From e6aae64318d437e77074114b6d7ffb6d838a4446 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Tue, 12 Nov 2024 20:42:53 +0100
Subject: [PATCH] Make the default stdenv phases do the right thing

Fixes #11858.
---
 doc/manual/source/development/building.md     | 24 +++++++--------
 .../source/development/documentation.md       |  4 +--
 doc/manual/source/development/testing.md      |  2 +-
 packaging/dev-shell.nix                       | 29 +++++++++++++++++++
 4 files changed, 44 insertions(+), 15 deletions(-)

diff --git a/doc/manual/source/development/building.md b/doc/manual/source/development/building.md
index dbf080296..409294682 100644
--- a/doc/manual/source/development/building.md
+++ b/doc/manual/source/development/building.md
@@ -35,20 +35,20 @@ To build Nix itself in this shell:
 
 ```console
 [nix-shell]$ mesonFlags+=" --prefix=$(pwd)/outputs/out"
-[nix-shell]$ dontAddPrefix=1 mesonConfigurePhase
-[nix-shell]$ ninjaBuildPhase
+[nix-shell]$ dontAddPrefix=1 configurePhase
+[nix-shell]$ buildPhase
 ```
 
 To test it:
 
 ```console
-[nix-shell]$ mesonCheckPhase
+[nix-shell]$ checkPhase
 ```
 
 To install it in `$(pwd)/outputs`:
 
 ```console
-[nix-shell]$ ninjaInstallPhase
+[nix-shell]$ installPhase
 [nix-shell]$ ./outputs/out/bin/nix --version
 nix (Nix) 2.12
 ```
@@ -90,20 +90,20 @@ $ nix develop .#native-clangStdenvPackages
 To build Nix itself in this shell:
 
 ```console
-[nix-shell]$ mesonConfigurePhase
-[nix-shell]$ ninjaBuildPhase
+[nix-shell]$ configurePhase
+[nix-shell]$ buildPhase
 ```
 
 To test it:
 
 ```console
-[nix-shell]$ mesonCheckPhase
+[nix-shell]$ checkPhase
 ```
 
 To install it in `$(pwd)/outputs`:
 
 ```console
-[nix-shell]$ ninjaInstallPhase
+[nix-shell]$ installPhase
 [nix-shell]$ nix --version
 nix (Nix) 2.12
 ```
@@ -167,7 +167,7 @@ It is useful to perform multiple cross and native builds on the same source tree
 for example to ensure that better support for one platform doesn't break the build for another.
 Meson thankfully makes this very easy by confining all build products to the build directory --- one simple shares the source directory between multiple build directories, each of which contains the build for Nix to a different platform.
 
-Nixpkgs's `mesonConfigurePhase` always chooses `build` in the current directory as the name and location of the build.
+Nixpkgs's `configurePhase` always chooses `build` in the current directory as the name and location of the build.
 This makes having multiple build directories slightly more inconvenient.
 The good news is that Meson/Ninja seem to cope well with relocating the build directory after it is created.
 
@@ -176,13 +176,13 @@ Here's how to do that
 1. Configure as usual
 
    ```bash
-   mesonConfigurePhase
+   configurePhase
    ```
 
 2. Rename the build directory
 
    ```bash
-   cd .. # since `mesonConfigurePhase` cd'd inside
+   cd .. # since `configurePhase` cd'd inside
    mv build build-linux # or whatever name we want
    cd build-linux
    ```
@@ -190,7 +190,7 @@ Here's how to do that
 3. Build as usual
 
    ```bash
-   ninjaBuildPhase
+   buildPhase
    ```
 
 > **N.B.**
diff --git a/doc/manual/source/development/documentation.md b/doc/manual/source/development/documentation.md
index d51373e7b..2e188f232 100644
--- a/doc/manual/source/development/documentation.md
+++ b/doc/manual/source/development/documentation.md
@@ -203,7 +203,7 @@ $ xdg-open ./result/share/doc/nix/internal-api/html/index.html
 or inside `nix-shell` or `nix develop`:
 
 ```console
-$ mesonConfigurePhase
+$ configurePhase
 $ ninja src/internal-api-docs/html
 $ xdg-open src/internal-api-docs/html/index.html
 ```
@@ -224,7 +224,7 @@ $ xdg-open ./result/share/doc/nix/external-api/html/index.html
 or inside `nix-shell` or `nix develop`:
 
 ```
-$ mesonConfigurePhase
+$ configurePhase
 $ ninja src/external-api-docs/html
 $ xdg-open src/external-api-docs/html/index.html
 ```
diff --git a/doc/manual/source/development/testing.md b/doc/manual/source/development/testing.md
index a9f7c939c..30aa7d0d5 100644
--- a/doc/manual/source/development/testing.md
+++ b/doc/manual/source/development/testing.md
@@ -137,7 +137,7 @@ Functional tests are run during `installCheck` in the `nix` package build, as we
 The whole test suite (functional and unit tests) can be run with:
 
 ```shell-session
-$ mesonCheckPhase
+$ checkPhase
 ```
 
 ### Grouping tests
diff --git a/packaging/dev-shell.nix b/packaging/dev-shell.nix
index 8ac17f61a..30ac518d5 100644
--- a/packaging/dev-shell.nix
+++ b/packaging/dev-shell.nix
@@ -31,6 +31,35 @@ in {
 
     # Make bash completion work.
     XDG_DATA_DIRS+=:$out/share
+
+    # Make the default phases do the right thing.
+    # FIXME: this wouldn't be needed if the ninja package set buildPhase() instead of $buildPhase.
+    # FIXME: mesonConfigurePhase shouldn't cd to the build directory. It would be better to pass '-C <dir>' to ninja.
+
+    cdToBuildDir() {
+        if [[ ! -e build.ninja ]]; then
+            cd build
+        fi
+    }
+
+    configurePhase() {
+        mesonConfigurePhase
+    }
+
+    buildPhase() {
+        cdToBuildDir
+        ninjaBuildPhase
+    }
+
+    checkPhase() {
+        cdToBuildDir
+        mesonCheckPhase
+    }
+
+    installPhase() {
+        cdToBuildDir
+        ninjaInstallPhase
+    }
   '';
 
   # We use this shell with the local checkout, not unpackPhase.