New build --stop-after (#1573)

* Basis for `build --stop-after`

* Implement build stages

* Test for new feature

* User changes

* Remove `sudo` that isn't available on Windows

* Code review

* s/Build_Stages/Stop_Points/

.github/workflows/ci-toolchain.yml

@@ -60,7 +60,7 @@ jobs:
       run: ./bin/alr -d -n printenv || ./bin/alr -n -v -d printenv
 
     - shell: bash
-      run: mv ./bin ./bin-old || { sleep 5s && sudo mv ./bin ./bin-old; }
+      run: mv ./bin ./bin-old || { sleep 5s && mv ./bin ./bin-old; }
       # Windows doesn't allow to replace a running exe so the next command
       # fails otherwise. Also, this mv fails sometimes so we try twice JIC.
 

alire.toml

@@ -49,7 +49,7 @@ windows = { ALIRE_OS = "windows" }
 [[pins]]
 aaa = { url = "https://github.com/mosteo/aaa", commit = "dff61d2615cc6332fa6205267bae19b4d044b9da" }
 ada_toml = { url = "https://github.com/mosteo/ada-toml", commit = "da4e59c382ceb0de6733d571ecbab7ea4919b33d" }
-clic = { url = "https://github.com/alire-project/clic", commit = "de0330053584bad4dbb3dbd5e1ba939c4e8c6b55" }
+clic = { url = "https://github.com/alire-project/clic", commit = "56bbdc008e16996b6f76e443fd0165a240de1b13" }
 dirty_booleans = { url = "https://github.com/mosteo/dirty_booleans", branch = "alire" }
 diskflags = { url = "https://github.com/mosteo/diskflags", branch = "alire" }
 gnatcoll = { url = "https://github.com/alire-project/gnatcoll-core.git", commit = "4e663b87a028252e7e074f054f8f453661397166" }

doc/user-changes.md

@@ -6,6 +6,23 @@ stay on top of `alr` new features.
 
 ## Release `2.0-dev`
 
+### New switch `alr build --stop-after=<build stage>`
+
+PR [#1573](https://github.com/alire-project/alire/pull/1573)
+
+From `alr help build`:
+
+**Build stages**
+
+   Instead of always doing a full build, the process can be stopped early using `--stop-after=<stage>`, where `<stage>` is one of:
+
+   * sync: sync pristine sources to build location
+   * generation: generate configuration-dependent files
+   * post-fetch: running of post-fetch actions
+   * pre-build: running of pre-build actions
+   * build: actual building of sources
+   * post-build: running of post-build actions
+
 ### Enable shared dependencies by default
 
 PR [#1449](https://github.com/alire-project/alire/pull/1449)

src/alire/alire-builds.ads

@@ -27,6 +27,32 @@ package Alire.Builds is
    --  many more shared releases in the vault, finding toolchains could take
    --  much more time, hence the separate storage.
 
+   --  The following are moments during the build process after which we can
+   --  interrupt the process "safely", that is, some consistency is to be
+   --  expected: actions run as a whole, config files all generated, etc.
+   type Stop_Points is
+     (Sync,
+      --  Synchronization of pristine sources from the vault to the build dir.
+      --  This stage does not exist when using sandboxed dependencies.
+
+      Generation,
+      --  Generation of files based on profiles/configuration variables
+
+      Post_Fetch,
+      --  Running of the post-fetch actions, which happens only on the first
+      --  build after syncing to a new build location.
+
+      Pre_Build,
+      --  Running of the pre-build actions, which happens on every build
+
+      Build,
+      --  The actual building of sources
+
+      Post_Build
+      --  Running of the post-build actions
+
+     );
+
    function Sandboxed_Dependencies return Boolean;
    --  Queries config to see if dependencies should be sandboxed in workspace
 

src/alire/alire-roots.adb

@@ -1,7 +1,6 @@
 with Ada.Directories;
 with Ada.Unchecked_Deallocation;
 
-with Alire.Builds;
 with Alire.Conditional;
 with Alire.Dependencies.Containers;
 with Alire.Environment.Loading;
@@ -33,13 +32,33 @@ package body Alire.Roots is
 
    use type UString;
 
