Enable -Wimplicit-fallthrough.
Falling through switch cases on a clang build must now annotate the fallthrough
with the FALLTHROUGH_INTENDED macro.
Bug: 17731372
Change-Id: I836451cd5f96b01d1ababdbf9eef677fe8fa8324
diff --git a/runtime/arch/x86/fault_handler_x86.cc b/runtime/arch/x86/fault_handler_x86.cc
index 17310b6..6715fd3 100644
--- a/runtime/arch/x86/fault_handler_x86.cc
+++ b/runtime/arch/x86/fault_handler_x86.cc
@@ -113,7 +113,7 @@
// Group 3
case 0x66:
operand_size_prefix = true;
- // fallthrough
+ FALLTHROUGH_INTENDED;
// Group 1
case 0xf0:
diff --git a/runtime/base/macros.h b/runtime/base/macros.h
index b66d528..f5a38bb 100644
--- a/runtime/base/macros.h
+++ b/runtime/base/macros.h
@@ -181,6 +181,48 @@
template<typename T> void UNUSED(const T&) {}
#define UNREACHABLE __builtin_unreachable
+// The FALLTHROUGH_INTENDED macro can be used to annotate implicit fall-through
+// between switch labels:
+// switch (x) {
+// case 40:
+// case 41:
+// if (truth_is_out_there) {
+// ++x;
+// FALLTHROUGH_INTENDED; // Use instead of/along with annotations in
+// // comments.
+// } else {
+// return x;
+// }
+// case 42:
+// ...
+//
+// As shown in the example above, the FALLTHROUGH_INTENDED macro should be
+// followed by a semicolon. It is designed to mimic control-flow statements
+// like 'break;', so it can be placed in most places where 'break;' can, but
+// only if there are no statements on the execution path between it and the
+// next switch label.
+//
+// When compiled with clang in C++11 mode, the FALLTHROUGH_INTENDED macro is
+// expanded to [[clang::fallthrough]] attribute, which is analysed when
+// performing switch labels fall-through diagnostic ('-Wimplicit-fallthrough').
+// See clang documentation on language extensions for details:
+// http://clang.llvm.org/docs/LanguageExtensions.html#clang__fallthrough
+//
+// When used with unsupported compilers, the FALLTHROUGH_INTENDED macro has no
+// effect on diagnostics.
+//
+// In either case this macro has no effect on runtime behavior and performance
+// of code.
+#if defined(__clang__) && __cplusplus >= 201103L && defined(__has_warning)
+#if __has_feature(cxx_attributes) && __has_warning("-Wimplicit-fallthrough")
+#define FALLTHROUGH_INTENDED [[clang::fallthrough]] // NOLINT
+#endif
+#endif
+
+#ifndef FALLTHROUGH_INTENDED
+#define FALLTHROUGH_INTENDED do { } while (0)
+#endif
+
// Annotalysis thread-safety analysis support.
#if defined(__SUPPORT_TS_ANNOTATION__) || defined(__clang__)
#define THREAD_ANNOTATION_ATTRIBUTE__(x) __attribute__((x))
diff --git a/runtime/check_jni.cc b/runtime/check_jni.cc
index bfe44a2..fec1824 100644
--- a/runtime/check_jni.cc
+++ b/runtime/check_jni.cc
@@ -1128,7 +1128,7 @@
*errorKind = "continuation";
return utf8;
}
- // Fall through to take care of the final byte.
+ FALLTHROUGH_INTENDED; // Fall-through to take care of the final byte.
case 0x0c:
case 0x0d:
// Bit pattern 110x, so there is one additional byte.
diff --git a/runtime/debugger.cc b/runtime/debugger.cc
index 96b44bf..c53f6b2 100644
--- a/runtime/debugger.cc
+++ b/runtime/debugger.cc
@@ -3504,6 +3504,7 @@
switch (tag) {
default:
LOG(FATAL) << "unknown JDWP tag: " << PrintableChar(tag);
+ UNREACHABLE();
// Primitives.
case JDWP::JT_BYTE: return 'B';
diff --git a/runtime/dex_file_verifier.cc b/runtime/dex_file_verifier.cc
index 0597253..a3f3de8 100644
--- a/runtime/dex_file_verifier.cc
+++ b/runtime/dex_file_verifier.cc
@@ -142,7 +142,7 @@
ErrorStringPrintf("Invalid use of void");
return false;
}
- // Intentional fallthrough.
