D155991 changed the file lookup to do a full string compare on the
filename; however, this added ~0.5% to compile time with -g.
Go back to the previous pointer-based lookup, but capture the main
file's checksum as well as its name to use when creating the extra
DIFile entry. This causes all entries to be consistent and also
avoids computing the checksum twice.
This reverts commit 5956648fc3ba11dd6b0d0f2d1d9b923e7f80f247.
There was a string lifetime issue that is now corrected.
Differential Revision: https://reviews.llvm.org/D156571
D155991 changed the file lookup to do a full string compare on the
filename; however, this added ~0.5% to compile time with -g.
Go back to the previous pointer-based lookup, but capture the main
file's checksum as well as its name to use when creating the extra
DIFile entry. This causes all entries to be consistent and also
avoids computing the checksum twice.
This reverts commit 21e7f73494663814e0296066895dfacdebfac6d4.
I'm unable to find a reason for the memory management issues
that caused the revert, so trying again.
D155991 changed the file lookup to do a full string compare on the
filename; however, this added ~0.5% to compile time with -g.
Go back to the previous pointer-based lookup, but capture the main
file's checksum as well as its name to use when creating the extra
DIFile entry. This causes all entries to be consistent and also
avoids computing the checksum twice.
Differential revision: https://reviews.llvm.org/D156571
In cases where a structured binding declaration is made to a struct with
bitfields:
struct A {
unsigned int x : 16;
unsigned int y : 16;
} g;
auto [a, b] = g; // structured binding declaration
Clang assigns the 'unsigned int' DWARF base type to 'a' and 'b' because
this is their deduced C++ type in the structured binding declaration.
However, their actual type in memory is 'unsigned short' as they have 16
bits allocated for each.
This is a problem for debug information consumers: if the debug
information for 'a' has the 'unsigned int' base type, a debugger will
assume it has 4 bytes, whereas it actually has a length of 2, resulting
in a read (or write) past its length.
This patch mimics GCC's behaviour: in case of structured bindings to
bitfields, the binding declaration's DWARF base type is of the target's
integer type with the same bitwidth as the bitfield.
If no suitable integer type is found in the target, no debug information
is emitted anymore in order to prevent wrong debug output.
Reviewed By: tmatheson
Differential Revision: https://reviews.llvm.org/D157479
The DIFile cache was keyed on a string pointer instead of string content,
which was causing misses and resulted in an entry without a checksum.
In DWARF v5 if any checksum is missing, we can't write any to the output
file, so this had consequences.
Fixes https://github.com/llvm/llvm-project/issues/63955
Differential revision: https://reviews.llvm.org/D155991
This patch adds copy/move assignment operator to the class which has user-defined copy/move constructor.
Reviewed By: tahonermann, NoQ, aaronpuchert
Differential Revision: https://reviews.llvm.org/D150411
For
`clang -c -g -fdebug-prefix-map=a/b=y -fdebug-prefix-map=a=x a/b/c.c`,
we apply the longest prefix substitution, but
GCC has always been picking the last applicable option (`a=x`, see
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109591).
I feel that GCC's behavior is reasonable given the convention that the last
value wins for the same option.
Before D49466, Clang appeared to apply the shortest prefix substitution,
which likely made the least sense.
Reviewed By: #debug-info, scott.linder
Differential Revision: https://reviews.llvm.org/D148975
With this patch, whenever we emit a `DW_AT_type` for some declaration
and the type is a template class with a `clang::PreferredNameAttr`, we
will emit the typedef that the attribute refers to instead. I.e.,
```
0x123 DW_TAG_variable
DW_AT_name "var"
DW_AT_type (0x123 "basic_string<char>")
0x124 DW_TAG_structure_type
DW_AT_name "basic_string<char>"
```
...becomes
```
0x123 DW_TAG_variable
DW_AT_name "var"
DW_AT_type (0x124 "std::string")
0x124 DW_TAG_structure_type
DW_AT_name "basic_string<char>"
0x125 DW_TAG_typedef
DW_AT_name "std::string"
DW_AT_type (0x124 "basic_string<char>")
```
We do this by returning the preferred name typedef `DIType` when
we create a structure definition. In some cases, e.g., with `-gmodules`,
we don't complete the structure definition immediately but do so later
via `completeClassData`, which overwrites the `TypeCache`. In such cases
we don't actually want to rewrite the cache with the preferred name. We
handle this by returning both the definition and the preferred typedef
from `CreateTypeDefinition` and let the callee decide what to do with
it.
