[v5,1/8] build: introduce optional internal dependencies

diff --git a/app/meson.build b/app/meson.build
index e2db888ae1..61202495bd 100644
--- a/app/meson.build
+++ b/app/meson.build
@@ -66,6 +66,7 @@  foreach app:apps
     # external package/library requirements
     ext_deps = []
     deps = []
+    optional_deps = []
 
     if not enable_apps.contains(app)
         build = false
@@ -83,10 +84,19 @@  foreach app:apps
         endif
     endif
 
+    # resolve any optional internal dependencies
+    def_lib = get_option('default_library')
+    foreach d: optional_deps
+        # if optional dependency is defined, add it to the deps list
+        if is_variable(def_lib + '_rte_' + d)
+            deps += [d]
+        endif
+    endforeach
+
     if build
         dep_objs = []
         foreach d:deps
-            var_name = get_option('default_library') + '_rte_' + d
+            var_name = def_lib + '_rte_' + d
             if not is_variable(var_name)
                 build = false
                 reason = 'missing internal dependency, "@0@"'.format(d)
@@ -111,7 +121,7 @@  foreach app:apps
 
     dpdk_apps_enabled += app
     link_libs = []
-    if get_option('default_library') == 'static'
+    if def_lib == 'static'
         link_libs = dpdk_static_libraries + dpdk_drivers
     endif
 
diff --git a/app/proc-info/meson.build b/app/proc-info/meson.build
index 4f83f29a64..5fefb0857e 100644
--- a/app/proc-info/meson.build
+++ b/app/proc-info/meson.build
@@ -9,6 +9,4 @@  endif
 
 sources = files('main.c')
 deps += ['ethdev', 'security', 'eventdev']
-if dpdk_conf.has('RTE_LIB_METRICS')
-    deps += 'metrics'
-endif
+optional_deps += 'metrics'
diff --git a/app/test-bbdev/meson.build b/app/test-bbdev/meson.build
index 926e0a5271..bd38694eaf 100644
--- a/app/test-bbdev/meson.build
+++ b/app/test-bbdev/meson.build
@@ -14,15 +14,9 @@  sources = files(
         'test_bbdev_vector.c',
 )
 deps += ['bbdev', 'bus_vdev']
-if dpdk_conf.has('RTE_BASEBAND_FPGA_LTE_FEC')
-    deps += ['baseband_fpga_lte_fec']
-endif
-if dpdk_conf.has('RTE_BASEBAND_FPGA_5GNR_FEC')
-    deps += ['baseband_fpga_5gnr_fec']
-endif
-if dpdk_conf.has('RTE_BASEBAND_ACC')
-    deps += ['baseband_acc']
-endif
-if dpdk_conf.has('RTE_BASEBAND_LA12XX')
-    deps += ['baseband_la12xx']
-endif
+optional_deps += [
+    'baseband_fpga_lte_fec',
+    'baseband_fpga_5gnr_fec',
+    'baseband_acc',
+    'baseband_la12xx'
+]
diff --git a/app/test-crypto-perf/meson.build b/app/test-crypto-perf/meson.build
index 7b02b518f0..1ac0ac1099 100644
--- a/app/test-crypto-perf/meson.build
+++ b/app/test-crypto-perf/meson.build
@@ -20,6 +20,4 @@  sources = files(
         'main.c',
 )
 deps += ['cryptodev', 'net', 'security']
-if dpdk_conf.has('RTE_CRYPTO_SCHEDULER')
-    deps += 'crypto_scheduler'
-endif
+optional_deps += 'crypto_scheduler'
diff --git a/app/test-pmd/meson.build b/app/test-pmd/meson.build
index f1c36529b4..bbb0c83fa5 100644
--- a/app/test-pmd/meson.build
+++ b/app/test-pmd/meson.build
@@ -34,47 +34,29 @@  sources = files(
 if dpdk_conf.has('RTE_HAS_JANSSON')
     ext_deps += jansson_dep
 endif
-
-deps += ['ethdev', 'cmdline']
-if dpdk_conf.has('RTE_CRYPTO_SCHEDULER')
-    deps += 'crypto_scheduler'
-endif
-if dpdk_conf.has('RTE_LIB_BITRATESTATS')
-    deps += 'bitratestats'
-endif
 if dpdk_conf.has('RTE_LIB_BPF')
     sources += files('bpf_cmd.c')
-    deps += 'bpf'
-endif
-if dpdk_conf.has('RTE_LIB_GRO')
-    deps += 'gro'
-endif
-if dpdk_conf.has('RTE_LIB_GSO')
-    deps += 'gso'
-endif
-if dpdk_conf.has('RTE_LIB_LATENCYSTATS')
-    deps += 'latencystats'
-endif
-if dpdk_conf.has('RTE_LIB_METRICS')
-    deps += 'metrics'
-endif
-if dpdk_conf.has('RTE_LIB_PDUMP')
-    deps += 'pdump'
-endif
-if dpdk_conf.has('RTE_NET_BNXT')
-    deps += 'net_bnxt'
-endif
-if dpdk_conf.has('RTE_NET_I40E')
-    deps += 'net_i40e'
-endif
-if dpdk_conf.has('RTE_NET_IXGBE')
-    deps += 'net_ixgbe'
-endif
-if dpdk_conf.has('RTE_NET_DPAA')
-    deps += ['bus_dpaa', 'mempool_dpaa', 'net_dpaa']
 endif
 
