Commit Graph

35 Commits

Author SHA1 Message Date
Matheus Izvekov 15f3cd6bfc
[clang] Implement ElaboratedType sugaring for types written bare
Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.

The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.

An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.

---

Troubleshooting list to deal with any breakage seen with this patch:

1) The most likely effect one would see by this patch is a change in how
   a type is printed. The type printer will, by design and default,
   print types as written. There are customization options there, but
   not that many, and they mainly apply to how to print a type that we
   somehow failed to track how it was written. This patch fixes a
   problem where we failed to distinguish between a type
   that was written without any elaborated-type qualifiers,
   such as a 'struct'/'class' tags and name spacifiers such as 'std::',
   and one that has been stripped of any 'metadata' that identifies such,
   the so called canonical types.
   Example:
   ```
   namespace foo {
     struct A {};
     A a;
   };
   ```
   If one were to print the type of `foo::a`, prior to this patch, this
   would result in `foo::A`. This is how the type printer would have,
   by default, printed the canonical type of A as well.
   As soon as you add any name qualifiers to A, the type printer would
   suddenly start accurately printing the type as written. This patch
   will make it print it accurately even when written without
   qualifiers, so we will just print `A` for the initial example, as
   the user did not really write that `foo::` namespace qualifier.

2) This patch could expose a bug in some AST matcher. Matching types
   is harder to get right when there is sugar involved. For example,
   if you want to match a type against being a pointer to some type A,
   then you have to account for getting a type that is sugar for a
   pointer to A, or being a pointer to sugar to A, or both! Usually
   you would get the second part wrong, and this would work for a
   very simple test where you don't use any name qualifiers, but
   you would discover is broken when you do. The usual fix is to
   either use the matcher which strips sugar, which is annoying
   to use as for example if you match an N level pointer, you have
   to put N+1 such matchers in there, beginning to end and between
   all those levels. But in a lot of cases, if the property you want
   to match is present in the canonical type, it's easier and faster
   to just match on that... This goes with what is said in 1), if
   you want to match against the name of a type, and you want
   the name string to be something stable, perhaps matching on
   the name of the canonical type is the better choice.

3) This patch could expose a bug in how you get the source range of some
   TypeLoc. For some reason, a lot of code is using getLocalSourceRange(),
   which only looks at the given TypeLoc node. This patch introduces a new,
   and more common TypeLoc node which contains no source locations on itself.
   This is not an inovation here, and some other, more rare TypeLoc nodes could
   also have this property, but if you use getLocalSourceRange on them, it's not
   going to return any valid locations, because it doesn't have any. The right fix
   here is to always use getSourceRange() or getBeginLoc/getEndLoc which will dive
   into the inner TypeLoc to get the source range if it doesn't find it on the
   top level one. You can use getLocalSourceRange if you are really into
   micro-optimizations and you have some outside knowledge that the TypeLocs you are
   dealing with will always include some source location.

4) Exposed a bug somewhere in the use of the normal clang type class API, where you
   have some type, you want to see if that type is some particular kind, you try a
   `dyn_cast` such as `dyn_cast<TypedefType>` and that fails because now you have an
   ElaboratedType which has a TypeDefType inside of it, which is what you wanted to match.
   Again, like 2), this would usually have been tested poorly with some simple tests with
   no qualifications, and would have been broken had there been any other kind of type sugar,
   be it an ElaboratedType or a TemplateSpecializationType or a SubstTemplateParmType.
   The usual fix here is to use `getAs` instead of `dyn_cast`, which will look deeper
   into the type. Or use `getAsAdjusted` when dealing with TypeLocs.
   For some reason the API is inconsistent there and on TypeLocs getAs behaves like a dyn_cast.

5) It could be a bug in this patch perhaps.

Let me know if you need any help!

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Differential Revision: https://reviews.llvm.org/D112374
2022-07-27 11:10:54 +02:00
Jonas Devlieghere 888673b6e3
Revert "[clang] Implement ElaboratedType sugaring for types written bare"
This reverts commit 7c51f02eff because it
stills breaks the LLDB tests. This was  re-landed without addressing the
issue or even agreement on how to address the issue. More details and
discussion in https://reviews.llvm.org/D112374.
2022-07-14 21:17:48 -07:00
Matheus Izvekov 7c51f02eff
[clang] Implement ElaboratedType sugaring for types written bare
Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.

The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.

An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.