Essentially we set up the types as:
```
TypeCache[Record] => DICompositeType
ReplaceMap[Record] => DIDerivedType(baseType: DICompositeType)
```
For now we keep this behind LLDB tuning.
**Testing**
- Added clang unit-test
- `check-llvm`, `check-clang` pass
- Confirmed that this change correctly repoints
`basic_string` references in some of my test programs.
- Will add follow-up LLDB API tests
Differential Revision: https://reviews.llvm.org/D145803
This patch moves the Debug Options to llvm/Frontend so that it can be shared by Flang as well.
Reviewed By: kiranchandramohan, awarzynski
Differential Revision: https://reviews.llvm.org/D142347
Consider the following sturctures when targetting:
struct foo {
int space[4];
char a : 8;
char b : 8;
char x : 8;
char y : 8;
};
struct bar {
int space[4];
char a : 8;
char b : 8;
char : 0;
char x : 8;
char y : 8;
};
Even if both structs have the same layout in memory, they are handled
differenlty by the AMDGPU ABI.
With the following code:
// clang --target=amdgcn-amd-amdhsa -g -O1 example.c -S
char use_foo(struct foo f) { return f.y; }
char use_bar(struct bar b) { return b.y; }
For use_foo, the 'y' field is passed in v4
; v_ashrrev_i32_e32 v0, 24, v4
; s_setpc_b64 s[30:31]
For use_bar, the 'y' field is passed in v5
; v_bfe_i32 v0, v5, 8, 8
; s_setpc_b64 s[30:31]
To make this distinction, we record a single 0-size bitfield for every member that is preceded
by it.
Reviewed By: probinson
Differential Revision: https://reviews.llvm.org/D144870
This patch introduces a new type __externref_t that denotes a WebAssembly opaque
reference type. It also implements builtin __builtin_wasm_ref_null_extern(),
that returns a null value of __externref_t. This lays the ground work
for further builtins and reference types.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D122215
The commit was reverted due to a regression in debug information of an
optimized code test in lldb. This has since been addressed by:
1. rGf753e5be8239: [LiveDebugValues] Allow EntryValue with OP_deref
expressions
2. rG055f2f04e658: [mem2reg][debuginfo] Handle op_deref when converting
dbg.declare
Differential Revision: https://reviews.llvm.org/D141381
This patch introduces a new type __externref_t that denotes a WebAssembly opaque
reference type. It also implements builtin __builtin_wasm_ref_null_extern(),
that returns a null value of __externref_t. This lays the ground work
for further builtins and reference types.
Differential Revision: https://reviews.llvm.org/D122215
With codegen prior to this patch, truly indirect arguments -- i.e.
those that are not `byval` -- can have their debug information lost even
at O0. Because indirect arguments are passed by pointer, and this
pointer is likely placed in a register as per the function call ABI,
debug information is lost as soon as the register gets clobbered.
This patch solves the issue by storing the address of the parameter on
the stack, using a similar strategy employed when C++ references are
passed. In other words, this patch changes codegen from:
```
define @foo(ptr %arg) {
call void @llvm.dbg.declare(%arg, [...], metadata !DIExpression())
```
To:
```
define @foo(ptr %arg) {
%ptr_storage = alloca ptr
store ptr %arg, ptr %ptr_storage
call void @llvm.dbg.declare(%ptr_storage, [...], metadata !DIExpression(DW_OP_deref))
```
Some common cases where this may happen with C or C++ function calls:
1. "Big enough" trivial structures passed by value under the ARM ABI.
2. Structures that are non-trivial for the purposes of call (as per
the Itanium ABI) when passed by value.
A few tests were matching the wrong alloca (matching against the new
alloca, instead of the old one), so they were updated to either match
both allocas or include a `,` right after the alloca type, to prevent
matching against a pointer type.
Differential Revision: https://reviews.llvm.org/D141381
Seems this complicated lldb sufficiently for some cases that it hasn't
been worth supporting/fixing there - and it so far hasn't provided any
new use cases/value for debug info consumers, so let's remove it until
someone has a use case for it.
(side note: the original implementation of this still had a bug (I
should've caught it in review) that we still didn't produce
auto-returning function declarations in types where the function wasn't
instantiatied (that requires a fix to remove the `if
getContainedAutoType` condition in
`CGDebugInfo::CollectCXXMemberFunctions` - without that, auto returning
functions were still being handled the same as member function templates
and special member functions - never added to the member list, only
attached to the type via the declaration chain from the definition)
Further discussion about this in D123319
This reverts commit 5ff992bca208a0e37ca6338fc735aec6aa848b72: [DEBUG-INFO] Change how we handle auto return types for lambda operator() to be consistent with gcc
This reverts commit c83602fdf51b2692e3bacb06bf861f20f74e987f: [DWARF5][clang]: Added support for DebugInfo generation for auto return type for C++ member functions.
