php7[01234].extension.decimal: Override decimal to allow use in PHP 7

Depends on the JSON extension, which was included in PHP starting from
version 8, so it's added when building for PHP 7. See:
https://www.php.net/manual/en/json.installation.php

Co-authored-by: agj <[email protected]>

Author: agj

.github/workflows/build.yaml

@@ -98,6 +98,10 @@ jobs:
       - name: Build Tidy extension
         run: nix-build -A outputs.checks.${{ matrix.archs.arch }}.${{ steps.params.outputs.attr }}-tidy
 
+      - name: Build Decimal extension
+        if: ${{ steps.params.outputs.major >= 7 }}
+        run: nix-build -A outputs.checks.${{ matrix.archs.arch }}.${{ steps.params.outputs.attr }}-decimal
+
       - name: Check that composer PHAR works
         run: nix-build -A outputs.checks.${{ matrix.archs.arch }}.${{ steps.params.outputs.attr }}-composer-phar
 

checks.nix

@@ -53,6 +53,12 @@ let
       drv = { php, ... }: php.extensions.tidy;
     };
 
+    decimal = {
+      description = "Build Decimal extension";
+      enabled = { php, lib, ... }: lib.versionAtLeast php.version "7";
+      drv = { php, ... }: php.extensions.decimal;
+    };
+
     composer-phar = {
       description = "Check that composer PHAR works";
       drv =

pkgs/package-overrides.nix

@@ -104,6 +104,22 @@ in
       else
         prev.extensions.datadog_trace;
 
+    decimal =
+      if lib.versionOlder prev.php.version "7.0" then
+        throw "php.extensions.decimal requires PHP version >= 7.0"
+      else if lib.versionOlder prev.php.version "8.0" then
+        prev.extensions.decimal.overrideAttrs (attrs: {
+          preConfigure = attrs.preConfigure or "" + linkInternalDeps [ final.extensions.json ];
+
+          env = mergeEnv attrs {
+            NIX_CFLAGS_COMPILE = lib.optionals (lib.versionOlder prev.php.version "7.4") [
+              "-Wno-incompatible-${lib.optionalString isClang "function-"}pointer-types"
+            ];
+          };
+        })
+      else
+        prev.extensions.decimal;
+
     dom = prev.extensions.dom.overrideAttrs (attrs: {
       patches =
         let