Commit Graph

45 Commits

Author SHA1 Message Date
Richard Smith 4b00299958 [c++20] Add deprecation warnings for the expression forms deprecated by P1120R0.
This covers:
 * usual arithmetic conversions (comparisons, arithmetic, conditionals)
   between different enumeration types
 * usual arithmetic conversions between enums and floating-point types
 * comparisons between two operands of array type

The deprecation warnings are on-by-default (in C++20 compilations); it
seems likely that these forms will become ill-formed in C++23, so
warning on them now by default seems wise.

For the first two bullets, off-by-default warnings were also added for
all the cases where we didn't already have warnings (covering language
modes prior to C++20). These warnings are in subgroups of the existing
-Wenum-conversion (except that the first case is not warned on if either
enumeration type is anonymous, consistent with our existing
-Wenum-conversion warnings).
2019-12-16 17:49:45 -08:00
Erik Pilkington d9957c7405 [Sema] Add a 'Semantic' parameter to Expr::isKnownToHaveBooleanValue
Some clients of this function want to know about any expression that is known
to produce a 0/1 value, and others care about expressions that are semantically
boolean.

This fixes a -Wswitch-bool regression I introduced in 8bfb353bb3, pointed out
by Chris Hamilton!
2019-11-20 16:29:31 -08:00
Richard Smith ef6c43dc0c Refactor checking of switch conditions and case values.
Check each case value in turn while parsing it, performing the
conversion to the switch type within the context of the expression
itself. This will become necessary in order to properly handle cleanups
for temporaries created as part of the case label (in an upcoming
patch). For now it's just good hygiene.

This necessitates moving the checking for the switch condition itself to
earlier, so that the destination type is available when checking the
case labels.

As a nice side-effect, we get slightly improved diagnostic quality and
error recovery by separating the case expression checking from the case
statement checking and from tracking whether there are discarded case
labels.

llvm-svn: 338056
2018-07-26 18:41:30 +00:00
Gabor Horvath 0284a20fba [Sema] Assign new flag -Wenum-compare-switch to switch-related parts of -Wenum-compare
Patch by: Reka Nikolett Kovacs

Differential Revision: https://reviews.llvm.org/D36526

llvm-svn: 310521
2017-08-09 20:56:43 +00:00
Gabor Horvath 64c3241154 [Sema] Extend -Wenum-compare to handle mixed enum comparisons in switch statements
Patch by: Reka Nikolett Kovacs

Differential Revision: https://reviews.llvm.org/D36407

llvm-svn: 310449
2017-08-09 08:57:09 +00:00
Richard Smith 077d083b4d PR11778: Fix the rejects-valid half of this bug. We still produce the same
poorly-worded warning for a case value that is not a possible value of the
switched-on expression.

llvm-svn: 214678
2014-08-04 00:40:48 +00:00
David Blaikie abe1a398e3 Render anonymous entities as '(anonymous <thing>)' (and lambdas as '(lambda at ... )')
For namespaces, this is consistent with mangling and GCC's debug info
behavior. For structs, GCC uses <anonymous struct> but we prefer
consistency between all anonymous entities but don't want to confuse
them with template arguments, etc, so we'll just go with parens in all
cases.

llvm-svn: 205398
2014-04-02 05:58:29 +00:00
Dmitri Gribenko 58683755ed Allow the warning 'case value not in enumerated type' to be silenced with
the following pattern.

If 'case' expression refers to a static const variable of the correct enum
type, then we count this as a sufficient declaration of intent by the user,
so we silence the warning.

llvm-svn: 196546
2013-12-05 22:52:07 +00:00
Richard Trieu 01cf09302d Add new -Wunique-enum which will warn on enums which all elements have the
same value and were initialized with literals.  Clang will warn on code like
this:

enum A {
  FIRST = 1,
  SECOND = 1
};

llvm-svn: 157666
2012-05-30 01:01:11 +00:00
Douglas Gregor 9841df655e Produce more useful 'duplicate case' diagnostics. Fixes PR9243, from Terry Long!
llvm-svn: 156904
2012-05-16 05:32:58 +00:00
Fariborz Jahanian a6983a9bce For enums with no tag name, display its location in
the diagnostic instead of displaying ''.
// rdar://11082110

llvm-svn: 153219
2012-03-21 20:56:29 +00:00
Dmitri Gribenko 800ddf3dda Generalize -Wempty-body: warn when statement body is empty (closes: PR11329)
* if, switch, range-based for: warn if semicolon is on the same line.
* for, while: warn if semicolon is on the same line and either next
statement is compound statement or next statement has more
indentation.

Replacing the semicolon with {} or moving the semicolon to the next
line will always silence the warning.

Tests from SemaCXX/if-empty-body.cpp merged into SemaCXX/warn-empty-body.cpp.

llvm-svn: 150515
2012-02-14 22:14:32 +00:00
Ted Kremenek 8d968ad5c0 Move -Wcovered-switch-default out of -Wswitch (and -Wall), and make it an opt-in warning.
This is a great warning, but it was observed that a ton of real world code violates
it all the time for (semi-)legitimate reasons.  This warnings is fairly pedantic, which is good,
but not for everyone.  For example, there is a fair amount of idiomatic code out there
that does "default: abort()", and similar idioms.

