From 05b39e6e9b5d57100e6003230afb1fdb2d8b625c Mon Sep 17 00:00:00 2001
From: midipix <writeonce@midipix.org>
Date: Nov 25 2018 14:17:30 +0000
Subject: build system: PE, ELF: defined DSO_REF_VER, DSO_REF_SONAME, DSO_REF_SOLINK.


These definitions come in handy when a project generates alongside
its ``primary shared library'' one or more ``extension libraries''
that depend on it. When the rules for generating extension
libraries use the $^ directive, the above dependency must
be declared in a target-aware manner.

In most cases, one would want to express this dependency by way
of $(DSO_REF_SONAME), thereby pulling in lib/libfoo.so.$(MAJOR)
on ELF targets, lib/libfoo.$(MAJOR).lib.a on midipix targets,
and lib/libfoo.$(MAJOR).dll.a on win32 targets.

---

diff --git a/sysinfo/os/elf.mk b/sysinfo/os/elf.mk
index 5a3940f..6878c6a 100644
--- a/sysinfo/os/elf.mk
+++ b/sysinfo/os/elf.mk
@@ -1,2 +1,6 @@
+DSO_REF_VER      = $(SHARED_LIB)
+DSO_REF_SONAME   = $(SHARED_SONAME)
+DSO_REF_SOLINK   = $(SHARED_SOLINK)
+
 LDFLAGS_SHARED	+= -Wl,-soname
 LDFLAGS_SHARED	+= -Wl,$(DSO_SONAME)
diff --git a/sysinfo/os/pe.mk b/sysinfo/os/pe.mk
index e8e1759..c3c5ba0 100644
--- a/sysinfo/os/pe.mk
+++ b/sysinfo/os/pe.mk
@@ -1,3 +1,7 @@
+DSO_REF_VER      = $(IMPLIB_VER)
+DSO_REF_SONAME   = $(IMPLIB_SONAME)
+DSO_REF_SOLINK   = $(IMPLIB_SOLINK)
+
 LDFLAGS_IMPLIB	+= -Wl,--output-def
 LDFLAGS_IMPLIB	+= -Wl,$(IMPLIB_DEF)
 LDFLAGS_SHARED	+= $(LDFLAGS_IMPLIB)