[flang] Use std::nullopt rather than {}.

Original-commit: flang-compiler/f18@9a740acf8346de10c0dda34ba2706980f9643802
Reviewed-on: https://github.com/flang-compiler/f18/pull/151

[flang] address review comments

Original-commit: flang-compiler/f18@a18aba21fd74fd34debee09a3d566b86d8749f76
Reviewed-on: https://github.com/flang-compiler/f18/pull/151
Tree-same-pre-rewrite: false

[flang] add isModuleFile flag to parser::Options, use it

Original-commit: flang-compiler/f18@0727140f53cadad7740e524fd9300a1ca8b12044
Reviewed-on: https://github.com/flang-compiler/f18/pull/151
Tree-same-pre-rewrite: false

[flang] Let multiple CookedSource instances share a ref-counted AllSources.

Original-commit: flang-compiler/f18@98a170e3e58b8937dd5770d2e0303aa9750b6f84
Reviewed-on: https://github.com/flang-compiler/f18/pull/151
Tree-same-pre-rewrite: false

[flang] Support resolution of provenances in messages from CharBlocks to ProvenanceRanges

Original-commit: flang-compiler/f18@aa5728795976f7b6c9205d7ef3d87e649f8e10d9
Reviewed-on: https://github.com/flang-compiler/f18/pull/151
Tree-same-pre-rewrite: false

[flang] complete merge to current master

Original-commit: flang-compiler/f18@ca43f45616397d92ed9e8dae3445edaa81089876
Reviewed-on: https://github.com/flang-compiler/f18/pull/151
Tree-same-pre-rewrite: false

[flang] fix double deallocation bug from previous commit

Original-commit: flang-compiler/f18@f216b6bb822bc230c40521d5444870add13eeeb1
Reviewed-on: https://github.com/flang-compiler/f18/pull/151
Tree-same-pre-rewrite: false

[flang] Tweaks to provenance data structures, in preparation for better module file support.

Original-commit: flang-compiler/f18@a7b7b2b6801aa8beadde3d05a29d40057a5f264e
Reviewed-on: https://github.com/flang-compiler/f18/pull/151
Tree-same-pre-rewrite: false

[flang] Merge pull request flang-compiler/f18#149 from flang-compiler/tsk5

Refactor ModFileReader to use parser::Parsing

Original-commit: flang-compiler/f18@451e9e4ee45304e8aaad828cf6a87844d6be8f40
Reviewed-on: https://github.com/flang-compiler/f18/pull/149

[flang] Remove unnecessary unique_ptr.

The unique_ptr around the vector of char was unnecessary. We can just
move the vector itself and it still keeps the same stream of chars.

Original-commit: flang-compiler/f18@24672adba9fb38703cc88b2b7ff35b6c8824e918
Reviewed-on: https://github.com/flang-compiler/f18/pull/149

[flang] Change how cooked source is saved

Rather than save the entire CookedSource object in the module scope,
all we need is the vector of characters that CharBlock has references
into. This avoids the problem that CookedSource object has a dangling
reference to an AllSources object (which shouldn't be needed by the
CharBlocks in the symbol table, but is there).

This also decouples Scope from parser classes other than CharBlock.

Original-commit: flang-compiler/f18@fdbf5c841e9913009ba84ae0fe83b3021848bf5b
Reviewed-on: https://github.com/flang-compiler/f18/pull/149
Tree-same-pre-rewrite: false

[flang] Refactor ModFileReader to use parser::Parsing

parser::Parsing does most of the work needed to prescan and parse a file.
The only problem is that for module files we need to take ownership of
the cooked character stream so that it lives as long as the module scope
does.

To achieve this, change Parsing::cooked_ to be a unique_ptr and add a
member function to allow the caller to take ownership of it.

