Author: rsmith
Date: Sun Jan 7 14:18:05 2018
New Revision: 321976
URL: http://llvm.org/viewvc/llvm-project?rev=321976&view=rev
Log:
Fix a couple of wrong self-comparison diagnostics.
Check whether we are comparing the same entity, not merely the same
declaration, and don't assume that weak declarations resolve to distinct
entities.
Modified:
cfe/trunk/lib/Sema/SemaExpr.cpp
cfe/trunk/test/Sema/self-comparison.c
cfe/trunk/test/SemaCXX/self-comparison.cpp
Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=321976&r1=321975&r2=321976&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Sun Jan 7 14:18:05 2018
@@ -9627,7 +9627,8 @@ static void diagnoseTautologicalComparis
// result.
ValueDecl *DL = getCompareDecl(LHSStripped);
ValueDecl *DR = getCompareDecl(RHSStripped);
- if (DL && DR && DL == DR && !IsWithinTemplateSpecialization(DL)) {
+ if (DL && DR && declaresSameEntity(DL, DR) &&
+ !IsWithinTemplateSpecialization(DL)) {
StringRef Result;
switch (Opc) {
case BO_EQ: case BO_LE: case BO_GE:
@@ -9648,10 +9649,9 @@ static void diagnoseTautologicalComparis
<< Result);
} else if (DL && DR && LHSType->isArrayType() && RHSType->isArrayType() &&
!DL->getType()->isReferenceType() &&
- !DR->getType()->isReferenceType()) {
+ !DR->getType()->isReferenceType() &&
+ !DL->isWeak() && !DR->isWeak()) {
// What is it always going to evaluate to?
- // FIXME: This is wrong if DL and DR are different Decls for the same
- // entity. It's also wrong if DL and/or DR are weak declarations.
StringRef Result;
switch(Opc) {
case BO_EQ: // e.g. array1 == array2
Modified: cfe/trunk/test/Sema/self-comparison.c
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/self-comparison.c?rev=321976&r1=321975&r2=321976&view=diff
==============================================================================
--- cfe/trunk/test/Sema/self-comparison.c (original)
+++ cfe/trunk/test/Sema/self-comparison.c Sun Jan 7 14:18:05 2018
@@ -86,3 +86,8 @@ int R8435950(int i) {
return 1;
}
+__attribute__((weak)) int weak_1[3];
+__attribute__((weak)) int weak_2[3];
+_Bool compare_weak() {
+ return weak_1 == weak_2;
+}
Modified: cfe/trunk/test/SemaCXX/self-comparison.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/self-comparison.cpp?rev=321976&r1=321975&r2=321976&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/self-comparison.cpp (original)
+++ cfe/trunk/test/SemaCXX/self-comparison.cpp Sun Jan 7 14:18:05 2018
@@ -21,3 +21,7 @@ struct A {
return a == c; // expected-warning {{array comparison always evaluates to
false}}
}
};
+
+namespace NA { extern "C" int x[3]; }
+namespace NB { extern "C" int x[3]; }
+bool k = NA::x == NB::x; // expected-warning {{self-comparison always
evaluates to true}}
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