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Fix #686: Add warning for bad line directives #687

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Merged
glankk merged 20 commits into from
Jul 24, 2026
+445 −124
Merged

Fix #686: Add warning for bad line directives #687

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40b8f3d
686
glankk Jul 22, 2026
be6e79e
Fix warnings
glankk Jul 22, 2026
a1240b3
Fix tests
glankk Jul 22, 2026
e5ecbd4
Fix formatting
glankk Jul 22, 2026
d4f1c1f
Fix clang-tidy issues
glankk Jul 22, 2026
036b59d
Add range, support type, and standard in error messages
glankk Jul 22, 2026
3ee1302
Fix getCStdName
glankk Jul 22, 2026
b33c236
Fix warnings
glankk Jul 22, 2026
d9fbdcd
Fix clang-tidy issues
glankk Jul 22, 2026
b9a7613
Fix formatting
glankk Jul 22, 2026
9642334
Fix formatting
glankk Jul 22, 2026
40a815f
Fix formatting
glankk Jul 22, 2026
0cca41f
Add syntax error for signed line numbers
glankk Jul 22, 2026
23ab6e7
Update simplecpp.cpp
glankk Jul 23, 2026
d3f8a97
Address PR comments
glankk Jul 23, 2026
a3c9318
Update simplecpp.cpp
glankk Jul 23, 2026
25988a1
Fix compilation errors
glankk Jul 23, 2026
f2bd340
Revert changes to getCStd and getCppStd
glankk Jul 23, 2026
2f1fd82
Limit line numbers to Location::line max value
glankk Jul 23, 2026
b9309c3
Fix warnings
glankk Jul 23, 2026
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9 changes: 5 additions & 4 deletions main.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -224,7 +224,7 @@ int main(int argc, char **argv)
{
simplecpp::TokenList *rawtokens;
if (toklist_inf == Fstream) {
rawtokens = new simplecpp::TokenList(f,files,filename,&outputList);
rawtokens = new simplecpp::TokenList(f,files,filename,dui,&outputList);
}
else if (toklist_inf == Sstream || toklist_inf == CharBuffer) {
std::ostringstream oss;
Expand All @@ -233,14 +233,14 @@ int main(int argc, char **argv)
const std::string s = oss.str();
if (toklist_inf == Sstream) {
std::istringstream iss(s);
rawtokens = new simplecpp::TokenList(iss,files,filename,&outputList);
rawtokens = new simplecpp::TokenList(iss,files,filename,dui,&outputList);
}
else {
rawtokens = new simplecpp::TokenList({s.data(),s.size()},files,filename,&outputList);
rawtokens = new simplecpp::TokenList({s.data(),s.size()},files,filename,dui,&outputList);
}
} else {
f.close();
rawtokens = new simplecpp::TokenList(filename,files,&outputList);
rawtokens = new simplecpp::TokenList(filename,files,dui,&outputList);
}
rawtokens->removeComments();
simplecpp::FileDataCache filedata;
Expand Down Expand Up @@ -276,6 +276,7 @@ int main(int argc, char **argv)
std::cerr << "directive as macro parameter: ";
break;
case simplecpp::Output::PORTABILITY_BACKSLASH:
case simplecpp::Output::PORTABILITY_LINE_DIRECTIVE:
std::cerr << "portability: ";
break;
case simplecpp::Output::PORTABILITY_NO_EOF_NEWLINE:
Expand Down
103 changes: 94 additions & 9 deletions simplecpp.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -475,26 +475,26 @@ namespace {

simplecpp::TokenList::TokenList(std::vector<std::string> &filenames) : frontToken(nullptr), backToken(nullptr), files(filenames) {}

simplecpp::TokenList::TokenList(std::istream &istr, std::vector<std::string> &filenames, const std::string &filename, OutputList *outputList)
simplecpp::TokenList::TokenList(std::istream &istr, std::vector<std::string> &filenames, const std::string &filename, const DUI &dui, OutputList *outputList)
: frontToken(nullptr), backToken(nullptr), files(filenames)
{
StdIStream stream(istr);
readfile(stream,filename,outputList);
readfile(stream,filename,dui,outputList);
}

simplecpp::TokenList::TokenList(const unsigned char* data, std::size_t size, std::vector<std::string> &filenames, const std::string &filename, OutputList *outputList, int /*unused*/)
simplecpp::TokenList::TokenList(const unsigned char* data, std::size_t size, std::vector<std::string> &filenames, const std::string &filename, const DUI &dui, OutputList *outputList, int /*unused*/)
: frontToken(nullptr), backToken(nullptr), files(filenames)
{
StdCharBufStream stream(data, size);
readfile(stream,filename,outputList);
readfile(stream,filename,dui,outputList);
}

