Don't automatically enable std and alloc features of dependencies

Part of #656.

crates/block2/Cargo.toml

@@ -22,8 +22,8 @@ workspace = true
 default = ["std"]
 
 # Currently not possible to turn off, put here for forwards compatibility.
-std = ["alloc", "objc2/std"]
-alloc = ["objc2/alloc"]
+std = ["alloc"]
+alloc = []
 
 # Deprecated; this is the default on Apple platforms, and not applicable on other platforms.
 apple = []
@@ -53,7 +53,7 @@ objc2 = { path = "../objc2", version = "0.5.2", default-features = false }
 [dev-dependencies.objc2-foundation]
 path = "../../framework-crates/objc2-foundation"
 default-features = false
-features = ["NSError"]
+features = ["alloc", "NSError"]
 
 [package.metadata.docs.rs]
 default-target = "aarch64-apple-darwin"

crates/dispatch2/Cargo.toml

@@ -41,8 +41,8 @@ targets = [
 default = ["std"]
 
 # Currently not possible to turn off, put here for forwards compatibility.
-std = ["alloc", "bitflags/std", "block2?/std", "libc?/std", "objc2?/std"]
-alloc = ["block2?/alloc", "objc2?/alloc"]
+std = ["alloc"]
+alloc = []
 block2 = ["dep:block2"]
 libc = ["dep:libc"]
 objc2 = ["dep:objc2"]

crates/header-translator/src/default_cargo.toml

@@ -26,7 +26,5 @@ targets = [
 
 [features]
 default = ["std"]
-
-# Currently not possible to turn off, put here for forwards compatibility.
 std = ["alloc"]
 alloc = []

crates/header-translator/src/library.rs

@@ -326,23 +326,6 @@ see that for related crates.", self.data.krate)?;
             dependency_table
                 .entry(krate)
                 .or_insert(Item::Value(Value::InlineTable(table)));
-
-            cargo_toml["features"]["std"]
-                .as_array_mut()
-                .unwrap()
-                .push(Value::from(format!(
-                    "{krate}{}/std",
-                    if *required { "" } else { "?" },
-                )));
-            if *krate != "bitflags" && *krate != "libc" {
-                cargo_toml["features"]["alloc"]
-                    .as_array_mut()
-                    .unwrap()
-                    .push(Value::from(format!(
-                        "{krate}{}/alloc",
-                        if *required { "" } else { "?" },
-                    )));
-            }
         }
 
         match fs::read_to_string(crate_dir.join("Cargo.modified.toml")) {

crates/objc2/Cargo.toml

@@ -25,8 +25,8 @@ workspace = true
 default = ["std"]
 
 # Currently not possible to turn off, put here for forwards compatibility.
-std = ["alloc", "objc2-encode/std", "block2/std", "objc2-foundation/std", "objc2-exception-helper?/std"]
-alloc = ["objc2-encode/alloc", "block2/alloc", "objc2-foundation/alloc", "objc2-exception-helper?/alloc"]
+std = ["alloc", "objc2-encode/std"]
+alloc = ["objc2-encode/alloc"]
 
 # Enables `objc2::exception::throw` and `objc2::exception::catch`
 exception = ["dep:objc2-exception-helper"]
@@ -125,11 +125,12 @@ objc2-exception-helper = { path = "../objc2-exception-helper", version = "0.1.0"
 iai = { version = "0.1", git = "https://github.com/madsmtm/iai", branch = "callgrind" }
 static_assertions = "1.1.0"
 memoffset = "0.9.0"
-block2 = { path = "../block2", default-features = false }
+block2 = { path = "../block2" }
 objc2-core-foundation = { path = "../../framework-crates/objc2-core-foundation", default-features = false, features = [
     "CFCGTypes",
 ] }
 objc2-foundation = { path = "../../framework-crates/objc2-foundation", default-features = false, features = [
+    "std",
     "NSArray",
     "NSDate",
     "NSDictionary",

crates/objc2/src/topics/about_generated/CHANGELOG.md

@@ -105,6 +105,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 * **BREAKING**: The feature flag guarding `SCSensitivityAnalysis` changed.
 * **BREAKING**: `-[NSSavePanel beginSheetForDirectory:file:modalForWindow:modalDelegate:didEndSelector:contextInfo:]`
   now takes an optional value as the file path.
+* **BREAKING**: No longer automatically enable `std` and `alloc` features of
+  dependencies. If you want a certain framework crate to use `std` or `alloc`
+  features, you cannot rely on a higher-level crate to enable that for you.
 
