Make Preprocessor::Lex non-recursive.
Before this patch, Lex() would recurse whenever the current lexer changed (e.g.
upon entry into a macro). This patch turns the recursion into a loop: the
various lex routines now don't return a token when the current lexer changes,
and at the top level Preprocessor::Lex() now loops until it finds a token.
Normally, the recursion wouldn't end up being very deep, but the recursion depth
can explode in edge cases like a bunch of consecutive macros which expand to
nothing (like in the testcase test/Preprocessor/macro_expand_empty.c in this
patch).
<rdar://problem/14569770>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190980 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/VerifyDiagnosticConsumer.cpp b/lib/Frontend/VerifyDiagnosticConsumer.cpp
index f555529..045e60a 100644
--- a/lib/Frontend/VerifyDiagnosticConsumer.cpp
+++ b/lib/Frontend/VerifyDiagnosticConsumer.cpp
@@ -555,7 +555,7 @@
VerifyDiagnosticConsumer::DirectiveStatus Status =
VerifyDiagnosticConsumer::HasNoDirectives;
while (Tok.isNot(tok::eof)) {
- RawLex.Lex(Tok);
+ RawLex.LexFromRawLexer(Tok);
if (!Tok.is(tok::comment)) continue;
std::string Comment = RawLex.getSpelling(Tok, SM, LangOpts);