**Summary**
The public lldb matrix bot is failing for tests compiled with clang-9, clang-11, clang-13.
This patch addresses these failures by evaluating the enum case that
doesn't cause malformed DWARF in older version of clang.
There was no particular reason we had to use `true` enum case
to reproduce the bug in #58383, so simply switch to use `false`
to get all bots passing again.
**Details**
In older versions of clang, the following snippet:
```
enum EnumBool : bool {
enum_bool_case1 = false,
enum_bool_case2 = true,
};
struct A {
const static EnumBool enum_bool_val = enum_bool_case2;
};
```
…results in following DWARF:
```
0x00000052: DW_TAG_structure_type
DW_AT_calling_convention (DW_CC_pass_by_value)
DW_AT_name ("A")
DW_AT_byte_size (0x01)
DW_AT_decl_file ("/Users/michaelbuch/Git/llvm-project/lldb/test/API/lang/cpp/const_static_integral_member/repro.cpp")
DW_AT_decl_line (6)
0x0000005b: DW_TAG_member
DW_AT_name ("enum_bool_val")
DW_AT_type (0x0000000000000068 "const EnumBool")
DW_AT_decl_file ("/Users/michaelbuch/Git/llvm-project/lldb/test/API/lang/cpp/const_static_integral_member/repro.cpp")
DW_AT_decl_line (7)
DW_AT_external (true)
DW_AT_declaration (true)
DW_AT_const_value (-1)
```
Note the `DW_AT_const_value == -1`
When evaluating `A::enum_bool_val` in the lldb we get:
```
(lldb) p A::enum_bool_val
error: expression failed to parse:
error: Couldn't lookup symbols:
__ZN1A13enum_bool_valE
```
Enabling the DWARF logs we see:
```
(arm64) clang-13.out: DWARFASTParserClang::ParseTypeFromDWARF (die = 0x00000068, decl_ctx = 0x136ac1e30 (die 0x0000000b)) DW_TAG_const_type name = '(null)')
Failed to add const value to variable A::enum_bool_val: Can't store unsigned value 18446744073709551615 in integer with 1 bits.
```
This occurs because a boolean enum is considered an unsigned integer
type, but we try to initialize it with a `-1`.
**Testing**
- Confirmed locally that top-of-tree lldb correctly
evaluates the previously failing expression when
the test program is compiled with clang-13
Differential Revision: https://reviews.llvm.org/D137793
Undoes a lot of the code added in D135169 to piggyback off of the enum logic in `TypeSystemClang::SetIntegerInitializerForVariable()`.
Fixes#58383.
Reviewed By: DavidSpickett
Differential Revision: https://reviews.llvm.org/D137045
Previously we had a bit of a mix of "signed char" "unsigned char" and
"char".
This adds seperate min and max checks for all three types.
Depends on D135170
Reviewed By: Michael137
Differential Revision: https://reviews.llvm.org/D135352
As with static bool for whatever reason printing them on their own
worked fine but wasn't handled when you printed the whole type.
I don't see a good way to test this from clang's side so our existing
tests will have to do.
We can now print all of the struct "A", so there's no need for a separate
one for static bool testing. I've not checked the output, just that it
succeeds. This saves us having to handle different min/max between systems.
Depends on D135169
Reviewed By: aeubanks, shafik
Differential Revision: https://reviews.llvm.org/D135170
Fixes#58135
Somehow lldb was able to print the member on its own but when we try
to print the whole type found by "image lookup -t" lldb would crash.
This is because we'd encoded the initial value of the member as an integer.
Which isn't the end of the world because bool is integral for C++.
However, clang has a special AST node to handle literal bool and it
expected us to use that instead.
This adds a new codepath to handle static bool which uses cxxBoolLiteralExpr
and we get the member printed as you'd expect.
For testing I added a struct with just the bool because trying to print
all of "A" crashes as well. Presumably because one of the other member's
types isn't handled properly either.
So for now I just added the bool case, we can merge it with A later.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D135169
This test fails for Clang versions < 14.0 for `dsym` variants.
`dsymutil` strips debug info for classes with only static members.
Thus move the failing assertions into the XFAIL test case.
Differential Revision: https://reviews.llvm.org/D132004
1438639a2f7eb9e9cba01454d3a9b1b16d179c9a removed a test
that was using undefined behaviour setting a non-typed enum
to a value outside its known range.
