For backwards compatiblity, we emit only a warning instead of an error if the
attribute is one of the existing type attributes that we have historically
allowed to "slide" to the `DeclSpec` just as if it had been specified in GNU
syntax. (We will call these "legacy type attributes" below.)
The high-level changes that achieve this are:
- We introduce a new field `Declarator::DeclarationAttrs` (with appropriate
accessors) to store C++11 attributes occurring in the attribute-specifier-seq
at the beginning of a simple-declaration (and other similar declarations).
Previously, these attributes were placed on the `DeclSpec`, which made it
impossible to reconstruct later on whether the attributes had in fact been
placed on the decl-specifier-seq or ahead of the declaration.
- In the parser, we propgate declaration attributes and decl-specifier-seq
attributes separately until we can place them in
`Declarator::DeclarationAttrs` or `DeclSpec::Attrs`, respectively.
- In `ProcessDeclAttributes()`, in addition to processing declarator attributes,
we now also process the attributes from `Declarator::DeclarationAttrs` (except
if they are legacy type attributes).
- In `ConvertDeclSpecToType()`, in addition to processing `DeclSpec` attributes,
we also process any legacy type attributes that occur in
`Declarator::DeclarationAttrs` (and emit a warning).
- We make `ProcessDeclAttribute` emit an error if it sees any non-declaration
attributes in C++11 syntax, except in the following cases:
- If it is being called for attributes on a `DeclSpec` or `DeclaratorChunk`
- If the attribute is a legacy type attribute (in which case we only emit
a warning)
The standard justifies treating attributes at the beginning of a
simple-declaration and attributes after a declarator-id the same. Here are some
relevant parts of the standard:
- The attribute-specifier-seq at the beginning of a simple-declaration
"appertains to each of the entities declared by the declarators of the
init-declarator-list" (https://eel.is/c++draft/dcl.dcl#dcl.pre-3)
- "In the declaration for an entity, attributes appertaining to that entity can
appear at the start of the declaration and after the declarator-id for that
declaration." (https://eel.is/c++draft/dcl.dcl#dcl.pre-note-2)
- "The optional attribute-specifier-seq following a declarator-id appertains to
the entity that is declared."
(https://eel.is/c++draft/dcl.dcl#dcl.meaning.general-1)
The standard contains similar wording to that for a simple-declaration in other
similar types of declarations, for example:
- "The optional attribute-specifier-seq in a parameter-declaration appertains to
the parameter." (https://eel.is/c++draft/dcl.fct#3)
- "The optional attribute-specifier-seq in an exception-declaration appertains
to the parameter of the catch clause" (https://eel.is/c++draft/except.pre#1)
The new behavior is tested both on the newly added type attribute
`annotate_type`, for which we emit errors, and for the legacy type attribute
`address_space` (chosen somewhat randomly from the various legacy type
attributes), for which we emit warnings.
Depends On D111548
Reviewed By: aaron.ballman, rsmith
Differential Revision: https://reviews.llvm.org/D126061
C89 allowed a type specifier to be elided with the resulting type being
int, aka implicit int behavior. This feature was subsequently removed
in C99 without a deprecation period, so implementations continued to
support the feature. Now, as with implicit function declarations, is a
good time to reevaluate the need for this support.
This patch allows -Wimplicit-int to issue warnings in C89 mode (off by
default), defaults the warning to an error in C99 through C17, and
disables support for the feature entirely in C2x. It also removes a
warning about missing declaration specifiers that really was just an
implicit int warning in disguise and other minor related cleanups.
This patch adds -Wno-strict-prototypes to all of the test cases that
use functions without prototypes, but not as the primary concern of the
test. e.g., attributes testing whether they can/cannot be applied to a
function without a prototype, etc.
This is done in preparation for enabling -Wstrict-prototypes by
default.
A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,
void func();
becomes
void func(void);
This is the fourth batch of tests being updated (there are a significant
number of other tests left to be updated).
into a separate "parse an attribute that takes a type argument" codepath. This
results in both codepaths being a lot cleaner and simpler, and fixes some bugs
where the type argument handling bled into the expression argument handling and
caused us to both accept invalid and reject valid attribute arguments.
llvm-svn: 193731
For compatibility with gcc, clang will now parse gcc attributes on
function definitions, but issue a warning if the attribute is not a
thread safety attribute. Warning controlled by -Wgcc-compat.
llvm-svn: 150698
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
scheme to be more useful.
The new scheme introduces a set of categories that should be more
readable, and also reflects what we want to consider as an extension
more accurately. Specifically, it makes the "what is a keyword"
determination accurately reflect whether the keyword is a GNU or
Microsoft extension.
I also introduced separate flags for keyword aliases; this is useful
because the classification of the aliases is mostly unrelated to the
classification of the original keyword.
This patch treats anything that's in the implementation
namespace (prefixed with "__", or "_X" where "X" is any upper-case
letter) as a keyword without marking it as an extension. This is
consistent with the standards in that an implementation is allowed to define
arbitrary extensions in the implementation namespace without violating
the standard. This gets rid of all the nasty "extension used" warnings
for stuff like __attribute__ in -pedantic mode. We still warn for
extensions outside of the the implementation namespace, like typeof.
If someone wants to implement -Wextensions or something like that, we
could add additional information to the keyword table.
This also removes processing for the unused "Boolean" language option;
such an extension isn't supported on any other C implementation, so I
don't see any point to adding it.
The changes to test/CodeGen/inline.c are required because previously, we
weren't actually disabling the "inline" keyword in -std=c89 mode.
I'll remove Boolean and NoExtensions from LangOptions in a follow-up
commit.
llvm-svn: 70281
of whether a '(' was a grouping paren or the start of a function declarator.
This is PR2796.
Now we eat the attribute before deciding whether the paren is grouping or
not, then apply it to the resultant decl or to the first argument as needed.
One somewhat surprising aspect of this is that attributes interact with
implicit int in cases like this:
void a(x, y) // k&r style function
void b(__attribute__(()) x, y); // function with two implicit int arguments
void c(x, __attribute__(()) y); // error, can't have attr in identifier list.
Fun stuff.
llvm-svn: 57790
using "-parse-ast -verify".
Updated all test cases (using a sed script) that invoked -parse-ast-check to
now use -parse-ast -verify.
Fixed a bug where using "-verify" instead of "-parse-ast-check" would not
correctly create the DiagClient needed to accumulate diagnostics.
llvm-svn: 42365
Martin Boehme