Merge pull request #30351 from jbytheway/clang_tidy_divide_zero

Enable clang-analyzer-core.DivideZero check
CleverRaven · May 10, 2019 · 61dbeea · 61dbeea
2 parents 28edf73 + aa606c7
commit 61dbeea
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Showing 5 changed files with 30 additions and 12 deletions.
diff --git a/.clang-tidy b/.clang-tidy
@@ -1,4 +1,4 @@
-Checks: 'clang-diagnostic-*,-clang-analyzer-deadcode.DeadStores,-clang-analyzer-security.FloatLoopCounter,-clang-analyzer-core.UndefinedBinaryOperatorResult,-clang-analyzer-core.uninitialized.Assign,-clang-analyzer-cplusplus.NewDelete,-clang-analyzer-cplusplus.NewDeleteLeaks,-clang-analyzer-core.CallAndMessage,-clang-analyzer-core.NonNullParamChecker,-clang-analyzer-core.DivideZero,-clang-diagnostic-defaulted-function-deleted,-clang-analyzer-optin.cplusplus.VirtualCall'
+Checks: 'clang-diagnostic-*,-clang-analyzer-deadcode.DeadStores,-clang-analyzer-security.FloatLoopCounter,-clang-analyzer-core.UndefinedBinaryOperatorResult,-clang-analyzer-core.uninitialized.Assign,-clang-analyzer-cplusplus.NewDeleteLeaks,-clang-analyzer-core.CallAndMessage,-clang-analyzer-core.NonNullParamChecker,-clang-analyzer-optin.cplusplus.VirtualCall,-clang-analyzer-core.NullDereference'
 WarningsAsErrors: '*'
 HeaderFilterRegex: '.*'
 FormatStyle:     none

diff --git a/src/item.cpp b/src/item.cpp
@@ -597,12 +597,22 @@ item item::in_container( const itype_id &cont ) const
 
 long item::charges_per_volume( const units::volume &vol ) const
 {
-    if( type->volume == 0_ml ) {
-        return INFINITE_CHARGES; // TODO: items should not have 0 volume at all!
+    if( count_by_charges() ) {
+        if( type->volume == 0_ml ) {
+            debugmsg( "Item '%s' with zero volume", tname() );
+            return INFINITE_CHARGES;
+        }
+        // Type cast to prevent integer overflow with large volume containers like the cargo
+        // dimension
+        return vol * static_cast<int64_t>( type->stack_size ) / type->volume;
+    } else {
+        units::volume my_volume = volume();
+        if( my_volume == 0_ml ) {
+            debugmsg( "Item '%s' with zero volume", tname() );
+            return INFINITE_CHARGES;
+        }
+        return vol / my_volume;
     }
-    // Type cast to prevent integer overflow with large volume containers like the cargo dimension
-    return count_by_charges() ? vol * static_cast<int64_t>( type->stack_size ) / type->volume
-           : vol / volume();
 }
 
 bool item::stacks_with( const item &rhs, bool check_components ) const

diff --git a/src/mission_companion.cpp b/src/mission_companion.cpp
@@ -1849,11 +1849,11 @@ std::vector<comp_rank> talk_function::companion_rank( const std::vector<npc_ptr>
     }
 
     std::vector<comp_rank> adjusted;
-    for( auto entry : raw ) {
+    for( const auto &entry : raw ) {
         comp_rank r;
-        r.combat = 100 * entry.combat / max_combat;
-        r.survival = 100 * entry.survival / max_survival;
-        r.industry = 100 * entry.industry / max_industry;
+        r.combat = max_combat ? 100 * entry.combat / max_combat : 0;
+        r.survival = max_survival ? 100 * entry.survival / max_survival : 0;
+        r.industry = max_industry ? 100 * entry.industry / max_industry : 0;
         adjusted.push_back( r );
     }
     return adjusted;

diff --git a/src/veh_interact.cpp b/src/veh_interact.cpp
@@ -2595,7 +2595,7 @@ void veh_interact::count_durability()
         return lhs + rhs.base.max_damage();
     } );
 
-    int pct = 100 * qty / total;
+    int pct = total ? 100 * qty / total : 0;
 
     if( pct < 5 ) {
         total_durability_text = _( "like new" );

diff --git a/src/vehicle.cpp b/src/vehicle.cpp
@@ -2972,7 +2972,15 @@ int vehicle::consumption_per_hour( const itype_id &ftype, int fuel_rate_w ) cons
         // add 3600 seconds worth of fuel consumption for the engine
         // HACK - engines consume 1 second worth of fuel per turn, even though a turn is 6 seconds
         if( vslowdown > 0 ) {
-            amount_pct += 600 * vslowdown / acceleration( true, target_v );
+            int accel = acceleration( true, target_v );
+            if( accel == 0 ) {
+                // FIXME: Long-term plan is to change the fuel consumption
+                // computation entirely; for now just warn if this would
+                // otherwise have been division-by-zero
+                debugmsg( "Vehicle unexpectedly has zero acceleration" );
+            } else {
+                amount_pct += 600 * vslowdown / accel;
+            }
         }
     }
     int energy_j_per_mL = fuel.fuel_energy() * 1000;