commit fc787ecd91127b2c8458afd94e5148e2ae51a1f5
author Ian Rogers <irogers@google.com> Thu Oct 09 21:56:44 2014 -0700
committer Ian Rogers <irogers@google.com> Thu Oct 09 22:22:46 2014 -0700
tree ef48c0f511ee9bf4ed85607cc4d530bace7e6cae
parent 8fa8c904f7c783204a1dc9438429391d256658da

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

compiler/dex/quick/arm/assemble_arm.cc

diff --git a/compiler/dex/quick/arm/assemble_arm.cc b/compiler/dex/quick/arm/assemble_arm.cc
index cf34948..4e20d76 100644
--- a/compiler/dex/quick/arm/assemble_arm.cc
+++ b/compiler/dex/quick/arm/assemble_arm.cc
@@ -1265,7 +1265,7 @@
           if (lir->operands[1] != rs_r15pc.GetReg()) {
             break;
           }
-          // NOTE: intentional fallthrough.
+          FALLTHROUGH_INTENDED;
         case kFixupLoad: {
           /*
            * PC-relative loads are mostly used to load immediates

compiler/dex/quick/arm/int_arm.cc

diff --git a/compiler/dex/quick/arm/int_arm.cc b/compiler/dex/quick/arm/int_arm.cc
index 8f1261d..018dc1c 100644
--- a/compiler/dex/quick/arm/int_arm.cc
+++ b/compiler/dex/quick/arm/int_arm.cc
@@ -49,12 +49,13 @@
   int cond_bit = code & 1;
   int alt_bit = cond_bit ^ 1;
 
-  // Note: case fallthroughs intentional
   switch (strlen(guide)) {
     case 3:
       mask1 = (guide[2] == 'T') ? cond_bit : alt_bit;
+      FALLTHROUGH_INTENDED;
     case 2:
       mask2 = (guide[1] == 'T') ? cond_bit : alt_bit;
+      FALLTHROUGH_INTENDED;
     case 1:
       mask3 = (guide[0] == 'T') ? cond_bit : alt_bit;
       break;
@@ -62,6 +63,7 @@
       break;
     default:
       LOG(FATAL) << "OAT: bad case in OpIT";
+      UNREACHABLE();
   }
   mask = (mask3 << 3) | (mask2 << 2) | (mask1 << 1) |
        (1 << (3 - strlen(guide)));
@@ -77,12 +79,13 @@
   int cond_bit = code & 1;
   int alt_bit = cond_bit ^ 1;
 
-  // Note: case fallthroughs intentional
   switch (strlen(new_guide)) {
     case 3:
       mask1 = (new_guide[2] == 'T') ? cond_bit : alt_bit;
+      FALLTHROUGH_INTENDED;
     case 2:
       mask2 = (new_guide[1] == 'T') ? cond_bit : alt_bit;
+      FALLTHROUGH_INTENDED;
     case 1:
       mask3 = (new_guide[0] == 'T') ? cond_bit : alt_bit;
       break;
@@ -90,6 +93,7 @@
       break;
     default:
       LOG(FATAL) << "OAT: bad case in UpdateIT";
+      UNREACHABLE();
   }
   mask = (mask3 << 3) | (mask2 << 2) | (mask1 << 1) |
       (1 << (3 - strlen(new_guide)));

compiler/dex/quick/arm/utility_arm.cc

diff --git a/compiler/dex/quick/arm/utility_arm.cc b/compiler/dex/quick/arm/utility_arm.cc
index bba1a8c..e833c9a 100644
--- a/compiler/dex/quick/arm/utility_arm.cc
+++ b/compiler/dex/quick/arm/utility_arm.cc
@@ -494,7 +494,7 @@
           (value <= 1020) && ((value & 0x3) == 0)) {
         return NewLIR3(kThumbAddPcRel, r_dest.GetReg(), r_src1.GetReg(), value >> 2);
       }
-      // Note: intentional fallthrough
+      FALLTHROUGH_INTENDED;
     case kOpSub:
       if (all_low_regs && ((abs_value & 0x7) == abs_value)) {
         if (op == kOpAdd)