diff --git a/clang/include/clang/Basic/LangOptions.h b/clang/include/clang/Basic/LangOptions.h
--- a/clang/include/clang/Basic/LangOptions.h
+++ b/clang/include/clang/Basic/LangOptions.h
@@ -365,6 +365,17 @@
All,
};
+ enum class StrictFlexArraysLevelKind {
+ /// Any trailing array member is a FAM.
+ Default = 0,
+ /// Any trailing array member of undefined, 0, or 1 size is a FAM.
+ OneZeroOrIncomplete = 1,
+ /// Any trailing array member of undefined or 0 size is a FAM.
+ ZeroOrIncomplete = 2,
+ /// Any trailing array member of undefined size is a FAM.
+ Incomplete = 3,
+ };
+
public:
/// The used language standard.
LangStandard::Kind LangStd;
diff --git a/clang/include/clang/Basic/LangOptions.def b/clang/include/clang/Basic/LangOptions.def
--- a/clang/include/clang/Basic/LangOptions.def
+++ b/clang/include/clang/Basic/LangOptions.def
@@ -427,7 +427,10 @@
LANGOPT(RegisterStaticDestructors, 1, 1, "Register C++ static destructors")
LANGOPT(MatrixTypes, 1, 0, "Enable or disable the builtin matrix type")
-LANGOPT(StrictFlexArrays, 2, 0, "Rely on strict definition of flexible arrays")
+
+ENUM_LANGOPT(StrictFlexArraysLevel, StrictFlexArraysLevelKind, 2,
+ StrictFlexArraysLevelKind::Default,
+ "Rely on strict definition of flexible arrays")
COMPATIBLE_VALUE_LANGOPT(MaxTokens, 32, 0, "Max number of tokens per TU or 0")
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1149,10 +1149,12 @@
MarshallingInfoFlag<LangOpts<"AppleKext">>;
def fstrict_flex_arrays_EQ : Joined<["-"], "fstrict-flex-arrays=">, Group<f_Group>,
MetaVarName<"<n>">, Values<"0,1,2">,
- LangOpts<"StrictFlexArrays">,
+ LangOpts<"StrictFlexArraysLevel">,
Flags<[CC1Option]>,
+ NormalizedValuesScope<"LangOptions::StrictFlexArraysLevelKind">,
+ NormalizedValues<["Default", "OneZeroOrIncomplete", "ZeroOrIncomplete", "Incomplete"]>,
HelpText<"Enable optimizations based on the strict definition of flexible arrays">,
- MarshallingInfoInt<LangOpts<"StrictFlexArrays">>;
+ MarshallingInfoEnum<LangOpts<"StrictFlexArraysLevel">, "Default">;
defm apple_pragma_pack : BoolFOption<"apple-pragma-pack",
LangOpts<"ApplePragmaPack">, DefaultFalse,
PosFlag<SetTrue, [CC1Option], "Enable Apple gcc-compatible #pragma pack handling">,
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -11613,15 +11613,17 @@
// conservative with the last element in structs (if it's an array), so our
// current behavior is more compatible than an explicit list approach would
// be.
- int StrictFlexArraysLevel = Ctx.getLangOpts().StrictFlexArrays;
+ using FAMKind = LangOptions::StrictFlexArraysLevelKind;
+ FAMKind StrictFlexArraysLevel = Ctx.getLangOpts().getStrictFlexArraysLevel();
return LVal.InvalidBase &&
Designator.Entries.size() == Designator.MostDerivedPathLength &&
Designator.MostDerivedIsArrayElement &&
(Designator.isMostDerivedAnUnsizedArray() ||
Designator.getMostDerivedArraySize() == 0 ||
(Designator.getMostDerivedArraySize() == 1 &&
- StrictFlexArraysLevel < 2) ||
- StrictFlexArraysLevel == 0) &&
+ StrictFlexArraysLevel != FAMKind::Incomplete &&
+ StrictFlexArraysLevel != FAMKind::ZeroOrIncomplete) ||
+ StrictFlexArraysLevel == FAMKind::Default) &&
isDesignatorAtObjectEnd(Ctx, LVal);
}
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -878,16 +878,20 @@
/// Determine whether this expression refers to a flexible array member in a
/// struct. We disable array bounds checks for such members.
static bool isFlexibleArrayMemberExpr(const Expr *E,
- unsigned StrictFlexArraysLevel) {
+ LangOptions::StrictFlexArraysLevelKind
+ StrictFlexArraysLevel) {
// For compatibility with existing code, we treat arrays of length 0 or
// 1 as flexible array members.
