[clang-tools-extra] [wip][clang-tidy] Add new `bugprone-suspicious-pointer-arithmetics-using-sizeof` (`cert-arr39-c`) check (PR #106061)
via cfe-commits
cfe-commits at lists.llvm.org
Mon Aug 26 08:51:20 PDT 2024
https://github.com/whisperity updated https://github.com/llvm/llvm-project/pull/106061
>From 0202caa773928bfc395b850f52191ab15afe0eb4 Mon Sep 17 00:00:00 2001
From: zporky <zporky at gmail.com>
Date: Thu, 26 Oct 2023 20:40:39 +0200
Subject: [PATCH 01/11] Initial pointer arithmetics using sizeof matcher
---
.../bugprone/BugproneTidyModule.cpp | 3 ++
.../clang-tidy/bugprone/CMakeLists.txt | 1 +
...iousPointerArithmeticsUsingSizeofCheck.cpp | 36 +++++++++++++++++++
...iciousPointerArithmeticsUsingSizeofCheck.h | 30 ++++++++++++++++
.../clang-tidy/cert/CERTTidyModule.cpp | 4 +++
5 files changed, 74 insertions(+)
create mode 100644 clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
create mode 100644 clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.h
diff --git a/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp b/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
index 543c522899d7a5..4f74fd9fd50543 100644
--- a/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
@@ -67,6 +67,7 @@
#include "SuspiciousMemoryComparisonCheck.h"
#include "SuspiciousMemsetUsageCheck.h"
#include "SuspiciousMissingCommaCheck.h"
+#include "SuspiciousPointerArithmeticsUsingSizeofCheck.h"
#include "SuspiciousReallocUsageCheck.h"
#include "SuspiciousSemicolonCheck.h"
#include "SuspiciousStringCompareCheck.h"
@@ -204,6 +205,8 @@ class BugproneModule : public ClangTidyModule {
"bugprone-suspicious-memset-usage");
CheckFactories.registerCheck<SuspiciousMissingCommaCheck>(
"bugprone-suspicious-missing-comma");
+ CheckFactories.registerCheck<SuspiciousPointerArithmeticsUsingSizeofCheck>(
+ "bugprone-suspicious-pointer-arithmetics-using-sizeof");
CheckFactories.registerCheck<SuspiciousReallocUsageCheck>(
"bugprone-suspicious-realloc-usage");
CheckFactories.registerCheck<SuspiciousSemicolonCheck>(
diff --git a/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt b/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
index 0df9e439b715e5..c9877e6f5a7ddc 100644
--- a/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
@@ -64,6 +64,7 @@ add_clang_library(clangTidyBugproneModule
SuspiciousMemoryComparisonCheck.cpp
SuspiciousMemsetUsageCheck.cpp
SuspiciousMissingCommaCheck.cpp
+ SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
SuspiciousReallocUsageCheck.cpp
SuspiciousSemicolonCheck.cpp
SuspiciousStringCompareCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
new file mode 100644
index 00000000000000..abfa1bc7f037ea
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
@@ -0,0 +1,36 @@
+//===--- SuspiciousPointerArithmeticsUsingSizeofCheck.cpp - clang-tidy --===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "SuspiciousPointerArithmeticsUsingSizeofCheck.h"
+#include "../utils/Matchers.h"
+#include "../utils/OptionsUtils.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::bugprone {
+
+SuspiciousPointerArithmeticsUsingSizeofCheck::SuspiciousPointerArithmeticsUsingSizeofCheck(
+ StringRef Name, ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context) {
+}
+
+void SuspiciousPointerArithmeticsUsingSizeofCheck::registerMatchers(MatchFinder *Finder) {
+ Finder->addMatcher(
+ sizeOfExpr(expr())
+ .bind("sizeof-expression"),
+ this);
+}
+
+void SuspiciousPointerArithmeticsUsingSizeofCheck::check(
+ const MatchFinder::MatchResult &Result) {
+}
+
+} // namespace clang::tidy::bugprone
diff --git a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.h b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.h
new file mode 100644
index 00000000000000..d39e15f0ccc3a0
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.h
