Upgrade PEGTL to latest version 3.2.7. In upcoming version 4+, they have

removed support for the amalgamated header.  In anticipation of this, we add a
new pxr/base/pegtl library rather than embedding it in pxr/base/tf.

(Internal change: 2324194)

LICENSE.txt

@@ -679,7 +679,7 @@ The Art of C++ : PEGTL (Parsing Expression Grammar Template Library)
 
 The MIT License (MIT)
 
-Copyright (c) 2007-2020 Dr. Colin Hirsch and Daniel Frey
+Copyright (c) 2007-2022 Dr. Colin Hirsch and Daniel Frey
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -748,4 +748,4 @@ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
+SOFTWARE.

pxr/base/CMakeLists.txt

@@ -2,6 +2,7 @@ set(DIRS
     arch
     tf
     gf
+    pegtl
     js
     trace
     work

pxr/base/pegtl/CMakeLists.txt

@@ -0,0 +1,206 @@
+set(PXR_PREFIX pxr/base)
+set(PXR_PACKAGE pegtl)
+
+pxr_library(pegtl
+    # Workaround lack of build support for header-only libs.
+    LIBRARIES
+       arch
+
+    PUBLIC_HEADERS
+        pegtl.hpp
+        pegtl/apply_mode.hpp
+        pegtl/argv_input.hpp
+        pegtl/ascii.hpp
+        pegtl/buffer_input.hpp
+        pegtl/change_action.hpp
+        pegtl/change_action_and_state.hpp
+        pegtl/change_action_and_states.hpp
+        pegtl/change_control.hpp
+        pegtl/change_state.hpp
+        pegtl/change_states.hpp
+        pegtl/config.hpp
+        pegtl/contrib/abnf.hpp
+        pegtl/contrib/add_state.hpp
+        pegtl/contrib/alphabet.hpp
+        pegtl/contrib/analyze.hpp
+        pegtl/contrib/analyze_traits.hpp
+        pegtl/contrib/check_bytes.hpp
+        pegtl/contrib/control_action.hpp
+        pegtl/contrib/coverage.hpp
+        pegtl/contrib/forward.hpp
+        pegtl/contrib/function.hpp
+        pegtl/contrib/http.hpp
+        pegtl/contrib/icu/internal.hpp
+        pegtl/contrib/icu/utf16.hpp
+        pegtl/contrib/icu/utf32.hpp
+        pegtl/contrib/icu/utf8.hpp
+        pegtl/contrib/if_then.hpp
+        pegtl/contrib/instantiate.hpp
+        pegtl/contrib/integer.hpp
+        pegtl/contrib/internal/endian.hpp
+        pegtl/contrib/internal/endian_gcc.hpp
+        pegtl/contrib/internal/endian_win.hpp
+        pegtl/contrib/internal/peek_mask_uint.hpp
+        pegtl/contrib/internal/peek_mask_uint8.hpp
+        pegtl/contrib/internal/peek_uint.hpp
+        pegtl/contrib/internal/peek_uint8.hpp
+        pegtl/contrib/internal/peek_utf16.hpp
+        pegtl/contrib/internal/peek_utf32.hpp
+        pegtl/contrib/internal/read_uint.hpp
+        pegtl/contrib/internal/set_stack_guard.hpp
+        pegtl/contrib/internal/vector_stack_guard.hpp
+        pegtl/contrib/iri.hpp
+        pegtl/contrib/json.hpp
+        pegtl/contrib/json_pointer.hpp
+        pegtl/contrib/limit_bytes.hpp
+        pegtl/contrib/limit_depth.hpp
+        pegtl/contrib/parse_tree.hpp
+        pegtl/contrib/parse_tree_to_dot.hpp
+        pegtl/contrib/peg.hpp
+        pegtl/contrib/predicates.hpp
+        pegtl/contrib/print.hpp
+        pegtl/contrib/print_coverage.hpp
+        pegtl/contrib/proto3.hpp
+        pegtl/contrib/raw_string.hpp
+        pegtl/contrib/remove_first_state.hpp
+        pegtl/contrib/remove_last_states.hpp
+        pegtl/contrib/rep_one_min_max.hpp
+        pegtl/contrib/rep_string.hpp
+        pegtl/contrib/separated_seq.hpp
+        pegtl/contrib/shuffle_states.hpp
+        pegtl/contrib/state_control.hpp
+        pegtl/contrib/to_string.hpp
+        pegtl/contrib/trace.hpp
+        pegtl/contrib/uint16.hpp
+        pegtl/contrib/uint32.hpp
+        pegtl/contrib/uint64.hpp
+        pegtl/contrib/uint8.hpp
+        pegtl/contrib/unescape.hpp
+        pegtl/contrib/uri.hpp
+        pegtl/contrib/utf16.hpp
+        pegtl/contrib/utf32.hpp
+        pegtl/cstream_input.hpp
+        pegtl/demangle.hpp
+        pegtl/disable_action.hpp
+        pegtl/discard_input.hpp
+        pegtl/discard_input_on_failure.hpp
+        pegtl/discard_input_on_success.hpp
+        pegtl/enable_action.hpp
+        pegtl/eol.hpp
+        pegtl/eol_pair.hpp