+ FALLTHROUGH_INTENDED;
case 'B':
case 'C':
case 'D':
diff --git a/runtime/dex_instruction-inl.h b/runtime/dex_instruction-inl.h
index ad9491f..dd65f2c 100644
--- a/runtime/dex_instruction-inl.h
+++ b/runtime/dex_instruction-inl.h
@@ -460,11 +460,21 @@
* copies of those.) Note that cases 5..2 fall through.
*/
switch (count) {
- case 5: arg[4] = InstA(inst_data);
- case 4: arg[3] = (regList >> 12) & 0x0f;
- case 3: arg[2] = (regList >> 8) & 0x0f;
- case 2: arg[1] = (regList >> 4) & 0x0f;
- case 1: arg[0] = regList & 0x0f; break;
+ case 5:
+ arg[4] = InstA(inst_data);
+ FALLTHROUGH_INTENDED;
+ case 4:
+ arg[3] = (regList >> 12) & 0x0f;
+ FALLTHROUGH_INTENDED;
+ case 3:
+ arg[2] = (regList >> 8) & 0x0f;
+ FALLTHROUGH_INTENDED;
+ case 2:
+ arg[1] = (regList >> 4) & 0x0f;
+ FALLTHROUGH_INTENDED;
+ case 1:
+ arg[0] = regList & 0x0f;
+ break;
default: // case 0
break; // Valid, but no need to do anything.
}
diff --git a/runtime/dex_instruction.cc b/runtime/dex_instruction.cc
index 0a71d62..7e775f4 100644
--- a/runtime/dex_instruction.cc
+++ b/runtime/dex_instruction.cc
@@ -111,7 +111,7 @@
if ((*insns & 0xFF) == 0) {
return 1; // NOP.
} else {
- LOG(FATAL) << "Unreachable: " << DumpString(NULL);
+ LOG(FATAL) << "Unreachable: " << DumpString(nullptr);
return 0;
}
}
@@ -161,21 +161,23 @@
case k21c: {
switch (Opcode()) {
case CONST_STRING:
- if (file != NULL) {
+ if (file != nullptr) {
uint32_t string_idx = VRegB_21c();
os << StringPrintf("const-string v%d, %s // string@%d", VRegA_21c(),
PrintableString(file->StringDataByIdx(string_idx)).c_str(), string_idx);
break;
- } // else fall-through
+ }
+ FALLTHROUGH_INTENDED;
case CHECK_CAST:
case CONST_CLASS:
case NEW_INSTANCE:
- if (file != NULL) {
+ if (file != nullptr) {
uint32_t type_idx = VRegB_21c();
os << opcode << " v" << static_cast<int>(VRegA_21c()) << ", " << PrettyType(type_idx, *file)
<< " // type@" << type_idx;
break;
- } // else fall-through
+ }
+ FALLTHROUGH_INTENDED;
case SGET:
case SGET_WIDE:
case SGET_OBJECT:
@@ -183,12 +185,13 @@
case SGET_BYTE:
case SGET_CHAR:
case SGET_SHORT:
- if (file != NULL) {
+ if (file != nullptr) {
uint32_t field_idx = VRegB_21c();
os << opcode << " v" << static_cast<int>(VRegA_21c()) << ", " << PrettyField(field_idx, *file, true)
<< " // field@" << field_idx;
break;
- } // else fall-through
+ }
+ FALLTHROUGH_INTENDED;
case SPUT:
case SPUT_WIDE:
case SPUT_OBJECT:
@@ -196,12 +199,13 @@
case SPUT_BYTE:
case SPUT_CHAR:
case SPUT_SHORT:
- if (file != NULL) {
+ if (file != nullptr) {
uint32_t field_idx = VRegB_21c();
os << opcode << " v" << static_cast<int>(VRegA_21c()) << ", " << PrettyField(field_idx, *file, true)
<< " // field@" << field_idx;
break;
- } // else fall-through
+ }
+ FALLTHROUGH_INTENDED;
default:
os << StringPrintf("%s v%d, thing@%d", opcode, VRegA_21c(), VRegB_21c());
break;
@@ -221,20 +225,22 @@
case IGET_BYTE:
case IGET_CHAR:
case IGET_SHORT:
- if (file != NULL) {
+ if (file != nullptr) {
uint32_t field_idx = VRegC_22c();
os << opcode << " v" << static_cast<int>(VRegA_22c()) << ", v" << static_cast<int>(VRegB_22c()) << ", "