@@ -0,0 +1,30 @@
+//===--- SuspiciousPointerArithmeticsUsingSizeofCheck.h - clang-tidy -*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SUSPICIOUSPOINTERARITHMETICSSIZEOFCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SUSPICIOUSPOINTERARITHMETICSSIZEOFCHECK_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang::tidy::bugprone {
+
+/// Find suspicious calls to string compare functions.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/bugprone/suspicious-pointer-arithmetics-sizeof.html
+class SuspiciousPointerArithmeticsUsingSizeofCheck : public ClangTidyCheck {
+public:
+ SuspiciousPointerArithmeticsUsingSizeofCheck(StringRef Name, ClangTidyContext *Context);
+// void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace clang::tidy::bugprone
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SUSPICIOUSPOINTERARITHMETICSSIZEOFCHECK_H
diff --git a/clang-tools-extra/clang-tidy/cert/CERTTidyModule.cpp b/clang-tools-extra/clang-tidy/cert/CERTTidyModule.cpp
index d448d9ba614548..17a7e4bc51049d 100644
--- a/clang-tools-extra/clang-tidy/cert/CERTTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/cert/CERTTidyModule.cpp
@@ -15,6 +15,7 @@
#include "../bugprone/SignedCharMisuseCheck.h"
#include "../bugprone/SpuriouslyWakeUpFunctionsCheck.h"
#include "../bugprone/SuspiciousMemoryComparisonCheck.h"
+#include "../bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.h"
#include "../bugprone/UnhandledSelfAssignmentCheck.h"
#include "../bugprone/UnsafeFunctionsCheck.h"
#include "../bugprone/UnusedReturnValueCheck.h"
@@ -278,6 +279,9 @@ class CERTModule : public ClangTidyModule {
"cert-oop58-cpp");
// C checkers
+ // ARR
+ CheckFactories.registerCheck<bugprone::SuspiciousPointerArithmeticsUsingSizeofCheck>(
+ "cert-arr39-c");
// CON
CheckFactories.registerCheck<bugprone::SpuriouslyWakeUpFunctionsCheck>(
"cert-con36-c");
>From f2d7d25549101d3250e65dc3a76dac766ccfc476 Mon Sep 17 00:00:00 2001
From: zporky <zporky at gmail.com>
Date: Fri, 3 Nov 2023 01:15:17 +0100
Subject: [PATCH 02/11] Working version of the checker.
---
...iousPointerArithmeticsUsingSizeofCheck.cpp | 21 +++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
index abfa1bc7f037ea..de7c7e62e99282 100644
--- a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
@@ -12,6 +12,7 @@
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Lex/Lexer.h"
+#include <iostream>
using namespace clang::ast_matchers;
@@ -24,13 +25,25 @@ SuspiciousPointerArithmeticsUsingSizeofCheck::SuspiciousPointerArithmeticsUsingS
void SuspiciousPointerArithmeticsUsingSizeofCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(
- sizeOfExpr(expr())
- .bind("sizeof-expression"),
+ expr(anyOf(
+ binaryOperator(hasAnyOperatorName("+","-"),
+ hasEitherOperand(hasType(pointerType())),
+ hasEitherOperand(sizeOfExpr(expr())),
+ unless(allOf(hasLHS(hasType(pointerType())),
+ hasRHS(hasType(pointerType()))))
+ ).bind("ptr-sizeof-expression"),
+ binaryOperator(hasAnyOperatorName("+=","-="),
+ hasLHS(hasType(pointerType())),
+ hasRHS(sizeOfExpr(expr()))
+ ).bind("ptr-sizeof-expression")
+ )),
this);
}
-void SuspiciousPointerArithmeticsUsingSizeofCheck::check(
- const MatchFinder::MatchResult &Result) {
+void SuspiciousPointerArithmeticsUsingSizeofCheck::check(const MatchFinder::MatchResult &Result) {
+ static const char *diag_msg = "Suspicious pointer arithmetics using sizeof() operator";
+ auto Matched = Result.Nodes.getNodeAs<BinaryOperator>("ptr-sizeof-expression");
+ diag(Matched->getExprLoc(),diag_msg)<< Matched->getSourceRange();
}
} // namespace clang::tidy::bugprone
>From 330dc16f6b7db1a34596f03105c1560bf94fea07 Mon Sep 17 00:00:00 2001
From: zporky <zporky at gmail.com>
Date: Fri, 3 Nov 2023 21:23:26 +0100
Subject: [PATCH 03/11] Code simplification with elevating string constants.
