This reverts commit d374b65f2d.
The changes lose AST fidelity (reported in #55778), but also may be
improperly dropping _Atomic qualifiers. I am rolling the changes back
until I've finished discussions in WG14 about the proper resolution to
DR423.
WG14 DR423 (https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2148.htm#dr_423),
resolved during the C11 time frame, changed the way qualifiers are
handled on function return types and in cast expressions after it was
noted that these types are now directly observable via generic
selection expressions. In C, the function declarator is adjusted to
ignore all qualifiers (including _Atomic qualifiers).
Clang already handles the cast expression case correctly (by performing
the lvalue conversion, which drops the qualifiers as well), but with
these changes it will now also handle function declarations
appropriately.
Fixes#39595
Differential Revision: https://reviews.llvm.org/D125919
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.
callee in constant evaluation.
We previously made a deep copy of function parameters of class type when
passing them, resulting in the destructor for the parameter applying to
the original argument value, ignoring any modifications made in the
function body. This also meant that the 'this' pointer of the function
parameter could be observed changing between the caller and the callee.
This change completely reimplements how we model function parameters
during constant evaluation. We now model them roughly as if they were
variables living in the caller, albeit with an artificially reduced
scope that covers only the duration of the function call, instead of
modeling them as temporaries in the caller that we partially "reparent"
into the callee at the point of the call. This brings some minor
diagnostic improvements, as well as significantly reduced stack usage
during constant evaluation.
callee in constant evaluation.
We previously made a deep copy of function parameters of class type when
passing them, resulting in the destructor for the parameter applying to
the original argument value, ignoring any modifications made in the
function body. This also meant that the 'this' pointer of the function
parameter could be observed changing between the caller and the callee.
This change completely reimplements how we model function parameters
during constant evaluation. We now model them roughly as if they were
variables living in the caller, albeit with an artificially reduced
scope that covers only the duration of the function call, instead of
modeling them as temporaries in the caller that we partially "reparent"
into the callee at the point of the call. This brings some minor
diagnostic improvements, as well as significantly reduced stack usage
during constant evaluation.
callee in constant evaluation.
We previously made a deep copy of function parameters of class type when
passing them, resulting in the destructor for the parameter applying to
the original argument value, ignoring any modifications made in the
function body. This also meant that the 'this' pointer of the function
parameter could be observed changing between the caller and the callee.
This change completely reimplements how we model function parameters
during constant evaluation. We now model them roughly as if they were
variables living in the caller, albeit with an artificially reduced
scope that covers only the duration of the function call, instead of
modeling them as temporaries in the caller that we partially "reparent"
into the callee at the point of the call. This brings some minor
diagnostic improvements, as well as significantly reduced stack usage
during constant evaluation.
WG14 has adopted N2480 (http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2480.pdf)
into C2x at the meetings last week, allowing parameter names of a function
definition to be elided. This patch relaxes the error so that C++ and C2x do not
diagnose this situation, and modes before C2x will allow it as an extension.
This also adds the same feature to ObjC blocks under the assumption that ObjC
wishes to follow the C standard in this regard.
C++ [basic.start.main]p1: "It shall have a return type of type int"
ISO C is also clear about this, so only accept 'int' with qualifiers in GNUMode
C.
llvm-svn: 212171
The determination of which diagnostics would be issued for certain
anonymous unions started to get a little ridiculous. Clean this up by
inverting the condition-tree's logic from dialect -> issue to
issue -> diagnostic.
As part of this cleanup, move ext_c99_flexible_array_member from
DiagnosticParseKinds.td to DiagnosticSemaKinds.td because it's driven by
Sema, not Parse.
Also, the liberty was taken to edit ext_c99_flexible_array_member to
match other, similar, diagnostics.
llvm-svn: 193919
they are treated as errors.
Doing typo correction when these are just warnings slows down the
compilation of source which deliberately uses implicit function
declarations.
llvm-svn: 146153
in several important ways:
- VLAs of non-POD types are not permitted.
- VLAs cannot be used in conjunction with C++ templates.
These restrictions are intended to keep VLAs out of the parts of the
C++ type system where they cause the most trouble. Fixes PR5678 and
<rdar://problem/8013618>.
llvm-svn: 104443
- 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
"function designator".
(This causes a minor glitch in the
diagnostics for C++ member pointers, but we weren't printing the
right diagnostic there anyway.)
llvm-svn: 70307
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
Aaron Ballman