https://github.com/budimirarandjelovicsyrmia updated
https://github.com/llvm/llvm-project/pull/70307
From 0ed347381cdd9e639ab5026dcf244ca4d7fcb6e3 Mon Sep 17 00:00:00 2001
From: budimirarandjelovicsyrmia <budimir.arandjelo...@syrmia.com>
Date: Thu, 26 Oct 2023 10:39:52 +0200
Subject: [PATCH] [clang] Emit bad shift warnings
---
clang/lib/AST/ExprConstant.cpp | 7 +++++++
clang/lib/Sema/SemaExpr.cpp | 17 +++++++++++++----
clang/test/C/drs/dr0xx.c | 2 +-
clang/test/Sema/shift-count-negative.c | 10 ++++++++++
clang/test/Sema/shift-count-overflow.c | 7 +++++++
clang/test/Sema/shift-negative-value.c | 10 ++++++++++
clang/test/Sema/vla-2.c | 6 ++++--
clang/test/SemaCXX/shift.cpp | 1 -
8 files changed, 52 insertions(+), 8 deletions(-)
create mode 100644 clang/test/Sema/shift-count-negative.c
create mode 100644 clang/test/Sema/shift-count-overflow.c
create mode 100644 clang/test/Sema/shift-negative-value.c
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index af1f18aa8ef24..0926bcf258f58 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -2856,6 +2856,9 @@ static bool handleIntIntBinOp(EvalInfo &Info, const
BinaryOperator *E,
else if (LHS.countl_zero() < SA)
Info.CCEDiag(E, diag::note_constexpr_lshift_discards);
}
+ if (Info.EvalStatus.Diag && !Info.EvalStatus.Diag->empty() &&
+ Info.getLangOpts().CPlusPlus)
+ return false;
Result = LHS << SA;
return true;
}
@@ -2879,6 +2882,10 @@ static bool handleIntIntBinOp(EvalInfo &Info, const
BinaryOperator *E,
if (SA != RHS)
Info.CCEDiag(E, diag::note_constexpr_large_shift)
<< RHS << E->getType() << LHS.getBitWidth();
+
+ if (Info.EvalStatus.Diag && !Info.EvalStatus.Diag->empty() &&
+ Info.getLangOpts().CPlusPlus)
+ return false;
Result = LHS >> SA;
return true;
}
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 44f886bf54e3a..c77a0e511a3a8 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -11246,7 +11246,7 @@ static void DiagnoseBadShiftValues(Sema& S, ExprResult
&LHS, ExprResult &RHS,
if (Right.isNegative()) {
S.DiagRuntimeBehavior(Loc, RHS.get(),
S.PDiag(diag::warn_shift_negative)
- << RHS.get()->getSourceRange());
+ << RHS.get()->getSourceRange());
return;
}
@@ -11261,7 +11261,7 @@ static void DiagnoseBadShiftValues(Sema& S, ExprResult
&LHS, ExprResult &RHS,
if (Right.uge(LeftSize)) {
S.DiagRuntimeBehavior(Loc, RHS.get(),
S.PDiag(diag::warn_shift_gt_typewidth)
- << RHS.get()->getSourceRange());
+ << RHS.get()->getSourceRange());
return;
}
@@ -11294,7 +11294,7 @@ static void DiagnoseBadShiftValues(Sema& S, ExprResult
&LHS, ExprResult &RHS,
if (Left.isNegative()) {
S.DiagRuntimeBehavior(Loc, LHS.get(),
S.PDiag(diag::warn_shift_lhs_negative)
- << LHS.get()->getSourceRange());
+ << LHS.get()->getSourceRange());
return;
}
@@ -17130,11 +17130,20 @@ Sema::VerifyIntegerConstantExpression(Expr *E,
llvm::APSInt *Result,
// Circumvent ICE checking in C++11 to avoid evaluating the expression twice
// in the non-ICE case.
if (!getLangOpts().CPlusPlus11 && E->isIntegerConstantExpr(Context)) {
+ SmallVector<PartialDiagnosticAt, 8> Notes;
if (Result)
- *Result = E->EvaluateKnownConstIntCheckOverflow(Context);
+ *Result = E->EvaluateKnownConstIntCheckOverflow(Context, &Notes);
if (!isa<ConstantExpr>(E))
E = Result ? ConstantExpr::Create(Context, E, APValue(*Result))
: ConstantExpr::Create(Context, E);
+
+ if (Notes.size() && !Diagnoser.Suppress) {
+ Diagnoser.diagnoseNotICE(*this, DiagLoc) << E->getSourceRange();
+ for (const PartialDiagnosticAt &Note : Notes)
+ Diag(Note.first, Note.second);
+ return ExprError();
+ }
+
return E;
}
diff --git a/clang/test/C/drs/dr0xx.c b/clang/test/C/drs/dr0xx.c
index 36de32a93da95..05045344efd91 100644
--- a/clang/test/C/drs/dr0xx.c
+++ b/clang/test/C/drs/dr0xx.c
@@ -430,7 +430,7 @@ void dr081(void) {
/* Demonstrate that we don't crash when left shifting a signed value; that's
* implementation defined behavior.