---
.../SuspiciousPointerArithmeticsUsingSizeofCheck.cpp | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
index de7c7e62e99282..90a8d308596cf6 100644
--- a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
@@ -12,10 +12,12 @@
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Lex/Lexer.h"
-#include <iostream>
using namespace clang::ast_matchers;
+namespace {
+ static const char *bin_op_bind = "ptr-sizeof-expression";
+}
namespace clang::tidy::bugprone {
SuspiciousPointerArithmeticsUsingSizeofCheck::SuspiciousPointerArithmeticsUsingSizeofCheck(
@@ -31,18 +33,18 @@ void SuspiciousPointerArithmeticsUsingSizeofCheck::registerMatchers(MatchFinder
hasEitherOperand(sizeOfExpr(expr())),
unless(allOf(hasLHS(hasType(pointerType())),
hasRHS(hasType(pointerType()))))
- ).bind("ptr-sizeof-expression"),
+ ).bind(bin_op_bind),
binaryOperator(hasAnyOperatorName("+=","-="),
hasLHS(hasType(pointerType())),
hasRHS(sizeOfExpr(expr()))
- ).bind("ptr-sizeof-expression")
+ ).bind(bin_op_bind)
)),
this);
}
void SuspiciousPointerArithmeticsUsingSizeofCheck::check(const MatchFinder::MatchResult &Result) {
static const char *diag_msg = "Suspicious pointer arithmetics using sizeof() operator";
- auto Matched = Result.Nodes.getNodeAs<BinaryOperator>("ptr-sizeof-expression");
+ auto Matched = Result.Nodes.getNodeAs<BinaryOperator>(bin_op_bind);
diag(Matched->getExprLoc(),diag_msg)<< Matched->getSourceRange();
}
>From 27a2ac5e7e6168c43dd9fec14994176b7ed18ea0 Mon Sep 17 00:00:00 2001
From: zporky <zporky at gmail.com>
Date: Thu, 9 Nov 2023 20:02:38 +0100
Subject: [PATCH 04/11] filtering out char* like matches
---
...iousPointerArithmeticsUsingSizeofCheck.cpp | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
index 90a8d308596cf6..02275a2cdfe747 100644
--- a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
@@ -15,11 +15,13 @@
using namespace clang::ast_matchers;
-namespace {
- static const char *bin_op_bind = "ptr-sizeof-expression";
-}
namespace clang::tidy::bugprone {
+//static const char *bin_op_bind = "ptr-sizeof-expression";
+static constexpr llvm::StringLiteral BinOp{"bin-op"};
+static const auto IgnoredType = qualType(anyOf(asString("char"),asString("unsigned char"),asString("signed char"),asString("int8_t"),asString("uint8_t"),asString("std::byte"),asString("const char"),asString("const unsigned char"),asString("const signed char"),asString("const int8_t"),asString("const uint8_t"),asString("const std::byte")));
+static const auto InterestingPointer = pointerType(unless(pointee(IgnoredType)));
+
SuspiciousPointerArithmeticsUsingSizeofCheck::SuspiciousPointerArithmeticsUsingSizeofCheck(
StringRef Name, ClangTidyContext *Context)
: ClangTidyCheck(Name, Context) {
@@ -28,7 +30,7 @@ SuspiciousPointerArithmeticsUsingSizeofCheck::SuspiciousPointerArithmeticsUsingS
void SuspiciousPointerArithmeticsUsingSizeofCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(
expr(anyOf(
- binaryOperator(hasAnyOperatorName("+","-"),
+/* binaryOperator(hasAnyOperatorName("+","-"),
hasEitherOperand(hasType(pointerType())),
hasEitherOperand(sizeOfExpr(expr())),
unless(allOf(hasLHS(hasType(pointerType())),
@@ -38,13 +40,20 @@ void SuspiciousPointerArithmeticsUsingSizeofCheck::registerMatchers(MatchFinder
hasLHS(hasType(pointerType())),
hasRHS(sizeOfExpr(expr()))
).bind(bin_op_bind)
+*/
+ binaryOperator(hasAnyOperatorName("+=","-=","+","-" ),
+ hasLHS(hasType(InterestingPointer)),
+ hasRHS(sizeOfExpr(expr()))).bind(BinOp),
+ binaryOperator(hasAnyOperatorName("+","-" ),
+ hasRHS(hasType(InterestingPointer)),
+ hasLHS(sizeOfExpr(expr()))).bind(BinOp)
)),
this);
}
void SuspiciousPointerArithmeticsUsingSizeofCheck::check(const MatchFinder::MatchResult &Result) {
static const char *diag_msg = "Suspicious pointer arithmetics using sizeof() operator";
- auto Matched = Result.Nodes.getNodeAs<BinaryOperator>(bin_op_bind);
+ auto Matched = Result.Nodes.getNodeAs<BinaryOperator>(BinOp);
diag(Matched->getExprLoc(),diag_msg)<< Matched->getSourceRange();
}
>From 3ed1e4fd39e9efd88e509637a345118a9a7b3300 Mon Sep 17 00:00:00 2001
From: zporky <zporky at gmail.com>
Date: Wed, 15 Nov 2023 23:03:45 +0100
Subject: [PATCH 05/11] Filtering out the uninteresting types in imperative
way.
