[Clang] omit parentheses in fold expressions with a single expansion (#110761)

Fixes #101863

Unrevert r166268, reverted in r166272, with a fix for the issue which Nick
found: if an overloaded operator& is present before a template definition,
the expression &T::foo is represented as a CXXOpe

Unrevert r166268, reverted in r166272, with a fix for the issue which Nick
found: if an overloaded operator& is present before a template definition,
the expression &T::foo is represented as a CXXOperatorCallExpr, not as a
UnaryOperator, so we didn't notice that it's permitted to reference a non-static
data member of an unrelated class.

While investigating this, I discovered another problem in this area: we are
treating template default arguments as unevaluated contexts during substitution,
resulting in performing incorrect checks for uses of non-static data members in
C++11. That is not fixed by this patch (I'll look into this soon; it's related
to the failure to correctly instantiate constexpr function templates), but was
resulting in this bug not firing in C++11 mode (except with -Wc++98-compat).

Original message:

PR14124: When performing template instantiation of a qualified-id outside of a
class, diagnose if the qualified-id instantiates to a non-static class member.

llvm-svn: 166385

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Revert r166268, this fix for a crash-on-invalid introduced a rejects-valid.
Richard has an unreduced testcase to work with.

llvm-svn: 166272

PR14124: When performing template instantiation of a qualified-id outside of a
class, diagnose if the qualified-id instantiates to a non-static class member.

llvm-svn: 166268

Place 'equality comparison with extraneous parentheses...' into a subgroup of -Wparentheses called -Wparentheses-equality.

llvm-svn: 139180

Don't do the checks of Sema::DiagnoseEqualityWithExtraParens() on type-dependent expressions. Fixes rdar://9027658.

llvm-svn: 128437

Remove redundant check to not warn for warn_equality_with_extra_parens if we are in a macro. This is checked twice.

llvm-svn: 124714

Don't warn about extraneous '()' around a comparison if it occurs within a macro.

Macros frequently contain extra '()' to make instantiation less error prone.
This warning was flagging a ton of time

Don't warn about extraneous '()' around a comparison if it occurs within a macro.

Macros frequently contain extra '()' to make instantiation less error prone.
This warning was flagging a ton of times on postgresql because of its use of macros.

llvm-svn: 124695

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Don't warn for "if ((a == b))" if the parens came from a macro. Thanks to Fariborz for the hint!

llvm-svn: 124689

For "if ((a == b))" only warn if 'a' is a modifiable l-value. Caught by John!

llvm-svn: 124675

Warn for "if ((a == b))" where the equality expression is needlessly wrapped inside parentheses.
It's highly likely that the user intended an assignment used as condition.

Addresses rdar://8848646.

Warn for "if ((a == b))" where the equality expression is needlessly wrapped inside parentheses.
It's highly likely that the user intended an assignment used as condition.

Addresses rdar://8848646.

llvm-svn: 124668

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Warn about the use of unparenthesized |= in conditionals (which may be
a typo for !=). Fixes PR9001, from Hans Wennborg!

llvm-svn: 123836

When diagnosing suspicious precedence or assignments, move the fix-it
that adds parentheses from the main diagnostic down to a new
note. This way, when the fix-it represents a choice between two
opti

When diagnosing suspicious precedence or assignments, move the fix-it
that adds parentheses from the main diagnostic down to a new
note. This way, when the fix-it represents a choice between two
options, each of the options is associted with a note. There is no
default option in such cases. For example:

/Users/dgregor/t.c:2:9: warning: & has lower precedence than ==; ==
will be
evaluated first [-Wparentheses]
if (x & y == 0) {
^~~~~~~~
/Users/dgregor/t.c:2:9: note: place parentheses around the &
expression to
evaluate it first
if (x & y == 0) {
^
( )
/Users/dgregor/t.c:2:9: note: place parentheses around the ==
expression to
silence this warning
if (x & y == 0) {
^
( )

llvm-svn: 101249

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Improve the fix-its for -Wparentheses to ensure that the fix-it
suggestions follow recovery. Additionally, add a note to these
diagnostics which suggests a fix-it for changing the behavior to what
th

Improve the fix-its for -Wparentheses to ensure that the fix-it
suggestions follow recovery. Additionally, add a note to these
diagnostics which suggests a fix-it for changing the behavior to what
the user probably meant. Examples:

t.cpp:2:9: warning: & has lower precedence than ==; == will be evaluated first
[-Wparentheses]
if (i & j == k) {
^~~~~~~~
( )
t.cpp:2:9: note: place parentheses around the & expression to evaluate it first
if (i & j == k) {
^
( )

t.cpp:14:9: warning: using the result of an assignment as a condition
without
parentheses [-Wparentheses]
if (i = f()) {
~~^~~~~
( )
t.cpp:14:9: note: use '==' to turn this assignment into an equality
comparison
if (i = f()) {
^
==

llvm-svn: 92975

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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 o

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

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Implement -Wparentheses: warn about using assignments in contexts that require
conditions. Add a fixit to insert the parentheses. Also fix a very minor
possible memory leak in 'for' conditions.

F

Implement -Wparentheses: warn about using assignments in contexts that require
conditions. Add a fixit to insert the parentheses. Also fix a very minor
possible memory leak in 'for' conditions.

Fixes PR 4876 and rdar://problem/7289172

llvm-svn: 83907

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