diff options
| -rw-r--r-- | ld/ChangeLog | 14 | ||||
| -rw-r--r-- | ld/NEWS | 10 | ||||
| -rw-r--r-- | ld/ld.h | 8 | ||||
| -rw-r--r-- | ld/ld.texi | 34 | ||||
| -rw-r--r-- | ld/ldlang.c | 10 | ||||
| -rw-r--r-- | ld/ldlex.h | 3 | ||||
| -rw-r--r-- | ld/lexsup.c | 29 |
7 files changed, 107 insertions, 1 deletions
diff --git a/ld/ChangeLog b/ld/ChangeLog index 02ce249..b45da76 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,17 @@ +2020-07-22 Nick Alcock <nick.alcock@oracle.com> + + * ldlex.h (option_values) <OPTION_CTF_VARIABLES, + OPTION_NO_CTF_VARIABLES, OPTION_CTF_SHARE_TYPES>: New. + * ld.h (ld_config_type) <ctf_variables, ctf_share_duplicated>: + New fields. + * ldlang.c (lang_merge_ctf): Use them. + * lexsup.c (ld_options): Add ctf-variables, no-ctf-variables, + ctf-share-types. + (parse_args) <OPTION_CTF_VARIABLES, OPTION_NO_CTF_VARIABLES, + OPTION_CTF_SHARE_TYPES>: New cases. + * ld.texi: Document new options. + * NEWS: Likewise. + 2020-07-22 Egeyar Bagcioglu <egeyar.bagcioglu@oracle.com> * ldlang.c (lang_merge_ctf): Turn errors into warnings. @@ -1,5 +1,15 @@ -*- text -*- +* The linker now deduplicates the types in .ctf sections. The new + command-line option --ctf-share-types describes how to do this: + its default value, share-unconflicted, produces the most compact + output. + +* The linker now omits the "variable section" from .ctf sections by + default, saving space. This is almost certainly what you want + unless you are working on a project that has its own analogue + of symbol tables that are not reflected in the ELF symtabs. + Changes in 2.35: * X86 NaCl target support is removed. @@ -302,6 +302,14 @@ typedef struct /* If set, print discarded sections in map file output. */ bfd_boolean print_map_discarded; + + /* If set, emit the names and types of statically-linked variables + into the CTF. */ + bfd_boolean ctf_variables; + + /* If set, share only duplicated types in CTF, rather than sharing + all types that are not in conflict. */ + bfd_boolean ctf_share_duplicated; } ld_config_type; extern ld_config_type config; @@ -1612,6 +1612,40 @@ definition. If the symbol is defined as a common value then any files where this happens appear next. Finally any files that reference the symbol are listed. +@cindex ctf variables +@kindex --ctf-variables +@kindex --no-ctf-variables +@item --ctf-variables +@item --no-ctf-variables +The CTF debuginfo format supports a section which encodes the names and +types of variables found in the program which do not appear in any symbol +table. These variables clearly cannot be looked up by address by +conventional debuggers, so the space used for their types and names is +usually wasted: the types are usually small but the names are often not. +@option{--ctf-variables} causes the generation of such a section. +The default behaviour can be restored with @option{--no-ctf-variables}. + +@cindex ctf type sharing +@kindex --ctf-share-types +@item --ctf-share-types=@var{method} +Adjust the method used to share types between translation units in CTF. + +@table @samp +@item share-unconflicted +Put all types that do not have ambiguous definitions into the shared dictionary, +where debuggers can easily access them, even if they only occur in one +translation unit. This is the default. + +@item share-duplicated +Put only types that occur in multiple translation units into the shared +dictionary: types with only one definition go into per-translation-unit +dictionaries. Types with ambiguous definitions in multiple translation units +always go into per-translation-unit dictionaries. This tends to make the CTF +larger, but may reduce the amount of CTF in the shared dictionary. For very +large projects this may speed up opening the CTF and save memory in the CTF +consumer at runtime. +@end table + @cindex common allocation @kindex --no-define-common @item --no-define-common diff --git a/ld/ldlang.c b/ld/ldlang.c index b0231a1..bf29144 100644 --- a/ld/ldlang.c +++ b/ld/ldlang.c @@ -3755,6 +3755,7 @@ static void lang_merge_ctf (void) { asection *output_sect; + int flags = 0; if (!ctf_output) return; @@ -3791,7 +3792,14 @@ lang_merge_ctf (void) } } - if (ctf_link (ctf_output, CTF_LINK_SHARE_UNCONFLICTED) < 0) + if (!config.ctf_share_duplicated) + flags = CTF_LINK_SHARE_UNCONFLICTED; + else + flags = CTF_LINK_SHARE_DUPLICATED; + if (!config.ctf_variables) + flags |= CTF_LINK_OMIT_VARIABLES_SECTION; + + if (ctf_link (ctf_output, flags) < 0) { einfo (_("%P: warning: CTF linking failed; " "output will have no CTF section: `%s'\n"), @@ -155,6 +155,9 @@ enum option_values OPTION_NON_CONTIGUOUS_REGIONS, OPTION_NON_CONTIGUOUS_REGIONS_WARNINGS, OPTION_DEPENDENCY_FILE, + OPTION_CTF_VARIABLES, + OPTION_NO_CTF_VARIABLES, + OPTION_CTF_SHARE_TYPES, }; /* The initial parser states. */ diff --git a/ld/lexsup.c b/ld/lexsup.c index a79bec0..2c2d0fc 100644 --- a/ld/lexsup.c +++ b/ld/lexsup.c @@ -572,6 +572,18 @@ static const struct ld_option ld_options[] = { {"no-print-map-discarded", no_argument, NULL, OPTION_NO_PRINT_MAP_DISCARDED}, '\0', NULL, N_("Do not show discarded sections in map file output"), TWO_DASHES }, + { {"ctf-variables", no_argument, NULL, OPTION_CTF_VARIABLES}, + '\0', NULL, N_("Emit names and types of static variables in CTF"), + TWO_DASHES }, + { {"no-ctf-variables", no_argument, NULL, OPTION_NO_CTF_VARIABLES}, + '\0', NULL, N_("Do not emit names and types of static variables in CTF"), + TWO_DASHES }, + { {"ctf-share-types=<method>", required_argument, NULL, + OPTION_CTF_SHARE_TYPES}, + '\0', NULL, N_("How to share CTF types between translation units.\n" + " <method> is: share-unconflicted (default),\n" + " share-duplicated"), + TWO_DASHES }, }; #define OPTION_COUNT ARRAY_SIZE (ld_options) @@ -1637,6 +1649,23 @@ parse_args (unsigned argc, char **argv) case OPTION_DEPENDENCY_FILE: config.dependency_file = optarg; break; + + case OPTION_CTF_VARIABLES: + config.ctf_variables = TRUE; + break; + + case OPTION_NO_CTF_VARIABLES: + config.ctf_variables = FALSE; + break; + + case OPTION_CTF_SHARE_TYPES: + if (strcmp (optarg, "share-unconflicted") == 0) + config.ctf_share_duplicated = FALSE; + else if (strcmp (optarg, "share-duplicated") == 0) + config.ctf_share_duplicated = TRUE; + else + einfo (_("%F%P: bad --ctf-share-types option: %s\n"), optarg); + break; } } |