[debugserver] Fix "control may reach end of non-void function" warnings.

[jasonmolenda]

Hm, won't we get some compiler warning about how there aren't default: cases for these switch statements? :) This change is fine if it helps eliminate unhelpful warnings.

[brucem]

It doesn't create new warnings in the cmake build (which appears to have a lot more warnings enabled than the xcode build). I'm trying to slowly work towards zero warnings in the OS X cmake build.

This shouldn't generate new warnings though since it is checking for numerical values rather than something like an enumeration where it can make sure the range of the value is covered by the switch statement's cases. (Which is another set of warnings to address...)

[jasonmolenda]

Good point. Thanks for doing this.

tools/debugserver/source/MacOSX/i386/DNBArchImplI386.cpp

size_and_rw_bits(nub_size_t size, bool read, bool write)
     case 1:
         return rw;
     case 2:
         return (0x1 << 2) | rw;
     case 4:
         return (0x3 << 2) | rw;
     case 8:
         return (0x2 << 2) | rw;
-    default:
-        assert(0 && "invalid size, must be one of 1, 2, 4, or 8");
     }    
+    assert(0 && "invalid size, must be one of 1, 2, 4, or 8");
+    return 0;
 }
+
 void
 DNBArchImplI386::SetWatchpoint(DBG &debug_state, uint32_t hw_index, nub_addr_t addr, nub_size_t size, bool read, bool write)
 {
     // Set both dr7 (debug control register) and dri (debug address register).
     
     // dr7{7-0} encodes the local/gloabl enable bits:
     //  global enable --. .-- local enable
     //                  | |
DNBArchImplI386::GetWatchAddress(const DBG &debug_state, uint32_t hw_index)
     case 0:
         return debug_state.__dr0;
     case 1:
         return debug_state.__dr1;
     case 2:
         return debug_state.__dr2;
     case 3:
         return debug_state.__dr3;
-    default:
-        assert(0 && "invalid hardware register index, must be one of 0, 1, 2, or 3");
     }
+    assert(0 && "invalid hardware register index, must be one of 0, 1, 2, or 3");
+    return 0;
 }
 
 bool
 DNBArchImplI386::StartTransForHWP()
 {
     if (m_2pc_trans_state != Trans_Done && m_2pc_trans_state != Trans_Rolled_Back)
         DNBLogError ("%s inconsistent state detected, expected %d or %d, got: %d", __FUNCTION__, Trans_Done, Trans_Rolled_Back, m_2pc_trans_state);
     m_2pc_dbg_checkpoint = m_state.context.dbg;

tools/debugserver/source/MacOSX/x86_64/DNBArchImplX86_64.cpp

size_and_rw_bits(nub_size_t size, bool read, bool write)
     case 1:
         return rw;
     case 2:
         return (0x1 << 2) | rw;
     case 4:
         return (0x3 << 2) | rw;
     case 8:
         return (0x2 << 2) | rw;
-    default:
-        assert(0 && "invalid size, must be one of 1, 2, 4, or 8");
     }    
+    assert(0 && "invalid size, must be one of 1, 2, 4, or 8");
+    return 0;
 }
 void
 DNBArchImplX86_64::SetWatchpoint(DBG &debug_state, uint32_t hw_index, nub_addr_t addr, nub_size_t size, bool read, bool write)
 {
     // Set both dr7 (debug control register) and dri (debug address register).
     
     // dr7{7-0} encodes the local/gloabl enable bits:
     //  global enable --. .-- local enable
DNBArchImplX86_64::GetWatchAddress(const DBG &debug_state, uint32_t hw_index)
     case 0:
         return debug_state.__dr0;
     case 1:
         return debug_state.__dr1;
     case 2:
         return debug_state.__dr2;
     case 3:
         return debug_state.__dr3;
-    default:
-        assert(0 && "invalid hardware register index, must be one of 0, 1, 2, or 3");
     }
+    assert(0 && "invalid hardware register index, must be one of 0, 1, 2, or 3");
+    return 0;
 }
 
 bool
 DNBArchImplX86_64::StartTransForHWP()
 {
     if (m_2pc_trans_state != Trans_Done && m_2pc_trans_state != Trans_Rolled_Back)
         DNBLogError ("%s inconsistent state detected, expected %d or %d, got: %d", __FUNCTION__, Trans_Done, Trans_Rolled_Back, m_2pc_trans_state);
     m_2pc_dbg_checkpoint = m_state.context.dbg;