<< PrettyField(field_idx, *file, true) << " // field@" << field_idx;
break;
- } // else fall-through
+ }
+ FALLTHROUGH_INTENDED;
case IGET_QUICK:
case IGET_OBJECT_QUICK:
- if (file != NULL) {
+ if (file != nullptr) {
uint32_t field_idx = VRegC_22c();
os << opcode << " v" << static_cast<int>(VRegA_22c()) << ", v" << static_cast<int>(VRegB_22c()) << ", "
<< "// offset@" << field_idx;
break;
- } // else fall-through
+ }
+ FALLTHROUGH_INTENDED;
case IPUT:
case IPUT_WIDE:
case IPUT_OBJECT:
@@ -242,34 +248,38 @@
case IPUT_BYTE:
case IPUT_CHAR:
case IPUT_SHORT:
- if (file != NULL) {
+ if (file != nullptr) {
uint32_t field_idx = VRegC_22c();
os << opcode << " v" << static_cast<int>(VRegA_22c()) << ", v" << static_cast<int>(VRegB_22c()) << ", "
<< PrettyField(field_idx, *file, true) << " // field@" << field_idx;
break;
- } // else fall-through
+ }
+ FALLTHROUGH_INTENDED;
case IPUT_QUICK:
case IPUT_OBJECT_QUICK:
- if (file != NULL) {
+ if (file != nullptr) {
uint32_t field_idx = VRegC_22c();
os << opcode << " v" << static_cast<int>(VRegA_22c()) << ", v" << static_cast<int>(VRegB_22c()) << ", "
<< "// offset@" << field_idx;
break;
- } // else fall-through
+ }
+ FALLTHROUGH_INTENDED;
case INSTANCE_OF:
- if (file != NULL) {
+ if (file != nullptr) {
uint32_t type_idx = VRegC_22c();
os << opcode << " v" << static_cast<int>(VRegA_22c()) << ", v" << static_cast<int>(VRegB_22c()) << ", "
<< PrettyType(type_idx, *file) << " // type@" << type_idx;
break;
}
+ FALLTHROUGH_INTENDED;
case NEW_ARRAY:
- if (file != NULL) {
+ if (file != nullptr) {
uint32_t type_idx = VRegC_22c();
os << opcode << " v" << static_cast<int>(VRegA_22c()) << ", v" << static_cast<int>(VRegB_22c()) << ", "
<< PrettyType(type_idx, *file) << " // type@" << type_idx;
break;
- } // else fall-through
+ }
+ FALLTHROUGH_INTENDED;
default:
os << StringPrintf("%s v%d, v%d, thing@%d", opcode, VRegA_22c(), VRegB_22c(), VRegC_22c());
break;
@@ -283,7 +293,7 @@
case k31c:
if (Opcode() == CONST_STRING_JUMBO) {
uint32_t string_idx = VRegB_31c();
- if (file != NULL) {
+ if (file != nullptr) {
os << StringPrintf("%s v%d, %s // string@%d", opcode, VRegA_31c(),
PrintableString(file->StringDataByIdx(string_idx)).c_str(),
string_idx);
@@ -317,7 +327,7 @@
case INVOKE_DIRECT:
case INVOKE_STATIC:
case INVOKE_INTERFACE:
- if (file != NULL) {
+ if (file != nullptr) {
os << opcode << " {";
uint32_t method_idx = VRegB_35c();
for (size_t i = 0; i < VRegA_35c(); ++i) {
@@ -328,9 +338,10 @@
}
os << "}, " << PrettyMethod(method_idx, *file) << " // method@" << method_idx;
break;
- } // else fall-through
+ }
+ FALLTHROUGH_INTENDED;
case INVOKE_VIRTUAL_QUICK:
- if (file != NULL) {
+ if (file != nullptr) {
os << opcode << " {";
uint32_t method_idx = VRegB_35c();
for (size_t i = 0; i < VRegA_35c(); ++i) {
@@ -341,7 +352,8 @@
}
os << "}, // vtable@" << method_idx;
break;
- } // else fall-through
+ }
+ FALLTHROUGH_INTENDED;
default:
os << opcode << " {v" << arg[0] << ", v" << arg[1] << ", v" << arg[2]
<< ", v" << arg[3] << ", v" << arg[4] << "}, thing@" << VRegB_35c();