---

Troubleshooting list to deal with any breakage seen with this patch:

1) The most likely effect one would see by this patch is a change in how
   a type is printed. The type printer will, by design and default,
   print types as written. There are customization options there, but
   not that many, and they mainly apply to how to print a type that we
   somehow failed to track how it was written. This patch fixes a
   problem where we failed to distinguish between a type
   that was written without any elaborated-type qualifiers,
   such as a 'struct'/'class' tags and name spacifiers such as 'std::',
   and one that has been stripped of any 'metadata' that identifies such,
   the so called canonical types.
   Example:
   ```
   namespace foo {
     struct A {};
     A a;
   };
   ```
   If one were to print the type of `foo::a`, prior to this patch, this
   would result in `foo::A`. This is how the type printer would have,
   by default, printed the canonical type of A as well.
   As soon as you add any name qualifiers to A, the type printer would
   suddenly start accurately printing the type as written. This patch
   will make it print it accurately even when written without
   qualifiers, so we will just print `A` for the initial example, as
   the user did not really write that `foo::` namespace qualifier.

2) This patch could expose a bug in some AST matcher. Matching types
   is harder to get right when there is sugar involved. For example,
   if you want to match a type against being a pointer to some type A,
   then you have to account for getting a type that is sugar for a
   pointer to A, or being a pointer to sugar to A, or both! Usually
   you would get the second part wrong, and this would work for a
   very simple test where you don't use any name qualifiers, but
   you would discover is broken when you do. The usual fix is to
   either use the matcher which strips sugar, which is annoying
   to use as for example if you match an N level pointer, you have
   to put N+1 such matchers in there, beginning to end and between
   all those levels. But in a lot of cases, if the property you want
   to match is present in the canonical type, it's easier and faster
   to just match on that... This goes with what is said in 1), if
   you want to match against the name of a type, and you want
   the name string to be something stable, perhaps matching on
   the name of the canonical type is the better choice.

3) This patch could exposed a bug in how you get the source range of some
   TypeLoc. For some reason, a lot of code is using getLocalSourceRange(),
   which only looks at the given TypeLoc node. This patch introduces a new,
   and more common TypeLoc node which contains no source locations on itself.
   This is not an inovation here, and some other, more rare TypeLoc nodes could
   also have this property, but if you use getLocalSourceRange on them, it's not
   going to return any valid locations, because it doesn't have any. The right fix
   here is to always use getSourceRange() or getBeginLoc/getEndLoc which will dive
   into the inner TypeLoc to get the source range if it doesn't find it on the
   top level one. You can use getLocalSourceRange if you are really into
   micro-optimizations and you have some outside knowledge that the TypeLocs you are
   dealing with will always include some source location.

4) Exposed a bug somewhere in the use of the normal clang type class API, where you
   have some type, you want to see if that type is some particular kind, you try a
   `dyn_cast` such as `dyn_cast<TypedefType>` and that fails because now you have an
   ElaboratedType which has a TypeDefType inside of it, which is what you wanted to match.
   Again, like 2), this would usually have been tested poorly with some simple tests with
   no qualifications, and would have been broken had there been any other kind of type sugar,
   be it an ElaboratedType or a TemplateSpecializationType or a SubstTemplateParmType.
   The usual fix here is to use `getAs` instead of `dyn_cast`, which will look deeper
   into the type. Or use `getAsAdjusted` when dealing with TypeLocs.
   For some reason the API is inconsistent there and on TypeLocs getAs behaves like a dyn_cast.

5) It could be a bug in this patch perhaps.

Let me know if you need any help!

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Differential Revision: https://reviews.llvm.org/D112374
2022-07-15 04:16:55 +02:00
Jonas Devlieghere 3968936b92
Revert "[clang] Implement ElaboratedType sugaring for types written bare"
This reverts commit bdc6974f92 because it
breaks all the LLDB tests that import the std module.

  import-std-module/array.TestArrayFromStdModule.py
  import-std-module/deque-basic.TestDequeFromStdModule.py
  import-std-module/deque-dbg-info-content.TestDbgInfoContentDequeFromStdModule.py
  import-std-module/forward_list.TestForwardListFromStdModule.py
  import-std-module/forward_list-dbg-info-content.TestDbgInfoContentForwardListFromStdModule.py
  import-std-module/list.TestListFromStdModule.py
  import-std-module/list-dbg-info-content.TestDbgInfoContentListFromStdModule.py
  import-std-module/queue.TestQueueFromStdModule.py
  import-std-module/stack.TestStackFromStdModule.py
  import-std-module/vector.TestVectorFromStdModule.py
  import-std-module/vector-bool.TestVectorBoolFromStdModule.py
  import-std-module/vector-dbg-info-content.TestDbgInfoContentVectorFromStdModule.py
  import-std-module/vector-of-vectors.TestVectorOfVectorsFromStdModule.py

https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/45301/
2022-07-13 09:20:30 -07:00
Matheus Izvekov bdc6974f92
[clang] Implement ElaboratedType sugaring for types written bare
Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.

