Fix return expr resetting temp locals.

fubark · Jan 31, 2023 · 3343587 · 3343587
1 parent bcc6bb8
commit 3343587
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Showing 4 changed files with 21 additions and 4 deletions.
diff --git a/src/bytecode.zig b/src/bytecode.zig
@@ -239,7 +239,7 @@ pub const ByteCodeBuffer = struct {
                     fmt.printStderr("{} {} startLocal={}, numArgs={}, numRet={}, symId={}\n", &.{v(pcOffset), v(code), v(startLocal), v(numArgs), v(numRet), v(symId)});
                 },
                 .jumpNotCond => {
-                    const jump = @ptrCast(*const align(1) u16, &(pc + 1)).*;
+                    const jump = @ptrCast(*const align(1) u16, pc + 1).*;
                     fmt.printStderr("{} {} offset={}, cond={}\n", &.{v(pcOffset), v(code), v(jump), v(pc[3].arg)});
                 },
                 else => {

diff --git a/src/codegen.zig b/src/codegen.zig
@@ -6,6 +6,7 @@ const sema = cy.sema;
 const CompileChunk = cy.CompileChunk;
 const fmt = @import("fmt.zig");
 const v = fmt.v;
+const log = stdx.log.scoped(.codegen);
 
 const LocalId = u8;
 
@@ -1581,8 +1582,6 @@ fn genStatement(self: *CompileChunk, nodeId: cy.NodeId, comptime discardTopExprR
 		.return_expr_stmt => {
 			const lastArcStart = self.beginArcExpr();
 
-			self.setFirstFreeTempLocal(@intCast(u8, self.curBlock.numLocals));
-
 			if (self.blocks.items.len == 1) {
 				var val: GenValue = undefined;
 				if (self.curBlock.resolvedFuncSymId != cy.NullId) {

diff --git a/src/vm_compiler.zig b/src/vm_compiler.zig
@@ -583,6 +583,12 @@ pub const CompileChunk = struct {
         self.prevSemaSubBlock();
     }
 
+    pub fn reserveIfTempLocal(self: *CompileChunk, local: LocalId) !void {
+        if (self.isTempLocal(local)) {
+            try self.setReservedTempLocal(local);
+        }
+    }
+
     pub fn setReservedTempLocal(self: *CompileChunk, local: LocalId) !void {
         // log.debug("set reserved {}", .{self.reservedTempLocalStack.items.len});
         try self.reservedTempLocalStack.append(self.alloc, .{
@@ -613,6 +619,7 @@ pub const CompileChunk = struct {
     }
 
     /// TODO: Rename to reserveNextTempLocal.
+    /// Assumes that if `firstFreeTempLocal` is in bounds, it is free.
     pub fn nextFreeTempLocal(self: *CompileChunk) !LocalId {
         if (self.curBlock.firstFreeTempLocal < 256) {
             if (self.curBlock.firstFreeTempLocal == self.curBlock.numLocals + self.curBlock.numTempLocals) {

diff --git a/test/for_iter_test.cy b/test/for_iter_test.cy
@@ -38,4 +38,15 @@ try t.eq(sum, 5)
 list = [1, 2, 3]
 sum = 0
 for list each it: sum += it
-try t.eq(sum, 6)
+try t.eq(sum, 6)
+
+-- Return expr inside loop body.
+list = [1, 2, 3]
+f = func (arr):
+   for arr each item:
+      if item == 4:
+         return 1
+      else item == 5:
+         return 1
+   return 0
+try t.eq(f(list), 0)