Differential Revision: https://reviews.llvm.org/D131933
An upcoming patch will extend llvm-symbolizer to provide the source line
information for global variables. The goal is to move AddressSanitizer
off of internal debug info for symbolization onto the DWARF standard
(and doing a clean-up in the process). Currently, ASan reports the line
information for constant strings if a memory safety bug happens around
them. We want to keep this behaviour, so we need to emit debuginfo for
these variables as well.
Reviewed By: dblaikie, rnk, aprantl
Differential Revision: https://reviews.llvm.org/D123534
This reverts commit 4680982b36a84770a1600fc438be8ec090671724.
Broke a fuchsia windows bot. More details in the review:
https://reviews.llvm.org/D123534
An upcoming patch will extend llvm-symbolizer to provide the source line
information for global variables. The goal is to move AddressSanitizer
off of internal debug info for symbolization onto the DWARF standard
(and doing a clean-up in the process). Currently, ASan reports the line
information for constant strings if a memory safety bug happens around
them. We want to keep this behaviour, so we need to emit debuginfo for
these variables as well.
Reviewed By: dblaikie, rnk, aprantl
Differential Revision: https://reviews.llvm.org/D123534
clang to emit DWARF information for global alias variable as
DW_TAG_imported_declaration. This change also handles nested
(recursive) imported declarations.
Reviewed by: dblaikie, aprantl
Differential Revision: https://reviews.llvm.org/D120989
Current ASTContext.getAttributedType() takes attribute kind,
ModifiedType and EquivType as the hash to decide whether an AST node
has been generated or note. But this is not enough for btf_type_tag
as the attribute might have the same ModifiedType and EquivType, but
still have different string associated with attribute.
For example, for a data structure like below,
struct map_value {
int __attribute__((btf_type_tag("tag1"))) __attribute__((btf_type_tag("tag3"))) *a;
int __attribute__((btf_type_tag("tag2"))) __attribute__((btf_type_tag("tag4"))) *b;
};
The current ASTContext.getAttributedType() will produce
an AST similar to below:
struct map_value {
int __attribute__((btf_type_tag("tag1"))) __attribute__((btf_type_tag("tag3"))) *a;
int __attribute__((btf_type_tag("tag1"))) __attribute__((btf_type_tag("tag3"))) *b;
};
and this is incorrect.
It is very difficult to use the current AttributedType as it is hard to
get the tag information. To fix the problem, this patch introduced
BTFTagAttributedType which is similar to AttributedType
in many ways but with an additional BTFTypeTagAttr. The tag itself can
be retrieved with BTFTypeTagAttr.
With the new BTFTagAttributed type, the debuginfo code can be greatly
simplified compared to previous TypeLoc based approach.
Differential Revision: https://reviews.llvm.org/D120296
Currently we are not emitting debug-info for all cases of structured bindings a
C++17 feature which allows us to bind names to subobjects in an initializer.
A structured binding is represented by a DecompositionDecl AST node and the
binding are represented by a BindingDecl. It looks the original implementation
only covered the tuple like case which be represented by a DeclRefExpr which
contains a VarDecl.
If the binding is to a subobject of the struct the binding will contain a
MemberExpr and in the case of arrays it will contain an ArraySubscriptExpr.
This PR adds support emitting debug-info for the MemberExpr and ArraySubscriptExpr
cases as well as llvm and lldb tests for these cases as well as the tuple case.
Differential Revision: https://reviews.llvm.org/D119178
WG14 adopted the _ExtInt feature from Clang for C23, but renamed the
type to be _BitInt. This patch does the vast majority of the work to
rename _ExtInt to _BitInt, which accounts for most of its size. The new
type is exposed in older C modes and all C++ modes as a conforming
extension. However, there are functional changes worth calling out:
* Deprecates _ExtInt with a fix-it to help users migrate to _BitInt.
* Updates the mangling for the type.
* Updates the documentation and adds a release note to warn users what
is going on.
* Adds new diagnostics for use of _BitInt to call out when it's used as
a Clang extension or as a pre-C23 compatibility concern.
* Adds new tests for the new diagnostic behaviors.
I want to call out the ABI break specifically. We do not believe that
this break will cause a significant imposition for early adopters of
the feature, and so this is being done as a full break. If it turns out
there are critical uses where recompilation is not an option for some
reason, we can consider using ABI tags to ease the transition.
