WIP: Allow building a "store-only" nix

This is a nix without the expression language or flakes, with just a few
commands.

TODO:

 - Do --help without libexper.

 - Dedup the two `main.cc`s

 - Dedup the two `nix.md`s

 - Dedup the two `help.md`s

Pop out parser

Fix completions

.gitignore

@@ -54,9 +54,11 @@ perl/Makefile.config
 # /src/libutil/
 /tests/unit/libutil/libnixutil-tests
 
-/src/nix/nix
+/src/nix/store/mini-nix
+/src/nix/full/nix
 
 /src/nix/generated-doc
+/src/nix/full/generated-doc
 
 # /src/nix-env/
 /src/nix-env/nix-env

Makefile

@@ -3,16 +3,16 @@ include mk/build-dir.mk
 -include $(buildprefix)Makefile.config
 clean-files += $(buildprefix)Makefile.config
 
+NIX_FULL ?= 1
+
 ifeq ($(ENABLE_BUILD), yes)
 makefiles = \
   mk/precompiled-headers.mk \
   local.mk \
   src/libutil/local.mk \
   src/libstore/local.mk \
-  src/libfetchers/local.mk \
   src/libmain/local.mk \
-  src/libexpr/local.mk \
-  src/libcmd/local.mk \
+  src/libstore-cmd/local.mk \
   src/nix/local.mk \
   src/resolve-system-dependencies/local.mk \
   scripts/local.mk \
@@ -22,25 +22,36 @@ makefiles = \
   misc/systemd/local.mk \
   misc/launchd/local.mk \
   misc/upstart/local.mk
+ifeq ($(NIX_FULL), 1)
+makefiles += \
+  src/libfetchers/local.mk \
+  src/libexpr/local.mk \
+  src/libcmd/local.mk
+endif
 endif
 
 ifeq ($(ENABLE_BUILD)_$(ENABLE_TESTS), yes_yes)
 makefiles += \
   tests/unit/libutil/local.mk \
   tests/unit/libutil-support/local.mk \
   tests/unit/libstore/local.mk \
-  tests/unit/libstore-support/local.mk \
+  tests/unit/libstore-support/local.mk
+ifeq ($(NIX_FULL), 1)
+makefiles += \
   tests/unit/libexpr/local.mk \
   tests/unit/libexpr-support/local.mk
 endif
+endif
 
 ifeq ($(ENABLE_TESTS), yes)
+ifeq ($(NIX_FULL), 1)
 makefiles += \
   tests/functional/local.mk \
   tests/functional/ca/local.mk \
   tests/functional/dyn-drv/local.mk \
   tests/functional/test-libstoreconsumer/local.mk \
   tests/functional/plugins/local.mk
+endif
 else
 makefiles += \
   mk/disable-tests.mk

doc/manual/local.mk

@@ -101,6 +101,8 @@ $(d)/src/SUMMARY.md: $(d)/src/SUMMARY.md.in $(d)/src/SUMMARY-rl-next.md $(d)/src
 	@cp $< $@
 	@$(call process-includes,$@,$@)
 
+ifeq ($(NIX_FULL), 1)
+
 $(d)/src/store/types: $(d)/nix.json $(d)/utils.nix $(d)/generate-store-info.nix  $(d)/generate-store-types.nix $(d)/src/store/types/index.md.in $(doc_nix)
 	@# FIXME: build out of tree!
 	@rm -rf $@.tmp
@@ -122,10 +124,14 @@ $(d)/nix.json: $(doc_nix)
 	$(trace-gen) $(dummy-env) $(doc_nix) __dump-cli > $@.tmp
 	@mv $@.tmp $@
 
+endif
+
 $(d)/conf-file.json: $(doc_nix)
 	$(trace-gen) $(dummy-env) $(doc_nix) config show --json --experimental-features nix-command > $@.tmp
 	@mv $@.tmp $@
 
+ifeq ($(NIX_FULL), 1)
+
 $(d)/src/contributing/experimental-feature-descriptions.md: $(d)/xp-features.json $(d)/utils.nix $(d)/generate-xp-features.nix $(doc_nix)
 	@rm -rf $@ $@.tmp
 	$(trace-gen) $(nix-eval) --write-to $@.tmp --expr 'import doc/manual/generate-xp-features.nix (builtins.fromJSON (builtins.readFile $<))'
@@ -156,6 +162,8 @@ $(d)/language.json: $(doc_nix)
 	$(trace-gen) $(dummy-env) $(doc_nix) __dump-language > $@.tmp
 	@mv $@.tmp $@
 
+endif
+
 # Generate "Upcoming release" notes (or clear it and remove from menu)
 $(d)/src/release-notes/rl-next.md: $(d)/rl-next $(d)/rl-next/*
 	@if type -p changelog-d > /dev/null; then \

local.mk

@@ -2,8 +2,7 @@ GLOBAL_CXXFLAGS += -Wno-deprecated-declarations -Werror=switch
 # Allow switch-enum to be overridden for files that do not support it, usually because of dependency headers.
 ERROR_SWITCH_ENUM = -Werror=switch-enum
 
-$(foreach i, config.h $(wildcard src/lib*/*.hh), \
-  $(eval $(call install-file-in, $(i), $(includedir)/nix, 0644)))
+$(eval $(call install-file-in, config.h, $(includedir)/nix, 0644))
 
 $(GCH): src/libutil/util.hh config.h
 

src/libcmd/command-installable-value.cc

@@ -2,6 +2,17 @@
 
 namespace nix {
 
+InstallableValueCommand::InstallableValueCommand()
+    : SourceExprCommand()
+{
+    expectArgs({
+        .label = "installable",
+        .optional = true,
+        .handler = {&_installable},
+        .completer = getCompleteInstallable(),
+    });
+}
+
 void InstallableValueCommand::run(ref<Store> store, ref<Installable> installable)
 {
     auto installableValue = InstallableValue::require(installable);

src/libcmd/command-installable-value.hh

@@ -10,8 +10,10 @@ namespace nix {
  * An InstallableCommand where the single positional argument must be an
  * InstallableValue in particular.
  */
-struct InstallableValueCommand : InstallableCommand
+struct InstallableValueCommand : AbstractInstallableCommand, SourceExprCommand
 {
+    InstallableValueCommand();
+
     /**
      * Entry point to this command
      */