Add standard library prelude (FuelLabs#2769)

* add standard library prelude * prelude: no shadow errors * glob imports never result in shadow error * std prelude: address review comments Co-authored-by: Mohammad Fawaz <[email protected]>
8siceVobpu · Sep 14, 2022 · 82a554e · 82a554e
1 parent 9aa7b8b
commit 82a554e
Show file tree

Hide file tree

Showing 21 changed files with 249 additions and 32 deletions.
diff --git a/forc-pkg/src/lib.rs b/forc-pkg/src/lib.rs
@@ -15,3 +15,4 @@ pub use pkg::*;
 
 const CORE: &str = "core";
 const STD: &str = "std";
+const PRELUDE: &str = "prelude";
diff --git a/forc-pkg/src/pkg.rs b/forc-pkg/src/pkg.rs
@@ -1,7 +1,7 @@
 use crate::{
     lock::Lock,
     manifest::{BuildProfile, ConfigTimeConstant, Dependency, Manifest, ManifestFile},
-    CORE, STD,
+    CORE, PRELUDE, STD,
 };
 use anyhow::{anyhow, bail, Context, Error, Result};
 use forc_util::{
@@ -29,7 +29,7 @@ use sway_core::{
     semantic_analysis::namespace, source_map::SourceMap, BytecodeCompilationResult,
     CompileAstResult, CompileError, CompileResult, ParseProgram, TreeType,
 };
-use sway_types::{JsonABIProgram, JsonTypeApplication, JsonTypeDeclaration};
+use sway_types::{Ident, JsonABIProgram, JsonTypeApplication, JsonTypeDeclaration};
 use sway_utils::constants;
 use tracing::{info, warn};
 use url::Url;
@@ -1483,6 +1483,9 @@ pub fn sway_build_config(
 ///
 /// This function ensures that if `core` exists in the graph (the vastly common case) it is also
 /// present within the namespace. This is a necessity for operators to work for example.
+///
+/// This function also ensures that if `std` exists in the graph,
+/// then the std prelude will also be added.
 pub fn dependency_namespace(
     namespace_map: &HashMap<NodeIx, namespace::Module>,
     graph: &Graph,
@@ -1512,9 +1515,29 @@ pub fn dependency_namespace(
         }
     }
 
+    if has_std_dep(graph, node) {
+        namespace.star_import_with_reexports(&[STD, PRELUDE].map(Ident::new_no_span), &[]);
+    }
+
     Ok(namespace)
 }
 
+/// Find the `std` dependency, if it is a direct one, of the given node.
+fn has_std_dep(graph: &Graph, node: NodeIx) -> bool {
+    // If we are `std`, do nothing.
+    let pkg = &graph[node];
+    if pkg.name == STD {
+        return false;
+    }
+
+    // If we have `std` as a direct dep, use it.
+    graph.edges_directed(node, Direction::Outgoing).any(|edge| {
+        let dep_node = edge.target();
+        let dep = &graph[dep_node];
+        matches!(&dep.name[..], STD)
+    })
+}
+
 /// Find the `core` dependency (whether direct or transitive) for the given node if it exists.
 fn find_core_dep(graph: &Graph, node: NodeIx) -> Option<NodeIx> {
     // If we are `core`, do nothing.
@@ -1531,7 +1554,7 @@ fn find_core_dep(graph: &Graph, node: NodeIx) -> Option<NodeIx> {
         match &dep.name[..] {
             CORE => return Some(dep_node),
             STD => maybe_std = Some(dep_node),
-            _ => (),
+            _ => {}
         }
     }
 

diff --git a/sway-core/src/error.rs b/sway-core/src/error.rs
@@ -917,8 +917,6 @@ pub enum CompileError {
     ShadowsOtherSymbol { name: Ident },
     #[error("The name \"{name}\" is already used for a generic parameter in this scope.")]
     GenericShadowsGeneric { name: Ident },
-    #[error("The name \"{name}\" imported through `*` shadows another symbol with the same name.")]
-    StarImportShadowsOtherSymbol { name: Ident },
     #[error(
         "Match expression arm has mismatched types.\n\
          expected: {expected}\n\
@@ -1199,7 +1197,6 @@ impl Spanned for CompileError {
             ArrayOutOfBounds { span, .. } => span.clone(),
             ShadowsOtherSymbol { name } => name.span(),
             GenericShadowsGeneric { name } => name.span(),
-            StarImportShadowsOtherSymbol { name } => name.span(),
             MatchWrongType { span, .. } => span.clone(),
             MatchExpressionNonExhaustive { span, .. } => span.clone(),
             MatchStructPatternMissingFields { span, .. } => span.clone(),

