include: libsframe: add APIs for offsetof FDE func start addr field

These APIs will be later used by the linker to arrange SFrame FDEs in
the output SFrame section.

include/
        * sframe-api.h (sframe_decoder_get_offsetof_fde_start_addr): New
	declaration.
        (sframe_encoder_get_offsetof_fde_start_addr): Likewise.

libsframe/
        * libsframe.ver: List the new APIs.
        * sframe.c (sframe_decoder_get_offsetof_fde_start_addr): New
	definition.
        (sframe_encoder_get_offsetof_fde_start_addr): Likewise.

1 files changed, 24 insertions, 0 deletions

diff --git a/include/sframe-api.h b/include/sframe-api.h
index e5262ae..3dc18b6 100644
--- a/include/sframe-api.h
+++ b/include/sframe-api.h
@@ -128,6 +128,18 @@ sframe_decoder_get_version (sframe_decoder_ctx *dctx);
 extern uint8_t
 sframe_decoder_get_flags (sframe_decoder_ctx *dctx);
 
+/* Get the offset of the sfde_func_start_address field (from the start of the
+   on-disk layout of the SFrame section) of the FDE at FUNC_IDX in the decoder
+   context DCTX.
+
+   If FUNC_IDX is more than the number of SFrame FDEs in the section, sets
+   error code in ERRP, but returns the (hypothetical) offset.  This is useful
+   for the linker when arranging input FDEs into the output section to be
+   emitted.  */
+uint32_t
+sframe_decoder_get_offsetof_fde_start_addr (sframe_decoder_ctx *dctx,
+					    uint32_t func_idx, int *errp);
+
 /* Return the number of function descriptor entries in the SFrame decoder
    DCTX.  */
 extern uint32_t
@@ -246,6 +258,18 @@ sframe_encoder_get_version (sframe_encoder_ctx *encoder);
 extern uint8_t
 sframe_encoder_get_flags (sframe_encoder_ctx *encoder);
 
+/* Get the offset of the sfde_func_start_address field (from the start of the
+   on-disk layout of the SFrame section) of the FDE at FUNC_IDX in the encoder
+   context ENCODER.
+
+   If FUNC_IDX is more than the number of SFrame FDEs in the section, sets
+   error code in ERRP, but returns the (hypothetical) offset.  This is useful
+   for the linker when arranging input FDEs into the output section to be
+   emitted.  */
+uint32_t
+sframe_encoder_get_offsetof_fde_start_addr (sframe_encoder_ctx *encoder,
+					    uint32_t func_idx, int *errp);
+
 /* Return the number of function descriptor entries in the SFrame encoder
    ENCODER.  */
 extern uint32_t