A `BLOCK` statement opens a new scope. It is different from other scopes
in that implicitly typed entities are defined in the enclosing non-block
scope, not immediately in the block. This means that `IMPORT` statements
can cause them to be hidden.
Check that blocks can't have `IMPLICIT` statements in them. It is simpler
for the parser not to deal with the different between a
specification-part and a block-specification-part.
Change `ImplicitRules` to have a parent that is consulted when there isn't
an answer in the current one. For an interface body that does not happen
but for all other nested scopes it does. This parent link eliminates the
need for the `implicitRules_` stack. Make `isImplicitNoneType_` and
`isImplicitNoneExternal_` optional: not set means look in parent.
Fixesflang-compiler/f18#71.
Remove `CurrNonTypeScope()` and put the logic in `Symbol::FindSymbol`.
Original-commit: flang-compiler/f18@a153a2ee33
Reviewed-on: https://github.com/flang-compiler/f18/pull/169
Tree-same-pre-rewrite: false
Host association is done by search for symbols using `Scope::FindSymbol()`
which looks for the the name in the parent scope if the import rules
permit it.
Import statements are implemented using `importKind_` and `importNames_`
in class `Scope`. Most of the constraints are checked when the
`ImportStmt` is encountered. `CheckImports()` is called at the end of
the `SpecificationPart` to verify the names mentioned in the IMPORT
statement. That has to happen then so that we can detect if an imported
name is hidden by a declaration in the current scope.
Original-commit: flang-compiler/f18@0d50c8a8ba
Reviewed-on: https://github.com/flang-compiler/f18/pull/167
Tree-same-pre-rewrite: false
Symbols for submodules have `ModuleDetails` with `isSubmodule` set.
Scopes for submodules have `Module` kind and have a parent scope that
is also `Module` kind.
Scopes for modules now contain a mapping of submodule name to scope
so that we can find them without having to search the scope tree or
re-read their `.mod` file.
The module file for submodule `s` with ancestor module `m` is named `m-s.mod`.
The tree structure of scopes means module file writing is now recursive.
Similarly, reading the module file for a submodule may require reading
the module files of its parent and ancestor. `ResolveNames` now requires
the parent scope to be passed in -- it is not always the global scope.
`test_modfiles.sh` now handles an argument that is a filename glob so
that the test can involve multiple files. This allows `modfile09` to
test reading of `.mod` files for modules and submodules.
Original-commit: flang-compiler/f18@2e4424dbc8
Reviewed-on: https://github.com/flang-compiler/f18/pull/160
Tree-same-pre-rewrite: false
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@207065999c
Reviewed-on: https://github.com/flang-compiler/f18/pull/145
This consists of:
- a new kind of symbols to represent them with DerivedTypeDetails
- creating symbols for derived types when they are declared
- creating a new kind of scope for the type to hold component symbols
- resolving entity declarations of objects of derived type
- resolving references to objects of derived type and to components
- handling derived types with same name as generic
Type parameters are not yet implemented.
Refactor DeclTypeSpec to be a value class wrapping an IntrinsicTypeSpec
or a DerivedTypeSpec (or neither in the TypeStar and ClassStar cases).
Store DerivedTypeSpec objects in a new structure the current scope
MakeDerivedTypeSpec so that DeclTypeSpec can just contain a pointer to
them, as it currently does for intrinsic types.
In GenericDetails, add derivedType field to handle case where generic
and derived type have the same name. The generic is in the scope and the
derived type is referenced from the generic, similar to the case where a
generic and specific have the same name. When one of these names is
mis-recognized, we sometimes have to fix up the 'occurrences' lists
of the symbols.
Assign implicit types as soon as an entity is encountered that requires
one. Otherwise implicit derived types won't work. When we see 'x%y' we
have to know the type of x in order to resolve y. Add an Implicit flag
to mark symbols that were implicitly typed
For symbols that introduce a new scope, include a pointer back to that
scope.
Add CurrNonTypeScope() for the times when we want the current scope but
ignoring derived type scopes. For example, that happens when looking for
types or parameters, or creating implicit symbols.
Original-commit: flang-compiler/f18@9bd16da020
Reviewed-on: https://github.com/flang-compiler/f18/pull/109
With this change, all instances Symbol are stored in class Symbols.
Scope.symbols_, which used to own the symbol memory, now maps names to
Symbol* instead. This causes a bunch of reference-to-pointer changes
because of the change in type of key-value pairs. It also requires a
default constructor for Symbol, which means owner_ can't be a reference.
Symbols manages Symbol instances by allocating a block of them at a time
and returning the next one when needed. They are never freed.
The reason for the change is that there are a few cases where we need
to have a two symbols with the same name, so they can't both live in
the map in Scope. Those are:
1. When there is an erroneous redeclaration of a name we may delete the
first symbol and replace it with a new one. If we have saved a pointer
to the first one it is now dangling. This can be seen by running
`f18 -fdebug-dump-symbols -fparse-only test/semantics/resolve19.f90`
under valgrind. Subroutine s is declared twice: each results in a
scope that contains a pointer back to the symbol for the subroutine.
After the second symbol for s is created the first is gone so the
pointer in the scope is invalid.
2. A generic and one of its specifics can have the same name. We currently
handle that by moving the symbol for the specific into a unique_ptr
in the generic. So in that case the symbol is owned by another symbol
instead of by the scope. It is simpler if we only have to deal with
moving the raw pointer around.
3. A generic and a derived type can have the same name. This case isn't
handled yet, but it can be done like flang-compiler/f18#2 above. It's more complicated
because the derived type and the generic can be declared in either
order.