diff --git a/sway-core/src/semantic_analysis/namespace/items.rs b/sway-core/src/semantic_analysis/namespace/items.rs
@@ -13,8 +13,15 @@ use sway_types::{span::Span, Spanned};
 
 use std::sync::Arc;
 
+/// Is this a glob (`use foo::*;`) import?
+#[derive(Clone, Copy, PartialEq, Debug)]
+pub(crate) enum GlobImport {
+    Yes,
+    No,
+}
+
 pub(super) type SymbolMap = im::OrdMap<Ident, TypedDeclaration>;
-pub(super) type UseSynonyms = im::HashMap<Ident, Vec<Ident>>;
+pub(super) type UseSynonyms = im::HashMap<Ident, (Vec<Ident>, GlobImport)>;
 pub(super) type UseAliases = im::HashMap<String, Ident>;
 
 /// The set of items that exist within some lexical scope via declaration or importing.
@@ -132,6 +139,7 @@ impl Items {
         let new_prefixes = if trait_name.prefixes.is_empty() {
             self.use_synonyms
                 .get(&trait_name.suffix)
+                .map(|us| &us.0)
                 .unwrap_or(&trait_name.prefixes)
                 .clone()
         } else {
@@ -155,7 +163,10 @@ impl Items {
     }
 
     pub(crate) fn get_canonical_path(&self, symbol: &Ident) -> &[Ident] {
-        self.use_synonyms.get(symbol).map(|v| &v[..]).unwrap_or(&[])
+        self.use_synonyms
+            .get(symbol)
+            .map(|v| &v.0[..])
+            .unwrap_or(&[])
     }
 
     pub(crate) fn has_storage_declared(&self) -> bool {

diff --git a/sway-core/src/semantic_analysis/namespace/module.rs b/sway-core/src/semantic_analysis/namespace/module.rs
@@ -10,7 +10,7 @@ use crate::{
 };
 
 use super::{
-    items::{Items, SymbolMap},
+    items::{GlobImport, Items, SymbolMap},
     root::Root,
     ModuleName, Path,
 };
@@ -213,6 +213,7 @@ impl Module {
             warnings,
             errors
         );
+
         let implemented_traits = src_ns.implemented_traits.clone();
         let mut symbols = vec![];
         for (symbol, decl) in src_ns.symbols.iter() {
@@ -230,13 +231,65 @@ impl Module {
         let dst_ns = &mut self[dst];
         dst_ns.implemented_traits.extend(implemented_traits);
         for symbol in symbols {
-            if dst_ns.use_synonyms.contains_key(&symbol) {
-                errors.push(CompileError::StarImportShadowsOtherSymbol {
-                    name: symbol.clone(),
-                });
+            dst_ns
+                .use_synonyms
+                .insert(symbol, (src.to_vec(), GlobImport::Yes));
+        }
+
+        ok((), warnings, errors)
+    }
+
+    /// Given a path to a `src` module, create synonyms to every symbol in that module to the given
+    /// `dst` module.
+    ///
+    /// This is used when an import path contains an asterisk.
+    ///
+    /// Paths are assumed to be relative to `self`.
+    pub fn star_import_with_reexports(&mut self, src: &Path, dst: &Path) -> CompileResult<()> {
+        let mut warnings = vec![];
+        let mut errors = vec![];
+        let src_ns = check!(
+            self.check_submodule(src),
+            return err(warnings, errors),
+            warnings,
+            errors
+        );
+
+        let implemented_traits = src_ns.implemented_traits.clone();
+        let use_synonyms = src_ns.use_synonyms.clone();
+        let mut symbols = src_ns.use_synonyms.keys().cloned().collect::<Vec<_>>();
+        for (symbol, decl) in src_ns.symbols.iter() {
+            let visibility = check!(
+                decl.visibility(),
+                return err(warnings, errors),
+                warnings,
+                errors
+            );
+            if visibility == Visibility::Public {
+                symbols.push(symbol.clone());
             }
-            dst_ns.use_synonyms.insert(symbol, src.to_vec());
         }
+
+        let dst_ns = &mut self[dst];
+        dst_ns.implemented_traits.extend(implemented_traits);
+        let mut try_add = |symbol, path| {
+            dst_ns.use_synonyms.insert(symbol, (path, GlobImport::Yes));
+        };
+
+        for symbol in symbols {
+            try_add(symbol, src.to_vec());
+        }
+        for (symbol, (mod_path, _)) in use_synonyms {
+            // N.B. We had a path like `::bar::baz`, which makes the module `bar` "crate-relative".
+            // Given that `bar`'s "crate" is `foo`, we'll need `foo::bar::baz` outside of it.
+            //
+            // FIXME(Centril, #2780): Seems like the compiler has no way of
+            // distinguishing between external and crate-relative paths?
+            let mut src = src[..1].to_vec();
+            src.extend(mod_path);
+            try_add(symbol, src);
+        }
+
         ok((), warnings, errors)
     }
 