---
...iousPointerArithmeticsUsingSizeofCheck.cpp | 29 +++++++++++++++++--
1 file changed, 26 insertions(+), 3 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
index 02275a2cdfe747..91f5ac55c508b6 100644
--- a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
@@ -19,6 +19,7 @@ namespace clang::tidy::bugprone {
//static const char *bin_op_bind = "ptr-sizeof-expression";
static constexpr llvm::StringLiteral BinOp{"bin-op"};
+static constexpr llvm::StringLiteral PointedType{"pointed-type"};
static const auto IgnoredType = qualType(anyOf(asString("char"),asString("unsigned char"),asString("signed char"),asString("int8_t"),asString("uint8_t"),asString("std::byte"),asString("const char"),asString("const unsigned char"),asString("const signed char"),asString("const int8_t"),asString("const uint8_t"),asString("const std::byte")));
static const auto InterestingPointer = pointerType(unless(pointee(IgnoredType)));
@@ -40,21 +41,43 @@ void SuspiciousPointerArithmeticsUsingSizeofCheck::registerMatchers(MatchFinder
hasLHS(hasType(pointerType())),
hasRHS(sizeOfExpr(expr()))
).bind(bin_op_bind)
-*/
+
binaryOperator(hasAnyOperatorName("+=","-=","+","-" ),
hasLHS(hasType(InterestingPointer)),
hasRHS(sizeOfExpr(expr()))).bind(BinOp),
binaryOperator(hasAnyOperatorName("+","-" ),
hasRHS(hasType(InterestingPointer)),
hasLHS(sizeOfExpr(expr()))).bind(BinOp)
+*/
+ binaryOperator(hasAnyOperatorName("+=","-=","+","-" ),
+ hasLHS(hasType(pointerType(pointee(qualType().bind(PointedType))))),
+ hasRHS(sizeOfExpr(expr()))).bind(BinOp),
+ binaryOperator(hasAnyOperatorName("+","-" ),
+ hasRHS(hasType(pointerType(pointee(qualType().bind(PointedType))))),
+ hasLHS(sizeOfExpr(expr()))).bind(BinOp)
)),
this);
}
+static CharUnits getSizeOfType(const ASTContext &Ctx, const Type *Ty) {
+ if (!Ty || Ty->isIncompleteType() || Ty->isDependentType() ||
+ isa<DependentSizedArrayType>(Ty) || !Ty->isConstantSizeType())
+ return CharUnits::Zero();
+ return Ctx.getTypeSizeInChars(Ty);
+}
+
void SuspiciousPointerArithmeticsUsingSizeofCheck::check(const MatchFinder::MatchResult &Result) {
static const char *diag_msg = "Suspicious pointer arithmetics using sizeof() operator";
- auto Matched = Result.Nodes.getNodeAs<BinaryOperator>(BinOp);
- diag(Matched->getExprLoc(),diag_msg)<< Matched->getSourceRange();
+ const ASTContext &Ctx = *Result.Context;
+ const auto Matched = Result.Nodes.getNodeAs<BinaryOperator>(BinOp);
+ const auto SuspiciousQualTypePtr = Result.Nodes.getNodeAs<QualType>(PointedType);
+ const auto SuspiciousTypePtr = SuspiciousQualTypePtr->getTypePtr();
+
+ auto sz = getSizeOfType(Ctx,SuspiciousTypePtr).getQuantity();
+ if ( sz > 1 )
+ {
+ diag(Matched->getExprLoc(),diag_msg)<< Matched->getSourceRange();
+ }
}
} // namespace clang::tidy::bugprone
>From 7e3b35dbf09d99fba55d42d9c4c5c571dd4703a6 Mon Sep 17 00:00:00 2001
From: zporky <zporky at gmail.com>
Date: Thu, 16 Nov 2023 20:35:03 +0100
Subject: [PATCH 06/11] Reporting the suspicious type and its size.
