From 5cc1e3450557f05d44d67beaa234b0cdd3dc2de1 Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907@163.com>
Date: Fri, 19 Aug 2022 10:24:10 +0800
Subject: [PATCH 1/9] add testcase #2447

---
 .../optional-typeparameters.debug.wat         | 146 ++++++++++++++---
 .../optional-typeparameters.release.wat       | 149 +++++++++++++-----
 tests/compiler/optional-typeparameters.ts     |  15 +-
 3 files changed, 247 insertions(+), 63 deletions(-)

diff --git a/tests/compiler/optional-typeparameters.debug.wat b/tests/compiler/optional-typeparameters.debug.wat
index b9bfe6b091..5c85c6f73d 100644
--- a/tests/compiler/optional-typeparameters.debug.wat
+++ b/tests/compiler/optional-typeparameters.debug.wat
@@ -26,10 +26,11 @@
  (global $~lib/native/ASC_LOW_MEMORY_LIMIT i32 (i32.const 0))
  (global $optional-typeparameters/tConcrete (mut i32) (i32.const 0))
  (global $optional-typeparameters/tDerived (mut i32) (i32.const 0))
+ (global $optional-typeparameters/tMethodDerived (mut i32) (i32.const 0))
  (global $~lib/rt/__rtti_base i32 (i32.const 416))
- (global $~lib/memory/__data_end i32 (i32.const 460))
- (global $~lib/memory/__stack_pointer (mut i32) (i32.const 16844))
- (global $~lib/memory/__heap_base i32 (i32.const 16844))
+ (global $~lib/memory/__data_end i32 (i32.const 476))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 16860))
+ (global $~lib/memory/__heap_base i32 (i32.const 16860))
  (memory $0 1)
  (data (i32.const 12) "<\00\00\00\00\00\00\00\00\00\00\00\01\00\00\00(\00\00\00A\00l\00l\00o\00c\00a\00t\00i\00o\00n\00 \00t\00o\00o\00 \00l\00a\00r\00g\00e\00\00\00\00\00")
  (data (i32.const 76) "<\00\00\00\00\00\00\00\00\00\00\00\01\00\00\00 \00\00\00~\00l\00i\00b\00/\00r\00t\00/\00i\00t\00c\00m\00s\00.\00t\00s\00\00\00\00\00\00\00\00\00\00\00\00\00")
@@ -39,7 +40,7 @@
  (data (i32.const 268) ",\00\00\00\00\00\00\00\00\00\00\00\01\00\00\00\14\00\00\00~\00l\00i\00b\00/\00r\00t\00.\00t\00s\00\00\00\00\00\00\00\00\00")
  (data (i32.const 320) "\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
  (data (i32.const 348) "<\00\00\00\00\00\00\00\00\00\00\00\01\00\00\00\1e\00\00\00~\00l\00i\00b\00/\00r\00t\00/\00t\00l\00s\00f\00.\00t\00s\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
- (data (i32.const 416) "\05\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\00\00\00\00\00\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00")
+ (data (i32.const 416) "\07\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\00\00\00\00\00\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\02A\00\00\00\00\00\00")
  (table $0 1 1 funcref)
  (elem $0 (i32.const 1))
  (export "memory" (memory $0))
@@ -2132,6 +2133,9 @@
   local.get $2
   f64.add
  )
+ (func $optional-typeparameters/TestMethodDerived<~lib/string/String>#test<~lib/array/Array<~lib/string/String>> (param $0 i32)
+  nop
+ )
  (func $~lib/rt/__visit_globals (param $0 i32)
   (local $1 i32)
   global.get $optional-typeparameters/tConcrete
@@ -2148,6 +2152,13 @@
    local.get $0
    call $~lib/rt/itcms/__visit
   end
+  global.get $optional-typeparameters/tMethodDerived
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
   i32.const 224
   local.get $0
   call $~lib/rt/itcms/__visit
@@ -2166,30 +2177,89 @@
    call $~lib/rt/itcms/__visit
   end
  )
+ (func $~lib/array/Array<~lib/string/String>#__visit (param $0 i32) (param $1 i32)
+  (local $2 i32)
+  (local $3 i32)
+  (local $4 i32)
+  (local $5 i32)
+  i32.const 1
+  drop
+  local.get $0
+  i32.load offset=4
+  local.set $2
+  local.get $2
+  local.get $0
+  i32.load offset=12
+  i32.const 2
+  i32.shl
+  i32.add
+  local.set $3
+  loop $while-continue|0
+   local.get $2
+   local.get $3
+   i32.lt_u
+   local.set $4
+   local.get $4
+   if
+    local.get $2
+    i32.load
+    local.set $5
+    local.get $5
+    if
+     local.get $5
