Change a few calls from getTypeInfo to getTypeInfoInChars. This fixes the
asserts on padding[1][Size]. This should fix the crashes on valid code. There
is still a similar crash on invalid code that this does not fix.
http://llvm-reviews.chandlerc.com/D781
CHANGE SINCE LAST DIFF
http://llvm-reviews.chandlerc.com/D781?vs=1945&id=1953#toc
Files:
test/Sema/offsetof.c
lib/AST/ASTContext.cpp
Index: test/Sema/offsetof.c
===================================================================
--- test/Sema/offsetof.c
+++ test/Sema/offsetof.c
@@ -69,3 +69,15 @@
int test5() {
return __builtin_offsetof(Array, array[*(int*)0]); //
expected-warning{{indirection of non-volatile null pointer}}
expected-note{{__builtin_trap}}
}
+
+// PR15216
+// Don't crash when taking computing the offset of structs with large arrays.
+const unsigned long Size = (1l << 62);
+
+struct Chunk {
+ char padding[Size];
+ char more_padding[1][Size];
+ char data;
+};
+
+int test6 = __builtin_offsetof(struct Chunk, data);
Index: lib/AST/ASTContext.cpp
===================================================================
--- lib/AST/ASTContext.cpp
+++ lib/AST/ASTContext.cpp
@@ -1343,8 +1343,27 @@
return sizeAndAlign;
}
+/// getConstantArrayInfoInChars - Performing the computation in CharUnits
+/// instead of in bits prevents overflowing the uint64_t for some large arrays.
+std::pair<CharUnits, CharUnits>
+static getConstantArrayInfoInChars(const ASTContext &Context,
+ const ConstantArrayType *CAT) {
+ std::pair<CharUnits, CharUnits> EltInfo =
+ Context.getTypeInfoInChars(CAT->getElementType());
+ uint64_t Size = CAT->getSize().getZExtValue();
+ assert((Size == 0 || EltInfo.first.getQuantity() <= (uint64_t)(-1)/Size) &&
+ "Overflow in array type char size evaluation");
+ uint64_t Width = EltInfo.first.getQuantity() * Size;
+ unsigned Align = EltInfo.second.getQuantity();
+ Width = llvm::RoundUpToAlignment(Width, Align);
+ return std::make_pair(CharUnits::fromQuantity(Width),
+ CharUnits::fromQuantity(Align));
+}
+
std::pair<CharUnits, CharUnits>
ASTContext::getTypeInfoInChars(const Type *T) const {
+ if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(T))
+ return getConstantArrayInfoInChars(*this, CAT);
std::pair<uint64_t, unsigned> Info = getTypeInfo(T);
return std::make_pair(toCharUnitsFromBits(Info.first),
toCharUnitsFromBits(Info.second));
@@ -1700,10 +1719,10 @@
/// getTypeSizeInChars - Return the size of the specified type, in characters.
/// This method does not work on incomplete types.
CharUnits ASTContext::getTypeSizeInChars(QualType T) const {
- return toCharUnitsFromBits(getTypeSize(T));
+ return getTypeInfoInChars(T).first;
}
CharUnits ASTContext::getTypeSizeInChars(const Type *T) const {
- return toCharUnitsFromBits(getTypeSize(T));
+ return getTypeInfoInChars(T).first;
}
/// getTypeAlignInChars - Return the ABI-specified alignment of a type, in
Index: test/Sema/offsetof.c
===================================================================
--- test/Sema/offsetof.c
+++ test/Sema/offsetof.c
@@ -69,3 +69,15 @@
int test5() {
return __builtin_offsetof(Array, array[*(int*)0]); // expected-warning{{indirection of non-volatile null pointer}} expected-note{{__builtin_trap}}
}
+
+// PR15216
+// Don't crash when taking computing the offset of structs with large arrays.
+const unsigned long Size = (1l << 62);
+
+struct Chunk {
+ char padding[Size];
+ char more_padding[1][Size];
+ char data;
+};
+
+int test6 = __builtin_offsetof(struct Chunk, data);
Index: lib/AST/ASTContext.cpp
===================================================================
--- lib/AST/ASTContext.cpp
+++ lib/AST/ASTContext.cpp
@@ -1343,8 +1343,27 @@
return sizeAndAlign;
}
+/// getConstantArrayInfoInChars - Performing the computation in CharUnits
+/// instead of in bits prevents overflowing the uint64_t for some large arrays.
+std::pair<CharUnits, CharUnits>
+static getConstantArrayInfoInChars(const ASTContext &Context,
+ const ConstantArrayType *CAT) {
+ std::pair<CharUnits, CharUnits> EltInfo =
+ Context.getTypeInfoInChars(CAT->getElementType());
+ uint64_t Size = CAT->getSize().getZExtValue();
+ assert((Size == 0 || EltInfo.first.getQuantity() <= (uint64_t)(-1)/Size) &&
+ "Overflow in array type char size evaluation");
+ uint64_t Width = EltInfo.first.getQuantity() * Size;
+ unsigned Align = EltInfo.second.getQuantity();
+ Width = llvm::RoundUpToAlignment(Width, Align);
+ return std::make_pair(CharUnits::fromQuantity(Width),
+ CharUnits::fromQuantity(Align));
+}
+
std::pair<CharUnits, CharUnits>
ASTContext::getTypeInfoInChars(const Type *T) const {
+ if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(T))
+ return getConstantArrayInfoInChars(*this, CAT);
std::pair<uint64_t, unsigned> Info = getTypeInfo(T);
return std::make_pair(toCharUnitsFromBits(Info.first),
toCharUnitsFromBits(Info.second));
@@ -1700,10 +1719,10 @@
/// getTypeSizeInChars - Return the size of the specified type, in characters.
/// This method does not work on incomplete types.
CharUnits ASTContext::getTypeSizeInChars(QualType T) const {
- return toCharUnitsFromBits(getTypeSize(T));
+ return getTypeInfoInChars(T).first;
}
CharUnits ASTContext::getTypeSizeInChars(const Type *T) const {
- return toCharUnitsFromBits(getTypeSize(T));
+ return getTypeInfoInChars(T).first;
}
/// getTypeAlignInChars - Return the ABI-specified alignment of a type, in
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