Fix sizeof for multiple array members (f'up to #12479) (#6081)

Author: chrchr-github

lib/valueflow.cpp

@@ -1116,11 +1116,10 @@ static size_t accumulateStructMembers(const Scope* scope, F f)
         if (const ValueType* vt = var.valueType()) {
             if (vt->type == ValueType::Type::RECORD && vt->typeScope == scope)
                 return 0;
-            total = f(total, *vt);
             const MathLib::bigint dim = std::accumulate(var.dimensions().cbegin(), var.dimensions().cend(), 1LL, [](MathLib::bigint i1, const Dimension& dim) {
                 return i1 * dim.num;
             });
-            total *= dim;
+            total = f(total, *vt, dim);
         }
         if (total == 0)
             return 0;
@@ -1149,7 +1148,7 @@ static size_t getAlignOf(const ValueType& vt, const Settings& settings)
         return align == 0 ? 0 : bitCeil(align);
     }
     if (vt.type == ValueType::Type::RECORD && vt.typeScope) {
-        return accumulateStructMembers(vt.typeScope, [&](size_t max, const ValueType& vt2) {
+        return accumulateStructMembers(vt.typeScope, [&](size_t max, const ValueType& vt2, size_t /*dim*/) {
             size_t a = getAlignOf(vt2, settings);
             return std::max(max, a);
         });
@@ -1187,11 +1186,12 @@ size_t ValueFlow::getSizeOf(const ValueType &vt, const Settings &settings)
     if (vt.type == ValueType::Type::LONGDOUBLE)
         return settings.platform.sizeof_long_double;
     if (vt.type == ValueType::Type::RECORD && vt.typeScope) {
-        size_t total = accumulateStructMembers(vt.typeScope, [&](size_t total, const ValueType& vt2) -> size_t {
+        size_t total = accumulateStructMembers(vt.typeScope, [&](size_t total, const ValueType& vt2, size_t dim) -> size_t {
             size_t n = ValueFlow::getSizeOf(vt2, settings);
             size_t a = getAlignOf(vt2, settings);
             if (n == 0 || a == 0)
                 return 0;
+            n *= dim;
             size_t padding = (a - (total % a)) % a;
             return total + padding + n;
         });

test/testvalueflow.cpp

@@ -1466,6 +1466,29 @@ class TestValueFlow : public TestFixture {
         values = tokenValues(code, "=");
         ASSERT_EQUALS(1U, values.size());
         ASSERT_EQUALS(4LL * 2 * 10, values.back().intvalue);
+
+        code = "struct S {\n"
+               "    int a[10];\n"
+               "    int b[20];\n"
+               "    int c[30];\n"
+               "};\n"
+               "void f() {\n"
+               "    x = sizeof(S);\n"
+               "}\n";
+        values = tokenValues(code, "=");
+        ASSERT_EQUALS(1U, values.size());
+        ASSERT_EQUALS(4LL * (10 + 20 + 30), values.back().intvalue);
+
+        code = "struct S {\n"
+               "    char c;\n"
+               "    int a[4];\n"
+               "};\n"
+               "void f() {\n"
+               "    x = sizeof(S);\n"
+               "}\n";
+        values = tokenValues(code, "=");
+        ASSERT_EQUALS(1U, values.size());
+        ASSERT_EQUALS(4LL * 5, values.back().intvalue);
     }
 
     void valueFlowComma()