Original-commit: flang-compiler/f18@9088891ab29d91a51c55edb031b5a974cc8254b9
Reviewed-on: https://github.com/flang-compiler/f18/pull/149
Tree-same-pre-rewrite: false

[flang] Update README.md (flang-compiler/f18#150)

Corrected the URL  in README.md to point to the correct public URL for this repository.

Original-commit: flang-compiler/f18@7005e9ad7b9597e946dd8ea6bb40a978f8326e03
Reviewed-on: https://github.com/flang-compiler/f18/pull/150

[flang] Merge pull request flang-compiler/f18#147 from flang-compiler/tsk5

Add support for -module option

Original-commit: flang-compiler/f18@e3d4d7e6fdf8068c768ca806a5371ec48519a731
Reviewed-on: https://github.com/flang-compiler/f18/pull/147

[flang] Add support for -module option

The `-module` option specifies where to write module files. It is also
the first place search for modules files. The current options name and
behavior match PGI compilers.

To support this, reorganize `ModFileWriter` to be more like `ModFileReader`.
The gives the client a way to set the output directory and fetch the
error messages. A bunch of static member functions in `ModFileWriter`
were changed to non-member functions so they didn't need to be exposed
in `mod-files.h`.

Original-commit: flang-compiler/f18@2717846e81a6be325a6eaec73c22eae5a7cf6577
Reviewed-on: https://github.com/flang-compiler/f18/pull/147

[flang] Merge pull request flang-compiler/f18#146 from flang-compiler/pmk1

OpenMP conditional compilation lines

Original-commit: flang-compiler/f18@e02c561e008b6f194b829d835177e5c0dd39b5d9
Reviewed-on: https://github.com/flang-compiler/f18/pull/146

[flang] OpenMP conditional compilation lines

Original-commit: flang-compiler/f18@5602f7e041bf9d58bf88d5d86dc1900d102d899c
Reviewed-on: https://github.com/flang-compiler/f18/pull/146

[flang] Merge pull request flang-compiler/f18#145 from flang-compiler/tsk5

Implement reading of module files

Original-commit: flang-compiler/f18@2b36d4c650ed52dd18d14e76c7e54d1d73831ae0
Reviewed-on: https://github.com/flang-compiler/f18/pull/145

[flang] Implement reading of module files

When a use-stmt is encountered for a module that isn't in the global
scope, search for and read the appropriate `.mod` file. To perform the
search, pass the search directories in to ResolveNames.

For modules that were read from `.mod` files, we have to keep the cooked
source from being deleted so that the names so that references to names
stay valid. So we store the cooked source in the Scope of the module as
a `unique_ptr`.

Add `Symbol::Flag::ModFile` to distinguish module symbols that were read
from a `.mod` file rather than from the current compilation. Use it to
prevent writing those back out.

Fix test_errors.sh to run the compiler in the temp subdirectory --
otherwise tests could be affected by `.mod` files left from previous
tests.

Original-commit: flang-compiler/f18@207065999ce09ca7361aeb0262d1b8bf8cf4b99e
Reviewed-on: https://github.com/flang-compiler/f18/pull/145

[flang] Merge pull request flang-compiler/f18#144 from flang-compiler/pmk0

Checkpoint development of expression analysis

Original-commit: flang-compiler/f18@a32c16f8952caa2bb38970e29968d54cd91c2b38
Reviewed-on: https://github.com/flang-compiler/f18/pull/144

[flang] Fix typo

Original-commit: flang-compiler/f18@b9837c01daea3d7ea65dfa3e7608a65f1f165a9a
Reviewed-on: https://github.com/flang-compiler/f18/pull/144

[flang] real expression folding

Original-commit: flang-compiler/f18@8757dc2c90057f45dcff113df777ce6d08913709
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] checkpoint

Original-commit: flang-compiler/f18@fc470dc85111b6370adc5db2c1965445f352d12a
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] Real->Integer conversion folding

Original-commit: flang-compiler/f18@5ad6505e782c9f5d748ff0c2d06be0f02c283694
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] Parameterize Expr on a type, not category+kind

Original-commit: flang-compiler/f18@f29b065d00d7becd0282b2a2e5f0fb103e1a243d
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] Better folding infrastructure checkpoint

Original-commit: flang-compiler/f18@85d16ace6cf3b158db0455f0bd204b8e1a4dae68
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] Be more clear that constants in expressions are scalars now.

