[clang] 7c00219 - [clang] trigger -Wcast-qual on functional casts
Aaron Ballman via cfe-commits
cfe-commits at lists.llvm.org
Fri Apr 21 04:46:01 PDT 2023
Author: Jorge Pinto Sousa
Date: 2023-04-21T07:45:05-04:00
New Revision: 7c0021923503a9a5fe1ba1f0b778b5b83c42aa43
URL: https://github.com/llvm/llvm-project/commit/7c0021923503a9a5fe1ba1f0b778b5b83c42aa43
DIFF: https://github.com/llvm/llvm-project/commit/7c0021923503a9a5fe1ba1f0b778b5b83c42aa43.diff
LOG: [clang] trigger -Wcast-qual on functional casts
-Wcast-qual does not trigger on the following code in Clang, but does
in GCC.
const auto i = 42;
using T = int*;
auto p = T(&i);
The expected behavior is that a functional cast should trigger
the warning the same as the equivalent C cast because
the meaning is the same, and nothing about the functional cast
makes it easier to recognize that a const_cast is occurring.
Fixes https://github.com/llvm/llvm-project/issues/62083
Differential Revision: https://reviews.llvm.org/D148276
Added:
Modified:
clang/docs/ReleaseNotes.rst
clang/lib/Sema/SemaCast.cpp
clang/test/SemaCXX/warn-cast-qual.cpp
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 7beae03247796..9cc3936745ac6 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -231,6 +231,8 @@ Improvements to Clang's diagnostics
- ``-Wformat`` now recognizes ``%lb`` for the ``printf``/``scanf`` family of
functions.
(`#62247: <https://github.com/llvm/llvm-project/issues/62247>`_).
+- ``-Wcast-qual`` now triggers on function-style casts.
+ (`#62083 <https://github.com/llvm/llvm-project/issues/62083>`_)
Bug Fixes in This Version
-------------------------
diff --git a/clang/lib/Sema/SemaCast.cpp b/clang/lib/Sema/SemaCast.cpp
index cd71288476345..be30d36a4f9a4 100644
--- a/clang/lib/Sema/SemaCast.cpp
+++ b/clang/lib/Sema/SemaCast.cpp
@@ -3332,6 +3332,9 @@ ExprResult Sema::BuildCXXFunctionalCastExpr(TypeSourceInfo *CastTypeInfo,
if (auto *ConstructExpr = dyn_cast<CXXConstructExpr>(SubExpr))
ConstructExpr->setParenOrBraceRange(SourceRange(LPLoc, RPLoc));
+ // -Wcast-qual
+ DiagnoseCastQual(Op.Self, Op.SrcExpr, Op.DestType);
+
return Op.complete(CXXFunctionalCastExpr::Create(
Context, Op.ResultType, Op.ValueKind, CastTypeInfo, Op.Kind,
Op.SrcExpr.get(), &Op.BasePath, CurFPFeatureOverrides(), LPLoc, RPLoc));
diff --git a/clang/test/SemaCXX/warn-cast-qual.cpp b/clang/test/SemaCXX/warn-cast-qual.cpp
index d1f0cc73a63d4..4fe8de9ae59c8 100644
--- a/clang/test/SemaCXX/warn-cast-qual.cpp
+++ b/clang/test/SemaCXX/warn-cast-qual.cpp
@@ -34,6 +34,17 @@ void foo_0() {
const int &a6 = (int &)((int &)a); // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
const int &a7 = (int &)((const int &)a); // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
const int &a8 = (const int &)((int &)a); // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
+
+ using T = int&;
+ using T2 = const int&;
+ const int &a11 =T2(a); // no warning
+ int a22 = T(a); // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
+ const int &a33 = T(a); // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
+ int &a44 = T(T2(a)); // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
+ int &a55 = T(T(a)); // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
+ const int &a66 = T(T(a)); // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
+ int &a77 = T(T2(a)); // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
+ const int &a88 = T2(T(a)); // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
}
void foo_1() {
@@ -49,6 +60,17 @@ void foo_1() {
volatile int &a6 = (int &)((int &)a); // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
volatile int &a7 = (int &)((volatile int &)a); // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
volatile int &a8 = (volatile int &)((int &)a); // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
+
+ using T = int&;
+ using T2 = volatile int&;
+ volatile int &a11 =T2(a); // no warning
+ int a22 = T(a); // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
+ volatile int &a33 = T(a); // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
+ int &a44 = T(T2(a)); // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
+ int &a55 = T(T(a)); // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
+ volatile int &a66 = T(T(a)); // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
+ int &a77 = T(T2(a)); // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
+ volatile int &a88 = T2(T(a)); // expected-warning {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
}
void foo_2() {
@@ -64,6 +86,17 @@ void foo_2() {
const volatile int &a6 = (int &)((int &)a); // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
const volatile int &a7 = (int &)((const volatile int &)a); // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