simplecpp::TokenList::TokenList(const std::string &filename, std::vector<std::string> &filenames, OutputList *outputList)
simplecpp::TokenList::TokenList(const std::string &filename, std::vector<std::string> &filenames, const DUI &dui, OutputList *outputList)
: frontToken(nullptr), backToken(nullptr), files(filenames)
{
try {
FileStream stream(filename, filenames);
readfile(stream,filename,outputList);
readfile(stream,filename,dui,outputList);
} catch (const simplecpp::Output & e) {
outputList->emplace_back(e);
}
Expand Down Expand Up @@ -659,13 +659,16 @@ void simplecpp::TokenList::lineDirective(unsigned int fileIndex_, unsigned int l

static const std::string COMMENT_END("*/");

void simplecpp::TokenList::readfile(Stream &stream, const std::string &filename, OutputList *outputList)
void simplecpp::TokenList::readfile(Stream &stream, const std::string &filename, const DUI &dui, OutputList *outputList)
{
unsigned int multiline = 0U;
bool trailing_nl = true;

const Token *oldLastToken = nullptr;

const cstd_t cstd = getCStd(dui.std);
const cppstd_t cppstd = getCppStd(dui.std);

Location location(fileIndex(filename), 1, 1);
while (stream.good()) {
unsigned char ch = stream.readChar();
Expand Down Expand Up @@ -727,10 +730,63 @@ void simplecpp::TokenList::readfile(Stream &stream, const std::string &filename,
if (ppTok->str() == "line")
ppTok = advanceAndSkipComments(ppTok);

if (ppTok && (ppTok->str()[0] == '-' || ppTok->str()[0] == '+')) {
if (outputList) {
simplecpp::Output err{
simplecpp::Output::SYNTAX_ERROR,
location,
"Invalid character in line directive: '" + ppTok->str() + "'."
};
outputList->emplace_back(std::move(err));
}
clear();
return;
}

if (!ppTok || !ppTok->number)
continue;

const unsigned int line = std::atol(ppTok->str().c_str());
unsigned long line;
try {
line = std::stoul(ppTok->str());
} catch (...) {
line = std::numeric_limits<unsigned long>::max();

@danmar danmar Jul 23, 2026

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this value might not work well.. it means tokens might get line number 0 which cppcheck interprets as "no line".

I suggest that the value passed in the lineDirective call will be 1. After reporting the error message.. change it to 1?

@danmar danmar Jul 23, 2026

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or assign maxvalue+1?

@glankk glankk Jul 23, 2026

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Sounds good.

@glankk glankk Jul 23, 2026

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Actually it might be better that we just ignore the line number and use the current one when it's out of range, what do you think?

@glankk glankk Jul 23, 2026

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Or just discard the line directive entirely.

@danmar danmar Jul 23, 2026

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I would be fine with both those options.

@glankk glankk Jul 23, 2026

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I've changed it to just use the maximum possible line number, I think that's alright. It's guaranteed to always be representable, and it's also the most lenient option in terms of conditional support.

}

unsigned long maxline;
if ((cstd != CUnknown && cstd < C99) || (cppstd != CPPUnknown && cppstd < CPP11))
maxline = 32767;
else
maxline = 2147483647;

if (line == 0 || line > maxline) {
if (outputList) {
const bool unknown_std = cstd == CUnknown && cppstd == CPPUnknown;
std::string msg = "Line number out of range: " + ppTok->str() + ". ";
if (line == 0) {
msg += "Line number zero is undefined behavior.";
} else {
msg += "Line numbers above " + std::to_string(maxline) + " are ";
if (unknown_std)
msg += "undefined behavior or conditionally supported";
else if (cppstd >= CPP26)
msg += "conditionally supported";
else
msg += "undefined behavior";
if (cstd != CUnknown)
msg += std::string(" in ") + getCStdName(cstd);
else if (cppstd != CPPUnknown)
msg += std::string(" in ") + getCppStdName(cppstd);
msg += ".";
}
simplecpp::Output err{
simplecpp::Output::PORTABILITY_LINE_DIRECTIVE,
location, msg
};
outputList->emplace_back(std::move(err));
}
}

ppTok = advanceAndSkipComments(ppTok);

unsigned int fileindex;
Expand Down Expand Up @@ -3163,7 +3219,7 @@ std::pair<simplecpp::FileData *, bool> simplecpp::FileDataCache::tryload(FileDat
return {id_it->second, false};
}

auto *const data = new FileData {path, TokenList(path, filenames, outputList)};
auto *const data = new FileData {path, TokenList(path, filenames, {}, outputList)};

if (dui.removeComments)
data->tokens.removeComments();
Expand Down Expand Up @@ -3987,6 +4043,20 @@ simplecpp::cstd_t simplecpp::getCStd(const std::string &std)
return CUnknown;
}

