Skip to content

Fix #653: defined() not recognizing ## token paste in its operand (GNU extension) #694

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
ludviggunne wants to merge 3 commits into
base: master
Choose a base branch
from
+43 −24
Open

Fix #653: defined() not recognizing ## token paste in its operand (GNU extension) #694

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
208326f
add test
ludviggunne Aug 5, 2026
ce06610
fix
ludviggunne Aug 5, 2026
e56a09a
fixes
ludviggunne Aug 5, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
55 changes: 31 additions & 24 deletions simplecpp.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2249,33 +2249,40 @@ namespace simplecpp {
}

if (tok->str() == DEFINED) {
const Token * const tok2 = tok->next;
const Token * const tok3 = tok2 ? tok2->next : nullptr;
const Token * const tok4 = tok3 ? tok3->next : nullptr;
const Token *defToken = nullptr;
const Token *lastToken = nullptr;
if (sameline(tok, tok4) && tok2->op == '(' && tok3->name && tok4->op == ')') {
defToken = tok3;
lastToken = tok4;
} else if (sameline(tok,tok2) && tok2->name) {
defToken = lastToken = tok2;
std::string macroName;
TokenList temp(files);
const Token *argTok = tok->next;
bool expectParen = false;
if (argTok->op == '(') {
argTok = argTok->next;
expectParen = true;
}
if (defToken) {
std::string macroName = defToken->str();
if (defToken->next && defToken->next->op == '#' && defToken->next->next && defToken->next->next->op == '#' && defToken->next->next->next && defToken->next->next->next->name && sameline(defToken,defToken->next->next->next)) {
TokenList temp(files);
if (expandArg(temp, defToken, parametertokens))
macroName = temp.cback()->str();
if (expandArg(temp, defToken->next->next->next, parametertokens))
macroName += temp.cback() ? temp.cback()->str() : "";
else
macroName += defToken->next->next->next->str();
lastToken = defToken->next->next->next;
while (argTok->name) {
if (expandArg(temp, argTok, parametertokens))

@danmar danmar Aug 5, 2026

Copy link
Copy Markdown
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I am not sure that we should expand macros unless they are operands. will this work:

#define x
#if defined(x)

the macroName will be empty string here now? and we will think that the condition is false?

@ludviggunne ludviggunne Aug 6, 2026

Copy link
Copy Markdown
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It works, it takes a different execution path.

macroName += temp.cback() ? temp.cback()->str() : "";
else
macroName += argTok->str();
argTok = argTok->next;
if (!sameline(tok, argTok))
break;
if (argTok->str() == "#") {
if (!argTok->next || argTok->next->str() != "#")
throw Error(argTok->location, "Expected '#'");
argTok = argTok->next->next;
Comment thread
ludviggunne marked this conversation as resolved.
if (!sameline(tok, argTok) || !argTok->name)
throw Error(argTok->location, "Expected name");
} else {
break;
}
const bool def = (macros.find(macroName) != macros.end());
output.push_back(newMacroToken(def ? "1" : "0", loc, true));
return lastToken->next;
}
if (expectParen) {
if (!sameline(tok, argTok) && argTok->op != ')')
throw Error(argTok->location, "Expected ')'");
argTok = argTok->next;
}
const bool def = (macros.find(macroName) != macros.end());
output.push_back(newMacroToken(def ? "1" : "0", loc, true));
return argTok;
}

output.push_back(newMacroToken(tok->str(), loc, true, tok));
Expand Down
12 changes: 12 additions & 0 deletions test.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2388,6 +2388,17 @@ static void ifDefinedHashHash2()
ASSERT_EQUALS("\n0", preprocess(code, &outputList));
}

static void ifDefinedHashHash3()
{
const char code[] = "#define ENABLED(x) (defined(x ## _ENABLED) && (x ## _ENABLED))\n"
"#define FOO_ENABLED 1\n"
"#if ENABLED(FOO)\n"
"int x;\n"
"#endif\n";
simplecpp::OutputList outputList;
ASSERT_EQUALS("\n\n\nint x ;", preprocess(code, &outputList));
}

static void ifLogical()
{
const char code[] = "#if defined(A) || defined(B)\n"
Expand Down Expand Up @@ -4701,6 +4712,7 @@ static void runTests(int argc, char **argv, Input input)
TEST_CASE(ifDefinedInvalid2);
TEST_CASE(ifDefinedHashHash);
TEST_CASE(ifDefinedHashHash2);
TEST_CASE(ifDefinedHashHash3);
TEST_CASE(ifLogical);
TEST_CASE(ifSizeof);
TEST_CASE(elif);
Expand Down
Loading