Re: ANNOUNCE: pahole v1.24 (Faster BTF encoding, 64-bit BTF enum entries)

From: Arnaldo Carvalho de Melo
Date: Wed Aug 24 2022 - 13:15:56 EST


Em Wed, Aug 24, 2022 at 09:24:49AM -0700, Nathan Chancellor escreveu:
> Hi Arnaldo,
>
> On Mon, Aug 22, 2022 at 08:28:42PM -0300, Arnaldo Carvalho de Melo wrote:
> > Hi,
> >
> > The v1.24 release of pahole and its friends is out, with faster
> > BTF generation by parallelizing the encoding part in addition to the
> > previoulsy parallelized DWARF loading, support for 64-bit BTF enumeration
> > entries, signed BTF encoding of 'char', exclude/select DWARF loading
> > based on the language that generated the objects, etc.
>
> <snip>
>
> > - Introduce --lang and --lang_exclude to specify the language the
> > DWARF compile units were originated from to use or filter.
>
> This appears to break building pahole with older versions of libdw (?).
> I build container images with older versions of compilers for easy
> matrix testing and my gcc-5 and gcc-6 images (based off Ubuntu Xenial
> and Debian Stretch respectively) fail to build.

I do it for perf, should have done it for pahole :-\

So I'll have to come up with a patch that checks if those are defined
and if not, define it :-\ Ooops, its an enumeration :-\ I'll have to
check how to fix this, thanks for the report!

Will rebuild it with the containers I have to see if there are other
cases.

- Arnaldo

> $ podman run --rm -ti -v $TMP_FOLDER/dwarves-1.24.tar.xz:/tmp/dwarves-1.24.tar.xz:ro docker.io/ubuntu:xenial
> # apt update
> # apt install build-essential cmake libdw-dev libelf-dev xz-utils zlib1g-dev
> # cd $(mktemp -d)
> # tar -xJf /tmp/dwarves-1.24.tar.xz
> # mkdir build
> # cd build
> # cmake -DBUILD_SHARED_LIBS=OFF -D__LIB=lib ../dwarves-1.24
> # make -j$(nproc)
> ...
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c: In function 'lang__str2int':
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2093:3: error: 'DW_LANG_BLISS' undeclared (first use in this function)
> [DW_LANG_BLISS] = "bliss",
> ^
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2093:3: note: each undeclared identifier is reported only once for each function it appears in
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2093:3: error: array index in initializer not of integer type
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2093:3: note: (near initialization for 'languages')
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2100:3: error: 'DW_LANG_C_plus_plus_03' undeclared (first use in this function)
> [DW_LANG_C_plus_plus_03] = "c++03",
> ^
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2100:3: error: array index in initializer not of integer type
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2100:3: note: (near initialization for 'languages')
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2105:3: error: 'DW_LANG_Dylan' undeclared (first use in this function)
> [DW_LANG_Dylan] = "dylan",
> ^
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2105:3: error: array index in initializer not of integer type
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2105:3: note: (near initialization for 'languages')
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2114:3: error: 'DW_LANG_Julia' undeclared (first use in this function)
> [DW_LANG_Julia] = "julia",
> ^
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2114:3: error: array index in initializer not of integer type
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2114:3: note: (near initialization for 'languages')
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2116:3: error: 'DW_LANG_Modula3' undeclared (first use in this function)
> [DW_LANG_Modula3] = "modula3",
> ^
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2116:3: error: array index in initializer not of integer type
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2116:3: note: (near initialization for 'languages')
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2119:3: error: 'DW_LANG_OCaml' undeclared (first use in this function)
> [DW_LANG_OCaml] = "ocaml",
> ^
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2119:3: error: array index in initializer not of integer type
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2119:3: note: (near initialization for 'languages')
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2120:3: error: 'DW_LANG_OpenCL' undeclared (first use in this function)
> [DW_LANG_OpenCL] = "opencl",
> ^
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2120:3: error: array index in initializer not of integer type
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2120:3: note: (near initialization for 'languages')
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2122:3: error: 'DW_LANG_PLI' undeclared (first use in this function)
> [DW_LANG_PLI] = "pli",
> ^
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2122:3: error: array index in initializer not of integer type
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2122:3: note: (near initialization for 'languages')
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2124:3: error: 'DW_LANG_RenderScript' undeclared (first use in this function)
> [DW_LANG_RenderScript] = "renderscript",
> ^
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2124:3: error: array index in initializer not of integer type
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2124:3: note: (near initialization for 'languages')
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2125:3: error: 'DW_LANG_Rust' undeclared (first use in this function)
> [DW_LANG_Rust] = "rust",
> ^
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2125:3: error: array index in initializer not of integer type
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2125:3: note: (near initialization for 'languages')
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2126:3: error: 'DW_LANG_Swift' undeclared (first use in this function)
> [DW_LANG_Swift] = "swift",
> ^
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2126:3: error: array index in initializer not of integer type
> /tmp/tmp.pQ2GsHbGAx/dwarves-1.24/dwarves.c:2126:3: note: (near initialization for 'languages')
> CMakeFiles/dwarves.dir/build.make:62: recipe for target 'CMakeFiles/dwarves.dir/dwarves.c.o' failed
> ...
>
> If there is any additional information I can provide or patches I can
> test, please let me know!
>
> Cheers,
> Nathan

--

- Arnaldo