---
...SuspiciousPointerArithmeticsUsingSizeofCheck.cpp | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
index 91f5ac55c508b6..a1710916f762ff 100644
--- a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
@@ -67,16 +67,17 @@ static CharUnits getSizeOfType(const ASTContext &Ctx, const Type *Ty) {
}
void SuspiciousPointerArithmeticsUsingSizeofCheck::check(const MatchFinder::MatchResult &Result) {
- static const char *diag_msg = "Suspicious pointer arithmetics using sizeof() operator";
const ASTContext &Ctx = *Result.Context;
- const auto Matched = Result.Nodes.getNodeAs<BinaryOperator>(BinOp);
- const auto SuspiciousQualTypePtr = Result.Nodes.getNodeAs<QualType>(PointedType);
- const auto SuspiciousTypePtr = SuspiciousQualTypePtr->getTypePtr();
+ const BinaryOperator* Matched = Result.Nodes.getNodeAs<BinaryOperator>(BinOp);
+ const QualType* SuspiciousQualTypePtr = Result.Nodes.getNodeAs<QualType>(PointedType);
+ const Type* SuspiciousTypePtr = SuspiciousQualTypePtr->getTypePtr();
- auto sz = getSizeOfType(Ctx,SuspiciousTypePtr).getQuantity();
+ std::size_t sz = getSizeOfType(Ctx,SuspiciousTypePtr).getQuantity();
if ( sz > 1 )
{
- diag(Matched->getExprLoc(),diag_msg)<< Matched->getSourceRange();
+ diag(Matched->getExprLoc(),"Suspicious pointer arithmetics using sizeof() operator: sizeof(%0) is %1") << SuspiciousQualTypePtr->getAsString(Ctx.getPrintingPolicy())
+ << sz
+ << Matched->getSourceRange();
}
}
>From fbbc8d2e75472ad8cdfdaef7f97083994f1ad3ef Mon Sep 17 00:00:00 2001
From: zporky <zporky at gmail.com>
Date: Fri, 5 Apr 2024 16:00:00 +0200
Subject: [PATCH 07/11] add initial test file
---
...picious-pointer-arithmetics-using-sizeof.c | 209 ++++++++++++++++++
1 file changed, 209 insertions(+)
create mode 100644 clang-tools-extra/test/clang-tidy/checkers/bugprone/suspicious-pointer-arithmetics-using-sizeof.c
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/suspicious-pointer-arithmetics-using-sizeof.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/suspicious-pointer-arithmetics-using-sizeof.c
new file mode 100644
index 00000000000000..353cbcc9e683ae
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/suspicious-pointer-arithmetics-using-sizeof.c
@@ -0,0 +1,209 @@
+
+struct mystruct {
+ long a;
+ long b;
+ long c;
+};
+void noncompliant_f1(void);
+void compliant_f1(void);
+void noncompliant_f3(struct mystruct *msptr);
+void compliant_f3(struct mystruct *msptr);
+extern void sink(const char *);
+
+enum { bufsize = 1024 };
+
+void noncompliant_f1(void) {
+ int buffer[bufsize];
+
+ int *bptr = &buffer[0];
+ int *ptr = bptr;
+ while ( ptr < bptr + sizeof(buffer) ) { // noncompliant
+ *ptr++ = 0; // compliant
+ }
+}
+void noncompliant_f1a(void) {
+ typedef int my_int_t;
+ my_int_t buffer[bufsize];
+
+ my_int_t *bptr = &buffer[0];
+ my_int_t *ptr = bptr;
+ while ( ptr < bptr + sizeof(buffer) ) { // noncompliant
+ *ptr++ = 0; // compliant
+ }
+}
+void compliant_f1(void) {
+ int buffer[bufsize];
+
+ int *bptr = &buffer[0];
+ int *ptr = bptr;
+ while ( ptr < bptr + bufsize ) { // compliant
+ *ptr++ = 0; // compliant
+ }
+}
+
+void noncompliant_f2(void) {
+ int buffer[bufsize];
+ int *ptr = buffer;
+
+ while ( ptr < buffer + sizeof(buffer) ) { // noncompliant
+ *ptr++ = 0; // compliant
+ }
+}
+
+void compliant_f2(void) {
+ int buffer[bufsize];
+ int *ptr = buffer;
+
+ while ( ptr < buffer + bufsize ) { // compliant
+ *ptr++ = 0; // compliant
+ }
+}
+
+void memset2(void*, int, unsigned int);
+
+void noncompliant_f3(struct mystruct *msptr) {
+ const unsigned int skip = sizeof(long); // why offsetof is declared?