Original-commit: flang-compiler/f18@3181b8d961a3f5a5c73a5a1e9aa5e44ac723423e
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] reformat

Original-commit: flang-compiler/f18@3c93a9edbc66206b9d18211d7ffa13b29ffa85c3
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] checkpoint

Original-commit: flang-compiler/f18@7fae33797a4245c0be531dda27ec0fb8cddf4d37
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] Begin semantic analysis of expressions.

Original-commit: flang-compiler/f18@34615fdc37736e2aadf440d67e57c192e0e3f66c
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] Use const_cast instead of static_cast for clarity.

Original-commit: flang-compiler/f18@b76ba42af0b1ede0d32cbce3d8112d1b95bccee2
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] More comments about 0**0.

Original-commit: flang-compiler/f18@3e9c0e88947a898989ad276f8659ada8fafa80a4
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] 0**0 case

Original-commit: flang-compiler/f18@fcba49ce6ff2d3a41ce02ccf760b5320d45f3dd2
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] Fold integer powers

Original-commit: flang-compiler/f18@6a9ec4d76b5161f1cbaecccd2e1844d4e3c1bcdc
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] Better folding.

Original-commit: flang-compiler/f18@4a3117968aabf5462dd25ff67a09073f3ef1c01a
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] Finish data hiding in variable.h.

Original-commit: flang-compiler/f18@597933032235727bfc8a49d47382bb12ab62cf69
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] more data hiding

Original-commit: flang-compiler/f18@2dc0d046e32be10533e6150358a8160fbf31ebde
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] Pull indirection into some constructors.

Original-commit: flang-compiler/f18@074e249499429da17aeb9393d9fb71e3241ca6e1
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] Data hiding

Original-commit: flang-compiler/f18@d33426637aa3745f81963efd14665537bde15f46
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] checkpoint once everything builds again

Original-commit: flang-compiler/f18@2075b88772400313885cbd6e4e956353b54f5cf2
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] issue#134

Original-commit: flang-compiler/f18@a40c38bdb532e7f9258e71f9d68935d79e767e38
Reviewed-on: https://github.com/flang-compiler/f18/pull/144
Tree-same-pre-rewrite: false

[flang] Merge pull request flang-compiler/f18#143 from flang-compiler/pmk1

issue#142 fix

Original-commit: flang-compiler/f18@69c72ac9551b219044f89ab657d51575bdc4415e
Reviewed-on: https://github.com/flang-compiler/f18/pull/143

[flang] issue#142, some refactoring of common patterns in basic-parsers.h, and reformatting

Original-commit: flang-compiler/f18@1faad40678ccb1a1af909f5ee51a5ea687e08a96
Reviewed-on: https://github.com/flang-compiler/f18/pull/143

[flang] Merge pull request flang-compiler/f18#140 from flang-compiler/omppar

Add predefined macro _OPENMP to 201511  - yyyymm of the OpenMP 4.5 Spec.

Original-commit: flang-compiler/f18@7b051951323b9678ee7004da9e9d2d6b6a0dd965
Reviewed-on: https://github.com/flang-compiler/f18/pull/140

[flang] Add predefined macro _OPENMP to 201511  - yyyymm of the OpenMP Spec.