Addresses <rdar://problem/10814651>.

llvm-svn: 150055
2012-02-08 05:08:58 +00:00
Richard Smith f4c51d9d76 In C++11 mode, when an integral constant expression is desired and we have a
value of class type, look for a unique conversion operator converting to
integral or unscoped enumeration type and use that. Implements [expr.const]p5.

Sema::VerifyIntegerConstantExpression now performs the conversion and returns
the converted result. Some important callers of Expr::isIntegralConstantExpr
have been switched over to using it (including all of those required for C++11
conformance); this switch brings a side-benefit of improved diagnostics and, in
several cases, simpler code. However, some language extensions and attributes
have not been moved across and will not perform implicit conversions on
constant expressions of literal class type where an ICE is required.

In passing, fix static_assert to perform a contextual conversion to bool on its
argument.

llvm-svn: 149776
2012-02-04 09:53:13 +00:00
David Blaikie 38d0d295ea Reword/rename -Wswitch-unreachable-default.
Rewording the diagnostic to be more precise/correct: "default label in switch
which covers all enumeration values" and changed the switch to
-Wcovered-switch-default

llvm-svn: 148783
2012-01-24 05:34:08 +00:00
David Blaikie 30feb29915 Improve -Wswitch-enum diagnostic message.
Changing wording to include the word "explicitly" (as in "enumeration value ...
not /explicitly/ handled by switch"), as suggested by Richard Smith.

Also, now that the diagnostic text differs between -Wswitch and -Wswitch-enum,
I've simplified the test cases a bit.

llvm-svn: 148781
2012-01-24 04:56:25 +00:00
David Blaikie e476f979ca Fix -Wswitch to warn about out of bounds enum cases even when there's a default
For consistency with GCC & reasonable sanity. The FIXME suggests that the
original author was perhaps using the default check for some other purpose,
not realizing the more obvious limitation/false-negatives it creates, but this
doesn't seem to produce any regressions & fixes the included test.

llvm-svn: 148649
2012-01-22 02:31:55 +00:00
David Blaikie 645ae0ce10 Add -Wswitch-enum-redundant-default.
This warning acts as the complement to the main -Wswitch-enum warning (which
warns whenever a switch over enum without a default doesn't cover all values of
 the enum) & has been an an-doc coding convention in LLVM and Clang in my
experience. The purpose is to ensure there's never a "dead" default in a
switch-over-enum because this would hide future -Wswitch-enum errors.

The name warning has a separate flag name so it can be disabled but it's grouped
under -Wswitch-enum & is on-by-default because of this.

The existing violations of this rule in test cases have had the warning disabled
& I've added a specific test for the new behavior (many negative cases already
exist in the same test file - and none regressed - so I didn't add more).

Reviewed by Ted Kremenek ( http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20120116/051690.html )

llvm-svn: 148640
2012-01-21 18:12:07 +00:00
Richard Smith f57d8cb131 C++11 constant expressions: Don't use CheckICE in C++11; instead, determine
whether an expression is a (core) constant expression as a side-effect of
evaluation. This takes us from accepting far too few expressions as ICEs to
accepting slightly too many -- fixes for the remaining cases are coming next.

The diagnostics produced when an expression is found to be non-constant are
currently quite poor (with generic wording but reasonable source locations),
and will be improved in subsequent commits.

llvm-svn: 146289
2011-12-09 22:58:01 +00:00
Douglas Gregor 0afa7f66cd Tweak the typo-correction implementation to determine corrections
solely based on the names it sees, rather than actual declarations it
gets. In essence, we determine the set of names that are "close
enough" to the typo'd name. Then, we perform name lookup for each of
those names, filtering out those that aren't actually visible, and
typo-correct from the remaining results.

Overall, there isn't much of a change in the behavior of typo
correction here. The only test-suite change comes from the fact that
we make good on our promise to require that the user type 3 characters
for each 1 character corrected. 

The real intent behind this change is to set the stage for an
optimization to typo correction (so that we don't need to deserialize
all declarations in a translation unit) and future work in finding
missing qualification ("'vector' isn't in scope; did you mean
'std::vector'?). Plus, the code is cleaner this way.

llvm-svn: 116511
2010-10-14 20:34:08 +00:00
Chris Lattner 938533db60 turn down the logical bitwise confusion warning to not warn
when the RHS of the ||/&& is ever 0 or 1.  This handles a variety of
creative idioms for "true" used in C programs and fixes many false 
positives at the expense of a few false negatives.  This fixes
rdar://8230351.

llvm-svn: 109314
2010-07-24 01:10:11 +00:00
Chris Lattner 8406c5197b Add a warning to catch a bug recently caught by code review, like this:
t2.c:2:12: warning: use of logical && with constant operand; switch to bitwise &
      or remove constant [-Wlogical-bitwise-confusion]
  return x && 4;
           ^  ~

wording improvement suggestions are welcome.

llvm-svn: 108260
2010-07-13 19:41:32 +00:00
John McCall 45d30c3e36 When deciding whether an expression has the boolean nature, don't look through
explicit casts.  Fixes PR7359.

llvm-svn: 105871
2010-06-12 01:56:02 +00:00
John McCall d3dfbd6f4f If a switch condition is constant, don't warn about missing enum cases.
If a switch condition is constant, warn if there's no case for it.