+ struct mystruct *ptr = msptr;
+
+ memset2(ptr + skip, // noncompliant, impossible with tidy
+ 0, sizeof(struct mystruct) - skip);
+}
+
+void compliant_f3(struct mystruct *msptr) {
+ const unsigned int skip = sizeof(long);
+ char *ptr = (char*)msptr;
+
+ memset2(ptr + skip, // compliant
+ 0, sizeof(struct mystruct) - skip);
+}
+
+void noncompliant_f4(void) {
+ int buffer[bufsize];
+
+ int *bptr = &buffer[0];
+ int *ptr = bptr;
+ while ( ptr < bptr + bufsize ) { // compliant
+ *ptr = 0;
+ ptr += sizeof(*ptr); // noncompliant
+ }
+}
+void noncompliant_f4w(void) { /* accidentally good */
+ char buffer[bufsize];
+
+ char *bptr = &buffer[0];
+ char *ptr = bptr;
+ while ( ptr < bptr + bufsize ) { // compliant
+ *ptr = 0;
+ ptr += sizeof(*ptr); // silenced
+ }
+}
+void compliant_f4w(void) {
+ char buffer[bufsize];
+
+ char *bptr = &buffer[0];
+ char *ptr = bptr;
+ while ( ptr < bptr + bufsize ) { // compliant
+ *ptr = 0;
+ ptr += 1; // compliant
+ }
+}
+
+void noncompliant_f5(void) {
+ int buffer[bufsize];
+
+ int *bptr = &buffer[0];
+ int *ptr = bptr;
+ while ( ptr < bptr + bufsize ) { // compliant
+ *ptr = 0;
+ ptr = ptr + sizeof(*ptr); // noncompliant
+ }
+}
+void noncompliant_f5w(void) {
+ char buffer[bufsize];
+
+ char*bptr = &buffer[0];
+ char *ptr = bptr;
+ while ( ptr < bptr + bufsize ) { // compliant
+ *ptr = 0;
+ ptr = ptr + sizeof(*ptr); // silenced
+ }
+}
+void noncompliant_f5c(void) {
+ char buffer[bufsize];
+
+ char*bptr = &buffer[0];
+ const char *ptr = bptr;
+ while ( ptr < bptr + bufsize ) { // compliant
+ sink(ptr);
+ ptr = ptr + sizeof(*ptr); // silenced
+ }
+}
+void compliant_f5c(void) {
+ char buffer[bufsize];
+
+ char *bptr = &buffer[0];
+ const char *ptr = bptr;
+ while ( ptr < bptr + bufsize ) { // compliant
+ sink(ptr);
+ ptr = ptr + 1; // compliant
+ }
+}
+
+void noncompliant_f6(void) {
+ int buffer[bufsize];
+
+ int *bptr = &buffer[0];
+ int *ptr = bptr + bufsize; // compliant
+ while ( ptr >= bptr ) {
+ *ptr = 0;
+ ptr = ptr - sizeof(*ptr); // noncompliant
+ }
+}
+void noncompliant_f6w(void) {
+ char buffer[bufsize];
+
+ char *bptr = &buffer[0];
+ char *ptr = bptr + bufsize; // compliant
+ while ( ptr >= bptr ) {
+ *ptr = 0;
+ ptr = ptr - sizeof(*ptr); // silenced
+ }
+}
+void compliant_f6(void) {
+ int buffer[bufsize];
+
+ int *bptr = &buffer[0];
+ int *ptr = bptr + bufsize; // compliant
+ while ( ptr >= bptr ) {
+ *ptr = 0;
+ ptr = ptr - 1; // compliant
+ }
+}
+
+void compliant_f7(void) {
+ int buffer[bufsize];
+
+ int *bptr = &buffer[0];
+ int *ptr = bptr + bufsize; // compliant
+ int i = ptr - bptr; // compliant
+ while ( i >= 0 ) {
+ ptr[i] = 0;
+ i = i - 1; // compliant
+ }
+}
+
+void compliant_f8(void) {
+ int buffer[bufsize];
+
+ int *bptr = &buffer[0];
+ int *ptr = bptr + bufsize; // compliant
+ int i = sizeof(*ptr) - sizeof(*bptr); // compliant
+}
+void compliant_f9(void) {
+ int buffer[bufsize];
+
+ int *bptr = &buffer[0];
+ int *ptr = bptr + bufsize; // compliant
+ int i = sizeof(ptr) - sizeof(*bptr); // compliant
+}
+
>From 80c67e581ad2debed748d7142ed72a468936122a Mon Sep 17 00:00:00 2001
From: Whisperity <whisperity at gmail.com>
Date: Mon, 26 Aug 2024 16:38:22 +0200
Subject: [PATCH 08/11] doc: Add documentation for the check
---
...iciousPointerArithmeticsUsingSizeofCheck.h | 15 ++++---
...cious-pointer-arithmetics-using-sizeof.rst | 44 +++++++++++++++++++
.../docs/clang-tidy/checks/cert/arr39-c.rst | 10 +++++
3 files changed, 62 insertions(+), 7 deletions(-)
create mode 100644 clang-tools-extra/docs/clang-tidy/checks/bugprone/suspicious-pointer-arithmetics-using-sizeof.rst
create mode 100644 clang-tools-extra/docs/clang-tidy/checks/cert/arr39-c.rst
diff --git a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.h b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.h
index d39e15f0ccc3a0..1dbc51dd3df84f 100644
--- a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.h
+++ b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.h
@@ -6,25 +6,26 @@
//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SUSPICIOUSPOINTERARITHMETICSSIZEOFCHECK_H
-#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SUSPICIOUSPOINTERARITHMETICSSIZEOFCHECK_H
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SUSPICIOUSPOINTERARITHMETICSUSINGSIZEOFCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SUSPICIOUSPOINTERARITHMETICSUSINGSIZEOFCHECK_H
#include "../ClangTidyCheck.h"
namespace clang::tidy::bugprone {
-/// Find suspicious calls to string compare functions.
