On Mon, 16 Jan 2023 at 22:36, Richard Henderson <richard.hender...@linaro.org> wrote: > > From: Ilya Leoshkevich <i...@linux.ibm.com> > > Add ability to dump /tmp/perf-<pid>.map and jit-<pid>.dump. > The first one allows the perf tool to map samples to each individual > translation block. The second one adds the ability to resolve symbol > names, line numbers and inspect JITed code. > > Example of use: > > perf record qemu-x86_64 -perfmap ./a.out > perf report > > or > > perf record -k 1 qemu-x86_64 -jitdump ./a.out > DEBUGINFOD_URLS= perf inject -j -i perf.data -o perf.data.jitted > perf report -i perf.data.jitted > > Co-developed-by: Vanderson M. do Rosario <vanderson...@gmail.com> > Co-developed-by: Alex Bennée <alex.ben...@linaro.org> > Signed-off-by: Ilya Leoshkevich <i...@linux.ibm.com> > Message-Id: <20230112152013.125680-4-...@linux.ibm.com> > Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
Apparently this doesn't build with current head-of-trunk clang: https://gitlab.com/qemu-project/qemu/-/issues/2970 > +struct debug_entry { > + uint64_t addr; > + int lineno; > + int discrim; > + const char name[]; > +}; > +struct jr_code_debug_info { > + struct jr_prefix p; > + > + uint64_t code_addr; > + uint64_t nr_entry; > + struct debug_entry entries[]; > +}; > +/* Write a JIT_CODE_DEBUG_INFO jitdump entry. */ > +static void write_jr_code_debug_info(const void *start, > + const struct debuginfo_query *q, > + size_t icount) > +{ > + struct jr_code_debug_info rec; > + struct debug_entry ent; ../tcg/perf.c:250:24: error: default initialization of an object of type 'struct debug_entry' with const member leaves the object uninitialized [-Werror,-Wdefault-const-init-field-unsafe] 250 | struct debug_entry ent; | ^ ../tcg/perf.c:157:16: note: member 'name' declared 'const' here 157 | const char name[]; | ^ I don't understand what's going on with this flexible-array name[] field: we never access it, and I don't see how we can sensibly have an array of debug_entry structs in jr_code_debug_info if the size of a debug_entry is variable. I also don't see why we've declared it 'const'. Anybody want to take a look at this? thanks -- PMM
