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[flang] Rework preprocessor fix for replacement in kind suffixes (#135406)

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Recent work to better handle macro replacement in literal constant kind
suffixes isn't handling fixed form well, leading to a crash in Fujitsu
test 0113/0113_0073.F. The look-ahead needs to be done with the
higher-level prescanner functions that skip over fixed form comment
fields after column 72. Rework.
This commit is contained in:
Peter Klausler 2025-04-14 08:59:28 -07:00 committed by GitHub
parent da6f493d4a
commit dba757a33c
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GPG Key ID: B5690EEEBB952194
2 changed files with 44 additions and 33 deletions
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72
flang/lib/Parser/prescan.cpp
View File

@ -891,51 +891,57 @@ bool Prescanner::HandleExponent(TokenSequence &tokens) {
if (char ed{ToLowerCaseLetter(*at_)}; ed == 'e' || ed == 'd') { if (char ed{ToLowerCaseLetter(*at_)}; ed == 'e' || ed == 'd') {
// Do some look-ahead to ensure that this 'e'/'d' is an exponent, // Do some look-ahead to ensure that this 'e'/'d' is an exponent,
// not the start of an identifier that could be a macro. // not the start of an identifier that could be a macro.
const char *p{SkipWhiteSpace(at_ + 1)}; const char *startAt{at_};
if (*p == '+' || *p == '-') { int startColumn{column_};
p = SkipWhiteSpace(p + 1); TokenSequence possible;
EmitCharAndAdvance(possible, *at_);
if (*at_ == '+' || *at_ == '-') {
EmitCharAndAdvance(possible, *at_);
} }
if (IsDecimalDigit(*p)) { // it's an exponent if (IsDecimalDigit(*at_)) { // it's an exponent; scan it
EmitCharAndAdvance(tokens, ed);
if (*at_ == '+' || *at_ == '-') {
EmitCharAndAdvance(tokens, *at_);
}
while (IsDecimalDigit(*at_)) { while (IsDecimalDigit(*at_)) {
EmitCharAndAdvance(tokens, *at_); EmitCharAndAdvance(possible, *at_);
} }
possible.CloseToken();
tokens.CloseToken();
tokens.Put(possible);
return true; return true;
} }
// Not an exponent; backtrack
at_ = startAt;
column_ = startColumn;
} }
return false; return false;
} }
bool Prescanner::HandleKindSuffix(TokenSequence &tokens) { bool Prescanner::HandleKindSuffix(TokenSequence &tokens) {
if (*at_ == '_' && IsLegalInIdentifier(at_[1])) { if (*at_ != '_') {
// The kind specifier might be a macro (with or without its leading
// underscore); put it into its own token if it has been defined.
const char *p{at_ + 1};
while (IsLegalInIdentifier(*++p)) {
}
if (CharBlock id{at_, static_cast<std::size_t>(p - at_)};
preprocessor_.IsNameDefined(id)) {
// In 1.0e0_foo, "_foo" is a defined name; retain the
// underscore
tokens.CloseToken();
} else {
EmitCharAndAdvance(tokens, '_');
if (CharBlock id{at_, static_cast<std::size_t>(p - at_)};
preprocessor_.IsNameDefined(id)) {
// In 1.0e0_foo, "foo" is a defined name
tokens.CloseToken();
}
}
while (IsLegalInIdentifier(*at_)) {
EmitCharAndAdvance(tokens, *at_);
}
return true;
} else {
return false; return false;
} }
TokenSequence withUnderscore, separate;
EmitChar(withUnderscore, '_');
EmitCharAndAdvance(separate, '_');
if (IsLegalInIdentifier(*at_)) {
separate.CloseToken();
EmitChar(withUnderscore, *at_);
EmitCharAndAdvance(separate, *at_);
while (IsLegalInIdentifier(*at_)) {
EmitChar(withUnderscore, *at_);
EmitCharAndAdvance(separate, *at_);
}
}
withUnderscore.CloseToken();
separate.CloseToken();
tokens.CloseToken();
if (separate.SizeInTokens() == 2 &&
preprocessor_.IsNameDefined(separate.TokenAt(1)) &&
!preprocessor_.IsNameDefined(withUnderscore.ToCharBlock())) {
// "_foo" is not defined, but "foo" is
tokens.Put(separate); // '_' "foo"
} else {
tokens.Put(withUnderscore); // "_foo"
}
return true;
} }
bool Prescanner::HandleExponentAndOrKindSuffix(TokenSequence &tokens) { bool Prescanner::HandleExponentAndOrKindSuffix(TokenSequence &tokens) {

5
flang/test/Preprocessing/bug518.F Normal file
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@ -0,0 +1,5 @@
! RUN: %flang -fc1 -fdebug-unparse %s 2>&1 | FileCheck %s
! CHECK: k=1_4
k= 1_99999999
&4
end