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Fix #14195 Show warning when main() throws an exception #7887

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Merged
chrchr-github merged 10 commits into from
Oct 27, 2025
+66 −31
Merged

Fix #14195 Show warning when main() throws an exception #7887

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f6f8dc1
Update checkexceptionsafety.cpp
chrchr-github Oct 14, 2025
260532b
Update checkexceptionsafety.h
chrchr-github Oct 14, 2025
999350f
Update testexceptionsafety.cpp
chrchr-github Oct 14, 2025
a5e9287
Update checkexceptionsafety.cpp
chrchr-github Oct 14, 2025
e369865
Format
chrchr-github Oct 14, 2025
83217b8
Format
chrchr-github Oct 14, 2025
8fe787f
Update checkexceptionsafety.cpp
chrchr-github Oct 20, 2025
3269329
Update checkexceptionsafety.cpp
chrchr-github Oct 20, 2025
8ab4575
Add test
web-flow Oct 27, 2025
2133a5d
Improve error message
web-flow Oct 27, 2025
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36 changes: 20 additions & 16 deletions lib/checkexceptionsafety.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -296,32 +296,35 @@ void CheckExceptionSafety::nothrowThrows()
if (!function)
continue;

// check noexcept and noexcept(true) functions
if (function->isNoExcept()) {
const Token *throws = functionThrows(function);
if (throws)
noexceptThrowError(throws);
bool isNoExcept = false, isEntryPoint = false;
if (function->isNoExcept() || // noexcept and noexcept(true) functions
(function->isThrow() && !function->throwArg) || // throw() functions
function->isAttributeNothrow()) { // __attribute__((nothrow)) or __declspec(nothrow) functions
isNoExcept = true;
}

// check throw() functions
else if (function->isThrow() && !function->throwArg) {
const Token *throws = functionThrows(function);
if (throws)
noexceptThrowError(throws);
else if (mSettings->library.isentrypoint(function->name())) {
isEntryPoint = true;
}
if (!isNoExcept && !isEntryPoint)
continue;

// check __attribute__((nothrow)) or __declspec(nothrow) functions
else if (function->isAttributeNothrow()) {
const Token *throws = functionThrows(function);
if (throws)
if (const Token* throws = functionThrows(function)) {
if (isEntryPoint)
entryPointThrowError(throws);
else
noexceptThrowError(throws);
}
}
}

void CheckExceptionSafety::noexceptThrowError(const Token * const tok)
{
reportError(tok, Severity::error, "throwInNoexceptFunction", "Exception thrown in function declared not to throw exceptions.", CWE398, Certainty::normal);
reportError(tok, Severity::error, "throwInNoexceptFunction", "Unhandled exception thrown in function declared not to throw exceptions.", CWE398, Certainty::normal);
}

void CheckExceptionSafety::entryPointThrowError(const Token * const tok)
{
reportError(tok, Severity::error, "throwInEntryPoint", "Unhandled exception thrown in function that is an entry point.", CWE398, Certainty::normal);
}

//--------------------------------------------------------------------------
Expand Down Expand Up @@ -433,6 +436,7 @@ void CheckExceptionSafety::getErrorMessages(ErrorLogger *errorLogger, const Sett
c.rethrowCopyError(nullptr, "varname");
c.catchExceptionByValueError(nullptr);
c.noexceptThrowError(nullptr);
c.entryPointThrowError(nullptr);
c.unhandledExceptionSpecificationError(nullptr, nullptr, "funcname");
c.rethrowNoCurrentExceptionError(nullptr);
}
1 change: 1 addition & 0 deletions lib/checkexceptionsafety.h
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Original file line number Diff line number Diff line change
Expand Up @@ -82,6 +82,7 @@ class CPPCHECKLIB CheckExceptionSafety : public Check {
void rethrowCopyError(const Token * tok, const std::string &varname);
void catchExceptionByValueError(const Token *tok);
void noexceptThrowError(const Token * tok);
void entryPointThrowError(const Token * tok);
/** Missing exception specification */
void unhandledExceptionSpecificationError(const Token * tok1, const Token * tok2, const std::string & funcname);
/** Rethrow without currently handled exception */
Expand Down
60 changes: 45 additions & 15 deletions test/testexceptionsafety.cpp
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Expand Up @@ -57,6 +57,7 @@ class TestExceptionSafety : public TestFixture {
TEST_CASE(rethrowNoCurrentException2);
TEST_CASE(rethrowNoCurrentException3);
TEST_CASE(noFunctionCall);
TEST_CASE(entryPoint);
}

struct CheckOptions
Expand Down Expand Up @@ -86,7 +87,7 @@ class TestExceptionSafety : public TestFixture {
" }\n"
"};");
ASSERT_EQUALS("[test.cpp:3:9]: (warning) Class x is not safe, destructor throws exception [exceptThrowInDestructor]\n"
"[test.cpp:3:9]: (error) Exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());
"[test.cpp:3:9]: (error) Unhandled exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());

check("class x {\n"
" ~x();\n"
Expand All @@ -95,7 +96,7 @@ class TestExceptionSafety : public TestFixture {
" throw e;\n"
"}");
ASSERT_EQUALS("[test.cpp:5:5]: (warning) Class x is not safe, destructor throws exception [exceptThrowInDestructor]\n"
"[test.cpp:5:5]: (error) Exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());
"[test.cpp:5:5]: (error) Unhandled exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());

// #3858 - throwing exception in try block in destructor.
check("class x {\n"
Expand All @@ -115,7 +116,7 @@ class TestExceptionSafety : public TestFixture {
" }\n"
" }\n"
"}");
ASSERT_EQUALS("[test.cpp:4:13]: (error) Exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());
ASSERT_EQUALS("[test.cpp:4:13]: (error) Unhandled exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());