The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.

An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Differential Revision: https://reviews.llvm.org/D112374
2022-07-13 02:10:09 +02:00
Shafik Yaghmour 50542d504d Modify TypePrinter to differentiate between anonymous struct and unnamed struct
Currently TypePrinter lumps anonymous classes and unnamed classes in one group "anonymous" this is not correct and can be confusing in some contexts.

Differential Revision: https://reviews.llvm.org/D96807
2021-02-22 14:16:43 -08:00
Shafik Yaghmour 9068dab1fd Revert "Modify TypePrinter to differentiate between anonymous struct and unnamed struct"
I missed clangd test suite and may need some time to get those working, so reverting for now.

This reverts commit ecb90b5545.
2021-02-18 18:17:24 -08:00
Shafik Yaghmour ecb90b5545 Modify TypePrinter to differentiate between anonymous struct and unnamed struct
Currently TypePrinter lumps anonymous classes and unnamed classes in one group "anonymous" this is not correct and can be confusing in some contexts.

Differential Revision: https://reviews.llvm.org/D96807
2021-02-18 17:44:45 -08:00
Richard Smith fc031d29be Switch the default of VerifyIntegerConstantExpression from constant
folding to not constant folding.

Constant folding of ICEs is done as a GCC compatibility measure, but new
code was picking it up, presumably by accident, due to the bad default.

While here, also switch the flag from a bool to an enum to make it more
obvious what it means at call sites. This highlighted a couple of places
where our behavior is different between C++11 and C++14 due to switching
from checking for an ICE to checking for a converted constant
expression (where there is no 'fold' codepath).
2020-10-15 16:58:47 -07:00
Richard Smith eea8ba097c Check whether the destination is a complete type in a static_cast (or
C-style cast) to an enumeration type.

We previously forgot to check this, and happened to get away with it
(with bad diagnostics) only because we misclassified incomplete
enumeration types as not being unscoped enumeration types. This also
fixes the misclassification.
2019-12-16 18:33:35 -08:00
David Bolvansky d46b05df84 [Test] Fix test file for C++98 mode
llvm-svn: 344762
2018-10-18 21:26:01 +00:00
David Bolvansky 1b2a9a3b53 [Diagnostics] Add missing expected warning to test file
llvm-svn: 344761
2018-10-18 21:06:14 +00:00
Volodymyr Sapsai 8b0bbc6fe0 [Sema] Error out early for tags defined inside an enumeration.
This fixes PR28903 by avoiding access check for inner enum constant. We
are performing access check because one enum constant references another
and because enum is defined in CXXRecordDecl. But access check doesn't
work because FindDeclaringClass doesn't expect more than one EnumDecl
and because inner enum has access AS_none due to not being an immediate
child of a record.

The change detects an enum is defined in wrong place and allows to skip
parsing its body. Access check is skipped together with body parsing.
There was no crash in C, added test case to cover the new error.

rdar://problem/28530809

Reviewers: rnk, doug.gregor, rsmith

Reviewed By: doug.gregor

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D37089

llvm-svn: 313386
2017-09-15 19:51:42 +00:00
Richard Smith ce8eca578d Explicitly permit undefined behavior in constant initializers for global
variables in C, in the cases where we can constant-fold it to a value
regardless (such as floating-point division by zero and signed integer
overflow). Strictly enforcing this rule breaks too much code.

llvm-svn: 254992
2015-12-08 03:21:47 +00:00
Richard Smith 2ec4061e39 Pedantic diagnostic correction: in C++, we have integral constant expressions,
not integer constant expressions. In passing, fix the 'folding is an extension'
diagnostic to not claim we're accepting the code, since that's not true in
-pedantic-errors mode, and add this diagnostic to -Wgnu.

llvm-svn: 148209
2012-01-15 03:51:30 +00:00
Douglas Gregor c87f4d4aba Don't perform integral promotions from an incompletion enumeration
type. Fixes PR8089 in a slightly different way than had been suggested.

llvm-svn: 113711
2010-09-12 03:38:25 +00:00
Eli Friedman 4202c34539 Fix for PR7911 and PR7921: make isIntegralOrEnumerationType return false
for incomplete enum types.  An incomplete enum can't really be treated as
an "integral or enumeration" type, and the incorrect treatment leads to
bad behavior for many callers.

