From a5d56626b97dd06d02d02821485df99e2068696d Mon Sep 17 00:00:00 2001
From: Neil Horman <nhorman@openssl.org>
Date: Tue, 13 Aug 2024 15:16:08 -0400
Subject: [PATCH] Add debuginfo build target

In the webinar we are currently producing on debugging openssl
applications, we talk about ways to allow debugable binaries without
having to ship all the debug DWARF information to production systems.

Add an optional target to do that DWARF separation to aid users

Reviewed-by: Tom Cosgrove <tom.cosgrove@arm.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/25174)
---
 Configurations/00-base-templates.conf | 1 +
 Configurations/unix-Makefile.tmpl     | 6 ++++++
 Configure                             | 1 +
 INSTALL.md                            | 6 ++++++
 4 files changed, 14 insertions(+)

diff --git a/Configurations/00-base-templates.conf b/Configurations/00-base-templates.conf
index d55ecea6dc4a9..86287c3a25a3c 100644
--- a/Configurations/00-base-templates.conf
+++ b/Configurations/00-base-templates.conf
@@ -78,6 +78,7 @@ my %targets=(
         AR              => "ar",
         ARFLAGS         => "qc",
         CC              => "cc",
+        OBJCOPY         => "objcopy",
         bin_cflags      =>
             sub {
                 my @flags = ();
diff --git a/Configurations/unix-Makefile.tmpl b/Configurations/unix-Makefile.tmpl
index 4c24cae7ab62e..966d8fec89848 100644
--- a/Configurations/unix-Makefile.tmpl
+++ b/Configurations/unix-Makefile.tmpl
@@ -373,6 +373,7 @@ CFLAGS={- join(' ', @{$config{CFLAGS}}) -}
 CXXFLAGS={- join(' ', @{$config{CXXFLAGS}}) -}
 LDFLAGS= {- join(' ', @{$config{LDFLAGS}}) -}
 EX_LIBS= {- join(' ', @{$config{LDLIBS}}) -}
+OBJCOPY={- $config{OBJCOPY} -}
 
 MAKEDEPEND={- $config{makedepcmd} -}
 
@@ -533,6 +534,11 @@ LANG=C
 {- dependmagic('build_programs', 'Build the openssl executables and scripts'); -}: build_programs_nodep
 
 all: build_sw {- "build_docs" if !$disabled{docs}; -} ## Build software and documentation
+debuginfo: $(SHLIBS)
+	@set -e; for i in $(SHLIBS); do \
+		$(OBJCOPY) --only-keep-debug $$i $$i.debug; \
+		$(OBJCOPY) --strip-debug --add-gnu-debuglink=$$i.debug $$i; \
+	done;
 
 ##@ Documentation
 build_generated_pods: $(GENERATED_PODS)
diff --git a/Configure b/Configure
index a6b66df4c4d1c..fff97bd6fc820 100755
--- a/Configure
+++ b/Configure
@@ -758,6 +758,7 @@ my %user = (
     RANLIB      => env('RANLIB'),
     RC          => env('RC') || env('WINDRES'),
     RCFLAGS     => [ env('RCFLAGS') || () ],
+    OBJCOPY     => undef,
     RM          => undef,
    );
 # Info about what "make variables" may be prefixed with the cross compiler
diff --git a/INSTALL.md b/INSTALL.md
index c25bec822500d..63ca4e37a5dc3 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -1676,6 +1676,12 @@ described here.  Examine the Makefiles themselves for the full list.
     build_docs
                    Build all documentation components.
 
+    debuginfo
+                    On unix platforms, this target can be used to create .debug
+                    libraries, which separate the DWARF information in the
+                    shared library ELF files into a separate file for use
+                    in post-mortem (core dump) debugging
+
     clean
                    Remove all build artefacts and return the directory to a "clean"
                    state.