Fixed zerodiv FN for '1/std::ceil(0)'

cfg/std.cfg

@@ -965,7 +965,7 @@
   <function name="ceil,std::ceil">
     <use-retval/>
     <pure/>
-    <returnValue type="double"/>
+    <returnValue type="double">ceil(arg1)</returnValue>
     <noreturn>false</noreturn>
     <leak-ignore/>
     <arg nr="1" direction="in">
@@ -976,7 +976,7 @@
   <function name="ceilf,std::ceilf">
     <use-retval/>
     <pure/>
-    <returnValue type="float"/>
+    <returnValue type="float">ceil(arg1)</returnValue>
     <noreturn>false</noreturn>
     <leak-ignore/>
     <arg nr="1" direction="in">
@@ -987,7 +987,7 @@
   <function name="ceill,std::ceill">
     <use-retval/>
     <pure/>
-    <returnValue type="long double"/>
+    <returnValue type="long double">ceil(arg1)</returnValue>
     <noreturn>false</noreturn>
     <leak-ignore/>
     <arg nr="1" direction="in">

lib/programmemory.cpp

@@ -741,6 +741,17 @@ static std::unordered_map<std::string, BuiltinLibraryFunction> createBuiltinLibr
         v.valueType = ValueFlow::Value::ValueType::FLOAT;
         return v;
     };
+    functions["ceil"] = [](const std::vector<ValueFlow::Value>& args) {
+        if (args.size() != 1)
+            return ValueFlow::Value::unknown();
+        ValueFlow::Value v = args[0];
+        if (!v.isFloatValue() && !v.isIntValue())
+            return ValueFlow::Value::unknown();
+        double value = args[0].isFloatValue() ? args[0].floatValue : args[0].intvalue;
+        v.floatValue = std::ceil(value);
+        v.valueType = ValueFlow::Value::ValueType::FLOAT;
+        return v;
+    };
     functions["exp"] = [](const std::vector<ValueFlow::Value>& args) {
         if (args.size() != 1)
             return ValueFlow::Value::unknown();

test/cfg/std.cpp

@@ -36,6 +36,13 @@
 #include <iterator>
 #include <vector>
 
+int zerodiv_ceil()
+{
+    int i = std::ceil(0);
+    // cppcheck-suppress zerodiv
+    return 42 / i;
+}
+
 int zerodiv_sqrt()
 {
     int i = std::sqrt(0);