This makes isIntegralOrEnumerationType equivalent to isIntegerType; I think
we should globally replace the latter with the former; thoughts?

llvm-svn: 111512
2010-08-19 04:39:37 +00:00
Douglas Gregor aa8c97262a Complain when an unnamed enumeration has no enumerations (in
C++). Fixes PR7466.

llvm-svn: 108231
2010-07-13 06:24:26 +00:00
Douglas Gregor c9ea2d5a67 In C++, allow a declaration of an enum to follow a definition of that
enum as a GNU extension.

llvm-svn: 106540
2010-06-22 14:26:35 +00:00
Douglas Gregor bea453a0fc In C++, one cannot assign from an arithmetic type to an enumeration
type. Fixes PR7051.

llvm-svn: 104475
2010-05-23 21:53:47 +00:00
Douglas Gregor b92a1565c3 Implement the lvalue-to-rvalue conversion where needed. The
lvalue-to-rvalue conversion adjusts lvalues of qualified, non-class
type to rvalue expressions of the unqualified variant of that
type. For example, given:

  const int i;
  (void)(i + 17);

the lvalue-to-rvalue conversion for the subexpression "i" will turn it
from an lvalue expression (a DeclRefExpr) with type 'const int' into
an rvalue expression with type 'int'. Both C and C++ mandate this
conversion, and somehow we've slid through without implementing it. 

We now have both DefaultFunctionArrayConversion and
DefaultFunctionArrayLvalueConversion, and which gets used depends on
whether we do the lvalue-to-rvalue conversion or not. Generally, we do
the lvalue-to-rvalue conversion, but there are a few notable
exceptions:
  - the left-hand side of a '.' operator
  - the left-hand side of an assignment
  - a C++ throw expression
  - a subscript expression that's subscripting a vector

Making this change exposed two issues with blocks:
  - we were deducing const-qualified return types of non-class type
  from a block return, which doesn't fit well
  - we weren't always setting the known return type of a block when it
  was provided with the ^return-type syntax

Fixes the current Clang-on-Clang compile failure and PR6076.

llvm-svn: 95167
2010-02-03 00:27:59 +00:00
Douglas Gregor 5204248f96 When looking up enumerator names for redeclaration, use the
ForRedeclaration flag so that we don't look into base classes. 
Fixes PR6061.

llvm-svn: 93862
2010-01-19 06:06:57 +00:00
Eli Friedman 8d0da8042b Fix test.
llvm-svn: 91566
2009-12-16 20:47:15 +00:00
Eli Friedman 6a8dc922b3 Make sure C-specific enum warning doesn't trigger in C++.
llvm-svn: 91563
2009-12-16 20:30:08 +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
John McCall 5677499fbf First pass at implementing C++ enum semantics: calculate (and store) an
"integer promotion" type associated with an enum decl, and use this type to
determine which type to promote to.  This type obeys C++ [conv.prom]p2 and
is therefore generally signed unless the range of the enumerators forces
it to be unsigned.

Kills off a lot of false positives from -Wsign-compare in C++, addressing
rdar://7455616

llvm-svn: 90965
2009-12-09 09:09:27 +00:00
John McCall 9f545181f7 When recovering from an invalid forward reference to an enum type in C++,
create the enum type in the same scope as you would a record type.

llvm-svn: 90500
2009-12-04 00:07:04 +00:00
Anders Carlsson 7f84ed9287 Add CheckCallReturnType and start using it for regular call expressions. This will improve error messages. For
struct B;

B f();

void g() {
f();
}

We now get

t.cpp:6:3: error: calling 'f' with incomplete return type 'struct B'
  f();
  ^~~
t.cpp:3:3: note: 'f' declared here
B f();
  ^
t.cpp:1:8: note: forward declaration of 'struct B'
struct B;
       ^

llvm-svn: 83692
2009-10-09 23:51:55 +00:00
Mike Stump 11289f4280 Remove tabs, and whitespace cleanups.
llvm-svn: 81346
2009-09-09 15:08:12 +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
Eli Friedman 3164fb15e2 Check that the return/argument types of calls are complete.
llvm-svn: 67485
2009-03-22 22:00:50 +00:00
Douglas Gregor 975e6d0ccd Print the context of tag types as part of pretty-printing, e.g.,
struct N::M::foo

llvm-svn: 67284
2009-03-19 04:25:59 +00:00
Douglas Gregor d45b93bdd6 Implement the GNU semantics for forward declarations of enum types in
C and C++. Fixes PR3688.

llvm-svn: 66282
2009-03-06 18:34:03 +00:00
Douglas Gregor 225b321a85 Fix <rdar://problem/6502934>. We were creating an ImplicitCastExpr
with reference type (it should be an lvalue with non-reference type).

llvm-svn: 62345
2009-01-16 19:38:23 +00:00
Douglas Gregor b9d2380204 Add test of enumerator types
llvm-svn: 60940
2008-12-12 07:27:10 +00:00