const char *simplecpp::getCStdName(cstd_t std)
{
switch (std) {
case CUnknown: return "C";
case C89: return "C89";
case C99: return "C99";
case C11: return "C11";
case C17: return "C17";
case C23: return "C23";
case C2Y: return "C2Y";
}
return "";
}

std::string simplecpp::getCStdString(cstd_t std)
{
switch (std) {
Expand Down Expand Up @@ -4039,6 +4109,21 @@ simplecpp::cppstd_t simplecpp::getCppStd(const std::string &std)
return CPPUnknown;
}

const char *simplecpp::getCppStdName(cppstd_t std)
{
switch (std) {
case CPPUnknown: return "C++";
case CPP03: return "C++03";
case CPP11: return "C++11";
case CPP14: return "C++14";
case CPP17: return "C++17";
case CPP20: return "C++20";
case CPP23: return "C++23";
case CPP26: return "C++26";
}
return "";
}

std::string simplecpp::getCppStdString(cppstd_t std)
{
switch (std) {
Expand Down
73 changes: 40 additions & 33 deletions simplecpp.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -249,6 +249,7 @@ namespace simplecpp {
SYNTAX_ERROR,
DIRECTIVE_AS_MACRO_PARAMETER,
PORTABILITY_BACKSLASH,
PORTABILITY_LINE_DIRECTIVE,
PORTABILITY_NO_EOF_NEWLINE,
UNHANDLED_CHAR_ERROR,
EXPLICIT_INCLUDE_NOT_FOUND,
Expand All @@ -262,52 +263,67 @@ namespace simplecpp {

using OutputList = std::list<Output>;

/**
* Command line preprocessor settings.
* On the command line these are configured by -D, -U, -I, --include, -std
*/
struct SIMPLECPP_LIB DUI {
DUI() = default;
std::list<std::string> defines;
std::set<std::string> undefined;
std::list<std::string> includePaths;
std::list<std::string> includes;
std::string std;
bool clearIncludeCache{};
bool removeComments{}; /** remove comment tokens from included files */
};

/** List of tokens. */
class SIMPLECPP_LIB TokenList {
public:
class Stream;

explicit TokenList(std::vector<std::string> &filenames);
/** generates a token list from the given std::istream parameter */
TokenList(std::istream &istr, std::vector<std::string> &filenames, const std::string &filename=std::string(), OutputList *outputList = nullptr);
TokenList(std::istream &istr, std::vector<std::string> &filenames, const std::string &filename=std::string(), const DUI &dui = {}, OutputList *outputList = nullptr);
/** generates a token list from the given buffer */
template<size_t size>
TokenList(const char (&data)[size], std::vector<std::string> &filenames, const std::string &filename=std::string(), OutputList *outputList = nullptr)
: TokenList(reinterpret_cast<const unsigned char*>(data), size-1, filenames, filename, outputList, 0)
TokenList(const char (&data)[size], std::vector<std::string> &filenames, const std::string &filename=std::string(), const DUI &dui = {}, OutputList *outputList = nullptr)
: TokenList(reinterpret_cast<const unsigned char*>(data), size-1, filenames, filename, dui, outputList, 0)
{}
/** generates a token list from the given buffer */
template<size_t size>
TokenList(const unsigned char (&data)[size], std::vector<std::string> &filenames, const std::string &filename=std::string(), OutputList *outputList = nullptr)
: TokenList(data, size-1, filenames, filename, outputList, 0)
TokenList(const unsigned char (&data)[size], std::vector<std::string> &filenames, const std::string &filename=std::string(), const DUI &dui = {}, OutputList *outputList = nullptr)
: TokenList(data, size-1, filenames, filename, dui, outputList, 0)
{}
#if SIMPLECPP_TOKENLIST_ALLOW_PTR
/** generates a token list from the given buffer */
TokenList(const unsigned char* data, std::size_t size, std::vector<std::string> &filenames, const std::string &filename=std::string(), OutputList *outputList = nullptr)
: TokenList(data, size, filenames, filename, outputList, 0)
TokenList(const unsigned char* data, std::size_t size, std::vector<std::string> &filenames, const std::string &filename=std::string(), const DUI &dui = {}, OutputList *outputList = nullptr)
: TokenList(data, size, filenames, filename, dui, outputList, 0)
{}
/** generates a token list from the given buffer */
TokenList(const char* data, std::size_t size, std::vector<std::string> &filenames, const std::string &filename=std::string(), OutputList *outputList = nullptr)
: TokenList(reinterpret_cast<const unsigned char*>(data), size, filenames, filename, outputList, 0)
TokenList(const char* data, std::size_t size, std::vector<std::string> &filenames, const std::string &filename=std::string(), const DUI &dui = {}, OutputList *outputList = nullptr)
: TokenList(reinterpret_cast<const unsigned char*>(data), size, filenames, filename, dui, outputList, 0)
{}
#endif // SIMPLECPP_TOKENLIST_ALLOW_PTR
/** generates a token list from the given buffer */
TokenList(View data, std::vector<std::string> &filenames, const std::string &filename=std::string(), OutputList *outputList = nullptr)
: TokenList(reinterpret_cast<const unsigned char*>(data.data()), data.size(), filenames, filename, outputList, 0)
TokenList(View data, std::vector<std::string> &filenames, const std::string &filename=std::string(), const DUI &dui = {}, OutputList *outputList = nullptr)
: TokenList(reinterpret_cast<const unsigned char*>(data.data()), data.size(), filenames, filename, dui, outputList, 0)
{}
#ifdef __cpp_lib_span
/** generates a token list from the given buffer */
TokenList(std::span<const char> data, std::vector<std::string> &filenames, const std::string &filename=std::string(), OutputList *outputList = nullptr)
: TokenList(reinterpret_cast<const unsigned char*>(data.data()), data.size(), filenames, filename, outputList, 0)
TokenList(std::span<const char> data, std::vector<std::string> &filenames, const std::string &filename=std::string(), const DUI &dui = {}, OutputList *outputList = nullptr)
: TokenList(reinterpret_cast<const unsigned char*>(data.data()), data.size(), filenames, filename, dui, outputList, 0)
{}