This is to revert commit f95bd18b5faa (Revert "[Attr] support
btf_type_tag attribute") plus a bug fix.
Previous change failed to handle cases like below:
$ cat reduced.c
void a(*);
void a() {}
$ clang -c reduced.c -O2 -g
In such cases, during clang IR generation, for function a(),
CGCodeGen has numParams = 1 for FunctionType. But for
FunctionTypeLoc we have FuncTypeLoc.NumParams = 0. By using
FunctionType.numParams as the bound to access FuncTypeLoc
params, a random crash is triggered. The bug fix is to
check against FuncTypeLoc.NumParams before accessing
FuncTypeLoc.getParam(Idx).
Differential Revision: https://reviews.llvm.org/D111199
This reverts commits 737e4216c537c33aab8ec51880f06b8a54325b94 and
ce7ac9e66aba2b937b3d3b5505ce6cc75dcc56ac.
After those commits, the compiler can crash with a reduced
testcase like this:
$ cat reduced.c
void a(*);
void a() {}
$ clang -c reduced.c -O2 -g
This patch added clang codegen and llvm support
for btf_type_tag support. Currently, btf_type_tag
attribute info is preserved in DebugInfo IR only for
pointer types associated with typedef, global variable
and function declaration. Eventually, such information
is emitted to dwarf.
The following is an example:
$ cat test.c
#define __tag __attribute__((btf_type_tag("tag")))
int __tag *g;
$ clang -O2 -g -c test.c
$ llvm-dwarfdump --debug-info test.o
...
0x0000001e: DW_TAG_variable
DW_AT_name ("g")
DW_AT_type (0x00000033 "int *")
DW_AT_external (true)
DW_AT_decl_file ("/home/yhs/test.c")
DW_AT_decl_line (2)
DW_AT_location (DW_OP_addr 0x0)
0x00000033: DW_TAG_pointer_type
DW_AT_type (0x00000042 "int")
0x00000038: DW_TAG_LLVM_annotation
DW_AT_name ("btf_type_tag")
DW_AT_const_value ("tag")
0x00000041: NULL
0x00000042: DW_TAG_base_type
DW_AT_name ("int")
DW_AT_encoding (DW_ATE_signed)
DW_AT_byte_size (0x04)
0x00000049: NULL
Basically, a DW_TAG_LLVM_annotation tag will be inserted
under DW_TAG_pointer_type tag if that pointer has a btf_type_tag
associated with it.
Differential Revision: https://reviews.llvm.org/D111199
Current btf_tag is applied to declaration only.
Per discussion in https://reviews.llvm.org/D111199,
we plan to introduce btf_type_tag attribute for types.
So rename btf_tag to btf_decl_tag to make it easily
differentiable from btf_type_tag.
Differential Revision: https://reviews.llvm.org/D111588
eg: t1<void () const> - DWARF doesn't have a particularly nice way to
encode this, for real member function types (like `void (t1::*)()
const`) the const-ness is encoded in the type of the artificial first
parameter. But `void () const` has no parameters, so encode it like a
normal const-qualified type, using DW_TAG_const_type. (similarly for
restrict and volatile)
Reference qualifiers (& and &&) coming in a separate commit shortly.
Streamline template arguments across types, variables, and functions -
for convenient reuse in experiments related to template argument list
reconstitution (not including template argument lists in the "name" of
those entities, and leaving it to debug info consumers to rebuild the
full template name from the semantic descriptions of the argument lists)
But the change seems like a good refactoring/cleanup anyway.
I'd certainly be open to suggestions about how this might be more
streamlined - like is there no generic way to query template argument
lists across the 3 kinds of entities, rather than needing special case
code?
Generate btf_tag annotations for record fields. The annotations
are represented as an DINodeArray in DebugInfo.
Differential Revision: https://reviews.llvm.org/D106616
Clang patch D106614 added attribute btf_tag support. This patch
generates btf_tag annotations for DIComposite types.
Each btf_tag annotation is represented as a 2D array of
meta strings. Each record may have more than one
btf_tag annotations.
Differential Revision: https://reviews.llvm.org/D106615
It's noteworthy that GCC has the same bug here, which is a bit
surprising. Both Clang and GCC's bug is only for function template
arguments that are themselves templates with default template arguments
(f1<t1<int[, missing_default_here]>>). Probably because function name
matching isn't generally necessary - whereas type matching is necessary
for DWARF consumers to associate declarations and definitions across
translation units, so the bug's been addressed there already - but
continued to exist for function templates since it's fairly benign
there.