+     local.get $1
+     call $~lib/rt/itcms/__visit
+    end
+    local.get $2
+    i32.const 4
+    i32.add
+    local.set $2
+    br $while-continue|0
+   end
+  end
+  local.get $0
+  i32.load
+  local.get $1
+  call $~lib/rt/itcms/__visit
+ )
+ (func $~lib/array/Array<~lib/string/String>~visit (param $0 i32) (param $1 i32)
+  local.get $0
+  local.get $1
+  call $~lib/array/Array<~lib/string/String>#__visit
+ )
  (func $~lib/rt/__visit_members (param $0 i32) (param $1 i32)
   block $invalid
-   block $optional-typeparameters/TestDerived<f64,f64>
-    block $optional-typeparameters/TestConcrete<i32,i32>
-     block $~lib/arraybuffer/ArrayBufferView
-      block $~lib/string/String
-       block $~lib/arraybuffer/ArrayBuffer
-        local.get $0
-        i32.const 8
-        i32.sub
-        i32.load
-        br_table $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $optional-typeparameters/TestConcrete<i32,i32> $optional-typeparameters/TestDerived<f64,f64> $invalid
+   block $~lib/array/Array<~lib/string/String>
+    block $optional-typeparameters/TestMethodDerived<~lib/string/String>
+     block $optional-typeparameters/TestDerived<f64,f64>
+      block $optional-typeparameters/TestConcrete<i32,i32>
+       block $~lib/arraybuffer/ArrayBufferView
+        block $~lib/string/String
+         block $~lib/arraybuffer/ArrayBuffer
+          local.get $0
+          i32.const 8
+          i32.sub
+          i32.load
+          br_table $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $optional-typeparameters/TestConcrete<i32,i32> $optional-typeparameters/TestDerived<f64,f64> $optional-typeparameters/TestMethodDerived<~lib/string/String> $~lib/array/Array<~lib/string/String> $invalid
+         end
+         return
+        end
+        return
        end
+       local.get $0
+       local.get $1
+       call $~lib/arraybuffer/ArrayBufferView~visit
        return
       end
       return
      end
-     local.get $0
-     local.get $1
-     call $~lib/arraybuffer/ArrayBufferView~visit
      return
     end
     return
    end
+   local.get $0
+   local.get $1
+   call $~lib/array/Array<~lib/string/String>~visit
    return
   end
   unreachable
@@ -2202,8 +2272,8 @@
   global.get $~lib/memory/__data_end
   i32.lt_s
   if
-   i32.const 16864
-   i32.const 16912
+   i32.const 16880
+   i32.const 16928
    i32.const 1
    i32.const 1
    call $~lib/builtins/abort
@@ -2269,6 +2339,16 @@
   f64.const 2
   call $optional-typeparameters/TestDerived<f64,f64>#test<f64>
   drop
+  i32.const 0
+  call $optional-typeparameters/TestMethodDerived<~lib/string/String>#constructor
+  global.set $optional-typeparameters/tMethodDerived
+  global.get $optional-typeparameters/tMethodDerived
+  local.set $0
+  global.get $~lib/memory/__stack_pointer
+  local.get $0
+  i32.store
+  local.get $0
+  call $optional-typeparameters/TestMethodDerived<~lib/string/String>#test<~lib/array/Array<~lib/string/String>>
   global.get $~lib/memory/__stack_pointer
   i32.const 4
   i32.add
@@ -2330,4 +2410,32 @@
   global.set $~lib/memory/__stack_pointer
   local.get $1
  )
+ (func $optional-typeparameters/TestMethodDerived<~lib/string/String>#constructor (param $0 i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  local.get $0
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 0
+   i32.const 5
+   call $~lib/rt/itcms/__new
+   local.tee $0
+   i32.store
+  end
+  local.get $0
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $1
+ )
 )
diff --git a/tests/compiler/optional-typeparameters.release.wat b/tests/compiler/optional-typeparameters.release.wat
index ddb8d5a540..fa50437e94 100644
--- a/tests/compiler/optional-typeparameters.release.wat
+++ b/tests/compiler/optional-typeparameters.release.wat
@@ -19,7 +19,8 @@
  (global $~lib/rt/tlsf/ROOT (mut i32) (i32.const 0))