@@ -304,24 +357,22 @@ impl Module {
                 impls_to_insert.append(&mut res);
                 // no matter what, import it this way though.
                 let dst_ns = &mut self[dst];
+                let mut add_synonym = |name| {
+                    if let Some((_, GlobImport::No)) = dst_ns.use_synonyms.get(name) {
+                        errors.push(CompileError::ShadowsOtherSymbol { name: name.clone() });
+                    }
+                    dst_ns
+                        .use_synonyms
+                        .insert(name.clone(), (src.to_vec(), GlobImport::No));
+                };
                 match alias {
                     Some(alias) => {
-                        if dst_ns.use_synonyms.contains_key(&alias) {
-                            errors.push(CompileError::ShadowsOtherSymbol {
-                                name: alias.clone(),
-                            });
-                        }
-                        dst_ns.use_synonyms.insert(alias.clone(), src.to_vec());
+                        add_synonym(&alias);
                         dst_ns
                             .use_aliases
                             .insert(alias.as_str().to_string(), item.clone());
                     }
-                    None => {
-                        if dst_ns.use_synonyms.contains_key(item) {
-                            errors.push(CompileError::ShadowsOtherSymbol { name: item.clone() });
-                        }
-                        dst_ns.use_synonyms.insert(item.clone(), src.to_vec());
-                    }
+                    None => add_synonym(item),
                 };
             }
             None => {

diff --git a/sway-core/src/semantic_analysis/namespace/root.rs b/sway-core/src/semantic_analysis/namespace/root.rs
@@ -62,7 +62,7 @@ impl Root {
                 .get(symbol.as_str())
                 .unwrap_or(symbol);
             match module.use_synonyms.get(symbol) {
-                Some(src_path) if mod_path != src_path => {
+                Some((src_path, _)) if mod_path != src_path => {
                     self.resolve_symbol(src_path, true_symbol)
                 }
                 _ => CompileResult::from(module.check_symbol(true_symbol)),

diff --git a/sway-lib-std/src/lib.sw b/sway-lib-std/src/lib.sw
@@ -30,5 +30,6 @@ dep flags;
 dep u128;
 dep u256;
 dep vec;
+dep prelude;
 
 use core::*;
diff --git a/sway-lib-std/src/prelude.sw b/sway-lib-std/src/prelude.sw
@@ -0,0 +1,13 @@
+library prelude;
+
+//! Defines the Sway standard library prelude.
+//! The prelude consists of implicitly available items,
+//! for which `use` is not required.
+
+use ::address::Address;
+use ::contract_id::ContractId;
+use ::identity::Identity;
+use ::vec::Vec;
+use ::assert::assert;
+use ::revert::require;
+use ::revert::revert;
diff --git a/test/src/e2e_vm_tests/test_programs/should_fail/shadow_import/src/main.sw b/test/src/e2e_vm_tests/test_programs/should_fail/shadow_import/src/main.sw
@@ -8,10 +8,10 @@ use ::bar::{Bar1, Bar1 as Foo};
 // This is not okay because symbol `Foo` is already reserved
 use ::bar::Bar2 as Foo;
 