+deps += ['ethdev', 'cmdline']
+optional_deps += [
+    'crypto_scheduler',
+    'bitratestats',
+    'bpf',
+    'gro',
+    'gso',
+    'latencystats',
+    'metrics',
+    'pdump',
+    'net_bnxt',
+    'net_i40e',
+    'net_ixgbe',
+    'bus_dpaa',
+    'mempool_dpaa',
+    'net_dpaa'
+]
+
 # Driver-specific commands are located in driver directories.
 includes = include_directories('.')
 sources += testpmd_drivers_sources
-deps += testpmd_drivers_deps
+optional_deps += testpmd_drivers_deps
diff --git a/app/test/meson.build b/app/test/meson.build
index d5cb6a7f7a..36c2016a49 100644
--- a/app/test/meson.build
+++ b/app/test/meson.build
@@ -7,7 +7,7 @@  sources += files('commands.c', 'test.c')
 
 # optional dependencies: some files may use these - and so we should link them in -
 # but do not explicitly require them so they are not listed in the per-file lists below
-optional_deps = ['crypto_scheduler', 'lpm']
+opt_deps = ['crypto_scheduler', 'lpm']
 
 # some other utility C files, providing functions used by various tests
 # so we need to include these deps in the dependency list for the files using those fns.
@@ -219,8 +219,8 @@  foreach f, f_deps : source_file_deps
             break
         else
             # technically we might not need this dep, but adding it is harmless
-            if d not in deps
-                deps += d
+            if d not in optional_deps and d not in deps
+                optional_deps += d
             endif
         endif
     endforeach
@@ -241,9 +241,9 @@  foreach f, f_deps : source_file_deps
     endif
 endforeach
 # add the optional dependencies
-foreach d:optional_deps
-    if is_variable(def_lib + '_rte_' + d) and d not in deps
-        deps += d
+foreach d:opt_deps
+    if d not in optional_deps and d not in deps
+        optional_deps += d
     endif
 endforeach
 
diff --git a/drivers/meson.build b/drivers/meson.build
index 495e21b54a..63b0bc1e37 100644
--- a/drivers/meson.build
+++ b/drivers/meson.build
@@ -132,6 +132,7 @@  foreach subpath:subdirs
         includes = [include_directories(drv_path)]
         # set up internal deps. Drivers can append/override as necessary
         deps = std_deps
+        optional_deps = []
         # ext_deps: Stores external library dependency got
         # using dependency() (preferred) or find_library().
         # For the find_library() case (but not with dependency()) we also
@@ -173,11 +174,21 @@  foreach subpath:subdirs
             # get dependency objs from strings
             shared_deps = ext_deps
             static_deps = ext_deps
+
+            # resolve any optional internal dependencies
+            def_lib = get_option('default_library')
+            foreach d: optional_deps
+                # if optional dependency is defined, add it to the deps list
+                if is_variable(def_lib + '_rte_' + d)
+                    deps += [d]
+                endif
+            endforeach
+
             foreach d:deps
                 if not build
                     break
                 endif
-                if not is_variable('shared_rte_' + d)
+                if not is_variable(def_lib + '_rte_' + d)
                     build = false
                     reason = 'missing internal dependency, "@0@"'.format(d)
                     if dpdk_libs_deprecated.contains(d)
diff --git a/examples/ethtool/meson.build b/examples/ethtool/meson.build
index d7f63d48af..bb2a7fbb89 100644
--- a/examples/ethtool/meson.build
+++ b/examples/ethtool/meson.build
@@ -19,8 +19,6 @@  sources = files(
 includes = include_directories('lib', 'ethtool-app')
 
