Create separate debug info files by default

Now that we have a built-in stacktrace on a segfault it would be useful
to have debug information on debug_release builds so that bugreports can
include this information. Without this debug info we will still get
function names in the backtrace but not file location.

This commit will by default build all targets with minimal debug info
and then strip the information into separate files. On MacOS this is a
.dSYM file, on Linux/MingW this is a .debug file. MacOSX will
automatically load a dSYM file if it exists in its debugger. On
Linux/MingW we create a 'gnu debuglink' meaning that gdb and friends
will automatically find the debug symbols if they exist.

Existing workflow for developers does not change at all, except that we
now create two instead of one build artifact by default.

This commit also adds a 'debug_symbols' option to X11, MacOS, and MingW
targets. The default is 'yes' which corresponds to -g1. The alternatives
are 'no' (don't generate debug infos at all) or 'full' which runs with
-g2. A target=debug build will now build with -g3.

8 files changed, 67 insertions, 19 deletions

diff --git a/.gitignore b/.gitignore
index 315dc7950f..d27b8b2b4b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -80,6 +80,8 @@ build/
 bld/
 [Bb]in/
 [Oo]bj/
+*.debug
+*.dSYM
 
 # MSTest test Results
 [Tt]est[Rr]esult*/
diff --git a/platform/haiku/detect.py b/platform/haiku/detect.py
index c0e003a3d2..61ee32d2dd 100644
--- a/platform/haiku/detect.py
+++ b/platform/haiku/detect.py
@@ -21,7 +21,7 @@ def can_build():
 def get_opts():
 
     return [
-        ('debug_release', 'Add debug symbols to release version', 'no')
+        ('debug_symbols', 'Add debug symbols to release version (yes/no/full)', 'yes')
     ]
 
 
@@ -36,16 +36,21 @@ def configure(env):
     ## Build type
 
     if (env["target"] == "release"):
-        if (env["debug_release"] == "yes"):
+        env.Prepend(CCFLAGS=['-O3', '-ffast-math'])
+        if (env["debug_symbols"] == "yes"):
+            env.Prepend(CCFLAGS=['-g1'])
+        if (env["debug_symbols"] == "full"):
             env.Prepend(CCFLAGS=['-g2'])
-        else:
-            env.Prepend(CCFLAGS=['-O3', '-ffast-math'])
 
     elif (env["target"] == "release_debug"):
         env.Prepend(CCFLAGS=['-O2', '-ffast-math', '-DDEBUG_ENABLED'])
+        if (env["debug_symbols"] == "yes"):
+            env.Prepend(CCFLAGS=['-g1'])
+        if (env["debug_symbols"] == "full"):
+            env.Prepend(CCFLAGS=['-g2'])
 
     elif (env["target"] == "debug"):
-        env.Prepend(CCFLAGS=['-g2', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
+        env.Prepend(CCFLAGS=['-g3', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
 
     ## Architecture
 
diff --git a/platform/osx/SCsub b/platform/osx/SCsub
index 5b2de54535..27bffbe80e 100644
--- a/platform/osx/SCsub
+++ b/platform/osx/SCsub
@@ -1,7 +1,11 @@
 #!/usr/bin/env python
 
+import os
 Import('env')
 
+def make_debug(target, source, env):
+    os.system('dsymutil %s -o %s.dSYM' % (target[0], target[0]))
+
 files = [
     'crash_handler_osx.mm',
     'os_osx.mm',
@@ -13,8 +17,7 @@ files = [
     'power_osx.cpp',
 ]
 