-// This is not okay 
+// This is not okay
 use ::bar::{Bar2, Bar2};
 
-// This not okay now because Bar1 and Bar2 have already been imported
+// This okay. Although Bar1 + Bar2 have already been imported, glob imports don't cause shadow errors.
 use ::bar::*;
 
 fn main() -> bool {

diff --git a/test/src/e2e_vm_tests/test_programs/should_fail/shadow_import/test.toml b/test/src/e2e_vm_tests/test_programs/should_fail/shadow_import/test.toml
@@ -2,5 +2,3 @@ category = "fail"
 
 # check: $()The name "Foo" shadows another symbol with the same name.
 # check: $()The name "Bar2" shadows another symbol with the same name.
-# check: $()The name "Bar1" imported through `*` shadows another symbol with the same name.
-# check: $()The name "Bar2" imported through `*` shadows another symbol with the same name.
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/language/asm_expr_basic/src/main.sw b/test/src/e2e_vm_tests/test_programs/should_pass/language/asm_expr_basic/src/main.sw
@@ -61,7 +61,7 @@ fn main() -> u32 {
     let bal = asm() { bal };
 
     let is = asm() { is };
-    
+
     let ret = asm() { ret };
 
     let retl = asm() { retl };

diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access/Forc.lock b/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access/Forc.lock
@@ -0,0 +1,14 @@
+[[package]]
+name = 'core'
+source = 'path+from-root-24E795B40E4736EB'
+dependencies = []
+
+[[package]]
+name = 'prelude_access'
+source = 'root'
+dependencies = ['std']
+
+[[package]]
+name = 'std'
+source = 'path+from-root-24E795B40E4736EB'
+dependencies = ['core']
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access/Forc.toml b/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access/Forc.toml
@@ -0,0 +1,8 @@
+[project]
+authors = ["Fuel Labs <[email protected]>"]
+entry = "main.sw"
+license = "Apache-2.0"
+name = "prelude_access"
+
+[dependencies]
+std = { path = "../../../../../../../sway-lib-std" }
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access/json_abi_oracle.json b/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access/json_abi_oracle.json
@@ -0,0 +1,22 @@
+{
+  "functions": [
+    {
+      "inputs": [],
+      "name": "main",
+      "output": {
+        "name": "",
+        "type": 0,
+        "typeArguments": null
+      }
+    }
+  ],
+  "loggedTypes": [],
+  "types": [
+    {
+      "components": [],
+      "type": "()",
+      "typeId": 0,
+      "typeParameters": null
+    }
+  ]
+}
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access/src/main.sw b/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access/src/main.sw
@@ -0,0 +1,11 @@
+script;
+
+struct A {
+    addr: Address,
+}
+
+// Ensure shadowing is allowed.
+use std::address::Address;
+
+fn main() {
+}
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access/test.toml b/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access/test.toml
@@ -0,0 +1,3 @@
+category = "run"
+expected_result = { action = "return", value = 0 }
+validate_abi = true
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access2/Forc.lock b/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access2/Forc.lock
@@ -0,0 +1,14 @@
+[[package]]
+name = 'core'
+source = 'path+from-root-B3B7F7F1BCA7D931'
+dependencies = []
+
+[[package]]
+name = 'prelude_access2'
+source = 'root'
+dependencies = ['std']
+
+[[package]]
+name = 'std'
+source = 'path+from-root-B3B7F7F1BCA7D931'
+dependencies = ['core']
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access2/Forc.toml b/test/src/e2e_vm_tests/test_programs/should_pass/language/prelude_access2/Forc.toml
@@ -0,0 +1,8 @@
+[project]
+authors = ["Fuel Labs <[email protected]>"]
+entry = "main.sw"
+license = "Apache-2.0"
+name = "prelude_access2"
+
+[dependencies]
+std = { path = "../../../../../../../sway-lib-std" }
Original file line number	Diff line number	Diff line change
Expand Up		@@ -15,3 +15,4 @@ pub use pkg::*;

		const CORE: &str = "core";
		const STD: &str = "std";
		const PRELUDE: &str = "prelude";