Commit 3b00e341fd8d1f12a3a14ee79a675a36549e716b | zig

author	Andrew Kelley <andrew@ziglang.org> 2023-03-09 18:08:54-07:00
committer	Andrew Kelley <andrew@ziglang.org> 2023-03-15 10:48:14-07:00
log	3b00e341fd8d1f12a3a14ee79a675a36549e716b
tree	23f3ee1522e9e9b980810b3516b90595beee73a8
parent	25c3878c00b92ffc884d89d32817ca9c244f7972

AstGen: skip walking the AST when there are parse errors

The AST -> ZIR lowering process assumes an AST that does not have any
parse errors.

1 files changed, 19 insertions(+), 15 deletions(-)

src
- AstGen.zig

src/AstGen.zig+19-15

 @@ -133,8 +133,6 @@ pub fn generate(gpa: Allocator, tree: Ast) Allocator.Error!Zir {
     try astgen.extra.ensureTotalCapacity(gpa, tree.nodes.len + reserved_count);
     astgen.extra.items.len += reserved_count;
-    try lowerAstErrors(&astgen);
     var top_scope: Scope.Top = .{};
     var gz_instructions: std.ArrayListUnmanaged(Zir.Inst.Index) = .{};
 @@ -150,18 +148,24 @@ pub fn generate(gpa: Allocator, tree: Ast) Allocator.Error!Zir {
     };
     defer gz_instructions.deinit(gpa);
-    if (AstGen.structDeclInner(
+    // The AST -> ZIR lowering process assumes an AST that does not have any
-        &gen_scope,
+    // parse errors.
-        &gen_scope.base,
+    if (tree.errors.len == 0) {
-        0,
+        if (AstGen.structDeclInner(
-        tree.containerDeclRoot(),
+            &gen_scope,
-        .Auto,
+            &gen_scope.base,
-        0,
+            0,
-    )) |struct_decl_ref| {
+            tree.containerDeclRoot(),
-        assert(refToIndex(struct_decl_ref).? == 0);
+            .Auto,
-    } else |err| switch (err) {
+            0,
-        error.OutOfMemory => return error.OutOfMemory,
+        )) |struct_decl_ref| {
-        error.AnalysisFail => {}, // Handled via compile_errors below.
+            assert(refToIndex(struct_decl_ref).? == 0);
+        } else |err| switch (err) {
+            error.OutOfMemory => return error.OutOfMemory,
+            error.AnalysisFail => {}, // Handled via compile_errors below.
+        }
+    } else {
+        try lowerAstErrors(&astgen);
     }
     const err_index = @enumToInt(Zir.ExtraIndex.compile_errors);
 @@ -12642,7 +12646,7 @@ fn emitDbgStmt(gz: *GenZir, line: u32, column: u32) !void {
 fn lowerAstErrors(astgen: *AstGen) !void {
     const tree = astgen.tree;
-    if (tree.errors.len == 0) return;
+    assert(tree.errors.len > 0);
     const gpa = astgen.gpa;
     const parse_err = tree.errors[0];