+        pegtl/file_input.hpp
+        pegtl/internal/action.hpp
+        pegtl/internal/action_input.hpp
+        pegtl/internal/any.hpp
+        pegtl/internal/apply.hpp
+        pegtl/internal/apply0.hpp
+        pegtl/internal/apply0_single.hpp
+        pegtl/internal/apply_single.hpp
+        pegtl/internal/at.hpp
+        pegtl/internal/bof.hpp
+        pegtl/internal/bol.hpp
+        pegtl/internal/bump.hpp
+        pegtl/internal/bump_help.hpp
+        pegtl/internal/bytes.hpp
+        pegtl/internal/control.hpp
+        pegtl/internal/cr_crlf_eol.hpp
+        pegtl/internal/cr_eol.hpp
+        pegtl/internal/crlf_eol.hpp
+        pegtl/internal/cstream_reader.hpp
+        pegtl/internal/cstring_reader.hpp
+        pegtl/internal/dependent_false.hpp
+        pegtl/internal/disable.hpp
+        pegtl/internal/discard.hpp
+        pegtl/internal/enable.hpp
+        pegtl/internal/enable_control.hpp
+        pegtl/internal/eof.hpp
+        pegtl/internal/eol.hpp
+        pegtl/internal/eolf.hpp
+        pegtl/internal/failure.hpp
+        pegtl/internal/file_mapper_posix.hpp
+        pegtl/internal/file_mapper_win32.hpp
+        pegtl/internal/file_reader.hpp
+        pegtl/internal/filesystem.hpp
+        pegtl/internal/has_apply.hpp
+        pegtl/internal/has_apply0.hpp
+        pegtl/internal/has_match.hpp
+        pegtl/internal/has_unwind.hpp
+        pegtl/internal/identifier.hpp
+        pegtl/internal/if_apply.hpp
+        pegtl/internal/if_must.hpp
+        pegtl/internal/if_must_else.hpp
+        pegtl/internal/if_then_else.hpp
+        pegtl/internal/input_pair.hpp
+        pegtl/internal/istream_reader.hpp
+        pegtl/internal/istring.hpp
+        pegtl/internal/iterator.hpp
+        pegtl/internal/lf_crlf_eol.hpp
+        pegtl/internal/lf_eol.hpp
+        pegtl/internal/list.hpp
+        pegtl/internal/list_must.hpp
+        pegtl/internal/list_tail.hpp
+        pegtl/internal/list_tail_pad.hpp
+        pegtl/internal/marker.hpp
+        pegtl/internal/minus.hpp
+        pegtl/internal/missing_apply.hpp
+        pegtl/internal/missing_apply0.hpp
+        pegtl/internal/must.hpp
+        pegtl/internal/not_at.hpp
+        pegtl/internal/one.hpp
+        pegtl/internal/opt.hpp
+        pegtl/internal/pad.hpp
+        pegtl/internal/pad_opt.hpp
+        pegtl/internal/path_to_string.hpp
+        pegtl/internal/peek_char.hpp
+        pegtl/internal/peek_utf8.hpp
+        pegtl/internal/pegtl_string.hpp
+        pegtl/internal/plus.hpp
+        pegtl/internal/raise.hpp
+        pegtl/internal/range.hpp
+        pegtl/internal/ranges.hpp
+        pegtl/internal/rematch.hpp
+        pegtl/internal/rep.hpp
+        pegtl/internal/rep_min.hpp
+        pegtl/internal/rep_min_max.hpp
+        pegtl/internal/rep_opt.hpp
+        pegtl/internal/require.hpp
+        pegtl/internal/result_on_found.hpp
+        pegtl/internal/rules.hpp
+        pegtl/internal/seq.hpp
+        pegtl/internal/sor.hpp
+        pegtl/internal/star.hpp
+        pegtl/internal/star_must.hpp
+        pegtl/internal/state.hpp
+        pegtl/internal/string.hpp
+        pegtl/internal/success.hpp
+        pegtl/internal/try_catch_type.hpp
+        pegtl/internal/until.hpp
+        pegtl/internal/unwind_guard.hpp
+        pegtl/istream_input.hpp
+        pegtl/match.hpp
+        pegtl/memory_input.hpp
+        pegtl/mmap_input.hpp
+        pegtl/must_if.hpp
+        pegtl/normal.hpp
+        pegtl/nothing.hpp
+        pegtl/parse.hpp
+        pegtl/parse_error.hpp
+        pegtl/position.hpp
+        pegtl/read_input.hpp
+        pegtl/require_apply.hpp
+        pegtl/require_apply0.hpp
+        pegtl/rewind_mode.hpp
+        pegtl/rules.hpp
+        pegtl/string_input.hpp
+        pegtl/tracking_mode.hpp
+        pegtl/type_list.hpp
+        pegtl/utf8.hpp
+        pegtl/version.hpp
+        pegtl/visit.hpp
+
+    CPPFILES
+        # Workaround lack of build support for header-only libs.
+        build-workaround.cpp
+
+    DISABLE_PRECOMPILED_HEADERS
+)