I came across this while working on a change that could reconstitute
these pretty printed names based on the rest of the DWARF, reducing the
size of the DWARF by not having to encode all the template parameters in
the name string. That reconstitution code can't tell the difference
between a defaulted argument or not, so couldn't create the current
buggy-ish output.
Making the names more consistent between direct and indirect references,
and between function and class templates seems all to the good.
(I fixed the function template version of this a few years back in
9fdd09a4ccd01feb8e00be22b17e944e46807746 - clearly I should've looked
more closely and generalized the code better so it only had to be fixed
once - well, doing that here now)
This implements the 'using enum maybe-qualified-enum-tag ;' part of
1099. It introduces a new 'UsingEnumDecl', subclassed from
'BaseUsingDecl'. Much of the diff is the boilerplate needed to get the
new class set up.
There is one case where we accept ill-formed, but I believe this is
merely an extended case of an existing bug, so consider it
orthogonal. AFAICT in class-scope the c++20 rule is that no 2 using
decls can bring in the same target decl ([namespace.udecl]/8). But we
already accept:
struct A { enum { a }; };
struct B : A { using A::a; };
struct C : B { using A::a;
using B::a; }; // same enumerator
this patch permits mixtures of 'using enum Bob;' and 'using Bob::member;' in the same way.
Differential Revision: https://reviews.llvm.org/D102241
This is a pre-patch for adding using-enum support. It breaks out
the shadow decl handling of UsingDecl to a new intermediate base
class, BaseUsingDecl, altering the decl hierarchy to
def BaseUsing : DeclNode<Named, "", 1>;
def Using : DeclNode<BaseUsing>;
def UsingPack : DeclNode<Named>;
def UsingShadow : DeclNode<Named>;
def ConstructorUsingShadow : DeclNode<UsingShadow>;
Differential Revision: https://reviews.llvm.org/D101777
The first one is the real parameters of the coroutine function, the
other one just for copying parameters to the coroutine frame.
Considering the following c++ code:
```
struct coro {
...
};
coro foo(struct test & t) {
...
co_await suspend_always();
...
co_await suspend_always();
...
co_await suspend_always();
}
int main(int argc, char *argv[]) {
auto c = foo(...);
c.handle.resume();
...
}
```
Function foo is the standard coroutine function, and it has only
one parameter named t (ignoring this at first),
when we use the llvm code to compile this function, we can get the
following ir:
```
!2921 = distinct !DISubprogram(name: "foo", linkageName:
"_ZN6Object3fooE4test", scope: !2211, file: !45, li\
ne: 48, type: !2329, scopeLine: 48, flags: DIFlagPrototyped |
DIFlagAllCallsDescribed, spFlags: DISPFlagDefi\
nition | DISPFlagOptimized, unit: !44, declaration: !2328,
retainedNodes: !2922)
!2924 = !DILocalVariable(name: "t", arg: 2, scope: !2921, file: !45,
line: 48, type: !838)
...
!2926 = !DILocalVariable(name: "t", scope: !2921, type: !838, flags:
DIFlagArtificial)
```
We can find there are two `the same` DIVariable named t in the same
dwarf scope for foo.resume.
And when we try to use llvm-dwarfdump to dump the dwarf info of this
elf, we get the following output:
```
0x00006684: DW_TAG_subprogram
DW_AT_low_pc (0x00000000004013a0)
DW_AT_high_pc (0x00000000004013a8)
DW_AT_frame_base (DW_OP_reg7 RSP)
DW_AT_object_pointer (0x0000669c)
DW_AT_GNU_all_call_sites (true)
DW_AT_specification (0x00005b5c "_ZN6Object3fooE4test")
0x000066a5: DW_TAG_formal_parameter
DW_AT_name ("t")
DW_AT_decl_file ("/disk1/yifeng.dongyifeng/my_code/llvm/build/bin/coro-debug-1.cpp")
DW_AT_decl_line (48)
DW_AT_type (0x00004146 "test")
0x000066ba: DW_TAG_variable
DW_AT_name ("t")
DW_AT_type (0x00004146 "test")
DW_AT_artificial (true)
```
The elf also has two 't' in the same scope.
But unluckily, it might let the debugger
confused. And failed to print parameters for O0 or above.
This patch will make coroutine parameters and move
parameters use the same DIVar and try to fix the problems
that I mentioned before.
Test Plan: check-clang
Reviewed By: aprantl, jmorse
Differential Revision: https://reviews.llvm.org/D97533
