Remove some autoconf references from docs and comments

[svenvh]

Summary

The autoconf build system support has been removed a while ago, remove
some outdated references.

[lebedev.ri]

Nice cleanup!

include/llvm/ADT/Triple.h

22

this should stay

40–42

same, this isn't specific about llvm autoconf buildsystem, but more about triples in general

[svenvh]

include/llvm/ADT/Triple.h

22

Fair enough, I've taken this file out of my local patch.

[svenvh]

Dropping changes to Triple.h.

[Anastasia]

LGTM! Thanks!

docs/CMake.rst

 for a quick solution.
 
 Also see the `LLVM-specific variables`_ section for variables used when
 cross-compiling.
 
 Embedding LLVM in your project
 ==============================
 
-From LLVM 3.5 onwards both the CMake and autoconf/Makefile build systems export
-LLVM libraries as importable CMake targets. This means that clients of LLVM can
-now reliably use CMake to develop their own LLVM-based projects against an
-installed version of LLVM regardless of how it was built.
+From LLVM 3.5 onwards the CMake build system exports LLVM libraries as
+importable CMake targets. This means that clients of LLVM can now reliably use
+CMake to develop their own LLVM-based projects against an installed version of
+LLVM regardless of how it was built.
 
 Here is a simple example of a CMakeLists.txt file that imports the LLVM libraries
 and uses them to build a simple application ``simple-tool``.
 
 .. code-block:: cmake
 
   cmake_minimum_required(VERSION 3.4.3)
   project(SimpleProject)

docs/FAQ.rst

 
 How portable is the LLVM source code?
 -------------------------------------
 The LLVM source code should be portable to most modern Unix-like operating
 systems.  Most of the code is written in standard C++ with operating system
 services abstracted to a support library.  The tools required to build and
 test LLVM have been ported to a plethora of platforms.
 
-Some porting problems may exist in the following areas:
-
-* The autoconf/makefile build system relies heavily on UNIX shell tools,
-  like the Bourne Shell and sed.  Porting to systems without these tools
-  (MacOS 9, Plan 9) will require more effort.
-
 What API do I use to store a value to one of the virtual registers in LLVM IR's SSA representation?
 ---------------------------------------------------------------------------------------------------
 
 In short: you can't. It's actually kind of a silly question once you grok
 what's going on. Basically, in code like:
 
 .. code-block:: llvm
 

docs/HowToReleaseLLVM.rst

::
      $ svn co https://llvm.org/svn/llvm-project/cfe/branches/release_XY clang-X.Y
 
      $ svn co https://llvm.org/svn/llvm-project/test-suite/branches/release_XY test-suite-X.Y
 
 Update LLVM Version
 ^^^^^^^^^^^^^^^^^^^
 
 After creating the LLVM release branch, update the release branches'
-``autoconf`` and ``configure.ac`` versions from '``X.Ysvn``' to '``X.Y``'.
+``CMakeLists.txt`` versions from '``X.Ysvn``' to '``X.Y``'.
 Update it on mainline as well to be the next version ('``X.Y+1svn``').
-Regenerate the configure scripts for both ``llvm`` and the ``test-suite``.
 
 In addition, the version numbers of all the Bugzilla components must be updated
 for the next release.
 
 Tagging the LLVM Release Candidates
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Tag release candidates using the tag.sh script in utils/release.

docs/ProgrammersManual.rst

 
 Checks and asserts that alter the LLVM C++ ABI are predicated on the
 preprocessor symbol `LLVM_ENABLE_ABI_BREAKING_CHECKS` -- LLVM
 libraries built with `LLVM_ENABLE_ABI_BREAKING_CHECKS` are not ABI
 compatible LLVM libraries built without it defined.  By default,
 turning on assertions also turns on `LLVM_ENABLE_ABI_BREAKING_CHECKS`
 so a default +Asserts build is not ABI compatible with a
 default -Asserts build.  Clients that want ABI compatibility
-between +Asserts and -Asserts builds should use the CMake or autoconf
-build systems to set `LLVM_ENABLE_ABI_BREAKING_CHECKS` independently
+between +Asserts and -Asserts builds should use the CMake build system
+to set `LLVM_ENABLE_ABI_BREAKING_CHECKS` independently
 of `LLVM_ENABLE_ASSERTIONS`.
 
 .. _coreclasses:
 
 The Core LLVM Class Hierarchy Reference
 =======================================
 
 ``#include "llvm/IR/Type.h"``

include/llvm/ADT/Triple.h

 // Some system headers or GCC predefined macros conflict with identifiers in
 // this file.  Undefine them here.
 #undef NetBSD
 #undef mips
 #undef sparc
 
 namespace llvm {
 
-/// Triple - Helper class for working with autoconf configuration names. For
+/// Triple - Helper class for working with configuration names. For
 /// historical reasons, we also call these 'triples' (they used to contain
 /// exactly three fields).
 ///
 /// Configuration names are strings in the canonical form:
 ///   ARCHITECTURE-VENDOR-OPERATING_SYSTEM
 /// or
 ///   ARCHITECTURE-VENDOR-OPERATING_SYSTEM-ENVIRONMENT
 ///
 /// This class is used for clients which want to support arbitrary
 /// configuration names, but also want to implement certain special
 /// behavior for particular configurations. This class isolates the mapping
 /// from the components of the configuration name to well known IDs.
 ///
 /// At its core the Triple class is designed to be a wrapper for a triple
 /// string; the constructor does not change or normalize the triple string.
 /// Clients that need to handle the non-canonical triples that users often
 /// specify should use the normalize method.
-///
-/// See autoconf/config.guess for a glimpse into what configuration names
-/// look like in practice.
 class Triple {
 public:
   enum ArchType {
     UnknownArch,
 
     arm,            // ARM (little endian): arm, armv.*, xscale
     armeb,          // ARM (big endian): armeb
     aarch64,        // AArch64 (little endian): aarch64

lib/Support/Errno.cpp

 //===- Errno.cpp - errno support --------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the errno wrappers.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/Errno.h"
-#include "llvm/Config/config.h" // Get autoconf configuration settings
+#include "llvm/Config/config.h"
 #include "llvm/Support/raw_ostream.h"
 #include <string.h>
 
 #if HAVE_ERRNO_H
 #include <errno.h>
 #endif
 
 //===----------------------------------------------------------------------===//

lib/Support/PrettyStackTrace.cpp

 //===- PrettyStackTrace.cpp - Pretty Crash Handling -----------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines some helpful functions for dealing with the possibility of
 // Unix signals occurring while your program is running.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/PrettyStackTrace.h"
 #include "llvm-c/ErrorHandling.h"
 #include "llvm/ADT/SmallString.h"
-#include "llvm/Config/config.h" // Get autoconf configuration settings
+#include "llvm/Config/config.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/Watchdog.h"
 #include "llvm/Support/raw_ostream.h"
 
 #include <cstdarg>
 #include <cstdio>
 #include <tuple>

lib/Support/Unix/Unix.h

 #ifndef LLVM_LIB_SUPPORT_UNIX_UNIX_H
 #define LLVM_LIB_SUPPORT_UNIX_UNIX_H
 
 //===----------------------------------------------------------------------===//
 //=== WARNING: Implementation here must contain only generic UNIX code that
 //===          is guaranteed to work on all UNIX variants.
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Config/config.h" // Get autoconf configuration settings
+#include "llvm/Config/config.h"
 #include "llvm/Support/Chrono.h"
 #include "llvm/Support/Errno.h"
 #include <algorithm>
 #include <assert.h>
 #include <cerrno>
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>