From 5b6de38dee4f5bd1bb32caa56ee9d547bc2e560e Mon Sep 17 00:00:00 2001
From: "Peter S. Housel" <housel@acm.org>
Date: Mon, 5 Dec 2022 21:52:16 -0800
Subject: [PATCH 1/3] jamfiles: Export dynamic symbols from unified executables

This change ensures that function names are added to the dynamic
symbol table so that they can be queried when printing a backtrace
from the default condition handler.

It also ensures that the copied .dbg files contain only debug
information and not program code and initialized data.

* sources/jamfiles/posix-build.jam
  (actions LinkDLL, actions LinkEXE, actions UnifyEXE): Supply the
   --only-keep-debug option to objcopy when constructing the .dbg
   file.
  (actions UnifyEXE): Export symbols in the dynamic symbol table to
   allow the run-time's backtrace code to find function symbol names.
---
 sources/jamfiles/posix-build.jam | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/sources/jamfiles/posix-build.jam b/sources/jamfiles/posix-build.jam
index 47b798368..f1b4589e0 100644
--- a/sources/jamfiles/posix-build.jam
+++ b/sources/jamfiles/posix-build.jam
@@ -486,7 +486,7 @@ rule LinkDLL {
 
 actions together LinkDLL bind NEEDLIBS {
   $(LINK) -shared -o $(<:Q) $(LINKFLAGS) $(>:Q) -L"$(LIBPATH)" $(NEEDLIBS:Q) $(LINKLIBS)
-  $(OBJCOPY) $(<:Q) $(<:Q).dbg
+  $(OBJCOPY) --only-keep-debug $(<:Q) $(<:Q).dbg
   $(STRIP) -s $(<:Q)
   $(OBJCOPY) --add-gnu-debuglink=$(<:Q).dbg $(<:Q)
 }
@@ -507,7 +507,7 @@ rule LinkEXE {
 
 actions LinkEXE bind NEEDLIBS {
   $(LINK) -o $(<:Q) $(LINKFLAGS) $(>:Q) -L"$(LIBPATH)" $(NEEDLIBS:Q) $(LINKLIBS)
-  $(OBJCOPY) $(<:Q) $(<:Q).dbg
+  $(OBJCOPY) --only-keep-debug $(<:Q) $(<:Q).dbg
   $(STRIP) -s $(<:Q)
   $(OBJCOPY) --add-gnu-debuglink=$(<:Q).dbg $(<:Q)
 }
@@ -518,9 +518,9 @@ rule UnifyEXE {
 }
 
 actions UnifyEXE bind NEEDLIBS {
-  $(UNIFYLINK) -o $(<:Q) $(LINKFLAGS) $(>:Q) -L"$(LIBPATH)" -Wl,--start-group $(NEEDLIBS:Q) $(LINKLIBS) -Wl,--end-group
-  $(OBJCOPY) $(<:Q) $(<:Q).dbg
-  $(STRIP) -s $(<:Q)
+  $(UNIFYLINK) -o $(<:Q) $(LINKFLAGS) -Wl,-E $(>:Q) -L"$(LIBPATH)" -Wl,--start-group $(NEEDLIBS:Q) $(LINKLIBS) -Wl,--end-group
+  $(OBJCOPY) --only-keep-debug $(<:Q) $(<:Q).dbg
+  $(STRIP) -g $(<:Q)
   $(OBJCOPY) --add-gnu-debuglink=$(<:Q).dbg $(<:Q)
 }
 

From 7bd16ea8e6b72fd980cdb31b30f40b6c6d77823e Mon Sep 17 00:00:00 2001
From: "Peter S. Housel" <housel@acm.org>
Date: Mon, 5 Dec 2022 22:08:32 -0800
Subject: [PATCH 2/3] jamfiles: Copy runtime libraries for unified executables

* sources/jamfiles/posix-build.jam (rule DylanLibrary): Ensure that
  "batteries included" runtime shared libraries are copied into the
  lib/ directory when unified exectables are built.
---
 sources/jamfiles/posix-build.jam | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sources/jamfiles/posix-build.jam b/sources/jamfiles/posix-build.jam
index f1b4589e0..21216bb4b 100644
--- a/sources/jamfiles/posix-build.jam
+++ b/sources/jamfiles/posix-build.jam
@@ -156,7 +156,7 @@ rule DylanLibrary image : version {
       local _rtlib = $(_i:D=) ;
       MakeLocate $(_rtlib) : $(LIBDIR) ;
       File $(_rtlib) : $(_i) ;
-      Depends $(_dll) : $(_rtlib) ;
+      Depends $(_dll) $(_ulib) : $(_rtlib) ;
     }
   }
 

From b34106767204c3492a6be0d8e6d5d0ccc724e743 Mon Sep 17 00:00:00 2001
From: "Peter S. Housel" <housel@acm.org>
Date: Thu, 2 May 2024 19:56:44 -0700
Subject: [PATCH 3/3] release-notes: Add entries for unified executables
 improvements

* documentation/release-notes/source/2024.2.rst: Add entries.
---
 documentation/release-notes/source/2024.2.rst | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/documentation/release-notes/source/2024.2.rst b/documentation/release-notes/source/2024.2.rst
index 1d7a4fb9a..733ecbb30 100644
--- a/documentation/release-notes/source/2024.2.rst
+++ b/documentation/release-notes/source/2024.2.rst
@@ -20,6 +20,12 @@ this release.
 Compiler
 ========
 
+* Unified executables now export symbols so that call stack dumping
+  works properly.
+
+* The build rules for unified executables now properly depend on
+  copying included run-time libraries such as libunwind.
+
 Tools
 =====