*/
- _Static_assert(-1 << 1 == -2, "fail"); /* Didn't shift a zero into the "sign
bit". */
+ _Static_assert(-1 << 1 == -2, "fail"); /* Undefined behavior since C99 */
_Static_assert(1 << 3 == 1u << 3u, "fail"); /* Shift of a positive signed
value does sensible things. */
}
diff --git a/clang/test/Sema/shift-count-negative.c
b/clang/test/Sema/shift-count-negative.c
new file mode 100644
index 0000000000000..34d51294b43d4
--- /dev/null
+++ b/clang/test/Sema/shift-count-negative.c
@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -x c -fsyntax-only -verify=expected,c
-Wshift-count-negative %s
+// RUN: %clang_cc1 -x c -fsyntax-only -verify=expected,c -Wall %s
+// RUN: %clang_cc1 -x c++ -fsyntax-only -verify=expected,cpp
-Wshift-count-negative %s
+// RUN: %clang_cc1 -x c++ -fsyntax-only -verify=expected,cpp -Wall %s
+
+enum shiftof {
+ X = (1<<-29) // c-error {{expression is not an integer constant
expression}}
+ // cpp-error@-1 {{expression is not an integral constant
expression}}
+ // expected-note@-2 {{negative shift count -29}}
+};
diff --git a/clang/test/Sema/shift-count-overflow.c
b/clang/test/Sema/shift-count-overflow.c
new file mode 100644
index 0000000000000..77dd4b3c6a401
--- /dev/null
+++ b/clang/test/Sema/shift-count-overflow.c
@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wshift-count-overflow %s
+// RUN: %clang_cc1 -fsyntax-only -verify -Wall %s
+
+enum shiftof {
+ X = (1<<32) // expected-error {{expression is not an integer constant
expression}}
+ // expected-note@-1 {{shift count 32 >= width of type 'int'}}
+};
diff --git a/clang/test/Sema/shift-negative-value.c
b/clang/test/Sema/shift-negative-value.c
new file mode 100644
index 0000000000000..0394c00e00d0f
--- /dev/null
+++ b/clang/test/Sema/shift-negative-value.c
@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -x c -fsyntax-only -verify=expected,c
-Wshift-negative-value %s
+// RUN: %clang_cc1 -x c -fsyntax-only -verify=expected,c -Wall %s
+// RUN: %clang_cc1 -x c++ -fsyntax-only -verify=expected,cpp
-Wshift-negative-value %s
+// RUN: %clang_cc1 -x c++ -fsyntax-only -verify=expected,cpp -Wall %s
+
+enum shiftof {
+ X = (-1<<29) // c-error {{expression is not an integer constant
expression}}
+ // cpp-error@-1 {{expression is not an integral constant
expression}}
+ // expected-note@-2 {{left shift of negative value -1}}
+};
diff --git a/clang/test/Sema/vla-2.c b/clang/test/Sema/vla-2.c
index 316931f270607..577407e15b479 100644
--- a/clang/test/Sema/vla-2.c
+++ b/clang/test/Sema/vla-2.c
@@ -4,11 +4,13 @@
// a different codepath when we have already emitted an error.)
int PotentiallyEvaluatedSizeofWarn(int n) {
- return (int)sizeof *(0 << 32,(int(*)[n])0); // expected-warning {{left
operand of comma operator has no effect}} expected-warning {{shift count >=
width of type}}
+ return (int)sizeof *(0 << 32,(int(*)[n])0); /* expected-warning {{shift
count >= width of type}}
+ expected-warning {{left
operand of comma operator has no effect}} */
}
void PotentiallyEvaluatedTypeofWarn(int n) {
- __typeof(*(0 << 32,(int(*)[n])0)) x; // expected-warning {{left operand of
comma operator has no effect}} expected-warning {{shift count >= width of type}}
+ __typeof(*(0 << 32,(int(*)[n])0)) x; /* expected-warning {{shift count >=
width of type}}
+ expected-warning {{left operand of
comma operator has no effect}} */
(void)x;
}
diff --git a/clang/test/SemaCXX/shift.cpp b/clang/test/SemaCXX/shift.cpp
index 89a98791d3eba..c3249b124e926 100644
--- a/clang/test/SemaCXX/shift.cpp
+++ b/clang/test/SemaCXX/shift.cpp
@@ -22,7 +22,6 @@ void test() {
c = 1 << -1; // expected-warning {{shift count is negative}}
c = 1 >> -1; // expected-warning {{shift count is negative}}
c = 1 << (unsigned)-1; // expected-warning {{shift count >= width of type}}
- // expected-warning@-1 {{implicit conversion}}
c = 1 >> (unsigned)-1; // expected-warning {{shift count >= width of type}}
c = 1 << c;
c <<= 0;
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