  (global $optional-typeparameters/tConcrete (mut i32) (i32.const 0))
  (global $optional-typeparameters/tDerived (mut i32) (i32.const 0))
- (global $~lib/memory/__stack_pointer (mut i32) (i32.const 17868))
+ (global $optional-typeparameters/tMethodDerived (mut i32) (i32.const 0))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 17884))
  (memory $0 1)
  (data (i32.const 1036) "<")
  (data (i32.const 1048) "\01\00\00\00(\00\00\00A\00l\00l\00o\00c\00a\00t\00i\00o\00n\00 \00t\00o\00o\00 \00l\00a\00r\00g\00e")
@@ -31,8 +32,8 @@
  (data (i32.const 1304) "\01\00\00\00\14\00\00\00~\00l\00i\00b\00/\00r\00t\00.\00t\00s")
  (data (i32.const 1372) "<")
  (data (i32.const 1384) "\01\00\00\00\1e\00\00\00~\00l\00i\00b\00/\00r\00t\00/\00t\00l\00s\00f\00.\00t\00s")
- (data (i32.const 1440) "\05\00\00\00 \00\00\00\00\00\00\00 ")
- (data (i32.const 1468) " \00\00\00\00\00\00\00 ")
+ (data (i32.const 1440) "\07\00\00\00 \00\00\00\00\00\00\00 ")
+ (data (i32.const 1468) " \00\00\00\00\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\02A")
  (export "memory" (memory $0))
  (start $~start)
  (func $~lib/rt/itcms/visitRoots
@@ -50,6 +51,12 @@
    local.get $0
    call $byn-split-outlined-A$~lib/rt/itcms/__visit
   end
+  global.get $optional-typeparameters/tMethodDerived
+  local.tee $0
+  if
+   local.get $0
+   call $byn-split-outlined-A$~lib/rt/itcms/__visit
+  end
   i32.const 1248
   call $byn-split-outlined-A$~lib/rt/itcms/__visit
   i32.const 1056
@@ -623,10 +630,10 @@
   if
    unreachable
   end
-  i32.const 17872
+  i32.const 17888
   i32.const 0
   i32.store
-  i32.const 19440
+  i32.const 19456
   i32.const 0
   i32.store
   loop $for-loop|0
@@ -637,7 +644,7 @@
     local.get $0
     i32.const 2
     i32.shl
-    i32.const 17872
+    i32.const 17888
     i32.add
     i32.const 0
     i32.store offset=4
@@ -655,7 +662,7 @@
       i32.add
       i32.const 2
       i32.shl
-      i32.const 17872
+      i32.const 17888
       i32.add
       i32.const 0
       i32.store offset=96
@@ -673,13 +680,13 @@
     br $for-loop|0
    end
   end
-  i32.const 17872
-  i32.const 19444
+  i32.const 17888
+  i32.const 19460
   memory.size
   i32.const 16
   i32.shl
   call $~lib/rt/tlsf/addMemory
-  i32.const 17872
+  i32.const 17888
   global.set $~lib/rt/tlsf/ROOT
  )
  (func $~lib/rt/itcms/step (result i32)
@@ -764,7 +771,7 @@
      local.set $0
      loop $while-continue|0
       local.get $0
-      i32.const 17868
+      i32.const 17884
       i32.lt_u
       if
        local.get $0
@@ -864,7 +871,7 @@
      unreachable
     end
     local.get $0
-    i32.const 17868
+    i32.const 17884
     i32.lt_u
     if
      local.get $0
@@ -887,7 +894,7 @@
      i32.const 4
      i32.add
      local.tee $0
-     i32.const 17868
+     i32.const 17884
      i32.ge_u
      if
       global.get $~lib/rt/tlsf/ROOT
@@ -1240,36 +1247,72 @@
   local.get $0
  )
  (func $~lib/rt/__visit_members (param $0 i32)
-  block $invalid
-   block $optional-typeparameters/TestDerived<f64,f64>
-    block $optional-typeparameters/TestConcrete<i32,i32>
-     block $~lib/arraybuffer/ArrayBufferView
-      block $~lib/string/String
-       block $~lib/arraybuffer/ArrayBuffer
-        local.get $0
-        i32.const 8
-        i32.sub
-        i32.load
-        br_table $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $optional-typeparameters/TestConcrete<i32,i32> $optional-typeparameters/TestDerived<f64,f64> $invalid
+  (local $1 i32)
+  (local $2 i32)
+  (local $3 i32)
+  block $folding-inner0
+   block $invalid
+    block $~lib/array/Array<~lib/string/String>
+     block $optional-typeparameters/TestMethodDerived<~lib/string/String>
+      block $optional-typeparameters/TestDerived<f64,f64>
+       block $optional-typeparameters/TestConcrete<i32,i32>
+        block $~lib/string/String