That test also checked if we formatted the value properly
when it could contain >1 valid enum value.
I don't think there's anything special about how we format
typed vs non-typed enums so I'm adding a test for ScopedEnum
that will expect to see 2 enum values plus extra.
Reviewed By: labath, Michael137, shafik
Differential Revision: https://reviews.llvm.org/D131472
Setting an enum without a fixed underlying type to a value which is outside the
value range is undefined behavior.
The initializer needs to be a constant expression and therefore this was always
ill-formed we just were not diagnosing it before.
See D130058 and D131307 for more details.
Differential Revision: https://reviews.llvm.org/D131460
`IntegerLiteral::Create` operates on integer types. For that reason
when we parse DWARF into an AST, when we encounter a constant
initialized enum member variable, we try to determine the underlying
integer type before creating the `IntegerLiteral`. However, we
currently don't desugar the type and for enum typedefs
`dyn_cast<EnumType>` fails. In debug builds this triggers following
assert:
```
Assertion failed: (type->isIntegerType() && "Illegal type in IntegerLiteral"), function IntegerLiteral, file Expr.cpp, line 892
```
This patch turns the `dyn_cast<EnumType>` into a `getAs<EnumType>`
which `dyn_cast`s the canonical type, allowing us to get to the
underlying integer type.
**Testing**
* API test
* Manual repro is fixed
Differential Revision: https://reviews.llvm.org/D130213
Reland 486787210d which broke tests on Arm and Windows.
* Windows -- on Windows const static data members with no out-of-class
definition do have valid addresses, in constract to other platforms
(Linux, macos) where they don't. Adjusted the test to expect success
on Windows and failure on other platforms.
* Arm -- `int128` is not available on 32-bit ARM, so disable the test
for this architecture.
This adds support for using const static integral data members as described by C++11 [class.static.data]p3
to LLDB's expression evaluator.
So far LLDB treated these data members are normal static variables. They already work as intended when they are declared in the class definition and then defined in a namespace scope. However, if they are declared and initialised in the class definition but never defined in a namespace scope, all LLDB expressions that use them will fail to link when LLDB can't find the respective symbol for the variable.
The reason for this is that the data members which are only declared in the class are not emitted into any object file so LLDB can never resolve them. Expressions that use these variables are expected to directly use their constant value if possible. Clang can do this for us during codegen, but it requires that we add the constant value to the VarDecl we generate for these data members.
This patch implements this by:
* parsing the constant values from the debug info and adding it to variable declarations we encounter.
* ensuring that LLDB doesn't implicitly try to take the address of expressions that might be an lvalue that points to such a special data member.
The second change is caused by LLDB's way of storing lvalues in the expression parser. When LLDB parses an expression, it tries to keep the result around via two mechanisms:
1. For lvalues, LLDB generates a static pointer variable and stores the address of the last expression in it: `T *$__lldb_expr_result_ptr = &LastExpression`
2. For everything else, LLDB generates a static variable of the same type as the last expression and then direct initialises that variable: `T $__lldb_expr_result(LastExpression)`
If we try to print a special const static data member via something like `expr Class::Member`, then LLDB will try to take the address of this expression as it's an lvalue. This means LLDB will try to take the address of the variable which causes that Clang can't replace the use with the constant value. There isn't any good way to detect this case (as there a lot of different expressions that could yield an lvalue that points to such a data member), so this patch also changes that we only use the first way of capturing the result if the last expression does not have a type that could potentially indicate it's coming from such a special data member.
This change shouldn't break most workflows for users. The only observable side effect I could find is that the implicit persistent result variables for const int's now have their own memory address:
Before this change:
```
(lldb) p i
(const int) $0 = 123
(lldb) p &$0
(const int *) $1 = 0x00007ffeefbff8e8
(lldb) p &i
(const int *) $2 = 0x00007ffeefbff8e8
```
After this change we capture `i` by value so it has its own value.
```
(lldb) p i
(const int) $0 = 123
(lldb) p &$0
(const int *) $1 = 0x0000000100155320
(lldb) p &i
(const int *) $2 = 0x00007ffeefbff8e8
```
Reviewed By: Michael137
Differential Revision: https://reviews.llvm.org/D81471
