Extend Attributes to 64 bits
Problem: LLVM needs more function attributes than currently available (32 bits).
One such proposed attribute is "address_safety", which shows that a function is being checked for address safety (by AddressSanitizer, SAFECode, etc).
Solution:
- extend the Attributes from 32 bits to 64-bits
- wrap the object into a class so that unsigned is never erroneously used instead
- change "unsigned" to "Attributes" throughout the code, including one place in clang.
- the class has no "operator uint64 ()", but it has "uint64_t Raw() " to support packing/unpacking.
- the class has "safe operator bool()" to support the common idiom: if (Attributes attr = getAttrs()) useAttrs(attr);
- The CTOR from uint64_t is marked explicit, so I had to add a few explicit CTOR calls
- Add the new attribute "address_safety". Doing it in the same commit to check that attributes beyond first 32 bits actually work.
- Some of the functions from the Attribute namespace are worth moving inside the class, but I'd prefer to have it as a separate commit.
Tested:
"make check" on Linux (32-bit and 64-bit) and Mac (10.6)
built/run spec CPU 2006 on Linux with clang -O2.
This change will break clang build in lib/CodeGen/CGCall.cpp.
The following patch will fix it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148553 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 9d10498..bddcde8 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -461,8 +461,8 @@
// If Function attributes are using index 0 then transfer them
// to index ~0. Index 0 is used for return value attributes but used to be
// used for function attributes.
- Attributes RetAttribute = Attribute::None;
- Attributes FnAttribute = Attribute::None;
+ Attributes RetAttribute;
+ Attributes FnAttribute;
for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
// FIXME: remove in LLVM 3.0
// The alignment is stored as a 16-bit raw value from bits 31--16.
@@ -472,23 +472,24 @@
if (Alignment && !isPowerOf2_32(Alignment))
return Error("Alignment is not a power of two.");
- Attributes ReconstitutedAttr = Record[i+1] & 0xffff;
+ Attributes ReconstitutedAttr(Record[i+1] & 0xffff);
if (Alignment)
ReconstitutedAttr |= Attribute::constructAlignmentFromInt(Alignment);
- ReconstitutedAttr |= (Record[i+1] & (0xffffull << 32)) >> 11;
- Record[i+1] = ReconstitutedAttr;
+ ReconstitutedAttr |=
+ Attributes((Record[i+1] & (0xffffull << 32)) >> 11);
+ Record[i+1] = ReconstitutedAttr.Raw();
if (Record[i] == 0)
- RetAttribute = Record[i+1];
+ RetAttribute = ReconstitutedAttr;
else if (Record[i] == ~0U)
- FnAttribute = Record[i+1];
+ FnAttribute = ReconstitutedAttr;
}
- unsigned OldRetAttrs = (Attribute::NoUnwind|Attribute::NoReturn|
+ Attributes OldRetAttrs = (Attribute::NoUnwind|Attribute::NoReturn|
Attribute::ReadOnly|Attribute::ReadNone);
if (FnAttribute == Attribute::None && RetAttribute != Attribute::None &&
- (RetAttribute & OldRetAttrs) != 0) {
+ (RetAttribute & OldRetAttrs)) {
if (FnAttribute == Attribute::None) { // add a slot so they get added.
Record.push_back(~0U);
Record.push_back(0);
@@ -505,8 +506,9 @@
} else if (Record[i] == ~0U) {
if (FnAttribute != Attribute::None)
Attrs.push_back(AttributeWithIndex::get(~0U, FnAttribute));
- } else if (Record[i+1] != Attribute::None)
- Attrs.push_back(AttributeWithIndex::get(Record[i], Record[i+1]));
+ } else if (Attributes(Record[i+1]) != Attribute::None)
+ Attrs.push_back(AttributeWithIndex::get(Record[i],
+ Attributes(Record[i+1])));
}
MAttributes.push_back(AttrListPtr::get(Attrs.begin(), Attrs.end()));
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index b6da85e..7fb57ea 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -179,10 +179,11 @@
// Store the alignment in the bitcode as a 16-bit raw value instead of a
// 5-bit log2 encoded value. Shift the bits above the alignment up by
// 11 bits.
- uint64_t FauxAttr = PAWI.Attrs & 0xffff;
+ uint64_t FauxAttr = PAWI.Attrs.Raw() & 0xffff;
if (PAWI.Attrs & Attribute::Alignment)
- FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
- FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
+ FauxAttr |= (1ull<<16)<<
+ (((PAWI.Attrs & Attribute::Alignment).Raw()-1) >> 16);
+ FauxAttr |= (PAWI.Attrs.Raw() & (0x3FFull << 21)) << 11;
Record.push_back(FauxAttr);
}