Original-commit: flang-compiler/f18@859912b54ed795e063c31ab11d4c1ce45724421b
Reviewed-on: https://github.com/flang-compiler/f18/pull/140

[flang] Merge pull request flang-compiler/f18#137 from flang-compiler/omppar

Omppar

Original-commit: flang-compiler/f18@d341464e7ffde700b94a11a2c3a82be71ddebf84
Reviewed-on: https://github.com/flang-compiler/f18/pull/137

Due to a conflicting rebase during the linearizing of flang-compiler/f18, this commit squashes a number of other commits:

flang-compiler/f18@cfbc8bd16b1c63da4f8cb5f501766f52e7f862d5 Add OpenMP Block directives and some declarative directive(TBD:declare reduction and declare target)
flang-compiler/f18@d198352f840ad51aa6ab944043e8879239ff5d15 Removed extra code from resolveing conflict of the merge.
flang-compiler/f18@85911a0e80b81913f9372456b7fdd0875777915c fix some grammar and unparsing.
flang-compiler/f18@43bcfb7cd3efb80ad15b5b853af6527981ef8182 OpenMP declartive directive can be after function declaration line. OpenMP Loop construct will be treated as if statement instead of block because currently parser cannot construct the loop if loop end with Label [Continue] Use DefinedOperator and ProcedureDesignator instead of create a new Parser and postpone the validity of operator in semantic.
flang-compiler/f18@5d83b50ad344c889afffa26552827433489b63da Merge branch 'master' into omppar
flang-compiler/f18@8c666436a5d29785a6480d4741d374fd0a5b3227 remove "HEAD" code and resolve conflict.

[flang] Merge pull request flang-compiler/f18#132 from flang-compiler/tsk5

Support writing interfaces in module files.

Original-commit: flang-compiler/f18@7d635193a89de8502188010978fff4af811419b9
Reviewed-on: https://github.com/flang-compiler/f18/pull/132

[flang] Correctly resolve generics with forward references

When a procedure is included by name in a generic (either with a
procedure statement in a generic interface or with a generic statement)
we can't immediately resolve it to a subprogram symbol. That is because
the subprogram may be defined later in the specification part. Instead,
collect the names (and whether they should be module procedures) and
resolve them to symbols at the end of the specification part. Also
detect duplicate names then.

This is needed for module file reading as these forward references can
occur there.

Write generics to module file using generic statements. This allows us to
include the access-spec.

Original-commit: flang-compiler/f18@d11d002084af4a25d0c9a63dbe6460530b56adc7
Reviewed-on: https://github.com/flang-compiler/f18/pull/132

[flang] Support writing interfaces in module files.

Write symbols for external subprogram interfaces as interface-stmts.
Those go in the decls part of the module file, as opposed to contained
subprograms which go in the contains part. See modfile06.f90.

Write symbols with GenericDetails to module files. The specific
procedures of a generic interface are always written as procedure-stmts.
If they also have specific interfaces those are written in a separate
interface-stmt. See modfile07.f90.

Fix a bug where `real, external :: f` was not written like
`real f; external f`. We have to notice the EXTERNAL attribute on the
type-declaration-stmt and convert the entity to a procedure entity.
See modfile08.f90.

Fix a bug where a use-associated symbol is referenced in a
procedure-designator. We were not resolving that correctly.

Change ModFileWriter::PutEntity to include the kind of Details when
it reports an internal error due to a kind it can't handle.
Make DetailsToString public to support that.

Change test_errors.sh to fail if the f18 command exits due to a signal.
We were missing bugs where the correct errors were written out but then
module file writing crashed (due to failure to handle generics mentioned
above). Non-zero exit status is okay because we are expecting
compilation errors.

Change test_modfile.sh to allow for the expected module file contents to
be indented so the tests are easier to read.

Original-commit: flang-compiler/f18@82a7931e51c63ba21f17261727e1e9dc4167dcc9
Reviewed-on: https://github.com/flang-compiler/f18/pull/132
Tree-same-pre-rewrite: false

[flang] Merge pull request flang-compiler/f18#133 from flang-compiler/pmk1

Fix remaining bugs with backslash escapes in character literals

Original-commit: flang-compiler/f18@8c41f0123d75e009bc32cc182ab9e7c182b29da7
Reviewed-on: https://github.com/flang-compiler/f18/pull/133

[flang] Pass -Mnobackslash to pgf90 unless f18 -fbackslash is used.

