diff --git a/lib/forwardanalyzer.cpp b/lib/forwardanalyzer.cpp index dbdb63901..aa54f245d 100644 --- a/lib/forwardanalyzer.cpp +++ b/lib/forwardanalyzer.cpp @@ -374,10 +374,23 @@ struct ForwardTraversal { Token* endBlock, Token* condTok, Token* initTok = nullptr, - Token* stepTok = nullptr) { + Token* stepTok = nullptr, + bool exit = false) { if (initTok && updateRecursive(initTok) == Progress::Break) return Break(); const bool isDoWhile = precedes(endBlock, condTok); + bool checkThen = true; + bool checkElse = false; + if (condTok && !Token::simpleMatch(condTok, ":")) + std::tie(checkThen, checkElse) = evalCond(condTok, isDoWhile ? endBlock->link()->previous() : nullptr); + if (checkElse && exit) + return Progress::Continue; + // do while(false) is not really a loop + if (checkElse && isDoWhile) { + if (updateRange(endBlock->link(), endBlock) == Progress::Break) + return Break(); + return updateRecursive(condTok); + } Analyzer::Action bodyAnalysis = analyzeScope(endBlock); Analyzer::Action allAnalysis = bodyAnalysis; if (condTok) @@ -392,14 +405,11 @@ struct ForwardTraversal { if (!analyzer->lowerToPossible()) return Break(Analyzer::Terminate::Bail); } - bool checkThen = true; - bool checkElse = false; + if (condTok && !Token::simpleMatch(condTok, ":")) { if (!isDoWhile || (!bodyAnalysis.isModified() && !bodyAnalysis.isIdempotent())) if (updateRecursive(condTok) == Progress::Break) return Break(); - // TODO: Check cond first before lowering - std::tie(checkThen, checkElse) = evalCond(condTok, isDoWhile ? endBlock->link()->previous() : nullptr); } // condition is false, we don't enter the loop if (checkElse) @@ -442,6 +452,15 @@ struct ForwardTraversal { return Progress::Continue; } + Progress updateLoopExit(const Token* endToken, + Token* endBlock, + Token* condTok, + Token* initTok = nullptr, + Token* stepTok = nullptr) + { + return updateLoop(endToken, endBlock, condTok, initTok, stepTok, true); + } + Progress updateScope(Token* endBlock) { if (forked) analyzer->forkScope(endBlock); @@ -528,7 +547,7 @@ struct ForwardTraversal { } else if (scope->type == Scope::eLambda) { return Break(); } else if (scope->type == Scope::eDo && Token::simpleMatch(tok, "} while (")) { - if (updateLoop(end, tok, tok->tokAt(2)->astOperand2()) == Progress::Break) + if (updateLoopExit(end, tok, tok->tokAt(2)->astOperand2()) == Progress::Break) return Break(); tok = tok->linkAt(2); } else if (Token::simpleMatch(tok->next(), "else {")) { diff --git a/test/testnullpointer.cpp b/test/testnullpointer.cpp index 1df8354da..dbfb28acd 100644 --- a/test/testnullpointer.cpp +++ b/test/testnullpointer.cpp @@ -114,6 +114,7 @@ private: TEST_CASE(nullpointer71); // #10178 TEST_CASE(nullpointer72); // #10215 TEST_CASE(nullpointer73); // #10321 + TEST_CASE(nullpointer74); TEST_CASE(nullpointer_addressOf); // address of TEST_CASE(nullpointerSwitch); // #2626 TEST_CASE(nullpointer_cast); // #4692 @@ -2289,6 +2290,45 @@ private: ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:10]: (warning) Either the condition 'ptr!=nullptr' is redundant or there is possible null pointer dereference: ptr.\n", errout.str()); } + void nullpointer74() { + check("struct d {\n" + " d* e();\n" + "};\n" + "void g(d* f) {\n" + " do {\n" + " f = f->e();\n" + " if (f) {}\n" + " } while (0);\n" + "}\n"); + ASSERT_EQUALS("", errout.str()); + + check("struct d {\n" + " d* e();\n" + "};\n" + "void g(d* f, int i) {\n" + " do {\n" + " i--;\n" + " f = f->e();\n" + " if (f) {}\n" + " } while (i > 0);\n" + "}\n"); + ASSERT_EQUALS( + "[test.cpp:8] -> [test.cpp:7]: (warning) Either the condition 'f' is redundant or there is possible null pointer dereference: f.\n", + errout.str()); + + check("struct d {\n" + " d* e();\n" + "};\n" + "void g(d* f, int i) {\n" + " do {\n" + " i--;\n" + " f = f->e();\n" + " if (f) {}\n" + " } while (f && i > 0);\n" + "}\n"); + ASSERT_EQUALS("", errout.str()); + } + void nullpointer_addressOf() { // address of check("void f() {\n" " struct X *x = 0;\n" diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp index 137dd5f4e..09c22a281 100644 --- a/test/testuninitvar.cpp +++ b/test/testuninitvar.cpp @@ -4845,6 +4845,17 @@ private: "}\n"); ASSERT_EQUALS("", errout.str()); + // #10326 + valueFlowUninit("void foo() {\n" + " int cnt;\n" + " do {\n" + " cnt = 32 ;\n" + " }\n" + " while ( 0 ) ;\n" + " if (cnt != 0) {}\n" + "}\n"); + ASSERT_EQUALS("", errout.str()); + // #10327 - avoid extra warnings for uninitialized variable valueFlowUninit("void dowork( int me ) {\n" " if ( me == 0 ) {}\n" // <- not uninitialized