diff --git a/lib/exprengine.cpp b/lib/exprengine.cpp index d646ec5b8..c1095a8c4 100644 --- a/lib/exprengine.cpp +++ b/lib/exprengine.cpp @@ -2669,6 +2669,10 @@ static std::string execute(const Token *start, const Token *end, Data &data) data.assignValue(tok, varid, loopValues); tok = tok->linkAt(1); loopValues->loopScope = tok->next()->scope(); + // Check whether the condition expression is always false + if (tok->next() && (initValue > lastValue)) { + tok = tok->next()->link(); + } continue; } } diff --git a/test/testexprengine.cpp b/test/testexprengine.cpp index daabd2bf9..42fbc5dd2 100644 --- a/test/testexprengine.cpp +++ b/test/testexprengine.cpp @@ -79,6 +79,7 @@ private: TEST_CASE(switch2); TEST_CASE(for1); + TEST_CASE(forAlwaysFalse1); TEST_CASE(while1); TEST_CASE(while2); @@ -660,6 +661,22 @@ private: expr(code, "==")); } + void forAlwaysFalse1() { + const char code[] = "int f() {\n" + " int a = 19;\n" + " for (int i = 0; i < 0; i++)\n" + " a += 8;\n" + " for (int i = 0; i < 1; i++)\n" + " a += 23;\n" + " for (int i = 100; i >= 1; i--)\n" + " a += 23;\n" + " return a == 42;\n" + "}"; + const char expected[] = "(and (>= $4 (- 2147483648)) (<= $4 2147483647))\n" + "(= (+ $4 23) 42)\n" + "z3::sat\n"; + ASSERT_EQUALS(expected, expr(code, "==")); + } void while1() { const char code[] = "void f(int y) {\n"