// FIXME: This is inconsistent with the warning code in SemaChecking. Unify
// the two mechanisms.
const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
+ using FAMKind = LangOptions::StrictFlexArraysLevelKind;
+
// FIXME: Sema doesn't treat [1] as a flexible array member if the bound
// was produced by macro expansion.
- if (StrictFlexArraysLevel >= 2 && CAT->getSize().ugt(0))
+ if (StrictFlexArraysLevel == FAMKind::ZeroOrIncomplete &&
+ CAT->getSize().ugt(0))
return false;
// FIXME: While the default -fstrict-flex-arrays=0 permits Size>1 trailing
// arrays to be treated as flexible-array-members, we still emit ubsan
@@ -963,7 +967,8 @@
static llvm::Value *getArrayIndexingBound(CodeGenFunction &CGF,
const Expr *Base,
QualType &IndexedType,
- unsigned StrictFlexArraysLevel) {
+ LangOptions::StrictFlexArraysLevelKind
+ StrictFlexArraysLevel) {
// For the vector indexing extension, the bound is the number of elements.
if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
IndexedType = Base->getType();
@@ -1001,7 +1006,8 @@
"should not be called unless adding bounds checks");
SanitizerScope SanScope(this);
- const unsigned StrictFlexArraysLevel = getLangOpts().StrictFlexArrays;
+ const LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel =
+ getLangOpts().getStrictFlexArraysLevel();
QualType IndexedType;
llvm::Value *Bound =
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -15904,7 +15904,8 @@
/// We avoid emitting out-of-bounds access warnings for such arrays.
static bool isFlexibleArrayMemberExpr(Sema &S, const Expr *E,
const NamedDecl *ND,
- unsigned StrictFlexArraysLevel) {
+ LangOptions::StrictFlexArraysLevelKind
+ StrictFlexArraysLevel) {
if (!ND)
return false;
@@ -15919,7 +15920,9 @@
// FIXME: While the default -fstrict-flex-arrays=0 permits Size>1 trailing
// arrays to be treated as flexible-array-members, we still emit diagnostics
// as if they are not. Pending further discussion...
- if (StrictFlexArraysLevel >= 2 || Size.uge(2))
+ using FAMKind = LangOptions::StrictFlexArraysLevelKind;
+ if (StrictFlexArraysLevel == FAMKind::ZeroOrIncomplete ||
+ Size.uge(2))
return false;
const FieldDecl *FD = dyn_cast<FieldDecl>(ND);
@@ -15981,7 +15984,8 @@
const ConstantArrayType *ArrayTy =
Context.getAsConstantArrayType(BaseExpr->getType());
- unsigned StrictFlexArraysLevel = getLangOpts().StrictFlexArrays;
+ LangOptions::StrictFlexArraysLevelKind
+ StrictFlexArraysLevel = getLangOpts().getStrictFlexArraysLevel();
const NamedDecl *ND = nullptr;
if (const auto *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
diff --git a/clang/lib/StaticAnalyzer/Core/MemRegion.cpp b/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
--- a/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
+++ b/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
@@ -794,7 +794,11 @@
if (Size.isZero())
return true;
- if (getContext().getLangOpts().StrictFlexArrays >= 2)
+ using FAMKind = LangOptions::StrictFlexArraysLevelKind;
+ const FAMKind StrictFlexArraysLevel =
+ getContext().getLangOpts().getStrictFlexArraysLevel();
+ if (StrictFlexArraysLevel == FAMKind::ZeroOrIncomplete ||
+ StrictFlexArraysLevel == FAMKind::Incomplete)
return false;
const AnalyzerOptions &Opts = SVB.getAnalyzerOptions();