pxr/base/pegtl/README.md

@@ -0,0 +1,47 @@
+# The Art of C++ : PEGTL (Parsing Expression Grammar Template Library)
+
+[PEGTL](https://github.com/taocpp/PEGTL) is a library for creating
+parsers according to a Parsing Expression Grammar.
+
+## Version
+
+v3.2.7
+
+## Setup
+
+Refer to the [Installing and Using](https://github.com/taocpp/PEGTL/blob/3.x/doc/Installing-and-Using.md)
+documentation
+
+## Copy headers
+
+1. Copy PEGTL-3.2.7/include/tao/... to pxr/base/pegtl/...
+
+2. Replace Macro Names
+
+Change macro names from TAO_PEGTL_ to PXR_PEGTL_.  You can do this in a
+bash-like shell with the following:
+
+`sed -i 's/TAO_PEGTL_/PXR_PEGTL_/g' $(find -name '[^.]*.[hc]pp')`
+
+3. Update CMakeLists.txt and any other build configuration files.
+
+You can get a full list of the header files by running:
+
+`find -type f`
+
+4. Update pxr/base/pegtl/pegtl/config.hpp
+
+This file defines the namespace name that PEGTL uses:
+
+```
+// Define PXR_PEGTL_NAMESPACE based on the internal namespace to isolate
+// it from other versions of USD/PEGTL in client code.
+#include "pxr/pxr.h"
+
+#if PXR_USE_NAMESPACES
+#define PXR_PEGTL_NAMESPACE PXR_INTERNAL_NS ## _pegtl
+#else
+#define PXR_PEGTL_NAMESPACE pxr_pegtl
+#endif
+```
+

pxr/base/pegtl/build-workaround.cpp

@@ -0,0 +1,8 @@
+// This is required since our build does not currently support header-only
+// libraries.  Without this the headers install okay, but other libs that try to
+// use this library will fail to link, like: `ld: cannot find -lpegtl`.  By
+// adding this, an "empty" .so gets built and other libs can link it.
+
+#include "pxr/base/arch/export.h"
+
+ARCH_EXPORT int __pxr_pegtl_workaround__;

pxr/base/pegtl/pegtl.hpp

@@ -0,0 +1,48 @@
+// Copyright (c) 2014-2022 Dr. Colin Hirsch and Daniel Frey
+// Please see LICENSE for license or visit https://github.com/taocpp/PEGTL/
+
+#ifndef PXR_PEGTL_HPP
+#define PXR_PEGTL_HPP
+
+#include "pegtl/config.hpp"
+#include "pegtl/demangle.hpp"
+#include "pegtl/parse.hpp"
+#include "pegtl/version.hpp"
+
+#include "pegtl/ascii.hpp"
+#include "pegtl/rules.hpp"
+#include "pegtl/utf8.hpp"
+
+#include "pegtl/argv_input.hpp"
+#include "pegtl/buffer_input.hpp"
+#include "pegtl/cstream_input.hpp"
+#include "pegtl/istream_input.hpp"
+#include "pegtl/memory_input.hpp"
+#include "pegtl/read_input.hpp"
+#include "pegtl/string_input.hpp"
+
+// This has to be included *after* the above inputs,
+// otherwise the amalgamated header will not work!
+#include "pegtl/file_input.hpp"
+
+#include "pegtl/change_action.hpp"
+#include "pegtl/change_action_and_state.hpp"
+#include "pegtl/change_action_and_states.hpp"
+#include "pegtl/change_control.hpp"
+#include "pegtl/change_state.hpp"
+#include "pegtl/change_states.hpp"
+
+#include "pegtl/disable_action.hpp"
+#include "pegtl/enable_action.hpp"
+
+#include "pegtl/discard_input.hpp"
+#include "pegtl/discard_input_on_failure.hpp"
+#include "pegtl/discard_input_on_success.hpp"
+
+#include "pegtl/visit.hpp"
+
+#if defined( __cpp_exceptions )
+#include "pegtl/must_if.hpp"
+#endif
+
+#endif

pxr/base/pegtl/pegtl/apply_mode.hpp

@@ -0,0 +1,19 @@
+// Copyright (c) 2014-2022 Dr. Colin Hirsch and Daniel Frey
+// Please see LICENSE for license or visit https://github.com/taocpp/PEGTL/
+
+#ifndef PXR_PEGTL_APPLY_MODE_HPP
+#define PXR_PEGTL_APPLY_MODE_HPP
+
+#include "config.hpp"
+
+namespace PXR_PEGTL_NAMESPACE
+{
+   enum class apply_mode : bool
+   {
+      action = true,
+      nothing = false
+   };
+
+}  // namespace PXR_PEGTL_NAMESPACE
+
+#endif