Constant switch conditions do come up in reasonable template code.

llvm-svn: 104010
2010-05-18 03:19:21 +00:00
Douglas Gregor a070ffa7b8 Don't warn about case-value conversions from a negative value to a
larger unsigned value, since this is implementation-defined
behavior. (We previously suppressed this warning when converting from
a signed value to an unsigned value of the same size).

llvm-svn: 97430
2010-03-01 01:04:55 +00:00
Douglas Gregor e5ad57a3ed Don't diagnose overflow in case statements when the conversion is a
signed<->unsigned conversion with the same bit width. Fixes
<rdar://problem/7658121>.

llvm-svn: 96545
2010-02-18 00:56:01 +00:00
Douglas Gregor 12ea0f4ef9 For -Wswitch-enum warnings, be sure to look through typedefs of enum
types. Fixes <rdar://problem/7643909>.

llvm-svn: 96531
2010-02-17 23:29:11 +00:00
Douglas Gregor bd683973c1 Warn when cases are missing from a switch on a value of enumeration
type (-Wswitch), from Michal! 

llvm-svn: 95592
2010-02-08 22:24:16 +00:00
Douglas Gregor 712dcfe921 Fix the search for visible declarations within a Scope to ensure that
we look into a Scope that corresponds to a compound statement whose
scope was combined with the scope of the function that owns it. This
improves typo correction in many common cases.

llvm-svn: 92879
2010-01-07 00:31:29 +00:00
Daniel Dunbar 8fbe78f6fc Update tests to use %clang_cc1 instead of 'clang-cc' or 'clang -cc1'.
- 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
2009-12-15 20:14:24 +00:00
Douglas Gregor 3ff3af4ff9 When the condition of a switch() statement is semantically invalid,
still parse the body of the switch to try to avoid spurious
diagnostics. Fixes PR5606.

llvm-svn: 89847
2009-11-25 06:20:02 +00:00
Chris Lattner a96d427966 Implement PR4407 - missing warnings on case value overflow,
patch by Zhanyong Wan!

llvm-svn: 84259
2009-10-16 16:45:22 +00:00
Daniel Dunbar a45cf5b6b0 Rename clang to clang-cc.
Tests and drivers updated, still need to shuffle dirs.

llvm-svn: 67602
2009-03-24 02:24:46 +00:00
Anders Carlsson f7fba46331 Use VerifyIntegerConstantExpression for case values.
llvm-svn: 60317
2008-12-01 02:13:02 +00:00
Chris Lattner 0369c57ac6 Make all the 'redefinition' diagnostics more consistent, and make the
"previously defined here" diagnostics all notes.

llvm-svn: 59920
2008-11-23 23:12:31 +00:00
Anders Carlsson 475f4bce36 Case values must be evaluated
llvm-svn: 59884
2008-11-22 21:50:49 +00:00
Anders Carlsson 59689ed764 Use Expr::Evaluate for case statements. Fixes PR2525
llvm-svn: 59881
2008-11-22 21:04:56 +00:00
Chris Lattner 5e4c75f4ef rename -parse-ast-print to -ast-print
rename -parse-ast-dump to -ast-dump
remove -parse-ast, which is redundant with -fsyntax-only

llvm-svn: 42852
2007-10-11 00:18:28 +00:00
Ted Kremenek 0883fd5817 Removed option "-parse-ast-check" from clang driver. This is now implemented
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
2007-09-26 20:14:22 +00:00
Chris Lattner 67998451c7 finish off switch case overlap checking, adding support for
verifying case ranges.

llvm-svn: 41331
2007-08-23 18:29:20 +00:00
Chris Lattner f81460f99c detect and diagnose empty case ranges:
switch.c:16:8: warning: empty case range specified
  case 100 ... 99: ;  // expected-warning {{empty case range}}
       ^~~~~~~~~~

llvm-svn: 41328
2007-08-23 17:48:14 +00:00
Chris Lattner fcb920d32b fix a segfault in cases where there are no cases.
llvm-svn: 41317
2007-08-23 14:29:07 +00:00
Chris Lattner 10cb5e520f report duplicate case values. TODO: report duplicate/overlapping ranges.
llvm-svn: 41315
2007-08-23 06:23:56 +00:00
Chris Lattner fc1c44ac7d start checking case values of switch stmts more closely. Emit overflow
warnings when converting case values to the expression type.

llvm-svn: 41313
2007-08-23 05:46:52 +00:00
Chris Lattner 54f4d2bd57 correctly verify that default and case are in a switchstmt,
this fixes test/Sema/switch.c.

llvm-svn: 40438
2007-07-23 17:05:23 +00:00