[clang] [clang] Fix a possible out-of-bounds read (PR #80023)

[Timm Baeder via cfe-commits]

Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/80023 at github.com>


https://github.com/tbaederr updated https://github.com/llvm/llvm-project/pull/80023

>From 58ceefe09cd992c3692bb3af7c2807ac8949ba67 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Thu, 1 Feb 2024 09:11:27 +0100
Subject: [PATCH 1/2] [clang][Interp] Support ChooseExprs

---
 clang/lib/AST/Interp/ByteCodeExprGen.cpp | 5 +++++
 clang/lib/AST/Interp/ByteCodeExprGen.h   | 1 +
 clang/test/AST/Interp/c.c                | 3 +++
 3 files changed, 9 insertions(+)

diff --git a/clang/lib/AST/Interp/ByteCodeExprGen.cpp b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
index ca7e529041188..01555b0fc7dac 100644
--- a/clang/lib/AST/Interp/ByteCodeExprGen.cpp
+++ b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -1948,6 +1948,11 @@ bool ByteCodeExprGen<Emitter>::VisitGenericSelectionExpr(
   return this->delegate(E->getResultExpr());
 }
 
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::VisitChooseExpr(const ChooseExpr *E) {
+  return this->delegate(E->getChosenSubExpr());
+}
+
 template <class Emitter> bool ByteCodeExprGen<Emitter>::discard(const Expr *E) {
   if (E->containsErrors())
     return false;
diff --git a/clang/lib/AST/Interp/ByteCodeExprGen.h b/clang/lib/AST/Interp/ByteCodeExprGen.h
index 1710b4446432b..4ed5d31e343a6 100644
--- a/clang/lib/AST/Interp/ByteCodeExprGen.h
+++ b/clang/lib/AST/Interp/ByteCodeExprGen.h
@@ -109,6 +109,7 @@ class ByteCodeExprGen : public ConstStmtVisitor<ByteCodeExprGen<Emitter>, bool>,
   bool VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E);
   bool VisitSizeOfPackExpr(const SizeOfPackExpr *E);
   bool VisitGenericSelectionExpr(const GenericSelectionExpr *E);
+  bool VisitChooseExpr(const ChooseExpr *E);
 
 protected:
   bool visitExpr(const Expr *E) override;
diff --git a/clang/test/AST/Interp/c.c b/clang/test/AST/Interp/c.c
index 385944d643a30..df3807b371dea 100644
--- a/clang/test/AST/Interp/c.c
+++ b/clang/test/AST/Interp/c.c
@@ -95,3 +95,6 @@ void f (int z) {
                   // pedantic-ref-error {{'default' statement not in switch}}
   }
 }
+
+int expr;
+int chooseexpr[__builtin_choose_expr(1, 1, expr)];

>From 0780dcad4cc4449bc7a58fb26669282337cdaf2c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Tue, 30 Jan 2024 17:04:23 +0100
Subject: [PATCH 2/2] [clang] Fix a possible out-of-bounds read

Fixes #79964
---
 clang/lib/Frontend/TextDiagnostic.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/lib/Frontend/TextDiagnostic.cpp b/clang/lib/Frontend/TextDiagnostic.cpp
index 291d71f6db61f..a32ed443ab2e9 100644
--- a/clang/lib/Frontend/TextDiagnostic.cpp
+++ b/clang/lib/Frontend/TextDiagnostic.cpp
@@ -1251,7 +1251,7 @@ highlightLines(StringRef FileData, unsigned StartLineNumber,
     unsigned LineLength = 0;
     for (unsigned I = 0; I <= Spelling.size(); ++I) {
       // This line is done.
-      if (isVerticalWhitespace(Spelling[I]) || I == Spelling.size()) {
+      if (I == Spelling.size() || isVerticalWhitespace(Spelling.at(I))) {
         SmallVector<TextDiagnostic::StyleRange> &LineRanges =
             SnippetRanges[L - StartLineNumber];