[flang][driver] Add debug options not requiring semantic checks
This patch adds two debugging options in the new Flang driver
(flang-new):
*fdebug-unparse-no-sema
*fdebug-dump-parse-tree-no-sema
Each of these options combines two options from the "throwaway" driver
(left: f18, right: flang-new):
* `-fdebug-uparse -fdebug-no-semantics` --> `-fdebug-unparse-no-sema`
* `-fdebug-dump-parse-tree -fdebug-no-semantics` -->
`-fdebug-dump-parse-tree-no-sema`
There are no plans to implement `-fdebug-no-semantics` in the new
driver. Such option would be too powerful. Also, it would only make
sense when combined with specific frontend actions (`-fdebug-unparse`
and `-fdebug-dump-parse-tree`). Instead, this patch adds 2 specialised
options listed above. Each of these is implemented through a dedicated
FrontendAction (also added).
The new frontend actions are implemented in terms of a new abstract base
action: `PrescanAndSemaAction`. This new base class was required so that
we can have finer control over what steps within the frontend are
executed:
* `PrescanAction`: run the _prescanner_
* `PrescanAndSemaAction`: run the _prescanner_ and the _parser_ (new
in this patch)
* `PrescanAndSemaAction`: run the _prescanner_, _parser_ and run the
_semantic checks_
This patch introduces `PrescanAndParseAction::BeginSourceFileAction`.
Apart from the semantic checks removed at the end, it is similar to
`PrescanAndSemaAction::BeginSourceFileAction`.
Differential Revision: https://reviews.llvm.org/D99645
GitOrigin-RevId: e81b3401177a67481605447ea5250d8345cb4341
1 file changed