+         block $~lib/arraybuffer/ArrayBuffer
+          local.get $0
+          i32.const 8
+          i32.sub
+          i32.load
+          br_table $~lib/arraybuffer/ArrayBuffer $~lib/string/String $folding-inner0 $optional-typeparameters/TestConcrete<i32,i32> $optional-typeparameters/TestDerived<f64,f64> $optional-typeparameters/TestMethodDerived<~lib/string/String> $~lib/array/Array<~lib/string/String> $invalid
+         end
+         return
+        end
+        return
        end
        return
       end
       return
      end
-     local.get $0
-     i32.load
-     local.tee $0
+     return
+    end
+    local.get $0
+    i32.load offset=4
+    local.tee $1
+    local.get $0
+    i32.load offset=12
+    i32.const 2
+    i32.shl
+    i32.add
+    local.set $3
+    loop $while-continue|0
+     local.get $1
+     local.get $3
+     i32.lt_u
      if
-      local.get $0
-      call $byn-split-outlined-A$~lib/rt/itcms/__visit
+      local.get $1
+      i32.load
+      local.tee $2
+      if
+       local.get $2
+       call $byn-split-outlined-A$~lib/rt/itcms/__visit
+      end
+      local.get $1
+      i32.const 4
+      i32.add
+      local.set $1
+      br $while-continue|0
      end
-     return
     end
-    return
+    br $folding-inner0
    end
-   return
+   unreachable
+  end
+  local.get $0
+  i32.load
+  local.tee $0
+  if
+   local.get $0
+   call $byn-split-outlined-A$~lib/rt/itcms/__visit
   end
-  unreachable
  )
  (func $~start
   (local $0 i32)
@@ -1279,7 +1322,7 @@
   global.set $~lib/memory/__stack_pointer
   block $folding-inner0
    global.get $~lib/memory/__stack_pointer
-   i32.const 1484
+   i32.const 1500
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1289,7 +1332,7 @@
    memory.size
    i32.const 16
    i32.shl
-   i32.const 17868
+   i32.const 17884
    i32.sub
    i32.const 1
    i32.shr_u
@@ -1323,7 +1366,7 @@
    i32.sub
    global.set $~lib/memory/__stack_pointer
    global.get $~lib/memory/__stack_pointer
-   i32.const 1484
+   i32.const 1500
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1349,7 +1392,7 @@
    i32.sub
    global.set $~lib/memory/__stack_pointer
    global.get $~lib/memory/__stack_pointer
-   i32.const 1484
+   i32.const 1500
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1372,12 +1415,38 @@
    i32.store
    global.get $~lib/memory/__stack_pointer
    i32.const 4
+   i32.sub
+   global.set $~lib/memory/__stack_pointer
+   global.get $~lib/memory/__stack_pointer
+   i32.const 1500
+   i32.lt_s
+   br_if $folding-inner0
+   global.get $~lib/memory/__stack_pointer
+   local.tee $0
+   i32.const 0
+   i32.store
+   local.get $0
+   i32.const 5
+   call $~lib/rt/itcms/__new
+   local.tee $0
+   i32.store
+   global.get $~lib/memory/__stack_pointer
+   i32.const 4
+   i32.add
+   global.set $~lib/memory/__stack_pointer
+   local.get $0
+   global.set $optional-typeparameters/tMethodDerived
+   global.get $~lib/memory/__stack_pointer
+   global.get $optional-typeparameters/tMethodDerived
+   i32.store
+   global.get $~lib/memory/__stack_pointer
+   i32.const 4
    i32.add
    global.set $~lib/memory/__stack_pointer
    return
   end
-  i32.const 17888
-  i32.const 17936
+  i32.const 17904
+  i32.const 17952
   i32.const 1
   i32.const 1
   call $~lib/builtins/abort
@@ -1426,7 +1495,7 @@
     if
      i32.const 0
      local.get $1
-     i32.const 17868
+     i32.const 17884
      i32.lt_u
      local.get $1
      i32.load offset=8
diff --git a/tests/compiler/optional-typeparameters.ts b/tests/compiler/optional-typeparameters.ts
index a726b28f4a..8fbf479197 100644
--- a/tests/compiler/optional-typeparameters.ts
+++ b/tests/compiler/optional-typeparameters.ts
@@ -1,21 +1,21 @@
-function testConcrete<T,U = i32>(a: T): U {
+function testConcrete<T, U = i32>(a: T): U {
   return a;
 }
 