// #11031 should not warn when noexcept false
check("class A {\n"
Expand Down Expand Up @@ -348,9 +349,9 @@ class TestExceptionSafety : public TestFixture {
"void func4() noexcept(false) { throw 1; }\n"
"void func5() noexcept(true) { func1(); }\n"
"void func6() noexcept(false) { func1(); }");
ASSERT_EQUALS("[test.cpp:2:25]: (error) Exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n"
"[test.cpp:3:31]: (error) Exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n"
"[test.cpp:5:31]: (error) Exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());
ASSERT_EQUALS("[test.cpp:2:25]: (error) Unhandled exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n"
"[test.cpp:3:31]: (error) Unhandled exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n"
"[test.cpp:5:31]: (error) Unhandled exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());

// avoid false positives
check("const char *func() noexcept { return 0; }\n"
Expand All @@ -364,8 +365,8 @@ class TestExceptionSafety : public TestFixture {
"void func3() throw(int) { throw 1; }\n"
"void func4() throw() { func1(); }\n"
"void func5() throw(int) { func1(); }");
ASSERT_EQUALS("[test.cpp:2:24]: (error) Exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n"
"[test.cpp:4:24]: (error) Exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());
ASSERT_EQUALS("[test.cpp:2:24]: (error) Unhandled exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n"
"[test.cpp:4:24]: (error) Unhandled exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());

// avoid false positives
check("const char *func() throw() { return 0; }");
Expand Down Expand Up @@ -404,7 +405,7 @@ class TestExceptionSafety : public TestFixture {
"{\n"
" f();\n"
"}\n", dinit(CheckOptions, $.inconclusive = true));
ASSERT_EQUALS("", errout_str());
ASSERT_EQUALS("[test.cpp:4:5]: (error) Unhandled exception thrown in function that is an entry point. [throwInEntryPoint]\n", errout_str());
}

void unhandledExceptionSpecification3() {
Expand All @@ -421,20 +422,24 @@ class TestExceptionSafety : public TestFixture {
"}\n";

check(code, dinit(CheckOptions, $.inconclusive = true));
ASSERT_EQUALS("[test.cpp:3:5] -> [test.cpp:1:6]: (style, inconclusive) Unhandled exception specification when calling function f(). [unhandledExceptionSpecification]\n"
ASSERT_EQUALS("[test.cpp:10:5]: (error) Unhandled exception thrown in function that is an entry point. [throwInEntryPoint]\n"
"[test.cpp:3:5] -> [test.cpp:1:6]: (style, inconclusive) Unhandled exception specification when calling function f(). [unhandledExceptionSpecification]\n"
"[test.cpp:6:5] -> [test.cpp:1:6]: (style, inconclusive) Unhandled exception specification when calling function f(). [unhandledExceptionSpecification]\n", errout_str());

const Settings s = settingsBuilder().library("gnu.cfg").build();
check(code, dinit(CheckOptions, $.inconclusive = true, $.s = &s));
ASSERT_EQUALS("", errout_str());
ASSERT_EQUALS("[test.cpp:3:5]: (error) Unhandled exception thrown in function that is an entry point. [throwInEntryPoint]\n"
"[test.cpp:6:5]: (error) Unhandled exception thrown in function that is an entry point. [throwInEntryPoint]\n"
"[test.cpp:10:5]: (error) Unhandled exception thrown in function that is an entry point. [throwInEntryPoint]\n",
errout_str());
}

void nothrowAttributeThrow() {
check("void func1() throw(int) { throw 1; }\n"
"void func2() __attribute((nothrow)); void func2() { throw 1; }\n"
"void func3() __attribute((nothrow)); void func3() { func1(); }");
ASSERT_EQUALS("[test.cpp:2:53]: (error) Exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n"
"[test.cpp:3:53]: (error) Exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());
ASSERT_EQUALS("[test.cpp:2:53]: (error) Unhandled exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n"
"[test.cpp:3:53]: (error) Unhandled exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());

// avoid false positives
check("const char *func() __attribute((nothrow)); void func1() { return 0; }");
Expand All @@ -454,8 +459,8 @@ class TestExceptionSafety : public TestFixture {
check("void func1() throw(int) { throw 1; }\n"
"void __declspec(nothrow) func2() { throw 1; }\n"
"void __declspec(nothrow) func3() { func1(); }");
ASSERT_EQUALS("[test.cpp:2:36]: (error) Exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n"
"[test.cpp:3:36]: (error) Exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());
ASSERT_EQUALS("[test.cpp:2:36]: (error) Unhandled exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n"
"[test.cpp:3:36]: (error) Unhandled exception thrown in function declared not to throw exceptions. [throwInNoexceptFunction]\n", errout_str());

// avoid false positives
check("const char *func() __attribute((nothrow)); void func1() { return 0; }");
Expand Down Expand Up @@ -490,6 +495,31 @@ class TestExceptionSafety : public TestFixture {
"}\n");
ASSERT_EQUALS("", errout_str());
}

void entryPoint() {
check("void f(int i) {\n" // #14195
" if (i < 2)\n"
" throw 0;\n"
"}\n"
"int main(int argc, char* argv[]) {\n"
" f(argc);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:6:5]: (error) Unhandled exception thrown in function that is an entry point. [throwInEntryPoint]\n",
errout_str());

check("void f(int i) {\n"
" if (i < 2)\n"
" throw 0;\n"
"}\n"
"int main(int argc, char* argv[]) {\n"
" try {\n"
" f(argc);\n"
" } catch (...) {\n"
" return 1;\n"
" }\n"
"}\n");
ASSERT_EQUALS("", errout_str());
}
};

REGISTER_TEST(TestExceptionSafety)