> Hey.
>
> During partial linking we ipa_prop_write_jump_functions twice from 2 IPA
> pass (fnsummary and cp). That produces 2 compressed blocks in an ELF section
> and then zstd complains as sections size does not correspond to the compressed
> stream.
>
> I'm adding both sanity check changes and the fix in ipa-prop.c.
> I guess Martin and Honza can explain it in more detail?
>
> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>
> Ready to be installed?
> Thanks,
> Martin
>
> gcc/ChangeLog:
>
> PR lto/97508
> * langhooks.c (lhd_begin_section): Call get_section with
> not_existing = true.
> * output.h (get_section): Add new argument.
> * varasm.c (get_section): Fail when NOT_EXISTING is true
> and a section already exists.
> * ipa-prop.c (ipa_prop_write_jump_functions): Do not stream
> twice.
I think the streaming should happen only from ipa-fnsummary.
Oriignally ipa-prop was ipa-cp only, then indirect inlining was added,
but these days we have specialized analysis pass and thus ipa-prop
should be intergrated to it.
Honza
> ---
> gcc/ipa-prop.c | 9 +++++++++
> gcc/langhooks.c | 2 +-
> gcc/output.h | 3 ++-
> gcc/varasm.c | 12 ++++++++++--
> 4 files changed, 22 insertions(+), 4 deletions(-)
>
> diff --git a/gcc/ipa-prop.c b/gcc/ipa-prop.c
> index a848f1db95e..d43fd2eee4f 100644
> --- a/gcc/ipa-prop.c
> +++ b/gcc/ipa-prop.c
> @@ -5067,6 +5067,13 @@ ipa_prop_write_jump_functions (void)
> lto_symtab_encoder_iterator lsei;
> lto_symtab_encoder_t encoder;
> + /* The function can be called from 2 IPA_PASSES: "fnsummary" and "cp"
> + which happens in partial linking (-r). Prevent double streaming
> + as reported in PR97508. */
> + static bool already_stremed = false;
> + if (already_stremed)
> + return;
> +
> if (!ipa_node_params_sum || !ipa_edge_args_sum)
> return;
> @@ -5096,6 +5103,8 @@ ipa_prop_write_jump_functions (void)
> streamer_write_char_stream (ob->main_stream, 0);
> produce_asm (ob, NULL);
> destroy_output_block (ob);
> +
> + already_stremed = true;
> }
> /* Read section in file FILE_DATA of length LEN with data DATA. */
> diff --git a/gcc/langhooks.c b/gcc/langhooks.c
> index 8819a8859d4..d82f54251fd 100644
> --- a/gcc/langhooks.c
> +++ b/gcc/langhooks.c
> @@ -790,7 +790,7 @@ lhd_begin_section (const char *name)
> saved_section = text_section;
> /* Create a new section and switch to it. */
> - section = get_section (name, SECTION_DEBUG | SECTION_EXCLUDE, NULL);
> + section = get_section (name, SECTION_DEBUG | SECTION_EXCLUDE, NULL, true);
> switch_to_section (section);
> }
> diff --git a/gcc/output.h b/gcc/output.h
> index eb253c50329..2f2f1697fd8 100644
> --- a/gcc/output.h
> +++ b/gcc/output.h
> @@ -523,7 +523,8 @@ extern GTY(()) bool in_cold_section_p;
> extern section *get_unnamed_section (unsigned int, void (*) (const void *),
> const void *);
> -extern section *get_section (const char *, unsigned int, tree);
> +extern section *get_section (const char *, unsigned int, tree,
> + bool not_existing = false);
> extern section *get_named_section (tree, const char *, int);
> extern section *get_variable_section (tree, bool);
> extern void place_block_symbol (rtx);
> diff --git a/gcc/varasm.c b/gcc/varasm.c
> index ea0b59cf44a..207c9b077d1 100644
> --- a/gcc/varasm.c
> +++ b/gcc/varasm.c
> @@ -277,10 +277,12 @@ get_noswitch_section (unsigned int flags,
> noswitch_section_callback callback)
> }
> /* Return the named section structure associated with NAME. Create
> - a new section with the given fields if no such structure exists. */
> + a new section with the given fields if no such structure exists.
> + When NOT_EXISTING, then fail if the section already exists. */
> section *
> -get_section (const char *name, unsigned int flags, tree decl)
> +get_section (const char *name, unsigned int flags, tree decl,
> + bool not_existing)
> {
> section *sect, **slot;
> @@ -297,6 +299,12 @@ get_section (const char *name, unsigned int flags, tree
> decl)
> }
> else
> {
> + if (not_existing)
> + {
> + error ("Section already exists: %qs", name);
> + gcc_unreachable ();
> + }
> +
> sect = *slot;
> /* It is fine if one of the sections has SECTION_NOTYPE as long as
> the other has none of the contrary flags (see the logic at the end
> --
> 2.28.0
>
