Merge bitcoin/bitcoin#23724: build: add systemtap's sys/sdt.h as depends for GUIX builds with USDT tracepoints

6200fbf54fa919899d99f1cdd5ef88ec8b074cd6 build: rename --enable-ebpf to --enable-usdt (0xb10c)
e158a2a7aa501da635cb34414abd0c092216e5f4 build: add systemtap's sys/sdt.h as depends (0xb10c)

Pull request description:

  There has been light conceptual agreement on including the Userspace, Statically Defined Tracing tracepoints in Bitcoin Core release builds. This, for example, enables user to hook into production deployments, if they need to. Binaries don't have to be switched out. This is possible because we don't do [expensive computations](https://github.com/bitcoin/bitcoin/blob/master/doc/tracing.md#no-expensive-computations-for-tracepoints) only needed for the tracepoints. The tracepoints are NOPs when not used.

  Systemtap's `sys/sdt.h` header is required to build Bitcoin Core with USDT support. The header file defines the `DTRACE_PROBE` macros used in [`src/util/trace.h`](https://github.com/bitcoin/bitcoin/blob/master/src/util/trace.h). This PR adds Systemtap 4.5 (May 2021) as dependency. GUIX builds for Linux hosts now include the tracepoints.

  Closes https://github.com/bitcoin/bitcoin/issues/23297.

ACKs for top commit:
  fanquake:
    ACK 6200fbf54fa919899d99f1cdd5ef88ec8b074cd6 - tested enabling / disabling and with/without SDT from depends. We can follow up with #23819, #23907 and #23296, and if any serious issues arise before feature freeze, it is easy for us to flip depends such that USDT becomes opt-in, rather than opt-out, and thus, releases would be tracepoint free.

Tree-SHA512: 0263f44892bf8450e8a593e4de7a498243687f8d81269e1c3283fa8354922c7cf93fddef4b92cf5192d33798424aa5812e03e68ef8de31af078a32dd34021382

5 files changed, 53 insertions, 1 deletions

diff --git a/depends/Makefile b/depends/Makefile
index 67adc6cc16..d2a3c35f1e 100644
--- a/depends/Makefile
+++ b/depends/Makefile
@@ -39,6 +39,7 @@ NO_SQLITE ?=
 NO_WALLET ?=
 NO_ZMQ ?=
 NO_UPNP ?=
+NO_USDT ?=
 NO_NATPMP ?=
 MULTIPROCESS ?=
 FALLBACK_DOWNLOAD_PATH ?= https://bitcoincore.org/depends-sources
@@ -149,8 +150,9 @@ natpmp_packages_$(NO_NATPMP) = $(natpmp_packages)
 
 zmq_packages_$(NO_ZMQ) = $(zmq_packages)
 multiprocess_packages_$(MULTIPROCESS) = $(multiprocess_packages)
+usdt_packages_$(NO_USDT) = $(usdt_$(host_os)_packages)
 
-packages += $($(host_arch)_$(host_os)_packages) $($(host_os)_packages) $(qt_packages_) $(wallet_packages_) $(upnp_packages_) $(natpmp_packages_)
+packages += $($(host_arch)_$(host_os)_packages) $($(host_os)_packages) $(qt_packages_) $(wallet_packages_) $(upnp_packages_) $(natpmp_packages_) $(usdt_packages_)
 native_packages += $($(host_arch)_$(host_os)_native_packages) $($(host_os)_native_packages)
 
 ifneq ($(zmq_packages_),)
@@ -228,6 +230,7 @@ $(host_prefix)/share/config.site : config.site.in $(host_prefix)/.stamp_$(final_
             -e 's|@no_bdb@|$(NO_BDB)|' \
             -e 's|@no_sqlite@|$(NO_SQLITE)|' \
             -e 's|@no_upnp@|$(NO_UPNP)|' \
+            -e 's|@no_usdt@|$(NO_USDT)|' \
             -e 's|@no_natpmp@|$(NO_NATPMP)|' \
             -e 's|@multiprocess@|$(MULTIPROCESS)|' \
             -e 's|@debug@|$(DEBUG)|' \
diff --git a/depends/config.site.in b/depends/config.site.in
index ed1a1f8d3d..95e6ae85cf 100644
--- a/depends/config.site.in
+++ b/depends/config.site.in
@@ -70,6 +70,10 @@ if test -z "$enable_zmq" && test -n "@no_zmq@"; then
   enable_zmq=no
 fi
 