 ### Deprecated
 * Moved `MainThreadMarker` from `objc2-foundation` to `objc2`.

crates/test-assembly/crates/test_define_class/Cargo.toml

@@ -8,22 +8,22 @@ publish = false
 path = "lib.rs"
 
 [dependencies]
-objc2 = { path = "../../../objc2", optional = true }
-objc2-foundation = { path = "../../../../framework-crates/objc2-foundation", optional = true }
+objc2 = { path = "../../../objc2" }
+objc2-foundation = { path = "../../../../framework-crates/objc2-foundation" }
 
 [features]
-default = ["all", "objc2", "objc2-foundation"]
+default = ["all"]
 # Runtime
-gnustep-1-7 = ["objc2?/gnustep-1-7", "objc2-foundation?/gnustep-1-7"]
-gnustep-1-8 = ["gnustep-1-7", "objc2?/gnustep-1-8", "objc2-foundation?/gnustep-1-8"]
-gnustep-1-9 = ["gnustep-1-8", "objc2?/gnustep-1-9", "objc2-foundation?/gnustep-1-9"]
-gnustep-2-0 = ["gnustep-1-9", "objc2?/gnustep-2-0", "objc2-foundation?/gnustep-2-0"]
-gnustep-2-1 = ["gnustep-2-0", "objc2?/gnustep-2-1", "objc2-foundation?/gnustep-2-1"]
+gnustep-1-7 = ["objc2/gnustep-1-7", "objc2-foundation/gnustep-1-7"]
+gnustep-1-8 = ["gnustep-1-7", "objc2/gnustep-1-8", "objc2-foundation/gnustep-1-8"]
+gnustep-1-9 = ["gnustep-1-8", "objc2/gnustep-1-9", "objc2-foundation/gnustep-1-9"]
+gnustep-2-0 = ["gnustep-1-9", "objc2/gnustep-2-0", "objc2-foundation/gnustep-2-0"]
+gnustep-2-1 = ["gnustep-2-0", "objc2/gnustep-2-1", "objc2-foundation/gnustep-2-1"]
 
-all = ["objc2-foundation?/block2", "objc2-foundation?/NSObject", "objc2-foundation?/NSZone"]
+all = ["objc2-foundation/block2", "objc2-foundation/NSObject", "objc2-foundation/NSZone"]
 
 # Hack to prevent the feature flag from being enabled in the entire project
-assembly-features = ["all", "objc2?/unstable-static-sel-inlined", "objc2?/unstable-static-class-inlined"]
+assembly-features = ["all", "objc2/unstable-static-sel-inlined", "objc2/unstable-static-class-inlined"]
 
 [package.metadata.release]
 release = false

crates/test-ui/Cargo.toml

@@ -39,13 +39,13 @@ gnustep-2-1 = ["gnustep-2-0", "block2/gnustep-2-1", "objc2/gnustep-2-1", "objc2-
 trybuild = { version = "1.0.72", optional = true }
 block2 = { path = "../block2" }
 objc2 = { path = "../objc2" }
-objc2-foundation = { path = "../../framework-crates/objc2-foundation" }
+objc2-foundation = { path = "../../framework-crates/objc2-foundation", default-features = false, features = ["std"] }
 
 # To make CI work
 [target.'cfg(not(target_vendor = "apple"))'.dependencies]
 block2 = { path = "../block2", features = ["gnustep-1-7"] }
 objc2 = { path = "../objc2", features = ["gnustep-1-7"] }
-objc2-foundation = { path = "../../framework-crates/objc2-foundation", features = ["gnustep-1-7"] }
+objc2-foundation = { path = "../../framework-crates/objc2-foundation", default-features = false, features = ["std", "gnustep-1-7"] }
 
 [[bin]]
 name = "test-ui"

crates/tests/Cargo.toml

@@ -38,7 +38,7 @@ unstable-objfw = ["block2/unstable-objfw", "objc2/unstable-objfw"]
 [dependencies]
 block2 = { path = "../block2" }
 objc2 = { path = "../objc2" }
-objc2-foundation = { path = "../../framework-crates/objc2-foundation" }
+objc2-foundation = { path = "../../framework-crates/objc2-foundation", default-features = false, features = ["std"] }
 
 [build-dependencies]
 cc = "1.0"