d61e77b68b64bc91d8709f5c9876 Mon Sep 17 00:00:00 2001 From: Christopher Grant Date: Mon, 4 Nov 2019 21:34:20 -0500 Subject: Add fallthrough annotations on new C++ switches A recent commit converted some source from C to C++. Chrome has checks against unannotated switch case fallthroughs in C++ code, so the converted source needs annotations. Bug: 990190 Change-Id: Ib92435b4877be936f837928a70b552ec4975d42a Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/1898429 Reviewed-by: Mark Mentovai Reviewed-by: Mike Frysinger --- src/common/convert_UTF.cc | 79 ++++++++++++++++++++++++++++++++--------------- src/common/macros.h | 45 +++++++++++++++++++++++++++ 2 files changed, 99 insertions(+), 25 deletions(-) create mode 100644 src/common/macros.h (limited to 'src/common') diff --git a/src/common/convert_UTF.cc b/src/common/convert_UTF.cc index fed04e78..fe0e1556 100644 --- a/src/common/convert_UTF.cc +++ b/src/common/convert_UTF.cc @@ -60,6 +60,8 @@ See the header file "ConvertUTF.h" for complete documentation. #include #endif +#include "common/macros.h" + namespace google_breakpad { namespace { @@ -295,10 +297,20 @@ ConversionResult ConvertUTF16toUTF8 (const UTF16** sourceStart, const UTF16* sou target -= bytesToWrite; result = targetExhausted; break; } switch (bytesToWrite) { /* note: everything falls through. */ - case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; - case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; - case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; - case 1: *--target = (UTF8)(ch | firstByteMark[bytesToWrite]); + case 4: + *--target = (UTF8)((ch | byteMark) & byteMask); + ch >>= 6; + BP_FALLTHROUGH; + case 3: + *--target = (UTF8)((ch | byteMark) & byteMask); + ch >>= 6; + BP_FALLTHROUGH; + case 2: + *--target = (UTF8)((ch | byteMark) & byteMask); + ch >>= 6; + BP_FALLTHROUGH; + case 1: + *--target = (UTF8)(ch | firstByteMark[bytesToWrite]); } target += bytesToWrite; } @@ -327,9 +339,14 @@ Boolean isLegalUTF8(const UTF8 *source, int length) { switch (length) { default: return false; /* Everything else falls through when "true"... */ - case 4: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; - case 3: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; - case 2: if ((a = (*--srcptr)) > 0xBF) return false; + case 4: + if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; + BP_FALLTHROUGH; + case 3: + if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; + BP_FALLTHROUGH; + case 2: + if ((a = (*--srcptr)) > 0xBF) return false; switch (*source) { /* no fall-through in this inner switch */ @@ -339,8 +356,8 @@ Boolean isLegalUTF8(const UTF8 *source, int length) { case 0xF4: if (a > 0x8F) return false; break; default: if (a < 0x80) return false; } - - case 1: if (*source >= 0x80 && *source < 0xC2) return false; + BP_FALLTHROUGH; + case 1: if (*source >= 0x80 && *source < 0xC2) return false; } if (*source > 0xF4) return false; return true; @@ -384,12 +401,14 @@ ConversionResult ConvertUTF8toUTF16 (const UTF8** sourceStart, const UTF8* sourc * The cases all fall through. See "Note A" below. */ switch (extraBytesToRead) { - case 5: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */ - case 4: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */ - case 3: ch += *source++; ch <<= 6; - case 2: ch += *source++; ch <<= 6; - case 1: ch += *source++; ch <<= 6; - case 0: ch += *source++; + /* remember, illegal UTF-8 */ + case 5: ch += *source++; ch <<= 6; BP_FALLTHROUGH; + /* remember, illegal UTF-8 */ + case 4: ch += *source++; ch <<= 6; BP_FALLTHROUGH; + case 3: ch += *source++; ch <<= 6; BP_FALLTHROUGH; + case 2: ch += *source++; ch <<= 6; BP_FALLTHROUGH; + case 1: ch += *source++; ch <<= 6; BP_FALLTHROUGH; + case 0: ch += *source++; } ch -= offsetsFromUTF8[extraBytesToRead]; @@ -474,10 +493,20 @@ ConversionResult ConvertUTF32toUTF8 (const UTF32** sourceStart, const UTF32* sou target -= bytesToWrite; result = targetExhausted; break; } switch (bytesToWrite) { /* note: everything falls through. */ - case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; - case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; - case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; - case 1: *--target = (UTF8) (ch | firstByteMark[bytesToWrite]); + case 4: + *--target = (UTF8)((ch | byteMark) & byteMask); + ch >>= 6; + BP_FALLTHROUGH; + case 3: + *--target = (UTF8)((ch | byteMark) & byteMask); + ch >>= 6; + BP_FALLTHROUGH; + case 2: + *--target = (UTF8)((ch | byteMark) & byteMask); + ch >>= 6; + BP_FALLTHROUGH; + case 1: + *--target = (UTF8) (ch | firstByteMark[bytesToWrite]); } target += bytesToWrite; } @@ -508,12 +537,12 @@ ConversionResult ConvertUTF8toUTF32 (const UTF8** sourceStart, const UTF8* sourc * The cases all fall through. See "Note A" below. */ switch (extraBytesToRead) { - case 5: ch += *source++; ch <<= 6; - case 4: ch += *source++; ch <<= 6; - case 3: ch += *source++; ch <<= 6; - case 2: ch += *source++; ch <<= 6; - case 1: ch += *source++; ch <<= 6; - case 0: ch += *source++; + case 5: ch += *source++; ch <<= 6; BP_FALLTHROUGH; + case 4: ch += *source++; ch <<= 6; BP_FALLTHROUGH; + case 3: ch += *source++; ch <<= 6; BP_FALLTHROUGH; + case 2: ch += *source++; ch <<= 6; BP_FALLTHROUGH; + case 1: ch += *source++; ch <<= 6; BP_FALLTHROUGH; + case 0: ch += *source++; } ch -= offsetsFromUTF8[extraBytesToRead]; diff --git a/src/common/macros.h b/src/common/macros.h new file mode 100644 index 00000000..14bb3f7b --- /dev/null +++ b/src/common/macros.h @@ -0,0 +1,45 @@ +// Copyright (c) 2019, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#ifndef BREAKPAD_COMMON_MACROS_H_ +#define BREAKPAD_COMMON_MACROS_H_ + +// Ensure that this macro definition stays in a private header file: clang +// suggests the first macro expanding to [[clang::fallthrough]] in its +// diagnostics, so if BP_FALLTHROUGH is visible in code depending on breakpad, +// clang would suggest BP_FALLTHROUGH for code depending on breakpad, instead of +// the client code's own fallthrough macro. +// TODO(thakis): Once everyone uses C++17, use its [[fallthrough]] instead. +#if defined(__clang__) +#define BP_FALLTHROUGH [[clang::fallthrough]] +#else +#define BP_FALLTHROUGH +#endif + +#endif // BREAKPAD_COMMON_MACROS_H_ -- cgit v1.2.1