@@ -356,19 +368,21 @@
case INVOKE_DIRECT_RANGE:
case INVOKE_STATIC_RANGE:
case INVOKE_INTERFACE_RANGE:
- if (file != NULL) {
+ if (file != nullptr) {
uint32_t method_idx = VRegB_3rc();
os << StringPrintf("%s, {v%d .. v%d}, ", opcode, VRegC_3rc(), (VRegC_3rc() + VRegA_3rc() - 1))
<< PrettyMethod(method_idx, *file) << " // method@" << method_idx;
break;
- } // else fall-through
+ }
+ FALLTHROUGH_INTENDED;
case INVOKE_VIRTUAL_RANGE_QUICK:
- if (file != NULL) {
+ if (file != nullptr) {
uint32_t method_idx = VRegB_3rc();
os << StringPrintf("%s, {v%d .. v%d}, ", opcode, VRegC_3rc(), (VRegC_3rc() + VRegA_3rc() - 1))
<< "// vtable@" << method_idx;
break;
- } // else fall-through
+ }
+ FALLTHROUGH_INTENDED;
default:
os << StringPrintf("%s, {v%d .. v%d}, thing@%d", opcode, VRegC_3rc(),
(VRegC_3rc() + VRegA_3rc() - 1), VRegB_3rc());
diff --git a/runtime/gc/allocator/rosalloc.cc b/runtime/gc/allocator/rosalloc.cc
index a3408cf..0cea89d 100644
--- a/runtime/gc/allocator/rosalloc.cc
+++ b/runtime/gc/allocator/rosalloc.cc
@@ -507,13 +507,12 @@
--pm_idx;
DCHECK_LT(pm_idx, capacity_ / kPageSize);
} while (page_map_[pm_idx] != kPageMapRun);
- // Fall-through.
+ FALLTHROUGH_INTENDED;
case kPageMapRun:
run = reinterpret_cast<Run*>(base_ + pm_idx * kPageSize);
DCHECK_EQ(run->magic_num_, kMagicNum);
break;
case kPageMapReleased:
- // Fall-through.
case kPageMapEmpty:
LOG(FATAL) << "Unreachable - page map type: " << page_map_[pm_idx];
return 0;
@@ -2138,7 +2137,7 @@
break;
}
}
- // Fall through.
+ FALLTHROUGH_INTENDED;
}
case kPageMapLargeObject: // Fall through.
case kPageMapLargeObjectPart: // Fall through.
diff --git a/runtime/hprof/hprof.cc b/runtime/hprof/hprof.cc
index fd67197..a2d37b3 100644
--- a/runtime/hprof/hprof.cc
+++ b/runtime/hprof/hprof.cc
@@ -719,9 +719,9 @@
case 'D': ret = hprof_basic_double; size = 8; break;
case 'B': ret = hprof_basic_byte; size = 1; break;
case 'S': ret = hprof_basic_short; size = 2; break;
- default: CHECK(false);
case 'I': ret = hprof_basic_int; size = 4; break;
case 'J': ret = hprof_basic_long; size = 8; break;
+ default: LOG(FATAL) << "UNREACHABLE"; UNREACHABLE();
}
if (sizeOut != NULL) {
@@ -742,9 +742,9 @@
case Primitive::kPrimDouble: ret = hprof_basic_double; size = 8; break;
case Primitive::kPrimByte: ret = hprof_basic_byte; size = 1; break;
case Primitive::kPrimShort: ret = hprof_basic_short; size = 2; break;
- default: CHECK(false);
case Primitive::kPrimInt: ret = hprof_basic_int; size = 4; break;
case Primitive::kPrimLong: ret = hprof_basic_long; size = 8; break;
+ default: LOG(FATAL) << "UNREACHABLE"; UNREACHABLE();
}
if (sizeOut != NULL) {
diff --git a/runtime/native/java_lang_reflect_Field.cc b/runtime/native/java_lang_reflect_Field.cc
index d166be0..7f5a611 100644
--- a/runtime/native/java_lang_reflect_Field.cc
+++ b/runtime/native/java_lang_reflect_Field.cc
@@ -268,6 +268,7 @@
break;
}
// Else fall through to report an error.
+ FALLTHROUGH_INTENDED;
case Primitive::kPrimVoid:
// Never okay.
ThrowIllegalArgumentException(nullptr, StringPrintf("Not a primitive field: %s",