Infinite loop in parser due to using tok::annot_repl_input_end instead of tok::eof #541
Description
- [X ] Checked for duplicates
Describe the bug
$ bin/cling
****************** CLING ******************
* Type C++ code and press enter to run it *
* Type .q to exit *
*******************************************
[cling]$ void (*test)() = [](){ if }
input_line_3:2:28: error: expected '(' after 'if'
void (*test)() = [](){ if }
^
input_line_3:4:2: error: expected ';' at end of declaration
}
^
;
<<< cling interactive line includer >>>:1:1: error: expected expression
^
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
<<< cling interactive line includer >>>:1:1: error: expected expression
fatal error: too many errors emitted, stopping now [-ferror-limit=]
The Parser is stuck in
StmtResult Parser::ParseCompoundStatementBody(bool isStmtExpr)
because there's a while loop that expects eof, but we're at annot_repl_input_end
while (!tryParseMisplacedModuleImport() && Tok.isNot(tok::r_brace) &&
Tok.isNot(tok::eof)) {
if (Tok.is(tok::annot_pragma_unused)) {
HandlePragmaUnused();
continue;
}
....
This turns into an infinite loop because it never encounters eof. I wonder if you guys are planning a general pattern to handle this thing without invasive modifications to llvm, or if there is some other general strategy. I'm a bit at a loss how to fix the bug in the optimal way, perhaps you guys can explain the best way to proceed.
This is not a bug in current released version of root, so I report it here instead of root repo.
Grepping through llvm, I see a lot of these kind of lines that don't seem to take annot_repl_input_end into account:
$ git grep isNot\(tok\:\:eof\)
...
clang/lib/Parse/ParseCXXInlineMethods.cpp: if (Tok.isNot(tok::eof) || Tok.getEofData() != Param) {
clang/lib/Parse/ParseCXXInlineMethods.cpp: while (Tok.isNot(tok::eof))
clang/lib/Parse/ParseCXXInlineMethods.cpp: if (Tok.isNot(tok::eof) || Tok.getEofData() != LM.Method)
clang/lib/Parse/ParseCXXInlineMethods.cpp: while (Tok.isNot(tok::eof))
clang/lib/Parse/ParseCXXInlineMethods.cpp: while (Tok.isNot(tok::eof))
clang/lib/Parse/ParseCXXInlineMethods.cpp: while (Tok.isNot(tok::eof))
clang/lib/Parse/ParseCXXInlineMethods.cpp: while (Tok.isNot(tok::eof))
clang/lib/Parse/ParseCXXInlineMethods.cpp: if (Tok.isNot(tok::eof)) {
clang/lib/Parse/ParseCXXInlineMethods.cpp: while (Tok.isNot(tok::eof))
clang/lib/Parse/ParseCXXInlineMethods.cpp: while (Tok.isNot(tok::eof))
clang/lib/Parse/ParseDecl.cpp: Tok.isNot(tok::eof)) {
clang/lib/Parse/ParseDecl.cpp: (Tok.isNot(tok::eof) || Tok.getEofData() != TypeStr.data())) {
clang/lib/Parse/ParseDecl.cpp: while (Tok.isNot(tok::eof))
clang/lib/Parse/ParseDeclCXX.cpp: Tok.isNot(tok::eof)) {
clang/lib/Parse/ParseDeclCXX.cpp: Tok.isNot(tok::eof)) {
clang/lib/Parse/ParseDeclCXX.cpp: Tok.isNot(tok::eof)) {
clang/lib/Parse/ParseExprCXX.cpp: while (Tok.isNot(tok::eof))
clang/lib/Parse/ParseHLSL.cpp: while (Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof)) {
clang/lib/Parse/ParseObjc.cpp: while (Tok.getLocation() != OrigLoc && Tok.isNot(tok::eof))
clang/lib/Parse/ParseOpenMP.cpp: while (Cnt && Tok.isNot(tok::eof)) {
clang/lib/Parse/ParsePragma.cpp: while (Tok.isNot(tok::eof))
clang/lib/Parse/ParsePragma.cpp: if (Tok.isNot(tok::eof)) {
clang/lib/Parse/ParsePragma.cpp: if (Tok.isNot(tok::eof)) {
clang/lib/Parse/ParsePragma.cpp: while (Tok.isNot(tok::eof))
clang/lib/Parse/ParsePragma.cpp: if (Tok.isNot(tok::eof)) {
clang/lib/Parse/ParsePragma.cpp: while (Tok.isNot(tok::eof))
clang/lib/Parse/ParsePragma.cpp: if (Tok.isNot(tok::eof)) {
clang/lib/Parse/ParsePragma.cpp: while (Tok.isNot(tok::eof))
clang/lib/Parse/ParsePragma.cpp: if (Tok.isNot(tok::eof)) {
clang/lib/Parse/ParsePragma.cpp: while (Tok.isNot(tok::eod) && Tok.isNot(tok::eof)) {
clang/lib/Parse/ParseStmt.cpp: Tok.isNot(tok::eof)) {
clang/lib/Parse/Parser.cpp: while (Tok.isNot(tok::eof))
...
Expected behavior
Not hang in infinite loop
To Reproduce
See description
Setup
Latest cling in GitHub: commit 1d49255 (tag: __internal-root-4bcc5846f4e5c29d70e8f72029ec308c460671b7, upstream/master)
cling-latest llvm: commit 72c4df7523d41a5502e4a53b0999a6844ceb16e8 (HEAD, tag: cling-llvm18-20250117-01, origin/cling-llvm18, origin/cling-latest)