[build] Add clang option to buildall

Add an option (-c) to build with clang as well as with gcc.  Also,
change the way that BUILDDIR_SUFFIX is handled.  If the environment
specifies a BUILDDIR_SUFFIX, always use it verbatim.   Otherwise,
append -clang or -release (or -clang-release) as appropriate.
Previously, the way the build scripts worked, saying "USE_CLANG=true
buildall -r" would produce build output dirs with no -clang in the
directory suffix.

TL;DR?
you can now say
  ./scripts/buildall -c -r
to build every flavor of every project.

Change-Id: I9bdac9bb348ab78f4f4a1d1c36a46104e1d9c3e4

kernel/engine.mk

@@ -31,13 +31,23 @@ LKNAME ?= magenta
 CLANG_TARGET_FUCHSIA ?= false
 USE_LINKER_GC ?= true
 
-# add -clang to the build-* dir if using clang and not otherwise overridden by the environment
-ifeq ($(call TOBOOL,$(USE_CLANG)),true)
-BUILDDIR_SUFFIX ?= -clang
-else
+# If no build directory suffix has been explicitly supplied by the environment,
+# generate a default based on build options.  Start with no suffix, then add
+# "-clang" if we are building with clang, and "-release" if we are building with
+# DEBUG=0
 BUILDDIR_SUFFIX ?=
+ifeq ($(strip $(BUILDDIR_SUFFIX)),)
+
+ifeq ($(call TOBOOL,$(USE_CLANG)),true)
+BUILDDIR_SUFFIX := $(BUILDDIR_SUFFIX)-clang
 endif
 
+ifeq ($(call TOBOOL,$(DEBUG)),false)
+BUILDDIR_SUFFIX := $(BUILDDIR_SUFFIX)-release
+endif
+
+endif   # if BUILDDIR_SUFFIX is empty
+
 # special rule for handling make spotless
 ifeq ($(MAKECMDGOALS),spotless)
 spotless:

scripts/buildall

@@ -13,21 +13,24 @@ function HELP {
     echo "-f                  : Exit on first failure"
     echo "-m                  : Build magenta targets only"
     echo "-r                  : Also build release mode builds"
+    echo "-c                  : Also build with clang"
     echo "-h for help"
     exit 1
 }
 
 FAIL_FAST=0
 DO_RELEASE=0
+DO_CLANG=0
 MAGENTA_ONLY=0
 MAKE_ARGS=
 
-while getopts a:fhmr FLAG; do
+while getopts a:fhmrc FLAG; do
     case $FLAG in
         a) MAKE_ARGS="${MAKE_ARGS} ${OPTARG}";;
         f) FAIL_FAST=1;;
         h) HELP;;
         r) DO_RELEASE=1;;
+        c) DO_CLANG=1;;
         m) MAGENTA_ONLY=1;;
         \?)
             echo unrecognized option
@@ -57,6 +60,17 @@ for p in $PROJECTS; do
     fi
   fi
 
+  if [ "$DO_CLANG" -eq 1 ]; then
+    nice $DIR/make-parallel $p ${MAKE_ARGS} USE_CLANG=true
+    STATUS=$?
+    if [ "$STATUS" -ne 0 ]; then
+      FAILED="$FAILED $p-clang"
+      if [ "$FAIL_FAST" -eq 1 ]; then
+        break
+      fi
+    fi
+  fi
+
   if [ "$DO_RELEASE" -eq 1 ]; then
     nice $DIR/make-release $p ${MAKE_ARGS}
     STATUS=$?
@@ -66,6 +80,16 @@ for p in $PROJECTS; do
         break
       fi
     fi
+    if [ "$DO_CLANG" -eq 1 ]; then
+      nice $DIR/make-release $p ${MAKE_ARGS} USE_CLANG=true
+      STATUS=$?
+      if [ "$STATUS" -ne 0 ]; then
+        FAILED="$FAILED $p-clang-release"
+        if [ "$FAIL_FAST" -eq 1 ]; then
+          break
+        fi
+      fi
+    fi
   fi
 done
 

scripts/make-release

@@ -11,4 +11,4 @@ DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 # make a release build
 #
 # release builds are regular builds with DEBUG=0 and the -release suffix added to the build dir
-DEBUG=0 BUILDDIR_SUFFIX=-release $DIR/make-parallel "$@"
+DEBUG=0 $DIR/make-parallel "$@"