-function testDerived<T,U = T>(a: T): U {
+function testDerived<T, U = T>(a: T): U {
   return a;
 }
 
 testConcrete<i32>(1);
 testDerived<i32>(2);
 
-class TestConcrete<T,U = i32> {
+class TestConcrete<T, U = i32> {
   test<V = i32>(a: T, b: U): V {
     return a + b;
   }
 }
 
-class TestDerived<T,U = T> {
+class TestDerived<T, U = T> {
   test<V = U>(a: T, b: U): V {
     return a + b;
   }
@@ -25,3 +25,10 @@ var tConcrete = new TestConcrete<i32>();
 tConcrete.test<i32>(1, 2);
 var tDerived = new TestDerived<f64>();
 tDerived.test<f64>(1, 2);
+
+class TestMethodDerived<T> {
+  test<U = T[]>(): void {}
+}
+
+var tMethodDerived = new TestMethodDerived<string>();
+tMethodDerived.test();

From e97a88fa4bb949e78efb988562c4502e8b756d17 Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907@163.com>
Date: Fri, 19 Aug 2022 10:28:59 +0800
Subject: [PATCH 2/9] fix: fix `resolveNamedType` cannot resolve type parameter
 in contextual element

---
 src/program.ts  | 24 ++++++++++++++++++++++++
 src/resolver.ts |  9 +++++++--
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/src/program.ts b/src/program.ts
index 5d47d44b88..43a43dc45e 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -2841,6 +2841,10 @@ export abstract class Element {
     return this.parent.lookup(name, isType);
   }
 
+  lookupGenericType(name: string): Type | null {
+    return this.parent.lookupGenericType(name);
+  }
+
   /** Adds an element as a member of this one. Reports and returns `false` if a duplicate. */
   add(name: string, element: DeclaredElement, localIdentifierIfImport: IdentifierExpression | null = null): bool {
     var originalDeclaration = element.declaration;
@@ -3124,6 +3128,10 @@ export class File extends Element {
     return this.program.lookup(name); // has no meaningful parent
   }
 
+  override lookupGenericType(name: string): Type | null {
+    return null;
+  }
+
   /** Ensures that an element is an export of this file. */
   ensureExport(name: string, element: DeclaredElement): void {
     var exports = this.exports;
@@ -3687,6 +3695,14 @@ export class Function extends TypedElement {
     registerConcreteElement(program, this);
   }
 