Original-commit: flang-compiler/f18@55a68cf023
Reviewed-on: https://github.com/flang-compiler/f18/pull/107
Add subprogram symbols for each interface-body and set isInterface on
them. Create a symbol with GenericDetails for each generic interface
block and add interface specifications to the specific procedures of
the generic. InterfaceVisitor takes care of this.
Before processing the specification part of modules and subprograms,
collect the names of module subprograms and internal subprograms and add
them to the symbol table with SubprogramNameDetails. This allows us to
reference them from interface blocks in the specification part.
SubprogramNameDetails is converted to SubprogramDetails when the real
subprogram is visited.
This is achieved by setting subpNamesOnly_ and then walking the
ModuleSubprogramPart or InternalSubprogramPart. Creating the symbol and
scope for a module or subprogram now happens when the Module,
SubroutineSubprogram, or FunctionSubprogram node is encountered so
this can happen in the right order.
Add BeginSubprogram and EndSubprogram to handle the parts in common
between subprograms and interface specifications.
Add GenericSpec to type.h to represent all possible generic specs.
Only generic names are resolved so far.
Add tests for new error messages. Change resolve02.f90 to reflect the
new errors reported.
Original-commit: flang-compiler/f18@03148b49dd
Reviewed-on: https://github.com/flang-compiler/f18/pull/88
Tree-same-pre-rewrite: false
When a USE statement is encountered, find the scope corresponding to the
module. This is now stored in the ModuleDetails of the module symbol.
useModuleScope_ tracks this while processing the USE. Currently only
modules defined in the same file work because we don't have module files.
At the end of a USE that isn't a use-only, add all public names that
were not renamed.
AddUse() handles recording of a USE by creating a local symbol with
UseDetails that tracks the use-symbol in the module and the location of
the USE (for error messages). If an ambiguous USE is detected, the
UseDetails are replaced by UseErrorDetails. This tracks the locations of
all the uses so that they can be referenced in a diagnostic.
Detect attempts to re-declare use-associated symbols as well as changing
their attributes (except for ASYNCHRONOUS and VOLATILE).
Add missing checks for access-stmt in scoping units other than modules.
Add tests for the new errors.
Reorganize the MessageHandler::Say() overloadings to prevent them from
becoming too numerous.
Original-commit: flang-compiler/f18@cc0523134c
Reviewed-on: https://github.com/flang-compiler/f18/pull/79
Add parse-tree-mutator.h like parse-tree-visitor.h except that the Walk
functions take non-const references to parse tree nodes so the Pre and
Post methods of the mutator that are passed around can make changes to
the parse tree.
Change ExecutionPart to be a class that wraps a list so that it can be
identified during parse tree walking.
Add Symbol* field to parser::Name for the result of symbol resolution.
In parse tree dumper, dump symbol when it is there instead of just name.
Add RewriteParseTree to walk the parse tree, fill in resolved symbols in
Name nodes, and make necessary changes to the structure. Currently that
consists of rewriting statement functions as array assignments when
appropriate.
In ResolveNames, call RewriteParseTree if the resolution was successful.
Recognize a statement function that comes after a mis-identified
statement function and report an error. resolve08.f90 tests this case.
Add -fdebug-dump-symbols to dump the scope tree and symbols in each scope.
This is implemented by DumpSymbols in resolve-names.cc. Add an optional
symbol to scopes that correspond to symbols (e.g. subprograms). Remove
debug output from ResolveNamesVisitor as this option can be used instead.
Original-commit: flang-compiler/f18@9cd3372265
Reviewed-on: https://github.com/flang-compiler/f18/pull/60
Tree-same-pre-rewrite: false
Use "namespace Fortran::semantics".
Add helper MakeSymbol() functions to ResolveNameVisitor to make a symbol
in the current scope.
Start work on subroutines, similar to what's been done for functions.
Original-commit: flang-compiler/f18@afe84af1c7
Reviewed-on: https://github.com/flang-compiler/f18/pull/30
A Symbol consists of a common part (in class Symbol) containing name,
owner, attributes. Information for a specific kind of symbol is in a
variant containing one of the *Details classes. So the kind of symbol is
determined by the type of details class stored in the details_ variant.
For scopes there is a single Scope class with an enum indicating the
kind. So far there isn't a need for extra kind-specific details as with
Symbols but that could change. Symbols defined in a Scope are stored
there in a simple map.
resolve-names.cc is a partial implementation of a parse-tree walker that
resolves names to Symbols. Currently is only handles functions (which
introduce a new Scope) and entity-decls. The test-type executable was
reused as a driver for this to avoid the need for a new one.
Sample output is below. When each "end function" is encountered the
scope is dumped, which shows the symbols defined in it.
$ cat a.f90
pure integer(8) function foo(arg1, arg2) result(res)
integer :: arg1
real :: arg2
contains
function bar(arg1)
real :: bar
real :: arg1
end function
end function
$ Debug/tools/f18/test-type a.f90
Subprogram scope: 0 children
arg1: Entity type: REAL
bar: Entity type: REAL
Subprogram scope: 1 children
arg1: Entity type: INTEGER
arg2: Entity type: REAL
bar: Subprogram (arg1)
foo: Subprogram (arg1, arg2) result(res)
res: Entity type: INTEGER(8)
Original-commit: flang-compiler/f18@1cd2fbc04d
Reviewed-on: https://github.com/flang-compiler/f18/pull/30
Tree-same-pre-rewrite: false