+/// Finds suspicious pointer arithmetic calculations where the pointer is
+/// offset by a sizeof() expression.
///
/// For the user-facing documentation see:
-/// http://clang.llvm.org/extra/clang-tidy/checks/bugprone/suspicious-pointer-arithmetics-sizeof.html
+/// http://clang.llvm.org/extra/clang-tidy/checks/bugprone/suspicious-pointer-arithmetics-using-sizeof.html
class SuspiciousPointerArithmeticsUsingSizeofCheck : public ClangTidyCheck {
public:
- SuspiciousPointerArithmeticsUsingSizeofCheck(StringRef Name, ClangTidyContext *Context);
-// void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+ SuspiciousPointerArithmeticsUsingSizeofCheck(StringRef Name,
+ ClangTidyContext *Context);
void registerMatchers(ast_matchers::MatchFinder *Finder) override;
void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
};
} // namespace clang::tidy::bugprone
-#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SUSPICIOUSPOINTERARITHMETICSSIZEOFCHECK_H
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SUSPICIOUSPOINTERARITHMETICSUSINGSIZEOFCHECK_H
diff --git a/clang-tools-extra/docs/clang-tidy/checks/bugprone/suspicious-pointer-arithmetics-using-sizeof.rst b/clang-tools-extra/docs/clang-tidy/checks/bugprone/suspicious-pointer-arithmetics-using-sizeof.rst
new file mode 100644
index 00000000000000..5188f947627ab0
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/checks/bugprone/suspicious-pointer-arithmetics-using-sizeof.rst
@@ -0,0 +1,44 @@
+.. title:: clang-tidy - bugprone-suspicious-pointer-arithmetics-using-sizeof
+
+bugprone-suspicious-pointer-arithmetics-using-sizeof
+====================================================
+
+Finds suspicious pointer arithmetic calculations where the pointer is offset by a ``sizeof()`` expression.
+
+Pointer arithmetic expressions implicitly scale the offset added to or subtracted from the address by the size of the pointee type.
+Scaling the offset expression manually effectively results in a squared offset, which creates an invalid pointer that points beyond the end of the intended array.
+
+.. code-block:: c++
+
+ void printEveryEvenIndexElement(int *Array, size_t N) {
+ int *P = Array;
+ while (P <= Array + N * sizeof(int)) { // Suspicious pointer arithmetics using sizeof()!
+ printf("%d ", *P);
+
+ P += 2 * sizeof(int); // Suspicious pointer arithmetics using sizeof()!
+ }
+ }
+
+The above example should be in the following, correct form:
+
+.. code-block:: c++
+
+ void printEveryEvenIndexElement(int *Array, size_t N) {
+ int *P = Array;
+ while (P <= Array + N) {
+ printf("%d ", *P);
+
+ P += 2;
+ }
+ }
+
+`cert-arr39-c` redirects here as an alias of this check.
+
+This check corresponds to the CERT C Coding Standard rule
+`ARR39-C. Do not add or subtract a scaled integer to a pointer
+<http://wiki.sei.cmu.edu/confluence/display/c/ARR39-C.+Do+not+add+or+subtract+a+scaled+integer+to+a+pointer>`_.
+
+Limitations
+-----------
+
+While incorrect from a technically rigorous point of view, the check does not warn for pointer arithmetics where the pointee type is ``char`` (``sizeof(char) == 1``, by definition) on purpose.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/cert/arr39-c.rst b/clang-tools-extra/docs/clang-tidy/checks/cert/arr39-c.rst
new file mode 100644
index 00000000000000..91e02e39952be9
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/checks/cert/arr39-c.rst
@@ -0,0 +1,10 @@
+.. title:: clang-tidy - cert-arr39-c
+.. meta::
+ :http-equiv=refresh: 5;URL=../bugprone/suspicious-pointer-arithmetics-using-sizeof.html
+
+cert-arr39-c
+============
+
+The `cert-arr39-c` check is an alias, please see
+:doc:`bugprone-suspicious-pointer-arithmetics-using-sizeof <../bugprone/suspicious-pointer-arithmetics-using-sizeof>`
+for more information.
