[11u] RFR: 8223678: Add Visual Studio Code workspace generation support (for native code)

[Volker Simonis]

Hi,
I'd like to downport the support for Visual Studio Code project
creation to 11u. I think we will have to support 11u for quite some
years and it makes sense to have as good as possible tool support in
11u as well:

https://bugs.openjdk.java.net/browse/JDK-8223678
http://cr.openjdk.java.net/~simonis/webrevs/2020/8223678/

This change is the third in a series of three changes (8210459,
8218807, 8223678) which are required to get VS Code support in 11u.
The first two changes (8210459, 8218807) have already been approved
and pushed.

This change only touch make files and actually only add new features
to the make system, so the normal build results shouldn't be affected.
I've tested that the build still works on Linux and Windows and "make
test-make" succeeds.

This change actually creates the VS Code project files (i.e. "make
vscode-project-ccls"). See
http://hg.openjdk.java.net/jdk/jdk/raw-file/tip/doc/ide.html for more
details.

It applies cleanly except the following two hunks. The first one had to
be moved back from "make/common/Utils.gmk" to
"make/common/MakeBase.gmk" where it still applies cleanly, because the
"RelativePath" macro is still in "MakeBase.gmk" in  jdk11u.

ORIGINAL
========
diff -r a82a367b2d8c -r 2ae056696b15 make/common/Utils.gmk
--- a/make/common/Utils.gmk    Mon Jun 03 17:14:23 2019 -0700
+++ b/make/common/Utils.gmk    Mon Jun 03 10:28:03 2019 +0200
@@ -122,7 +122,8 @@
 # $2 - Directory to compute the relative path from
 RelativePath = \
     $(eval $1_prefix := $(call FindCommonPathPrefix, $1, $2)) \
-    $(eval $1_dotdots := $(call DirToDotDot, $(patsubst $($(strip
$1)_prefix)/%, %, $2))) \
+    $(eval $1_dotdots := $(call DirToDotDot, $(patsubst $($(strip
$1)_prefix)%, %, $2))) \
+    $(eval $1_dotdots := $(if $($(strip $1)_dotdots),$($(strip
$1)_dotdots),.)) \
     $(eval $1_suffix := $(patsubst $($(strip $1)_prefix)/%, %, $1)) \
     $($(strip $1)_dotdots)/$($(strip $1)_suffix)

JDK11u
======
diff -r 8599975f5b33 make/common/MakeBase.gmk
--- a/make/common/MakeBase.gmk    Tue Feb 12 08:40:43 2019 +0100
+++ b/make/common/MakeBase.gmk    Mon Dec 23 22:10:46 2019 +0100
@@ -611,7 +611,8 @@
 # $2 - Directory to compute the relative path from
 RelativePath = \
     $(eval $1_prefix := $(call FindCommonPathPrefix, $1, $2)) \
-    $(eval $1_dotdots := $(call DirToDotDot, $(patsubst $($(strip
$1)_prefix)/%, %, $2))) \
+    $(eval $1_dotdots := $(call DirToDotDot, $(patsubst $($(strip
$1)_prefix)%, %, $2))) \
+    $(eval $1_dotdots := $(if $($(strip $1)_dotdots),$($(strip
$1)_dotdots),.)) \
     $(eval $1_suffix := $(patsubst $($(strip $1)_prefix)/%, %, $1)) \
     $($(strip $1)_dotdots)/$($(strip $1)_suffix)

For the second changed hunk, the simple call of the "AssertEquals"
macro had to be renamed to "assert-equals" and wrapped with "eval"
because the corresponding macros haven't been updated in jdk11u yet.
Notice that these are only test changes (for testing the make system
itself) and don't effect the build at all.

ORIGINAL
========
diff -r a82a367b2d8c -r 2ae056696b15 test/make/TestMakeBase.gmk
--- a/test/make/TestMakeBase.gmk    Mon Jun 03 17:14:23 2019 -0700
+++ b/test/make/TestMakeBase.gmk    Mon Jun 03 10:28:03 2019 +0200
@@ -361,6 +361,18 @@
     RelativePath, \
 )

+$(call AssertEquals, \
+    $(call RelativePath, /foo/bar/baz/banan/kung, /foo/bar/baz), \
+    ./banan/kung, \
+    RelativePath, \
+)
+
+$(call AssertEquals, \
+    $(call RelativePath, /foo/bar/baz/banan/kung, /foo/bar/baz/), \
+    ./banan/kung, \
+    RelativePath, \
+)

JDK11u
======
diff -r 8599975f5b33 test/make/TestMakeBase.gmk
--- a/test/make/TestMakeBase.gmk    Tue Feb 12 08:40:43 2019 +0100
+++ b/test/make/TestMakeBase.gmk    Mon Dec 23 22:10:46 2019 +0100
@@ -325,13 +325,25 @@
     RelativePath, \
 ))

+$(eval $(call assert-equals, \
+    $(call RelativePath, /foo/bar/baz/banan/kung, /foo/bar/baz), \
+    ./banan/kung, \
+    RelativePath, \
+))
+
+$(eval $(call assert-equals, \
+    $(call RelativePath, /foo/bar/baz/banan/kung, /foo/bar/baz/), \
+    ./banan/kung, \
+    RelativePath, \
+))