Skip to content

[flang] Support #if defined when no definitions #156080

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

Merged
merged 1 commit into from
Aug 29, 2025
Merged

[flang] Support #if defined when no definitions #156080

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
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
2 changes: 1 addition & 1 deletion flang/lib/Parser/preprocessor.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -414,7 +414,7 @@ std::optional<TokenSequence> Preprocessor::MacroReplacement(
const TokenSequence &input, Prescanner &prescanner,
std::optional<std::size_t> *partialFunctionLikeMacro, bool inIfExpression) {
// Do quick scan for any use of a defined name.
if (definitions_.empty()) {
if (!inIfExpression && definitions_.empty()) {
return std::nullopt;
}
std::size_t tokens{input.SizeInTokens()};
Expand Down
10 changes: 10 additions & 0 deletions flang/test/Preprocessing/no-pp-if.f90
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,10 @@
!RUN: %flang -fc1 -fdebug-unparse %s 2>&1 | FileCheck %s
!CHECK-NOT: ERROR STOP
!CHECK: CONTINUE
#if defined UNDEFINED
error stop
#endif
#if !defined UNDEFINED
continue
#endif
end