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e169351252
The architecture enumeration is shared across ARM and AArch64. However, the data is not. The code incorrectly would index into the array using the architecture index which was offset by the ARMv7 architecture enumeration. We do not have a marker for indicating the architectural family to which the enumeration belongs so we cannot be clever about offsetting the index (at least it is not immediately apparent to me). Instead, fall back to the tried-and-true method of slowly iterating the array (its not a large array, so the impact of this is not too high). Because of the incorrect indexing, if we were lucky, we would crash, but usually we would return an invalid StringRef. We did not have any tests for the AArch64 target parser previously;. Extend the previous tests I had added for ARM to cover AArch64 for ensuring that we return expected StringRefs. Take the opportunity to change some iterator types to references. This work is needed to support parsing `.arch name` directives in the AArch64 target asm parser. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272145 91177308-0d34-0410-b5e6-96231b3b80d8
Design Of lib/System
====================
The software in this directory is designed to completely shield LLVM from any
and all operating system specific functionality. It is not intended to be a
complete operating system wrapper (such as ACE), but only to provide the
functionality necessary to support LLVM.
The software located here, of necessity, has very specific and stringent design
rules. Violation of these rules means that cracks in the shield could form and
the primary goal of the library is defeated. By consistently using this library,
LLVM becomes more easily ported to new platforms since the only thing requiring
porting is this library.
Complete documentation for the library can be found in the file:
llvm/docs/SystemLibrary.html
or at this URL:
http://llvm.org/docs/SystemLibrary.html
While we recommend that you read the more detailed documentation, for the
impatient, here's a high level summary of the library's requirements.
1. No system header files are to be exposed through the interface.
2. Std C++ and Std C header files are okay to be exposed through the interface.
3. No exposed system-specific functions.
4. No exposed system-specific data.
5. Data in lib/System classes must use only simple C++ intrinsic types.
6. Errors are handled by returning "true" and setting an optional std::string
7. Library must not throw any exceptions, period.
8. Interface functions must not have throw() specifications.
9. No duplicate function impementations are permitted within an operating
system class.
To accomplish these requirements, the library has numerous design criteria that
must be satisfied. Here's a high level summary of the library's design criteria:
1. No unused functionality (only what LLVM needs)
2. High-Level Interfaces
3. Use Opaque Classes
4. Common Implementations
5. Multiple Implementations
6. Minimize Memory Allocation
7. No Virtual Methods