>From be6c05aa90caa29b7e6a7b9aff5fd3e3c7082c73 Mon Sep 17 00:00:00 2001
From: Whisperity <whisperity at gmail.com>
Date: Mon, 26 Aug 2024 17:09:51 +0200
Subject: [PATCH 09/11] chore(doc): Added release notes entries
---
clang-tools-extra/docs/ReleaseNotes.rst | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 1b025e8f90f7ba..ba2ffb6f8970ff 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -98,9 +98,19 @@ Improvements to clang-tidy
New checks
^^^^^^^^^^
+- New :doc:`bugprone-suspicious-pointer-arithmetics-using-sizeof
+ <clang-tidy/checks/bugprone/suspicious-pointer-arithmetics-using-sizeof>`
+ check that finds suspicious pointer arithmetic calculations where the pointer
+ is offset by a ``sizeof()`` expression.
+
New check aliases
^^^^^^^^^^^^^^^^^
+- New alias :doc:`cert-arr39-c <clang-tidy/checks/cert/arr39-c>` to
+ :doc:`bugprone-suspicious-pointer-arithmetics-using-sizeof
+ <clang-tidy/checks/bugprone/suspicious-pointer-arithmetics-using-sizeof>`
+ was added.
+
Changes in existing checks
^^^^^^^^^^^^^^^^^^^^^^^^^^
>From cc5de412e09f44df8489a817edc8f219d71f6557 Mon Sep 17 00:00:00 2001
From: Whisperity <whisperity at gmail.com>
Date: Mon, 26 Aug 2024 17:11:50 +0200
Subject: [PATCH 10/11] style: Format out line break from `CERTModule`
---
clang-tools-extra/clang-tidy/cert/CERTTidyModule.cpp | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/cert/CERTTidyModule.cpp b/clang-tools-extra/clang-tidy/cert/CERTTidyModule.cpp
index 9e90f363367496..39ba55142da4bc 100644
--- a/clang-tools-extra/clang-tidy/cert/CERTTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/cert/CERTTidyModule.cpp
@@ -283,8 +283,9 @@ class CERTModule : public ClangTidyModule {
// C checkers
// ARR
- CheckFactories.registerCheck<bugprone::SuspiciousPointerArithmeticsUsingSizeofCheck>(
- "cert-arr39-c");
+ CheckFactories
+ .registerCheck<bugprone::SuspiciousPointerArithmeticsUsingSizeofCheck>(
+ "cert-arr39-c");
// CON
CheckFactories.registerCheck<bugprone::SpuriouslyWakeUpFunctionsCheck>(
"cert-con36-c");
>From 590a7718fb39c918ca8182ab2782c2d235dc8c07 Mon Sep 17 00:00:00 2001
From: Whisperity <whisperity at gmail.com>
Date: Mon, 26 Aug 2024 17:50:16 +0200
Subject: [PATCH 11/11] style: Apply some formatting fixes
---
.../SuspiciousPointerArithmeticsUsingSizeofCheck.cpp | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
index a1710916f762ff..fc9c6eac38f91f 100644
--- a/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/SuspiciousPointerArithmeticsUsingSizeofCheck.cpp
@@ -1,4 +1,4 @@
-//===--- SuspiciousPointerArithmeticsUsingSizeofCheck.cpp - clang-tidy --===//
+//===--- SuspiciousPointerArithmeticsUsingSizeofCheck.cpp - clang-tidy ----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
@@ -68,9 +68,10 @@ static CharUnits getSizeOfType(const ASTContext &Ctx, const Type *Ty) {
void SuspiciousPointerArithmeticsUsingSizeofCheck::check(const MatchFinder::MatchResult &Result) {
const ASTContext &Ctx = *Result.Context;
- const BinaryOperator* Matched = Result.Nodes.getNodeAs<BinaryOperator>(BinOp);
- const QualType* SuspiciousQualTypePtr = Result.Nodes.getNodeAs<QualType>(PointedType);
- const Type* SuspiciousTypePtr = SuspiciousQualTypePtr->getTypePtr();
+ const auto *Matched = Result.Nodes.getNodeAs<BinaryOperator>(BinOp);
+ const auto *SuspiciousQualTypePtr =
+ Result.Nodes.getNodeAs<QualType>(PointedType);
+ const auto *SuspiciousTypePtr = SuspiciousQualTypePtr->getTypePtr();
std::size_t sz = getSizeOfType(Ctx,SuspiciousTypePtr).getQuantity();
if ( sz > 1 )
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