similar to: Question WRT llvm.dbg.value

> On Mar 30, 2020, at 4:13 AM, Jeremy Morse via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Hi Sourabh, > > On Mon, Mar 30, 2020 at 8:09 AM Sourabh Singh Tomar via llvm-dev > <llvm-dev at lists.llvm.org> wrote: >> Under what circumstances should a frontend choose to emit(at -O0(No optimization)) llvm.dbg.value for a local variable. >> >> I

> On Apr 1, 2020, at 2:56 AM, Sourabh Singh Tomar <sourav0311 at gmail.com> wrote: > > > Do you mean documenting the desired frontend behavior, or adding some verifier in > LLVM? A warning for the latter is that SROA may currently emit IR that contains a > mix of declares and values for different fragments of an aggregate variable, so I > assume that is something that

> On Mar 30, 2020, at 11:57 PM, Sourabh Singh Tomar <sourav0311 at gmail.com> wrote: > >> > My understanding is that this isn't correct: dbg.declare specifies the >> memory address of a variable for the whole lifetime of the function, >> whereas dbg.value (and dbg.addr) specify the value/address until the >> next debug intrinsic. Mixing these two kinds

Hi folks, While building openmpi.4.0.0(Optimized debug build), using trunk clang we encountered a crash(assertion failure). Initially assertion seems trivial: [...] void llvm::DwarfExpression::addFragmentOffset(const llvm::DIExpression*): Assertion `FragmentOffset >= OffsetInBits && "overlapping or duplicate fragments"' failed. [...] But, narrowing to RC. We discovered

Thank You for suggestion Adrian! Generated reproducer for the crash using clang reproducer and CReduce. ::Attachment:: C file. NIT: some clean up is done on this file just to silent some compiler warnings(like implicit declaration etc.) Crash can be reproduced using above test case with following commandline: $clang -g -O3 -mllvm –enable-partial-inlining creducegenerated-cleaned.c -c ---CRASH---

Hi Sourabh, Thanks for raising this issue. To answer your question, (afaik) there isn’t anyone working on DW_AT_start_scope support in tree. We’re looking for a solution to this problem for Swift debugging, where it's important not to make a debug location for a variable available until its (guaranteed) initialization is complete. If at all possible, I’d /much/ rather we use the existing

*From:* flang-dev <flang-dev-bounces at lists.flang-compiler.org> *On Behalf Of *Eric Schweitz (PGI) *Sent:* Thursday, November 01, 2018 1:02 PM *To:* flang-dev at lists.flang-compiler.org *Subject:* [Flang-dev] RFC: Adding debug information to LLVM to support Fortran In order to support debugging in the Flang project, work has been done to extend LLVM debug information for the Fortran

> That makes sense, and I think for "direct" values in your definition it is true that all direct values are r-values. > Why do we need DW_OP_LLVM_direct when we already have DW_OP_LLVM_stack_value? Can you give an example of something that is definitely not a stack value, but direct? The difference in definition is the intention: DW_OP_LLVM_direct means "we'd like this

> I can see how that could potentially be useful. I'm not sure how often we could practically make use of a situation like this, but I understand your motivation. Indeed, I don't expect us to cancel out DWARF expressions like that very often. Although that edge case is likely to be very rare, the _direct operator itself will appear very frequently, as it would be used for every

Hi Tom, I do not have SVN account, for accessing LLVM. Thanks, Sourabh On Tue 29 Oct, 2019, 9:08 AM Tom Stellard, <tstellar at redhat.com> wrote: > On 10/26/2019 03:39 AM, Sourabh Singh Tomar wrote: > > Hi All, > > > > I recently requested Chris regarding commit access to LLVM. > > He asked me to wait till the GitHub migration completes and then ask in >

Hello Everyone, I need to have your thoughts on this. Consider the following test case -- ------------------------------------------- 1 int main(int Argc, char **Argv) { 2 int Local = 6; 3 printf("%d\n",Local); 4 5 { 6 printf("%d\n",Local); 7 int Local = 7; 8 printf("%d\n",Local); 9 }

> I don't see how this is a meaningful distinction in LLVM IR. In LLVM IR we only have SSA values. An SSA value could be an alloca, or a gep into an alloca, or spilled onto the stack at the MIR level, in which case the dbg.value should get lowered into a memory location (if it isn't explicitly a DW_OP_stack_value). I think the distinction is still important; even at the IR level, if we

> Can you elaborate what "direct" means? I'm having trouble understanding what the opposite (a non-exact value) would be. Apologies, "exact" was a misleading/incorrect term. By direct, I mean that the expression computes the value of the variable, as opposed to its memory address, or the value that it points to. Within LLVM, where we don't have DW_OP_reg/DW_OP_breg

Currently there is a series of patches undergoing review[0] that seek to enable the use of multiple IR/MIR values when describing a source variable's location. The current plan for the MIR is to add a new instruction, DBG_VALUE_LIST, that supports this functionality by having a variable number of operands. It may be better however to simply replace the existing DBG_VALUE behaviour entirely

On Wed, Sep 6, 2017 at 10:01 AM, David Blaikie <dblaikie at gmail.com> wrote: > On Tue, Sep 5, 2017 at 1:00 PM Reid Kleckner via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> LLVM SSA values obviously do not have an address that we can take and >> they don’t live in registers, so neither the default memory location model >> nor DW_OP_regN make sense

Hi Adrian & Stephen, One thought here: But — not all memory locations are l-values. If we have a DWARF location list for variable "x" which points to a memory address for the first n instructions and the switches to a constant for the remainder of the scope, the memory address is not guaranteed to be an l-value, because writing the the memory address cannot affect the later part of

Hi llvm-dev, cfe-dev, It's been a while since our team is investigating DebugInfo in LLVM, we're looking forward to contribute and enhance in LLVM DebugInfo. We,'ve been investigating mostly on DWARF-5 aspects -- couple of them to mention-- 1. Language aspects 2. Location mostly optimized out ones 3. DebugInfo conformance to DWARF-5 To avoid getting conflicted with some body

> On Sep 19, 2017, at 8:44 AM, Reid Kleckner <rnk at google.com> wrote: > > On Tue, Sep 19, 2017 at 8:40 AM, Adrian Prantl via llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: > > Later loop unroll comes and unrolls the loop and then suddenly we have two absolutely identical dbg.declares and the assert in addFragmentOffset() blows.

On Wed, Sep 6, 2017 at 5:01 PM, David Blaikie <dblaikie at gmail.com> wrote: > On Wed, Sep 6, 2017 at 2:01 PM Reid Kleckner <rnk at google.com> wrote: > >> On Wed, Sep 6, 2017 at 10:01 AM, David Blaikie <dblaikie at gmail.com> >> wrote: >> >>> I guess you described this already, but talking it through for >>> myself/maybe others will

Thanks, David for updating us. Regarding, mail address, can use anyone{@gmail or @amd}. but sourav0311 at gmail.com works best for me for mailing lists related stuff. Regarding, GDB side of DWARFv5 side of things, we've testing GDB-8.3 WRT DWARFv5 clang and gcc binaries to get better idea of debuggability of clang generated binaries with GDB. Primary motivation being GDB better handling of