+  override lookupGenericType(name: string): Type | null {
+    let contextualTypeArguments = this.contextualTypeArguments;
+    if (contextualTypeArguments && contextualTypeArguments.has(name)) {
+      return assert(contextualTypeArguments.get(name));
+    }
+    return this.parent.lookupGenericType(name);
+  }
+
   /** Gets the name of the parameter at the specified index. */
   getParameterName(index: i32): string {
     var parameters = (<FunctionDeclaration>this.declaration).signature.parameters;
@@ -4297,6 +4313,14 @@ export class Class extends TypedElement {
     registerConcreteElement(program, this);
   }
 
+  override lookupGenericType(name: string): Type | null {
+    let contextualTypeArguments = this.contextualTypeArguments;
+    if (contextualTypeArguments && contextualTypeArguments.has(name)) {
+      return assert(contextualTypeArguments.get(name));
+    }
+    return this.parent.lookupGenericType(name);
+  }
+
   /** Sets the base class. */
   setBase(base: Class): void {
     assert(!this.base);
diff --git a/src/resolver.ts b/src/resolver.ts
index 5a19f8e152..fb61c38963 100644
--- a/src/resolver.ts
+++ b/src/resolver.ts
@@ -188,8 +188,13 @@ export class Resolver extends DiagnosticEmitter {
     // Look up in contextual types if a simple type
     if (isSimpleType) {
       let simpleName = nameNode.identifier.text;
+      let type: Type | null = null;
       if (ctxTypes && ctxTypes.has(simpleName)) {
-        let type = assert(ctxTypes.get(simpleName));
+        type = assert(ctxTypes.get(simpleName));
+      } else {
+        type = ctxElement.lookupGenericType(simpleName);
+      }
+      if (type) {
         if (typeArgumentNodes && typeArgumentNodes.length > 0) {
           if (reportMode == ReportMode.REPORT) {
             this.error(
@@ -763,7 +768,7 @@ export class Resolver extends DiagnosticEmitter {
           }
           let defaultType = typeParameterNode.defaultType;
           if (defaultType) {
-            let resolvedDefaultType = this.resolveType(defaultType, ctxFlow.actualFunction, contextualTypeArguments, reportMode);
+            let resolvedDefaultType = this.resolveType(defaultType, prototype, contextualTypeArguments, reportMode);
             if (!resolvedDefaultType) return null;
             resolvedTypeArguments[i] = resolvedDefaultType;
             continue;

From 749140c9d55db5754d38d7af75296b0dfa0bbf1d Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907@163.com>
Date: Fri, 19 Aug 2022 10:47:28 +0800
Subject: [PATCH 3/9] fix bootstrap

---
 src/program.ts | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/program.ts b/src/program.ts
index 43a43dc45e..0085d95aa1 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -3128,7 +3128,8 @@ export class File extends Element {
     return this.program.lookup(name); // has no meaningful parent
   }
 
-  override lookupGenericType(name: string): Type | null {
+  /* @override */
+  lookupGenericType(name: string): Type | null {
     return null;
   }
 
@@ -3695,12 +3696,13 @@ export class Function extends TypedElement {
     registerConcreteElement(program, this);
   }
 
-  override lookupGenericType(name: string): Type | null {
+  /* @override */
+  lookupGenericType(name: string): Type | null {
     let contextualTypeArguments = this.contextualTypeArguments;
     if (contextualTypeArguments && contextualTypeArguments.has(name)) {
       return assert(contextualTypeArguments.get(name));
     }
-    return this.parent.lookupGenericType(name);
+    return super.lookupGenericType(name);
   }
 
   /** Gets the name of the parameter at the specified index. */
@@ -4313,12 +4315,13 @@ export class Class extends TypedElement {
     registerConcreteElement(program, this);
   }
 
-  override lookupGenericType(name: string): Type | null {
+  /* @override */
+  lookupGenericType(name: string): Type | null {
     let contextualTypeArguments = this.contextualTypeArguments;
     if (contextualTypeArguments && contextualTypeArguments.has(name)) {
       return assert(contextualTypeArguments.get(name));
     }
-    return this.parent.lookupGenericType(name);
+    return super.lookupGenericType(name);
   }
 
