Handle static and external linkage for BTF subprograms (functions).
Signed-off-by: Will Hawkins <hawkinsw@xxxxxx>
---
btf_loader.c | 4 +++-
dwarves.h | 2 +-
pfunct.c | 15 ++++++++++++++-
3 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/btf_loader.c b/btf_loader.c
index e0d029a..16962f9 100644
--- a/btf_loader.c
+++ b/btf_loader.c
@@ -85,8 +85,10 @@ static int create_new_function(struct cu *cu, const struct btf_type *tp, uint32_
return -ENOMEM;
// for BTF this is not really the type of the return of the function,
- // but the prototype, the return type is the one in type_id
+ // but the prototype, the return type is the one in type_id.
func->btf = 1;
+ func->declaration = BTF_INFO_VLEN(tp->info) == BTF_FUNC_EXTERN;
+ func->external = BTF_INFO_VLEN(tp->info) == BTF_FUNC_GLOBAL;
func->proto.tag.tag = DW_TAG_subprogram;
func->proto.tag.type = tp->type;
func->name = cu__btf_str(cu, tp->name_off);
diff --git a/dwarves.h b/dwarves.h
index f5ae79f..c6d2b63 100644
--- a/dwarves.h
+++ b/dwarves.h
@@ -983,7 +983,7 @@ struct function {
uint16_t cu_total_nr_inline_expansions;
uint8_t inlined:2;
uint8_t abstract_origin:1;
- uint8_t external:1;
+ uint8_t external:1; /* DW_AT_external */
uint8_t accessibility:2; /* DW_ACCESS_{public,protected,private} */
uint8_t virtuality:2; /* DW_VIRTUALITY_{none,virtual,pure_virtual} */
uint8_t declaration:1;
diff --git a/pfunct.c b/pfunct.c
index 938dd72..725cc2e 100644
--- a/pfunct.c
+++ b/pfunct.c
@@ -366,9 +366,22 @@ static void function__show(struct function *func, struct cu *cu)
{
struct tag *tag = function__tag(func);
- if (func->abstract_origin || func->external)
+ if (func->abstract_origin)
return;
+ // If this function is more than a declaration, then be
+ // explicit about its linkage. For dwarf, external comes
+ // from DW_AT_external which, when combined with whether
+ // the DIE represents a defined subprogram, determines
+ // the linkage. BTF maintains these semantics when it reads
+ // type information.
+ if (!func->declaration) {
+ if (func->external)
+ fprintf(stdout, "extern ");
+ else
+ fprintf(stdout, "static ");
+ }
+
if (expand_types)
function__emit_type_definitions(func, cu, stdout);
tag__fprintf(tag, cu, &conf, stdout);
--
2.45.2
