Commit Graph

6 Commits

Author SHA1 Message Date
Andrzej Warzynski 7d246cb19d [flang][driver] Add support for `-fsyntax-only`
The behaviour triggered with this flag is consistent with `-fparse-only`
in `flang` (i.e. the throwaway driver). This new spelling is consistent
with Clang and gfortran, and was proposed and agreed on for the new
driver in [1].

This patch also adds some minimal logic to communicate whether the
semantic checks have failed or not. When semantic checks fail, a
frontend driver error is generated. The return code from the frontend
driver is then determined by checking the driver diagnostics - the
presence of driver errors means that the compilation has failed. This
logic is consistent with `clang -cc1`.

[1] http://lists.llvm.org/pipermail/flang-dev/2020-November/000588.html

Differential Revision: https://reviews.llvm.org/D92854
2020-12-18 09:35:02 +00:00
Andrzej Warzynski fdbc7e505c [flang][driver] Make sure that `-###` is marked as supported (NFC)
`-###` has always been supported in the new flang driver. This patch
merely makes sure that it's included when printing the help screen (i.e.
`flang-new -help`).
2020-11-11 13:12:51 +00:00
Caroline Concatto d28de0d7f2 [Flang][Driver] Add PrintPreprocessedInput FrontendAction (`flang-new -E`)
This patch implements the first frontend action for the Flang parser (i.e.
Fortran::parser). This action runs the preprocessor and is invoked with the
`-E` flag. (i.e. `flang-new -E <input-file>). The generated output is printed
to either stdout or the output file (specified with `-` or `-o <output-file>`).

Note that currently there is no mechanism to map options for the
frontend driver (i.e. Fortran::frontend::FrontendOptions) to options for
the parser (i.e. Fortran::parser::Options). Instead,
Frotran::parser::options are hard-coded to:

```
std::vector<std::string> searchDirectories{"."s};
searchDirectories = searchDirectories;
isFixedForm = false;
_encoding(Fortran::parser::Encoding::UTF_8);
```

These default settings are compatible with the current Flang driver. Further
work is required in order for CompilerInvocation to read and map
clang::driver::options to Fortran::parser::options.

Co-authored-by: Andrzej Warzynski <andrzej.warzynski@arm.com>

Differential Revision: https://reviews.llvm.org/D88381
2020-11-02 14:03:35 +00:00
Caroline Concatto 4c5906cffd [Flang][Driver] Add infrastructure for basic frontend actions and file I/O
This patch introduces the dependencies required to read and manage input files
provided by the command line option. It also adds the infrastructure to create
and write to output files. The output is sent to either stdout or a file
(specified with the `-o` flag).

Separately, in order to be able to test the code for file I/O, it adds
infrastructure to create frontend actions. As a basic testable example, it adds
the `InputOutputTest` FrontendAction. The sole purpose of this action is to
read a file from the command line and print it either to stdout or the output
file.  This action is run by using the `-test-io` flag also introduced in this
patch (available for `flang-new` and `flang-new -fc1`). With this patch:
```
flang-new -test-io input-file.f90
```
will read input-file.f90 and print it in the output file.

The `InputOutputTest` frontend action has been introduced primarily to
facilitate testing. It is hidden from users (i.e. it's only displayed with
`--help-hidden`). Currently Clang doesn’t have an equivalent action.

`-test-io` is used to trigger the InputOutputTest action in the Flang frontend
driver. This patch makes sure that “flang-new” forwards it to “flang-new -fc1"
by creating a preprocessor job. However, in Flang.cpp, `-test-io` is passed to
“flang-new -fc1” without `-E`. This way we make sure that the preprocessor is
_not_ run in the frontend driver. This is the desired behaviour: `-test-io`
should only read the input file and print it to the output stream.

co-authored-by: Andrzej Warzynski <andrzej.warzynski@arm.com>

Differential Revision: https://reviews.llvm.org/D87989
2020-10-24 14:58:32 +01:00
Andrzej Warzynski 8d51d37e06 [flang] Introduce DiagnosticConsumer classes in libflangFrontend
Currently Flang uses TextDiagnostic, TextDiagnosticPrinter &
TestDiagnosticBuffer classes from Clang (more specifically, from
libclangFrontend). This patch introduces simplified equivalents of these
classes in Flang (i.e. it removes the dependency on libclangFrontend).

Flang only needs these diagnostics classes for the compiler driver
diagnostics. This is unlike in Clang in which similar diagnostic classes
are used for e.g. Lexing/Parsing/Sema diagnostics. For this reason, the
implementations introduced here are relatively basic. We can extend them
in the future if this is required.

This patch also enhances how the diagnostics are printed. In particular,
this is the diagnostic that you'd get _before_  the changes introduced here
(no text formatting):

```
$ bin/flang-new
error: no input files
```

This is the diagnostic that you get _after_ the changes introduced here
(in terminals that support it, the text is formatted - bold + red):

```
$ bin/flang-new
flang-new: error: no input files
```

Tests are updated accordingly and options related to enabling/disabling
color diagnostics are flagged as supported by Flang.

Reviewed By: sameeranjoshi, CarolineConcatto

Differential Revision: https://reviews.llvm.org/D87774
2020-10-05 17:46:44 +01:00
Caroline Concatto 257b29715b [flang][driver] Add the new flang compiler and frontend drivers
Summary:

This is the first patch implementing the new Flang driver as outlined in [1],
[2] & [3]. It creates Flang driver (`flang-new`) and Flang frontend driver
(`flang-new -fc1`). These will be renamed as `flang` and `flang -fc1` once the
current Flang throwaway driver, `flang`, can be replaced with `flang-new`.

Currently only 2 options are supported: `-help` and `--version`.

`flang-new` is implemented in terms of libclangDriver, defaulting the driver
mode to `FlangMode` (added to libclangDriver in [4]). This ensures that the
driver runs in Flang mode regardless of the name of the binary inferred from
argv[0].

The design of the new Flang compiler and frontend drivers is inspired by it
counterparts in Clang [3]. Currently, the new Flang compiler and frontend
drivers re-use Clang libraries: clangBasic, clangDriver and clangFrontend.

To identify Flang options, this patch adds FlangOption/FC1Option enums.
Driver::printHelp is updated so that `flang-new` prints only Flang options.
The new Flang driver is disabled by default. To enable it, set
`-DBUILD_FLANG_NEW_DRIVER=ON` when configuring CMake and add clang to
`LLVM_ENABLE_PROJECTS` (e.g. -DLLVM_ENABLE_PROJECTS=“clang;flang;mlir”).

[1] “RFC: new Flang driver - next steps”
http://lists.llvm.org/pipermail/flang-dev/2020-July/000470.html
[2] “RFC: Adding a fortran mode to the clang driver for flang”
http://lists.llvm.org/pipermail/cfe-dev/2019-June/062669.html
[3] “RFC: refactoring libclangDriver/libclangFrontend to share with Flang”
http://lists.llvm.org/pipermail/cfe-dev/2020-July/066393.html
[4] https://reviews.llvm.org/rG6bf55804924d5a1d902925ad080b1a2b57c5c75c

co-authored-by: Andrzej Warzynski <andrzej.warzynski@arm.com>

Reviewed By: richard.barton.arm, sameeranjoshi

Differential Revision: https://reviews.llvm.org/D86089
2020-09-11 10:55:54 +01:00