https://github.com/malavikasamak created
https://github.com/llvm/llvm-project/pull/78815
The patch fixes the crash introduced by the DataInvocation warning gadget
designed to warn against unsafe invocations of span::data method.
Radar: 121223051
>From 6334cd361f79fc79f32b8ca95c6f31a083704332 Mon Sep 17 00:00:00 2001
From: MalavikaSamak <malavi...@apple.com>
Date: Fri, 19 Jan 2024 15:16:12 -0800
Subject: [PATCH] [-Wunsafe-buffer-usage] Fix the crash introduced by the
unsafe invocation of span::data warning
Radar: 121223051
---
clang/lib/Analysis/UnsafeBufferUsage.cpp | 5 ++--
clang/lib/Sema/AnalysisBasedWarnings.cpp | 26 ++++++++++++++-----
...e-buffer-usage-warning-data-invocation.cpp | 24 +++++++++++------
3 files changed, 38 insertions(+), 17 deletions(-)
diff --git a/clang/lib/Analysis/UnsafeBufferUsage.cpp
b/clang/lib/Analysis/UnsafeBufferUsage.cpp
index 724c4304a07242..7df706beb22662 100644
--- a/clang/lib/Analysis/UnsafeBufferUsage.cpp
+++ b/clang/lib/Analysis/UnsafeBufferUsage.cpp
@@ -739,9 +739,10 @@ class DataInvocationGadget : public WarningGadget {
}
static Matcher matcher() {
+ Matcher callExpr = cxxMemberCallExpr(
+ callee(cxxMethodDecl(hasName("data"), ofClass(hasName("std::span")))));
return stmt(
- explicitCastExpr(has(cxxMemberCallExpr(callee(cxxMethodDecl(
- hasName("data"),
ofClass(hasName("std::span")))))))
+ explicitCastExpr(anyOf(has(callExpr), has(parenExpr(has(callExpr)))))
.bind(OpTag));
}
const Stmt *getBaseStmt() const override { return Op; }
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp
b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 9eb1df5f024059..749655d03342cc 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2263,15 +2263,27 @@ class UnsafeBufferUsageReporter : public
UnsafeBufferUsageHandler {
MsgParam = 3;
} else if (const auto *ECE = dyn_cast<ExplicitCastExpr>(Operation)) {
QualType destType = ECE->getType();
- const uint64_t dSize =
- Ctx.getTypeSize(destType.getTypePtr()->getPointeeType());
- if (const auto *CE = dyn_cast<CXXMemberCallExpr>(ECE->getSubExpr())) {
- QualType srcType = CE->getType();
- const uint64_t sSize =
- Ctx.getTypeSize(srcType.getTypePtr()->getPointeeType());
- if (sSize >= dSize)
+ if (!isa<PointerType>(destType))
+ return;
+
+ const Expr *subExpr = ECE->getSubExpr();
+ // Check if related to DataInvocation warning gadget.
+ if (!isa<CXXMemberCallExpr>(subExpr)) {
+ if (const auto *SE = dyn_cast<ParenExpr>(subExpr)) {
+ if (!isa<CXXMemberCallExpr>(SE->getSubExpr()))
+ return;
+ } else
return;
}
+ const uint64_t dSize =
+ Ctx.getTypeSize(destType.getTypePtr()->getPointeeType());
+
+ QualType srcType = ECE->getSubExpr()->getType();
+ const uint64_t sSize =
+ Ctx.getTypeSize(srcType.getTypePtr()->getPointeeType());
+ if (sSize >= dSize)
+ return;
+
MsgParam = 4;
}
Loc = Operation->getBeginLoc();
diff --git
a/clang/test/SemaCXX/warn-unsafe-buffer-usage-warning-data-invocation.cpp
b/clang/test/SemaCXX/warn-unsafe-buffer-usage-warning-data-invocation.cpp
index 79eb3bb4bacc6e..7b39bef0411423 100644
--- a/clang/test/SemaCXX/warn-unsafe-buffer-usage-warning-data-invocation.cpp
+++ b/clang/test/SemaCXX/warn-unsafe-buffer-usage-warning-data-invocation.cpp
@@ -22,6 +22,8 @@ namespace std {
using size_t = __typeof(sizeof(int));
void *malloc(size_t);
+typedef long int intptr_t;
+
void foo(int v) {
}
@@ -90,15 +92,18 @@ void cast_without_data(int *ptr) {
void warned_patterns(std::span<int> span_ptr, std::span<Base> base_span,
span<int> span_without_qual) {
A *a1 = (A*)span_ptr.data(); // expected-warning{{unsafe invocation of
span::data}}
a1 = (A*)span_ptr.data(); // expected-warning{{unsafe invocation of
span::data}}
-
- A *a2 = (A*) span_without_qual.data(); // expected-warning{{unsafe
invocation of span::data}}
-
- // TODO:: Should we warn when we cast from base to derived type?
- Derived *b = dynamic_cast<Derived*> (base_span.data());//
expected-warning{{unsafe invocation of span::data}}
- // TODO:: This pattern is safe. We can add special handling for it, if we
decide this
- // is the recommended fixit for the unsafe invocations.
- A *a3 = (A*)span_ptr.subspan(0, sizeof(A)).data(); //
expected-warning{{unsafe invocation of span::data}}
+ a1 = (A*)(span_ptr.data()); // expected-warning{{unsafe invocation of
span::data}}
+ A *a2 = (A*) (span_without_qual.data()); // expected-warning{{unsafe
invocation of span::data}}
+
+ a2 = (A*) span_without_qual.data(); // expected-warning{{unsafe invocation
of span::data}}
+
+ // TODO:: Should we warn when we cast from base to derived type?
+ Derived *b = dynamic_cast<Derived*> (base_span.data());//
expected-warning{{unsafe invocation of span::data}}
+
+ // TODO:: This pattern is safe. We can add special handling for it, if we
decide this
+ // is the recommended fixit for the unsafe invocations.
+ A *a3 = (A*)span_ptr.subspan(0, sizeof(A)).data(); //
expected-warning{{unsafe invocation of span::data}}
}
void not_warned_patterns(std::span<A> span_ptr, std::span<Base> base_span) {
@@ -108,6 +113,9 @@ void not_warned_patterns(std::span<A> span_ptr,
std::span<Base> base_span) {
p = (int*) span_ptr.data();
A *a = (A*) span_ptr.hello(); // Invoking other methods.
+
+ intptr_t k = (intptr_t) span_ptr.data();
+ k = (intptr_t) (span_ptr.data());
}
// We do not want to warn about other types
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