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.

llvm-svn: 148553

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/docs/LangRef.html b/llvm/docs/LangRef.html
index 1172b7cb938..e214c5fd555 100644
--- a/llvm/docs/LangRef.html
+++ b/llvm/docs/LangRef.html
@@ -1143,6 +1143,10 @@ define void @f() optsize { ... }
 </pre>
 
 <dl>
+  <dt><tt><b>address_safety</b></tt></dt>
+  <dd>This attribute indicates that the address safety analysis
+  is enabled for this function.  </dd>
+
   <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
   <dd>This attribute indicates that, when emitting the prologue and epilogue,
       the backend should forcibly align the stack pointer. Specify the