Original-commit: flang-compiler/f18@df5058ff976dc7c5b8e0450a13a9ac345cd098d1
Reviewed-on: https://github.com/flang-compiler/f18/pull/133

[flang] prep for merge

Original-commit: flang-compiler/f18@fa72384520af15c0901a41ebcea457fa1aa733a8
Reviewed-on: https://github.com/flang-compiler/f18/pull/133
Tree-same-pre-rewrite: false

[flang] Really fix backslash escapes.

Original-commit: flang-compiler/f18@a8c702c103fad51c9a1fb59d4088d9c037b778bd
Reviewed-on: https://github.com/flang-compiler/f18/pull/133
Tree-same-pre-rewrite: false

[flang] Merge pull request flang-compiler/f18#130 from flang-compiler/pmk1

Roll up parsing changes for several topics

Original-commit: flang-compiler/f18@57e051eafa1088e83c7d1cef565add6903aed20a
Reviewed-on: https://github.com/flang-compiler/f18/pull/130

[flang] Ready for merge.

Original-commit: flang-compiler/f18@f39949fc7de5d319c180c3c76322df0fa462140c
Reviewed-on: https://github.com/flang-compiler/f18/pull/130

[flang] Do not enable OpenMP by default, oops.

Original-commit: flang-compiler/f18@7a627ac040b07e9f03e0883e4b5680ec432ff98f
Reviewed-on: https://github.com/flang-compiler/f18/pull/130
Tree-same-pre-rewrite: false

[flang] Define LanguageFeatureControl, use it everywhere.

Original-commit: flang-compiler/f18@9a95107610c0d785c8b56576909ea4cf6efd5814
Reviewed-on: https://github.com/flang-compiler/f18/pull/130
Tree-same-pre-rewrite: false

[flang] Better language feature enablement and warnings.

Original-commit: flang-compiler/f18@359e4d2c600a31f26774a46f01b2a70fc62bc558
Reviewed-on: https://github.com/flang-compiler/f18/pull/130
Tree-same-pre-rewrite: false

[flang] Another SUBMODULE unparsing tweak, and restore buildability with gcc < 8.1

Original-commit: flang-compiler/f18@86b5db4b234da659702320a3c614f3f6b5ba3757
Reviewed-on: https://github.com/flang-compiler/f18/pull/130
Tree-same-pre-rewrite: false

[flang] Fix clang build warning in mod-file.cc

Original-commit: flang-compiler/f18@53ad3bd59cfcdfe2500a567a0892aca26bfb84da
Reviewed-on: https://github.com/flang-compiler/f18/pull/130
Tree-same-pre-rewrite: false

[flang] Address issue#125, flang-compiler/f18#115, and improve error recovery on previous issues.

Original-commit: flang-compiler/f18@98e26d6245e93e17520fc64be1eff3b4b7db5d9f
Reviewed-on: https://github.com/flang-compiler/f18/pull/130
Tree-same-pre-rewrite: false

[flang] Merge pull request flang-compiler/f18#131 from flang-compiler/tsk2

Update module file documentation

Original-commit: flang-compiler/f18@8981007d1c2093320cf671648ea139b20fefe9ae
Reviewed-on: https://github.com/flang-compiler/f18/pull/131

[flang] Update module file documentation

Address some review comments, add more information.

Original-commit: flang-compiler/f18@75c97b6f9bf6a5274e0e2398312587d92d3e0064
Reviewed-on: https://github.com/flang-compiler/f18/pull/131

[flang] Merge pull request flang-compiler/f18#127 from flang-compiler/tsk5

Use brace initialization with auto

Original-commit: flang-compiler/f18@f767ea2e1a0d1b1a39d6bcaee8559bddb0c624be
Reviewed-on: https://github.com/flang-compiler/f18/pull/127

[flang] Use brace initialization in tools/f18

Also reformat dump.cc.