+if test -z "$enable_usdt" && test -n "@no_usdt@"; then
+  enable_usdt=no
+fi
+
 if test "@host_os@" = darwin; then
   BREW=no
 fi
diff --git a/depends/packages/packages.mk b/depends/packages/packages.mk
index 426fa2e748..77866c8e7a 100644
--- a/depends/packages/packages.mk
+++ b/depends/packages/packages.mk
@@ -19,6 +19,8 @@ natpmp_packages=libnatpmp
 multiprocess_packages = libmultiprocess capnp
 multiprocess_native_packages = native_libmultiprocess native_capnp
 
+usdt_linux_packages=systemtap
+
 darwin_native_packages = native_ds_store native_mac_alias
 
 $(host_arch)_$(host_os)_native_packages += native_b2
diff --git a/depends/packages/systemtap.mk b/depends/packages/systemtap.mk
new file mode 100644
index 0000000000..833e75b978
--- /dev/null
+++ b/depends/packages/systemtap.mk
@@ -0,0 +1,12 @@
+package=systemtap
+$(package)_version=4.5
+$(package)_download_path=https://sourceware.org/systemtap/ftp/releases/
+$(package)_file_name=$(package)-$($(package)_version).tar.gz
+$(package)_sha256_hash=75078ed37e0dd2a769c9d1f9394170b2d9f4d7daa425f43ca80c13bad6cfc925
+$(package)_patches=remove_SDT_ASM_SECTION_AUTOGROUP_SUPPORT_check.patch
+
+define $(package)_preprocess_cmds
+  patch -p1 < $($(package)_patch_dir)/remove_SDT_ASM_SECTION_AUTOGROUP_SUPPORT_check.patch && \
+  mkdir -p $($(package)_staging_prefix_dir)/include/sys && \
+  cp includes/sys/sdt.h $($(package)_staging_prefix_dir)/include/sys/sdt.h
+endef
diff --git a/depends/patches/systemtap/remove_SDT_ASM_SECTION_AUTOGROUP_SUPPORT_check.patch b/depends/patches/systemtap/remove_SDT_ASM_SECTION_AUTOGROUP_SUPPORT_check.patch
new file mode 100644
index 0000000000..eae0cf72d6
--- /dev/null
+++ b/depends/patches/systemtap/remove_SDT_ASM_SECTION_AUTOGROUP_SUPPORT_check.patch
@@ -0,0 +1,31 @@
+commit b92d4c121486f3c6e8a2cea537c53eb09894479a
+Author: 0xb10c <0xb10c@gmail.com>
+Date:   Tue Dec 7 11:02:07 2021 +0100
+
+    Remove _SDT_ASM_SECTION_AUTOGROUP_SUPPORT check
+    
+    We assume that the assembler supports "?" in .pushsection directives.
+    This enables us to skip configure and make.
+    
+    See https://github.com/bitcoin/bitcoin/issues/23297.
+
+diff --git a/includes/sys/sdt.h b/includes/sys/sdt.h
+index 97766e710..352b4ee25 100644
+--- a/includes/sys/sdt.h
++++ b/includes/sys/sdt.h
+@@ -230,12 +230,10 @@ __extension__ extern unsigned long long __sdt_unsp;
+    nice with code in COMDAT sections, which comes up in C++ code.
+    Without that assembler support, some combinations of probe placements
+    in certain kinds of C++ code may produce link-time errors.  */
+-#include "sdt-config.h"
+-#if _SDT_ASM_SECTION_AUTOGROUP_SUPPORT
++/* PATCH: We assume that the assembler supports the feature. This
++   enables us to skip configure and make. In turn, this means we
++   require fewer dependencies and have shorter depend build times. */
+ # define _SDT_ASM_AUTOGROUP "?"
+-#else
+-# define _SDT_ASM_AUTOGROUP ""
+-#endif
+ 
+ #define _SDT_ASM_BODY(provider, name, pack_args, args)			      \
+   _SDT_ASM_1(990:	_SDT_NOP)					      \