Improve the coverage of debug symbols for MK_DEBUG_FILES.

- Include debug symbols in static libraries.  This permits binaries
  to include debug symbols for functions obtained from static libraries.
- Permit the C/C++ compiler flags added for MK_DEBUG_FILES to be
  overridden by setting DEBUG_FILES_CFLAGS.  Use this to limit the debug
  information for llvm libraries and binaries.

Reviewed by:	emaste
Sponsored by:	DARPA / AFRL
Differential Revision:	https://reviews.freebsd.org/D12025

lib/clang/Makefile.inc

@@ -0,0 +1,9 @@
+# $FreeBSD$
+
+.include <bsd.compiler.mk>
+
+.if ${COMPILER_TYPE} == "clang"
+DEBUG_FILES_CFLAGS= -gline-tables-only
+.else
+DEBUG_FILES_CFLAGS= -g1
+.endif

share/mk/bsd.lib.mk

@@ -69,8 +69,8 @@ TAG_ARGS=	-T ${TAGS:[*]:S/ /,/g}
 
 .if ${MK_DEBUG_FILES} != "no" && empty(DEBUG_FLAGS:M-g) && \
     empty(DEBUG_FLAGS:M-gdwarf*)
-SHARED_CFLAGS+= -g
-SHARED_CXXFLAGS+= -g
+CFLAGS+= ${DEBUG_FILES_CFLAGS}
+CXXFLAGS+= ${DEBUG_FILES_CFLAGS}
 CTFFLAGS+= -g
 .endif
 

share/mk/bsd.prog.mk

@@ -39,7 +39,7 @@ CFLAGS+=${CRUNCH_CFLAGS}
 .else
 .if ${MK_DEBUG_FILES} != "no" && empty(DEBUG_FLAGS:M-g) && \
     empty(DEBUG_FLAGS:M-gdwarf-*)
-CFLAGS+= -g
+CFLAGS+= ${DEBUG_FILES_CFLAGS}
 CTFFLAGS+= -g
 .endif
 .endif

share/mk/bsd.sys.mk

@@ -212,6 +212,10 @@ SSP_CFLAGS?=	-fstack-protector
 CFLAGS+=	${SSP_CFLAGS}
 .endif # SSP && !ARM && !MIPS
 
+# Additional flags passed in CFLAGS and CXXFLAGS when MK_DEBUG_FILES is
+# enabled.
+DEBUG_FILES_CFLAGS?= -g
+
 # Allow user-specified additional warning flags, plus compiler and file
 # specific flag overrides, unless we've overriden this...
 .if ${MK_WARNS} != "no"

usr.bin/clang/Makefile.inc

@@ -2,4 +2,12 @@
 
 WARNS?=		0
 
+.include <bsd.compiler.mk>
+
+.if ${COMPILER_TYPE} == "clang"
+DEBUG_FILES_CFLAGS= -gline-tables-only
+.else
+DEBUG_FILES_CFLAGS= -g1
+.endif
+
 .include "../Makefile.inc"