Add an option to keep native debug symbols (#39203)

When packaging .NET for Linux distributions, the package builders
generally use a different workflow for shipping symbols to users:

1. The package maintainer builds code with the debug flags (such as
   `-g`) to generate full native debug info and symbols.

2. Nothing is stripped from build by the package maintainer.

3. The build system (`rpmbuild`, `debuild`) removes the debug
   info (or debug symbols) from the code and creates separate
   `-debuginfo` or `-debug` packages that contain just the debug
   symbols.

4. These debug packages are then distributed along with the normal
   packages using the normal Linux distribution mechanisms. This lets
   users install the exact set of debug symbols matching their other
   package.

To support this workflow in dotnet/runtime, we need to add optional
support for not stripping debug symbols. I used it has follows:

    CFLAGS=-g CXXFLAGS=-g ./build.sh --keepnativesymbols true

After this build, the built binaries include all debug symbols.

I can then rely on the distro package build system to identify, strip,
package and ship the debug info/symbols separately.

See https://github.com/dotnet/runtime/issues/3781 and
https://github.com/dotnet/source-build/issues/267 for more details on
the background and motivation.

For some related fixes, see:

- https://github.com/dotnet/coreclr/pull/3445
- https://github.com/dotnet/corefx/pull/24979

1 files changed, 10 insertions, 4 deletions

diff --git a/eng/native/functions.cmake b/eng/native/functions.cmake
index 525c289d988..27396aa5bb5 100644
--- a/eng/native/functions.cmake
+++ b/eng/native/functions.cmake
@@ -336,8 +336,10 @@ function(strip_symbols targetName outputFilename)
 endfunction()
 
 function(install_with_stripped_symbols targetName kind destination)
-    strip_symbols(${targetName} symbol_file)
-    install_symbols(${symbol_file} ${destination})
+    if(NOT CLR_CMAKE_KEEP_NATIVE_SYMBOLS)
+      strip_symbols(${targetName} symbol_file)
+      install_symbols(${symbol_file} ${destination})
+    endif()
     if ("${kind}" STREQUAL "TARGETS")
       set(install_source ${targetName})
     elseif("${kind}" STREQUAL "PROGRAMS")
@@ -374,13 +376,17 @@ function(install_clr)
   foreach(targetName ${INSTALL_CLR_TARGETS})
     list(FIND CLR_CROSS_COMPONENTS_LIST ${targetName} INDEX)
     if (NOT DEFINED CLR_CROSS_COMPONENTS_LIST OR NOT ${INDEX} EQUAL -1)
-        strip_symbols(${targetName} symbol_file)
+        if (NOT CLR_CMAKE_KEEP_NATIVE_SYMBOLS)
+          strip_symbols(${targetName} symbol_file)
+        endif()
 
         foreach(destination ${destinations})
           # We don't need to install the export libraries for our DLLs
           # since they won't be directly linked against.
           install(PROGRAMS $<TARGET_FILE:${targetName}> DESTINATION ${destination})
-          install_symbols(${symbol_file} ${destination})
+          if (NOT CLR_CMAKE_KEEP_NATIVE_SYMBOLS)
+            install_symbols(${symbol_file} ${destination})
+          endif()
 
           if(CLR_CMAKE_PGO_INSTRUMENT)
               if(WIN32)