search for: dw_at_const_valu

On 2015/8/4 3:44, Alexei Starovoitov wrote: [SNIP] >> I'll post 2 LLVM patches by replying this mail. Please have a look and >> help me >> send them to LLVM if you think my code is correct. > > [SNIP] > patch 2: > do we really need to hack clang? > Can you just define a function that aliases to intrinsic, > like we do for ld_abs/ld_ind ? > void

.../reviews.llvm.org/D18109. > Would that work though? Unless I'm misunderstanding something, the DIExpression would appear as a DW_AT_location attribute on the global variable, which would tell the debugger how to calculate its address. But if the global has no address we would instead need a DW_AT_const_value attribute to represent the value, wouldn't we? Peter -- adrian > > 2) change the logic in the debug info emitter > (DwarfCompileUnit::getOrCreateGlobalVariableDIE) to look like this: > > if (the DIGlobalVariable was attached to a GlobalVariable) { > // add a location to t...

...W_TAG_enumeration_type) <60> DW_AT_name : (indirect string, offset: 0x140): .llvm.aux.attr <64> DW_AT_byte_size : 0 <3><65>: Abbrev Number: 6 (DW_TAG_enumerator) <66> DW_AT_name : (indirect string, offset: 0x13c): .ID <6a> DW_AT_const_value : 1234 By DW_TAG_enumeration_type '.llvm.aux.attr', we can connect an attribute named ".ID" to this structure type, whose value should be 1234. Note that enumeration types and enumerators generated by EmitTypeAuxAttribute() are all leaded with a '.', which would be neve...

...ec): TYPEINFO <2f> DW_AT_byte_size : 4 <30> DW_AT_decl_file : 1 <31> DW_AT_decl_line : 3 <2><32>: Abbrev Number: 3 (DW_TAG_enumerator) <33> DW_AT_name : (indirect string, offset: 0xcc): __typeinfo_strA <37> DW_AT_const_value : 2 <2><38>: Abbrev Number: 3 (DW_TAG_enumerator) <39> DW_AT_name : (indirect string, offset: 0xdc): __typeinfo_strB <3d> DW_AT_const_value : 3 or this: <3><54>: Abbrev Number: 4 (DW_TAG_variable) <55> DW_AT_const_value :...

This is for BPF output. BPF program output bytes to perf through a tracepoint. For decoding such data, we need a way to describe the format of the buffer. This patch is a try which gives each variable a unique number by introducing a new intrinsic 'llvm.typeid.for'. At the bottom is an example of using that intrinsic and the result of $ clang -target bpf -O2 -c -S ./test_typeid.c

...(location list) <d4> DW_AT_name : (indirect string, offset: 0xc7): argv <d8> DW_AT_decl_file : 1 <d9> DW_AT_decl_line : 16 <da> DW_AT_type : <0x5e> <2><de>: Abbrev Number: 10 (DW_TAG_variable) <df> DW_AT_const_value : 0 <e0> DW_AT_name : (indirect string, offset: 0xcc): i <e4> DW_AT_decl_file : 1 <e5> DW_AT_decl_line : 18 <e6> DW_AT_type : <0x3f> <2><ea>: Abbrev Number: 11 (DW_TAG_variable) <eb> DW_AT_name...

...t;> >> return res; >> } >> ----------------------------------------------- >> >> This is the case of reference using DW_OP_implicit_pointer >> ----------------------------------------------- >> 0x00000076: DW_TAG_variable >> DW_AT_const_value (4) >> DW_AT_name ("var") >> DW_AT_decl_file ("ref.cc") >> DW_AT_decl_line (9) >> DW_AT_type (0x00000037 "int") >> >> 0x0000007f: DW_T...

Let me try to summarize the implementation first. At the moment, there are two branches. 1. When an existing variable is optimized out and that variable is used to get the de-refereced value, pointed to by another pointer/reference variable. Such cases are being addressed using Dwarf expression DW_OP_implicit_pointer as de-referenced value of a pointer can be seen implicitly (using another

On Mon, May 9, 2016 at 4:26 PM, David Blaikie <dblaikie at gmail.com> wrote: > > > On Mon, May 9, 2016 at 3:38 PM, Peter Collingbourne <peter at pcc.me.uk> > wrote: > >> >> >> On Mon, May 9, 2016 at 3:17 PM, Peter Collingbourne <peter at pcc.me.uk> >> wrote: >> >>> >>> >>> On Mon, May 9, 2016 at 2:33 PM,