+   ----------------
+   -- Stop_Build --
+   ----------------
+
+   function Stop_Build (Wanted, Actual : Builds.Stop_Points) return Boolean
+   is
+     use type Builds.Stop_Points;
+   begin
+      if Wanted <= Actual then
+         Trace.Debug ("Stopping build as requested at stage: " & Wanted'Image);
+         return True;
+      else
+         return False;
+      end if;
+   end Stop_Build;
+
    -------------------
    -- Build_Prepare --
    -------------------
 
    procedure Build_Prepare (This           : in out Root;
                             Saved_Profiles : Boolean;
-                            Force_Regen    : Boolean) is
+                            Force_Regen    : Boolean;
+                            Stop_After     : Builds.Stop_Points :=
+                              Builds.Stop_Points'Last)
+   is
+      use all type Builds.Stop_Points;
    begin
       --  Check whether we should override configuration with the last one used
       --  and stored on disk. Since the first time the one from disk will be be
@@ -68,6 +87,10 @@ package body Alire.Roots is
          --  Changes in configuration may require new build dirs.
       end if;
 
+      if Stop_Build (Stop_After, Actual => Sync) then
+         return;
+      end if;
+
       --  Ensure configurations are in place and up-to-date
 
       This.Generate_Configuration (Full => Force or else Force_Regen);
@@ -83,11 +106,15 @@ package body Alire.Roots is
    function Build (This             : in out Root;
                    Cmd_Args         : AAA.Strings.Vector;
                    Build_All_Deps   : Boolean := False;
-                   Saved_Profiles   : Boolean := True)
+                   Saved_Profiles   : Boolean := True;
+                   Stop_After       : Builds.Stop_Points :=
+                     Builds.Stop_Points'Last)
                    return Boolean
    is
       Build_Failed : exception;
 
+      use all type Builds.Stop_Points;
+
       --------------------------
       -- Build_Single_Release --
       --------------------------
@@ -193,18 +220,29 @@ package body Alire.Roots is
             end if;
 
             --  Run post-fetch, it will be skipped if already ran
+
             Properties.Actions.Executor.Execute_Actions
               (This,
                State,
                Properties.Actions.Post_Fetch);
 
+            if Stop_Build (Stop_After, Actual => Post_Fetch) then
+               return;
+            end if;
+
             --  Pre-build must run always
+
             Properties.Actions.Executor.Execute_Actions
               (This,
                State,
                Properties.Actions.Pre_Build);
 
+            if Stop_Build (Stop_After, Actual => Pre_Build) then
+               return;
+            end if;
+
             --  Actual build
+
             if Release.Origin.Requires_Build then
                Call_Gprbuild (Release);
             else
@@ -213,7 +251,12 @@ package body Alire.Roots is
                   & ": release has no sources.", Detail);
             end if;
 
+            if Stop_Build (Stop_After, Actual => Build) then
+               return;
+            end if;
+
             --  Post-build must run always
+
             Properties.Actions.Executor.Execute_Actions
               (This,
                State,
@@ -224,9 +267,13 @@ package body Alire.Roots is
       end Build_Single_Release;
 
    begin
-
       This.Build_Prepare (Saved_Profiles => Saved_Profiles,
-                          Force_Regen    => False);
+                          Force_Regen    => False,
+                          Stop_After     => stop_after);
+
+      if Stop_Build (Stop_After, Actual => Generation) then
+         return True;
+      end if;
 
       This.Export_Build_Environment;
 

src/alire/alire-roots.ads

@@ -3,6 +3,7 @@ private with Ada.Finalization;
 
 with AAA.Strings;
 
+with Alire.Builds;
 private with Alire.Builds.Hashes;
 with Alire.Containers;
 with Alire.Crate_Configuration;
@@ -264,7 +265,9 @@ package Alire.Roots is
    function Build (This             : in out Root;
                    Cmd_Args         : AAA.Strings.Vector;
                    Build_All_Deps   : Boolean := False;
-                   Saved_Profiles   : Boolean := True)
+                   Saved_Profiles   : Boolean := True;
+                   Stop_After       : Builds.Stop_Points :=
+                     Builds.Stop_Points'Last)
                    return Boolean;
    --  Recursively build all dependencies that declare executables, and finally
    --  the root release. Also executes all pre-build/post-build actions for
@@ -286,7 +289,9 @@ package Alire.Roots is
 
    procedure Build_Prepare (This           : in out Root;
                             Saved_Profiles : Boolean;
-                            Force_Regen    : Boolean);
+                            Force_Regen    : Boolean;
+                            Stop_After     : Builds.Stop_Points :=
+                              Builds.Stop_Points'Last);
    --  Perform all preparations but the building step itself. This will require
    --  complete configuration, and will leave all files on disk as if an actual
    --  build were attempted. May optionally use saved profiles from the command