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[Sema] -Wzero-as-null-pointer-constant: don't warn for __null #69126

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Merged
merged 3 commits into from
Oct 25, 2023
Merged

[Sema] -Wzero-as-null-pointer-constant: don't warn for __null #69126

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357a21c
[Sema] -Wzero-as-null-pointer-constant: don't warn for __null
zeux Oct 15, 2023
b1fab4a
Add release note
zeux Oct 24, 2023
c401c03
Merge branch 'main' into gnunull-warn
zeux Oct 24, 2023
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8 changes: 7 additions & 1 deletion clang/lib/Sema/Sema.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -590,7 +590,11 @@ void Sema::diagnoseZeroToNullptrConversion(CastKind Kind, const Expr *E) {

if (Kind != CK_NullToPointer && Kind != CK_NullToMemberPointer)
return;
if (E->IgnoreParenImpCasts()->getType()->isNullPtrType())

const Expr *EStripped = E->IgnoreParenImpCasts();
if (EStripped->getType()->isNullPtrType())
return;
if (isa<GNUNullExpr>(EStripped))
return;

if (Diags.isIgnored(diag::warn_zero_as_null_pointer_constant,
Expand All @@ -612,6 +616,8 @@ void Sema::diagnoseZeroToNullptrConversion(CastKind Kind, const Expr *E) {

// If it is a macro from system header, and if the macro name is not "NULL",
// do not warn.
// Note that uses of "NULL" will be ignored above on systems that define it
// as __null.
SourceLocation MaybeMacroLoc = E->getBeginLoc();
if (Diags.getSuppressSystemWarnings() &&
SourceMgr.isInSystemMacro(MaybeMacroLoc) &&
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8 changes: 4 additions & 4 deletions clang/test/SemaCXX/warn-zero-nullptr.cpp
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Expand Up @@ -16,10 +16,10 @@ int (S::*mp1) = 0; // expected-warning{{zero as null pointer constant}}
void (*fp1)() = 0; // expected-warning{{zero as null pointer constant}}
void* p1 = 0; // expected-warning{{zero as null pointer constant}}

// NULL is an integer constant expression, so warn on it too:
void* p2 = __null; // expected-warning{{zero as null pointer constant}}
void (*fp2)() = __null; // expected-warning{{zero as null pointer constant}}
int (S::*mp2) = __null; // expected-warning{{zero as null pointer constant}}
// __null is not treated as an integer constant expression for GCC compatibility
void* p2 = __null;
void (*fp2)() = __null;
int (S::*mp2) = __null;

void f0(void* v = MACRO); // expected-warning{{zero as null pointer constant}}
void f1(void* v = NULL); // expected-warning{{zero as null pointer constant}}
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