Original-commit: flang-compiler/f18@1cc4fe278841b22437d4f3857b84e10dedbf71e5
Reviewed-on: https://github.com/flang-compiler/f18/pull/127

[flang] Use brace initialization in lib/semantics

Syntax only, no functional changes.

Original-commit: flang-compiler/f18@8cc9743c9cddbda0d93cb171d623277715c3c7e2
Reviewed-on: https://github.com/flang-compiler/f18/pull/127
Tree-same-pre-rewrite: false

[flang] Merge pull request flang-compiler/f18#129 from flang-compiler/tsk2

Fix test script portability problems.

Original-commit: flang-compiler/f18@e7f83218a310d02932a2429e8330ae3c48a3432d
Reviewed-on: https://github.com/flang-compiler/f18/pull/129

[flang] Fix test script portability problems.

Allow for bash anywhere on path.

Allow for utilites to be in /bin as well as /usr/bin.

Don't count on sed understanding '\t'.

The options to mktemp aren't portable. Instead just create a per-test
temp directory in the working directory (i.e. <build-dir>/test/semantics).
Setting the KEEP environment variable causes them all to be kept to help
in investigating failures.

Fixes flang-compiler/f18#128.

Original-commit: flang-compiler/f18@3736ceeca83965e3c9e282e92ddb6323523b9e5b
Reviewed-on: https://github.com/flang-compiler/f18/pull/129

[flang] Merge pull request flang-compiler/f18#126 from flang-compiler/tsk5

Implement writing of .mod files.

Original-commit: flang-compiler/f18@94c1f72fbdcd0c0f5c6e91ae907b9d54bbfb4721
Reviewed-on: https://github.com/flang-compiler/f18/pull/126

[flang] Handle VOLATILE or ASYNCHRONOUS added to use-associated entity

When a symbol is use-associated, the VOLATILE and ASYNCHRONOUS
attributes can be added. When that happens it must be recorded
in the .mod file.

Original-commit: flang-compiler/f18@44fa9e5ba4172f75abe4194e7f58b26a99646cdc
Reviewed-on: https://github.com/flang-compiler/f18/pull/126

[flang] Fix typo

Original-commit: flang-compiler/f18@242ff9d229c376fbff9942844af12c876bd3e13f
Reviewed-on: https://github.com/flang-compiler/f18/pull/126
Tree-same-pre-rewrite: false

[flang] Add a .mod file test with subprograms

The .mod file just contains the API. Test that prefixes and suffixes
on the declaration get correctly persisted.

Original-commit: flang-compiler/f18@eb2a6deb4fe12bae83fc3cb2366d056cf50cc9a5
Reviewed-on: https://github.com/flang-compiler/f18/pull/126
Tree-same-pre-rewrite: false

[flang] Initial documentation for .mod files

Original-commit: flang-compiler/f18@f1809b833f2d4265221677dcfb8b38577f6e69ba
Reviewed-on: https://github.com/flang-compiler/f18/pull/126
Tree-same-pre-rewrite: false

[flang] Add tests for .mod file writing

The source files contain the expected contents of generated .mod files.
`test_modfile.sh` compiles the source file and verifies that the correct
.mod files are generated.

Original-commit: flang-compiler/f18@a23f53c1a7d6f1dba157c1bc87ebc046d3b818e6
Reviewed-on: https://github.com/flang-compiler/f18/pull/126
Tree-same-pre-rewrite: false

[flang] Implement writing of .mod files.

Module file writing is implemented in mod-file.cc. They need to be
written after all semantic checking. Until then, for testing, write
them out whenever names are resolved.

There is a header comment in the .mod files but it is mostly a
placeholder until we can read them in and do something with it.

Rename `Symbol::details<D>` to `Symbol::get<D>`. This asserts that the
details of the symbol match D and returns that type. But we need a way
to access the details as a variant as well (not just one of its types).
`details()` is the best name for that, especially as we already have
`set_details()`. Renaming the old `details` to `get` also better matches
`has` which is used to check which variant is present.