-prog = env.Program('#bin/godot', files)
-if (env['target'] == "debug" or env['target'] == "release_debug"):
-    # Build the .dSYM file for atos
-    action = "dsymutil " + File(prog)[0].path + " -o " + File(prog)[0].path + ".dSYM"
-    env.AddPostAction(prog, action)
+binary = env.Program('#bin/godot', files)
+if env["debug_symbols"] == "full" or env["debug_symbols"] == "yes":
+    env.AddPostAction(binary, make_debug)
+
diff --git a/platform/osx/detect.py b/platform/osx/detect.py
index d3ebdfe992..24302b5ff9 100644
--- a/platform/osx/detect.py
+++ b/platform/osx/detect.py
@@ -22,6 +22,7 @@ def get_opts():
 
     return [
         ('osxcross_sdk', 'OSXCross SDK version', 'darwin14'),
+        ('debug_symbols', 'Add debug symbols to release version (yes/no/full)', 'yes'),
     ]
 
 
@@ -36,10 +37,18 @@ def configure(env):
 	## Build type
 
     if (env["target"] == "release"):
-        env.Prepend(CCFLAGS=['-O2', '-ffast-math', '-fomit-frame-pointer', '-ftree-vectorize', '-msse2'])
+        env.Prepend(CCFLAGS=['-O3', '-ffast-math', '-fomit-frame-pointer', '-ftree-vectorize', '-msse2'])
+        if (env["debug_symbols"] == "yes"):
+            env.Prepend(CCFLAGS=['-g1'])
+        if (env["debug_symbols"] == "full"):
+            env.Prepend(CCFLAGS=['-g2'])
 
     elif (env["target"] == "release_debug"):
         env.Prepend(CCFLAGS=['-O2', '-DDEBUG_ENABLED'])
+        if (env["debug_symbols"] == "yes"):
+            env.Prepend(CCFLAGS=['-g1'])
+        if (env["debug_symbols"] == "full"):
+            env.Prepend(CCFLAGS=['-g2'])
 
     elif (env["target"] == "debug"):
         env.Prepend(CCFLAGS=['-g3', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
diff --git a/platform/windows/SCsub b/platform/windows/SCsub
index b56a5c6a80..fd041e096e 100644
--- a/platform/windows/SCsub
+++ b/platform/windows/SCsub
@@ -1,7 +1,12 @@
 #!/usr/bin/env python
 
+import os
 Import('env')
 
+def make_debug_mingw(target, source, env):
+    os.system('objcopy --only-keep-debug %s %s.debug' % (target[0], target[0]))
+    os.system('strip --strip-debug --strip-unneeded %s' % (target[0]))
+    os.system('objcopy --add-gnu-debuglink=%s.debug %s' % (target[0], target[0]))
 
 common_win = [
     "context_gl_win.cpp",
@@ -22,10 +27,14 @@ obj = env.RES(restarget, 'godot_res.rc')
 
 common_win.append(obj)
 
-env.Program('#bin/godot', ['godot_win.cpp'] + common_win, PROGSUFFIX=env["PROGSUFFIX"])
+binary = env.Program('#bin/godot', ['godot_win.cpp'] + common_win, PROGSUFFIX=env["PROGSUFFIX"])
 
 # Microsoft Visual Studio Project Generation
 if (env['vsproj']) == "yes":
     env.vs_srcs = env.vs_srcs + ["platform/windows/godot_win.cpp"]
     for x in common_win:
         env.vs_srcs = env.vs_srcs + ["platform/windows/" + str(x)]
+
+if not os.getenv("VCINSTALLDIR"):
+    if env["debug_symbols"] == "full" or env["debug_symbols"] == "yes":
+        env.AddPostAction(binary, make_debug_mingw)
diff --git a/platform/windows/detect.py b/platform/windows/detect.py
index 5bd9a78f49..65eb51a2f3 100644
--- a/platform/windows/detect.py
+++ b/platform/windows/detect.py
@@ -64,6 +64,7 @@ def get_opts():
     return [
         ('mingw_prefix_32', 'MinGW prefix (Win32)', mingw32),
         ('mingw_prefix_64', 'MinGW prefix (Win64)', mingw64),
+        ('debug_symbols', 'Add debug symbols to release version (yes/no/full)', 'yes')
     ]
 
 
@@ -213,11 +214,20 @@ def configure(env):
 
             env.Append(LINKFLAGS=['-Wl,--subsystem,windows'])
 