 deps += 'bus_pci'
-if dpdk_conf.has('RTE_NET_IXGBE')
-    deps += 'net_ixgbe'
-endif
+optional_deps += 'net_ixgbe'
 
 allow_experimental_apis = true
diff --git a/examples/l2fwd-crypto/meson.build b/examples/l2fwd-crypto/meson.build
index bb44c88882..3081573f05 100644
--- a/examples/l2fwd-crypto/meson.build
+++ b/examples/l2fwd-crypto/meson.build
@@ -7,9 +7,7 @@ 
 # DPDK instance, use 'make'
 
 deps += 'cryptodev'
-if dpdk_conf.has('RTE_CRYPTO_SCHEDULER')
-    deps += 'crypto_scheduler'
-endif
+optional_deps += 'crypto_scheduler'
 allow_experimental_apis = true
 sources = files(
         'main.c',
diff --git a/examples/l3fwd/meson.build b/examples/l3fwd/meson.build
index c25de77bba..9a5f487429 100644
--- a/examples/l3fwd/meson.build
+++ b/examples/l3fwd/meson.build
@@ -18,6 +18,4 @@  sources = files(
         'l3fwd_lpm.c',
         'main.c',
 )
-if dpdk_conf.has('RTE_LIB_EVENTDEV')
-    deps += 'eventdev'
-endif
+optional_deps += 'eventdev'
diff --git a/examples/meson.build b/examples/meson.build
index 8e8968a1fa..14b8aadf68 100644
--- a/examples/meson.build
+++ b/examples/meson.build
@@ -98,12 +98,23 @@  foreach example: examples
     ext_deps = []
     includes = [include_directories(example, 'common')]
     deps = ['eal', 'mempool', 'net', 'mbuf', 'ethdev', 'cmdline']
+    optional_deps = []
     subdir(example)
 
     if build
         dep_objs = ext_deps
+
+        # resolve any optional internal dependencies
+        def_lib = get_option('default_library')
+        foreach d: optional_deps
+            # if optional dependency is defined, add it to the deps list
+            if is_variable(def_lib + '_rte_' + d)
+                deps += [d]
+            endif
+        endforeach
+
         foreach d:deps
-            var_name = get_option('default_library') + '_rte_' + d
+            var_name = def_lib + '_rte_' + d
             if not is_variable(var_name)
                 build = false
                 message('Missing dependency "@0@" for example "@1@"'.format(d, name))
diff --git a/examples/vm_power_manager/meson.build b/examples/vm_power_manager/meson.build
index dcf23198eb..ba39b2cfab 100644
--- a/examples/vm_power_manager/meson.build
+++ b/examples/vm_power_manager/meson.build
@@ -8,17 +8,11 @@ 
 
 deps += ['power', 'power_kvm_vm']
 
-if dpdk_conf.has('RTE_NET_BNXT')
-    deps += ['net_bnxt']
-endif
-
-if dpdk_conf.has('RTE_NET_I40E')
-    deps += ['net_i40e']
-endif
-
-if dpdk_conf.has('RTE_NET_IXGBE')
-    deps += ['net_ixgbe']
-endif
+optional_deps += [
+    'net_bnxt',
+    'net_i40e',
+    'net_ixgbe'
+]
 
 allow_experimental_apis = true
 sources = files(
diff --git a/lib/meson.build b/lib/meson.build
index ce92cb5537..76bf849852 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -134,6 +134,7 @@  foreach l:libraries
     # external package/library requirements
     ext_deps = []
     deps = []
+    optional_deps = []
     # eal is standard dependency once built
     if dpdk_conf.has('RTE_LIB_EAL')
         deps += ['eal']
@@ -171,11 +172,21 @@  foreach l:libraries
 
     shared_deps = ext_deps
     static_deps = ext_deps
+
+    # resolve any optional internal dependencies
+    def_lib = get_option('default_library')
+    foreach d: optional_deps
+        # if optional dependency is defined, add it to the deps list
+        if is_variable(def_lib + '_rte_' + d)
+            deps += [d]
+        endif
+    endforeach
+
     foreach d:deps
         if not build
             break
         endif
-        if not is_variable('shared_rte_' + d)
+        if not is_variable(def_lib + '_rte_' + d)
             build = false
             reason = 'missing internal dependency, "@0@"'.format(d)
             if dpdk_libs_deprecated.contains(d)