Original-commit: flang-compiler/f18@8d14be1a1633ab2e8ee700a3709989769fbc1f14
Reviewed-on: https://github.com/flang-compiler/f18/pull/126
Tree-same-pre-rewrite: false

[flang] Merge pull request flang-compiler/f18#123 from flang-compiler/pmk1

Improve error recovery further, using a test case from Tim.

Original-commit: flang-compiler/f18@cd850a75df0c768bfe54a6ff54a59fe25f48c924
Reviewed-on: https://github.com/flang-compiler/f18/pull/123

[flang] Improve error recovery further, using a test case from Tim.

Original-commit: flang-compiler/f18@9ef79fa9913804168d151a5b15588dbfaa02957a
Reviewed-on: https://github.com/flang-compiler/f18/pull/123

[flang] Merge pull request flang-compiler/f18#122 from flang-compiler/pmk1

Fix two problems described in issue#121

Original-commit: flang-compiler/f18@4d8203ad354310de16a690fe83bfad3eb5c3ce68
Reviewed-on: https://github.com/flang-compiler/f18/pull/122

[flang] Extend documentation on extensions.

Original-commit: flang-compiler/f18@672e468252b221d53e5b87aad805b42820b2bfff
Reviewed-on: https://github.com/flang-compiler/f18/pull/122

[flang] Tweak code for readability and maybe better performance.

Original-commit: flang-compiler/f18@e4d9b8587e84714df3476f8f32ac156f36b32449
Reviewed-on: https://github.com/flang-compiler/f18/pull/122
Tree-same-pre-rewrite: false

[flang] More documentation.  These changes fix two bugs noted in f18 issue#121.

Original-commit: flang-compiler/f18@f386472c5ce6cf2f4f485c118213ae3fae6040e3
Reviewed-on: https://github.com/flang-compiler/f18/pull/122
Tree-same-pre-rewrite: false

[flang] Allow empty statements and improve error recovery error messages.

Original-commit: flang-compiler/f18@018e81e2c441ca54763e617a42457100c1291b42
Reviewed-on: https://github.com/flang-compiler/f18/pull/122
Tree-same-pre-rewrite: false

[flang] Merge pull request flang-compiler/f18#120 from flang-compiler/tsk1

Support intent-stmt and resolve subprogram prefixes and suffixes.

Original-commit: flang-compiler/f18@2206d453e1e7554f09ab01cfb5da8d48b5691cfd
Reviewed-on: https://github.com/flang-compiler/f18/pull/120

[flang] Sort enumerators in `enum class Attr`.

Original-commit: flang-compiler/f18@ce43e4e556e891e68d36377add88fecd13ab4f2e
Reviewed-on: https://github.com/flang-compiler/f18/pull/120

[flang] Support intent-stmt and resolve subprogram prefixes and suffixes.

Recognize `IntentStmt` and use `HandleAttributeStmt()` to implement it
as is done with other attribute statements. Add `Attr::INTENT_INOUT` as
a separate attribute for `INTENT(INOUT)`.

Collect attributes from the prefix and suffix of `FunctionStmt` and
`SubroutineStmt` (including `BIND(C)`) and set them on the subprogram
symbol.

Create a test for this using `test_symbol.sh`. It compiles with
`-funparse-with-symbols` and compares the output with the symbols in
comments in the input.

Change `test_errors.sh` to be similar to `test_symbol.sh`: check usage
and allow `F18` environment variable to override the path to the
compiler.