/** generates a token list from the given buffer */
TokenList(std::span<const unsigned char> data, std::vector<std::string> &filenames, const std::string &filename=std::string(), OutputList *outputList = nullptr)
: TokenList(data.data(), data.size(), filenames, filename, outputList, 0)
TokenList(std::span<const unsigned char> data, std::vector<std::string> &filenames, const std::string &filename=std::string(), const DUI &dui = {}, OutputList *outputList = nullptr)
: TokenList(data.data(), data.size(), filenames, filename, dui, outputList, 0)
{}
#endif // __cpp_lib_span

/** generates a token list from the given filename parameter */
TokenList(const std::string &filename, std::vector<std::string> &filenames, OutputList *outputList = nullptr);
TokenList(const std::string &filename, std::vector<std::string> &filenames, const DUI &dui = {}, OutputList *outputList = nullptr);
TokenList(const TokenList &other);
TokenList(TokenList &&other);
~TokenList();
Expand All @@ -323,7 +339,7 @@ namespace simplecpp {
void dump(bool linenrs = false) const;
std::string stringify(bool linenrs = false) const;

void readfile(Stream &stream, const std::string &filename=std::string(), OutputList *outputList = nullptr);
void readfile(Stream &stream, const std::string &filename=std::string(), const DUI &dui = {}, OutputList *outputList = nullptr);
/**
* @throws std::overflow_error thrown on overflow or division by zero
* @throws std::runtime_error thrown on invalid expressions
Expand Down Expand Up @@ -387,7 +403,7 @@ namespace simplecpp {
const std::string& file(const Location& loc) const;

private:
TokenList(const unsigned char* data, std::size_t size, std::vector<std::string> &filenames, const std::string &filename, OutputList *outputList, int /*unused*/);
TokenList(const unsigned char* data, std::size_t size, std::vector<std::string> &filenames, const std::string &filename, const DUI &dui, OutputList *outputList, int /*unused*/);

void combineOperators();

Expand Down Expand Up @@ -436,21 +452,6 @@ namespace simplecpp {
long long result; // condition result
};

/**
* Command line preprocessor settings.
* On the command line these are configured by -D, -U, -I, --include, -std
*/
struct SIMPLECPP_LIB DUI {
DUI() = default;
std::list<std::string> defines;
std::set<std::string> undefined;
std::list<std::string> includePaths;
std::list<std::string> includes;
std::string std;
bool clearIncludeCache{};
bool removeComments{}; /** remove comment tokens from included files */
};

struct SIMPLECPP_LIB FileData {
/** The canonical filename associated with this data */
std::string filename;
Expand Down Expand Up @@ -589,9 +590,15 @@ namespace simplecpp {
/** Returns the C version a given standard */
SIMPLECPP_LIB cstd_t getCStd(const std::string &std);

/** Returns the name of a C standard */
SIMPLECPP_LIB const char *getCStdName(cstd_t std);

/** Returns the C++ version a given standard */
SIMPLECPP_LIB cppstd_t getCppStd(const std::string &std);

/** Returns the name of a C++ standard */
SIMPLECPP_LIB const char *getCppStdName(cppstd_t std);

/** Returns the __STDC_VERSION__ value for a given standard */
SIMPLECPP_LIB std::string getCStdString(const std::string &std);
SIMPLECPP_LIB std::string getCStdString(cstd_t std);
Expand Down
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