[preprocessor] When #including something that contributes no tokens at all,
don't recursively continue lexing.
This avoids a stack overflow with a sequence of many empty #includes.
rdar://11988695
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@167801 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/TokenKinds.def b/include/clang/Basic/TokenKinds.def
index 25e8d5a..704f1d9 100644
--- a/include/clang/Basic/TokenKinds.def
+++ b/include/clang/Basic/TokenKinds.def
@@ -103,6 +103,8 @@
TOK(eof) // End of file.
TOK(eod) // End of preprocessing directive (end of line inside a
// directive).
+TOK(included_eof) // End of included file, only if
+ // PreprocessorLexer::EnableIncludedEOF is true.
TOK(code_completion) // Code completion marker
TOK(cxx_defaultarg_end) // C++ default argument end marker
diff --git a/include/clang/Lex/PreprocessorLexer.h b/include/clang/Lex/PreprocessorLexer.h
index 20fb8a0..b85729d 100644
--- a/include/clang/Lex/PreprocessorLexer.h
+++ b/include/clang/Lex/PreprocessorLexer.h
@@ -61,6 +61,10 @@
/// Note that in raw mode that the PP pointer may be null.
bool LexingRawMode;
+ /// \brief When true, if EOF of the current lexer is found, tok::included_eof
+ /// is returned instead of continuing lexing higher in the include stack.
+ bool EnableIncludedEOF;
+
/// \brief A state machine that detects the \#ifndef-wrapping a file
/// idiom for the multiple-include optimization.
MultipleIncludeOpt MIOpt;
@@ -79,7 +83,8 @@
: PP(0), InitialNumSLocEntries(0),
ParsingPreprocessorDirective(false),
ParsingFilename(false),
- LexingRawMode(false) {}
+ LexingRawMode(false),
+ EnableIncludedEOF(false) {}
virtual ~PreprocessorLexer() {}
@@ -147,6 +152,11 @@
/// \brief Return true if this lexer is in raw mode or not.
bool isLexingRawMode() const { return LexingRawMode; }
+ /// \brief When true, if EOF of the current lexer is found, tok::included_eof
+ /// is returned instead of continuing lexing higher in the include stack.
+ /// False is the default behavior.
+ void setEnableIncludedEOF(bool Enable) { EnableIncludedEOF = Enable; }
+
/// \brief Return the preprocessor object for this lexer.
Preprocessor *getPP() const { return PP; }
diff --git a/lib/Lex/Lexer.cpp b/lib/Lex/Lexer.cpp
index e6e7ca5..7983a6b 100644
--- a/lib/Lex/Lexer.cpp
+++ b/lib/Lex/Lexer.cpp
@@ -2595,8 +2595,14 @@
// Read the PP instance variable into an automatic variable, because
// LexEndOfFile will often delete 'this'.
Preprocessor *PPCache = PP;
+ bool EnableIncludedEOFCache = EnableIncludedEOF;
if (LexEndOfFile(Result, CurPtr-1)) // Retreat back into the file.
return; // Got a token to return.
+
+ if (EnableIncludedEOFCache) {
+ Result.setKind(tok::included_eof);
+ return;
+ }
assert(PPCache && "Raw buffer::LexEndOfFile should return a token");
return PPCache->Lex(Result);
}
@@ -3234,5 +3240,21 @@
}
goto LexNextToken; // GCC isn't tail call eliminating.
}
+
+ if (PreprocessorLexer *PPLex = PP->getCurrentLexer()) {
+ // If we #include something that contributes no tokens at all, return with
+ // a tok::included_eof instead of recursively continuing lexing.
+ // This avoids a stack overflow with a sequence of many empty #includes.
+ PPLex->setEnableIncludedEOF(true);
+ PP->Lex(Result);
+ if (Result.isNot(tok::included_eof)) {
+ if (Result.isNot(tok::eof) && Result.isNot(tok::eod))
+ PPLex->setEnableIncludedEOF(false);
+ return;
+ }
+ if (PP->isCurrentLexer(this))
+ goto LexNextToken;
+ }
+
return PP->Lex(Result);
}
diff --git a/lib/Lex/PreprocessorLexer.cpp b/lib/Lex/PreprocessorLexer.cpp
index a64c84d..390d4c4 100644
--- a/lib/Lex/PreprocessorLexer.cpp
+++ b/lib/Lex/PreprocessorLexer.cpp
@@ -22,7 +22,7 @@
PreprocessorLexer::PreprocessorLexer(Preprocessor *pp, FileID fid)
: PP(pp), FID(fid), InitialNumSLocEntries(0),
ParsingPreprocessorDirective(false),
- ParsingFilename(false), LexingRawMode(false) {
+ ParsingFilename(false), LexingRawMode(false), EnableIncludedEOF(false) {
if (pp)
InitialNumSLocEntries = pp->getSourceManager().local_sloc_entry_size();
}
diff --git a/test/Index/Inputs/empty.h b/test/Index/Inputs/empty.h
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/Index/Inputs/empty.h
diff --git a/test/Index/pp-many-includes.c b/test/Index/pp-many-includes.c
new file mode 100644
index 0000000..8a53b4f
--- /dev/null
+++ b/test/Index/pp-many-includes.c
@@ -0,0 +1,208 @@
+// RUN: env LIBCLANG_THREAD_SMALLSTACK=1 c-index-test -index-file %s | FileCheck %s
+
+// rdar://11988695
+// Check that we don't get stack overflow while including a lot of empty includes.
+
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+#include "Inputs/empty.h"
+
+// CHECK: [indexDeclaration]: kind: function | name: foo
+void foo();
diff --git a/tools/libclang/CIndex.cpp b/tools/libclang/CIndex.cpp
index 3a6c408..bb75db3 100644
--- a/tools/libclang/CIndex.cpp
+++ b/tools/libclang/CIndex.cpp
@@ -6119,6 +6119,8 @@
bool RunSafely(llvm::CrashRecoveryContext &CRC,
void (*Fn)(void*), void *UserData,
unsigned Size) {
+ if (getenv("LIBCLANG_THREAD_SMALLSTACK"))
+ Size = 0x10000; // 64K.
if (!Size)
Size = GetSafetyThreadStackSize();
if (Size)