Original-commit: flang-compiler/f18@384828a22f53d828a3140640ca89f5819ada394d
Reviewed-on: https://github.com/flang-compiler/f18/pull/120
Tree-same-pre-rewrite: false

[flang] Merge pull request flang-compiler/f18#119 from flang-compiler/pmk1

Use braces in `auto` initializers in lib/{parser,common,evaluate}

Original-commit: flang-compiler/f18@1aeba0c214b3a6388de630345eb5164749be598d
Reviewed-on: https://github.com/flang-compiler/f18/pull/119

[flang] Documentation

Original-commit: flang-compiler/f18@d2855c6474b273987492f7f879c0f7a674f35c8f
Reviewed-on: https://github.com/flang-compiler/f18/pull/119

[flang] merge and reformat

Original-commit: flang-compiler/f18@2e3d67aa79e1e7e0af58e1d21bb500a987338c03
Reviewed-on: https://github.com/flang-compiler/f18/pull/119
Tree-same-pre-rewrite: false

[flang] correct typo in unparse.cc found in test

Original-commit: flang-compiler/f18@1aa60cccc4f0a56802551d2ecae8eba4f5ed668b
Reviewed-on: https://github.com/flang-compiler/f18/pull/119
Tree-same-pre-rewrite: false

[flang] Use braces for auto initialization in lib/common and lib/evaluate

Original-commit: flang-compiler/f18@b0d1dd434bbcd55613d2f0b67863905baa8f818b
Reviewed-on: https://github.com/flang-compiler/f18/pull/119
Tree-same-pre-rewrite: false

[flang] Use braces in auto initializers.

Original-commit: flang-compiler/f18@b68fdff537abc5402751d2f2842ff6d191f4d1fe
Reviewed-on: https://github.com/flang-compiler/f18/pull/119
Tree-same-pre-rewrite: false

[flang] Merge pull request flang-compiler/f18#118 from flang-compiler/pmk2

Better error recovery in the face of input that's not Fortran at all

Original-commit: flang-compiler/f18@7edf728444614f0eeda94c6b6dddd407a0cf380b
Reviewed-on: https://github.com/flang-compiler/f18/pull/118

[flang] Better error recovery (for a case from Tim) and fix a problem where context is lost.

Original-commit: flang-compiler/f18@522822fd5a44aee41998e25f0691e44cbaaa202c
Reviewed-on: https://github.com/flang-compiler/f18/pull/118

[flang] Merge pull request flang-compiler/f18#117 from flang-compiler/pmk1

Variables

Original-commit: flang-compiler/f18@d38c14ef24b2785534f1b79d885a444cb64e978a
Reviewed-on: https://github.com/flang-compiler/f18/pull/117

[flang] Extend documentation

Original-commit: flang-compiler/f18@ac375a00ba871cc11244c5e111b42e7807648a14
Reviewed-on: https://github.com/flang-compiler/f18/pull/117

[flang] Address review comments

Original-commit: flang-compiler/f18@9e59b9b79d690e0293c61a889da28cbd42ac5194
Reviewed-on: https://github.com/flang-compiler/f18/pull/117
Tree-same-pre-rewrite: false

[flang] Resolve build issues with older compilers.

Original-commit: flang-compiler/f18@d8723284d3750e05fbf6290d99faecd5cd8a774e
Reviewed-on: https://github.com/flang-compiler/f18/pull/117
Tree-same-pre-rewrite: false

[flang] Refine variable structure definitions, add references to Standard.

Original-commit: flang-compiler/f18@dbc6d45e02ded14d01ac856857e3e45b4cc0aa1a
Reviewed-on: https://github.com/flang-compiler/f18/pull/117
Tree-same-pre-rewrite: false

[flang] Start cleaning up for merging.

Original-commit: flang-compiler/f18@7355bd5b4238a5fe57da8c1446a20bb0caf26fc7
Reviewed-on: https://github.com/flang-compiler/f18/pull/117
Tree-same-pre-rewrite: false

[flang] Use Indirection.  Get variables to work in int expressions.

Original-commit: flang-compiler/f18@1000717da820d87b330719034281a69eaf37bb89
Reviewed-on: https://github.com/flang-compiler/f18/pull/117
Tree-same-pre-rewrite: false