const volatile int &a8 = (const volatile int &)((int &)a); // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
+
+ using T = int&;
+ using T2 = const volatile int&;
+ const volatile int &a11 =T2(a); // no warning
+ int a22 = T(a); // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
+ const volatile int &a33 = T(a); // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
+ int &a44 = T(T2(a)); // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
+ int &a55 = T(T(a)); // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
+ const volatile int &a66 = T(T(a)); // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
+ const volatile int &a77 = T(T2(a)); // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
+ const volatile int &a88 = T2(T(a)); // expected-warning {{cast from 'const volatile int' to 'int &' drops const and volatile qualifiers}}
}
void bar_0() {
@@ -78,6 +111,16 @@ void bar_0() {
const int **a4 = (const int **)((int **)a); // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}} expected-warning {{cast from 'int **' to 'const int **' must have all intermediate pointers const qualified to be safe}}
const int **a5 = (const int **)((const int **)a); // no warning
+
+ using T = int**;
+ using T2 = const int**;
+
+ int **a00 = T(T2(a)) ; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
+ int **a11 = T(T(a)); // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
+
+ const int **a44 = T2(T(a)); // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}} expected-warning {{cast from 'T' (aka 'int **') to 'T2' (aka 'const int **') must have all intermediate pointers const qualified to be safe}}
+ const int **a55 = T2(T2(a)); // no warning
+
}
void bar_1() {
@@ -92,6 +135,15 @@ void bar_1() {
const int *&a4 = (const int *&)((int *&)a); // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}} expected-warning {{cast from 'int *' to 'const int *&' must have all intermediate pointers const qualified to be safe}}
const int *&a5 = (const int *&)((const int *&)a); // no warning
+
+ using T = int*&;
+ using T2 = const int*&;
+
+ int *&a00 = T(T2(a)); // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
+ int *&a11 = T(T(a)); // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
+
+ const int *&a44 = T2(T(a)); // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}} expected-warning {{cast from 'int *' to 'T2' (aka 'const int *&') must have all intermediate pointers const qualified to be safe}}
+ const int *&a55 = T2(T2(a)); // no warning
}
void baz_0() {
@@ -108,6 +160,14 @@ void baz_0() {
((C *)&S)->B(); // expected-warning {{cast from 'const C *' to 'C *' drops const qualifier}}
((C *)&S)->A(); // expected-warning {{cast from 'const C *' to 'C *' drops const qualifier}}
+
+ using T = C&;
+ using T2 = C*;
+ T(S).B(); // expected-warning {{cast from 'const C' to 'C &' drops const qualifier}}
+ T(S).A(); // expected-warning {{cast from 'const C' to 'C &' drops const qualifier}}
+
+ T2(&S)->B(); // expected-warning {{cast from 'const C *' to 'C *' drops const qualifier}}
+ T2(&S)->A(); // expected-warning {{cast from 'const C *' to 'C *' drops const qualifier}}
}
void baz_1() {
@@ -127,6 +187,14 @@ void baz_1() {
*(int *)(&S.a) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
*(int *)(&S.b) = 0; // no warning
+
+ using T = int&;
+ using T2 = int*;
+ T(S.a) = 0; // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
+ T(S.b) = 0; // no warning
+
+ *T2(&S.a) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
+ *T2(&S.b) = 0; // no warning
}
{
const C S;
@@ -136,5 +204,39 @@ void baz_1() {
*(int *)(&S.a) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
*(int *)(&S.b) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
+
+ using T = int&;
+ using T2 = int*;
+ T(S.a) = 0; // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
+ T(S.b) = 0; // expected-warning {{cast from 'const int' to 'int &' drops const qualifier}}
+
+ *T2(&S.a) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
+ *T2(&S.b) = 0; // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
}
}
+
+void qux_0() {
+ const auto i = 42;
+ using T = int*;
+ auto p = T(&i); // expected-warning {{cast from 'const int *' to 'int *' drops const qualifier}}
+
+ const auto i2 = 42;
+ using T2 = const int*;
+ auto p2 = T2(&i2);
+
+ volatile auto i3 = 42;
+ using T3= int*;
+ auto p3 = T3(&i3); // expected-warning {{cast from 'volatile int *' to 'int *' drops volatile qualifier}}
+
+ volatile auto i4 = 42;
+ using T4 = volatile int*;
+ auto p4 = T4(&i4);
+
+ const volatile auto i5 = 42;
+ using T5= int*;
+ auto p5 = T5(&i5); // expected-warning {{cast from 'const volatile int *' to 'int *' drops const and volatile qualifiers}}
+
+ const volatile auto i6 = 42;
+ using T6= const volatile int*;
+ auto p6 = T6(&i6);
+}
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