This patch implements input annotations for diagnostics that suggest
fuzzy matches for directives for which no matches were found. Instead
of using the usual `^~~`, which is used by later patches for good
matches, these annotations use `?` so that fuzzy matches are visually
distinct. No tildes are included as these diagnostics (independently
of this patch) currently identify only the start of the match.
For example:
```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:
- L: labels line number L of the input file
- T:L labels the only match result for a pattern of type T from line L of
the check file
- T:L'N labels the Nth match result for a pattern of type T from line L of
the check file
- X~~ marks search range when no match is found
- ? marks fuzzy match when no match is found
- colors error, fuzzy match
If you are not seeing color above or in input dumps, try: -color
$ FileCheck -v -dump-input=always check1 < input1 |& sed -n '/^<<<</,$p'
<<<<<<
1: ; abc def
2: ; ghI jkl
next:3'0 X~~~~~~~~ error: no match found
next:3'1 ? possible intended match
>>>>>>
$ cat check1
CHECK: abc
CHECK-SAME: def
CHECK-NEXT: ghi
CHECK-SAME: jkl
$ cat input1
; abc def
; ghI jkl
```
This patch introduces the concept of multiple "match results" per
directive. In the above example, the first match result for the
CHECK-NEXT directive is the failed match, for which the annotation
shows the search range. The second match result is the fuzzy match.
Later patches will introduce other cases of multiple match results per
directive.
When colors are enabled, `?` is colored magenta. That is, it doesn't
indicate the actual error, which a red `X~~` marker indicates, but its
color suggests it's closely related.
Reviewed By: george.karpenkov, probinson
Differential Revision: https://reviews.llvm.org/D53893
llvm-svn: 349419
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
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