https://github.com/Endilll created
https://github.com/llvm/llvm-project/pull/101297
There are 5 unary operators that can be followed by a non-parenthesized
expression: `sizeof`, `__datasizeof`, `__alignof`, `alignof`, `_Alignof`. When
we nest them too deep, `BalancedDelimiterTracker` does not help, because there
are no parentheses, and we crash. Instead, this patch recognize chains of those
operators, and parse them with sufficient stack space.
Fixes #45061
>From d75b3cef41c370fef939a347935a4f3ed53c46ea Mon Sep 17 00:00:00 2001
From: Vlad Serebrennikov <serebrennikov.vladis...@gmail.com>
Date: Wed, 31 Jul 2024 10:29:04 +0300
Subject: [PATCH] [clang] Fix crash with multiple non-parenthsized `sizeof`
---
clang/lib/Parse/ParseExpr.cpp | 14 +-
.../parser-overflow-non-parenthesized.c | 135 ++++++++++++++++++
2 files changed, 148 insertions(+), 1 deletion(-)
create mode 100644 clang/test/Parser/parser-overflow-non-parenthesized.c
diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
index e82b565272831..e501d5e91e77d 100644
--- a/clang/lib/Parse/ParseExpr.cpp
+++ b/clang/lib/Parse/ParseExpr.cpp
@@ -2479,7 +2479,19 @@ Parser::ParseExprAfterUnaryExprOrTypeTrait(const Token
&OpTok,
return ExprError();
}
- Operand = ParseCastExpression(UnaryExprOnly);
+ // If we're parsing a chain that consists of keywords that could be
+ // followed by a non-parenthesized expression, BalancedDelimiterTracker
+ // is not going to help when the nesting is too deep. In this corner case
+ // we continue to parse with sufficient stack space to avoid crashing.
+ if (OpTok.isOneOf(tok::kw_sizeof, tok::kw___datasizeof, tok::kw___alignof,
+ tok::kw_alignof, tok::kw__Alignof) &&
+ Tok.isOneOf(tok::kw_sizeof, tok::kw___datasizeof, tok::kw___alignof,
+ tok::kw_alignof, tok::kw__Alignof))
+ Actions.runWithSufficientStackSpace(Tok.getLocation(), [&] {
+ Operand = ParseCastExpression(UnaryExprOnly);
+ });
+ else
+ Operand = ParseCastExpression(UnaryExprOnly);
} else {
// If it starts with a '(', we know that it is either a parenthesized
// type-name, or it is a unary-expression that starts with a compound
diff --git a/clang/test/Parser/parser-overflow-non-parenthesized.c
b/clang/test/Parser/parser-overflow-non-parenthesized.c
new file mode 100644
index 0000000000000..b6c7485274090
--- /dev/null
+++ b/clang/test/Parser/parser-overflow-non-parenthesized.c
@@ -0,0 +1,135 @@
+// RUN: %clang_cc1 %s 2>&1 | FileCheck %s
+
+void f(void) {
+ // 600 sizeof's
+ int a =
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof sizeof
+ 0;
+ (void)a;
+
+ // 600 of sizeof and __alignof
+ int b =
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ sizeof __alignof sizeof __alignof sizeof __alignof sizeof __alignof sizeof
__alignof
+ 0;
+ (void)b;
+}
+
+// CHECK: warning: stack nearly exhausted; compilation time may suffer, and
crashes due to stack overflow are likely
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