+            if (env["debug_symbols"] == "yes"):
+               env.Prepend(CCFLAGS=['-g1'])
+            if (env["debug_symbols"] == "full"):
+               env.Prepend(CCFLAGS=['-g2'])
+
         elif (env["target"] == "release_debug"):
             env.Append(CCFLAGS=['-O2', '-DDEBUG_ENABLED'])
+            if (env["debug_symbols"] == "yes"):
+               env.Prepend(CCFLAGS=['-g1'])
+            if (env["debug_symbols"] == "full"):
+               env.Prepend(CCFLAGS=['-g2'])
 
         elif (env["target"] == "debug"):
-            env.Append(CCFLAGS=['-g', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
+            env.Append(CCFLAGS=['-g3', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
 
         ## Compiler configuration
 
diff --git a/platform/x11/SCsub b/platform/x11/SCsub
index 62717f3221..aabc49149f 100644
--- a/platform/x11/SCsub
+++ b/platform/x11/SCsub
@@ -1,7 +1,12 @@
 #!/usr/bin/env python
 
+import os
 Import('env')
 
+def make_debug(target, source, env):
+    os.system('objcopy --only-keep-debug %s %s.debug' % (target[0], target[0]))
+    os.system('strip --strip-debug --strip-unneeded %s' % (target[0]))
+    os.system('objcopy --add-gnu-debuglink=%s.debug %s' % (target[0], target[0]))
 
 common_x11 = [
     "context_gl_x11.cpp",
@@ -12,4 +17,6 @@ common_x11 = [
     "power_x11.cpp",
 ]
 
-env.Program('#bin/godot', ['godot_x11.cpp'] + common_x11)
+binary = env.Program('#bin/godot', ['godot_x11.cpp'] + common_x11)
+if env["debug_symbols"] == "full" or env["debug_symbols"] == "yes":
+    env.AddPostAction(binary, make_debug)
diff --git a/platform/x11/detect.py b/platform/x11/detect.py
index d61175da60..efd388e44f 100644
--- a/platform/x11/detect.py
+++ b/platform/x11/detect.py
@@ -44,7 +44,6 @@ def can_build():
 
     return True
 
-
 def get_opts():
 
     return [
@@ -55,7 +54,7 @@ def get_opts():
         ('use_lto', 'Use link time optimization', 'no'),
         ('pulseaudio', 'Detect & use pulseaudio', 'yes'),
         ('udev', 'Use udev for gamepad connection callbacks', 'no'),
-        ('debug_release', 'Add debug symbols to release version', 'no'),
+        ('debug_symbols', 'Add debug symbols to release version (yes/no/full)', 'yes')
     ]
 
 
@@ -77,16 +76,20 @@ def configure(env):
         # -O3 -ffast-math is identical to -Ofast. We need to split it out so we can selectively disable
         # -ffast-math in code for which it generates wrong results.
         env.Prepend(CCFLAGS=['-O3', '-ffast-math'])
-        if (env["debug_release"] == "yes"):
+        if (env["debug_symbols"] == "yes"):
+            env.Prepend(CCFLAGS=['-g1'])
+        if (env["debug_symbols"] == "full"):
             env.Prepend(CCFLAGS=['-g2'])
 
     elif (env["target"] == "release_debug"):
         env.Prepend(CCFLAGS=['-O2', '-ffast-math', '-DDEBUG_ENABLED'])
-        if (env["debug_release"] == "yes"):
+        if (env["debug_symbols"] == "yes"):
+            env.Prepend(CCFLAGS=['-g1'])
+        if (env["debug_symbols"] == "full"):
             env.Prepend(CCFLAGS=['-g2'])
 
     elif (env["target"] == "debug"):
-        env.Prepend(CCFLAGS=['-g2', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
+        env.Prepend(CCFLAGS=['-g3', '-DDEBUG_ENABLED', '-DDEBUG_MEMORY_ENABLED'])
         env.Append(LINKFLAGS=['-rdynamic'])
 
     ## Architecture