   /** Sets the base class. */

From b0bb7c485cfd87f5a2d0ebff8ea410774ff952ac Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907@163.com>
Date: Sun, 21 Aug 2022 07:51:13 +0800
Subject: [PATCH 4/9] Revert "fix bootstrap"

This reverts commit 749140c9d55db5754d38d7af75296b0dfa0bbf1d.
---
 src/program.ts | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/src/program.ts b/src/program.ts
index 0085d95aa1..43a43dc45e 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -3128,8 +3128,7 @@ export class File extends Element {
     return this.program.lookup(name); // has no meaningful parent
   }
 
-  /* @override */
-  lookupGenericType(name: string): Type | null {
+  override lookupGenericType(name: string): Type | null {
     return null;
   }
 
@@ -3696,13 +3695,12 @@ export class Function extends TypedElement {
     registerConcreteElement(program, this);
   }
 
-  /* @override */
-  lookupGenericType(name: string): Type | null {
+  override lookupGenericType(name: string): Type | null {
     let contextualTypeArguments = this.contextualTypeArguments;
     if (contextualTypeArguments && contextualTypeArguments.has(name)) {
       return assert(contextualTypeArguments.get(name));
     }
-    return super.lookupGenericType(name);
+    return this.parent.lookupGenericType(name);
   }
 
   /** Gets the name of the parameter at the specified index. */
@@ -4315,13 +4313,12 @@ export class Class extends TypedElement {
     registerConcreteElement(program, this);
   }
 
-  /* @override */
-  lookupGenericType(name: string): Type | null {
+  override lookupGenericType(name: string): Type | null {
     let contextualTypeArguments = this.contextualTypeArguments;
     if (contextualTypeArguments && contextualTypeArguments.has(name)) {
       return assert(contextualTypeArguments.get(name));
     }
-    return super.lookupGenericType(name);
+    return this.parent.lookupGenericType(name);
   }
 
   /** Sets the base class. */

From 4ffbfb6beda1ec3e9cc893edbbad44c605c4e339 Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907@163.com>
Date: Sun, 21 Aug 2022 07:51:54 +0800
Subject: [PATCH 5/9] Revert "fix: fix `resolveNamedType` cannot resolve type
 parameter in contextual element"

This reverts commit e97a88fa4bb949e78efb988562c4502e8b756d17.
---
 src/program.ts  | 24 ------------------------
 src/resolver.ts |  9 ++-------
 2 files changed, 2 insertions(+), 31 deletions(-)

diff --git a/src/program.ts b/src/program.ts
index 43a43dc45e..5d47d44b88 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -2841,10 +2841,6 @@ export abstract class Element {
     return this.parent.lookup(name, isType);
   }
 
-  lookupGenericType(name: string): Type | null {
-    return this.parent.lookupGenericType(name);
-  }
-
   /** Adds an element as a member of this one. Reports and returns `false` if a duplicate. */
   add(name: string, element: DeclaredElement, localIdentifierIfImport: IdentifierExpression | null = null): bool {
     var originalDeclaration = element.declaration;
@@ -3128,10 +3124,6 @@ export class File extends Element {
     return this.program.lookup(name); // has no meaningful parent
   }
 
-  override lookupGenericType(name: string): Type | null {
-    return null;
-  }
-
   /** Ensures that an element is an export of this file. */
   ensureExport(name: string, element: DeclaredElement): void {
     var exports = this.exports;
@@ -3695,14 +3687,6 @@ export class Function extends TypedElement {
     registerConcreteElement(program, this);
   }
 
-  override lookupGenericType(name: string): Type | null {
-    let contextualTypeArguments = this.contextualTypeArguments;
-    if (contextualTypeArguments && contextualTypeArguments.has(name)) {
-      return assert(contextualTypeArguments.get(name));
-    }
-    return this.parent.lookupGenericType(name);
-  }
-
   /** Gets the name of the parameter at the specified index. */
   getParameterName(index: i32): string {
     var parameters = (<FunctionDeclaration>this.declaration).signature.parameters;
@@ -4313,14 +4297,6 @@ export class Class extends TypedElement {
     registerConcreteElement(program, this);
   }
 
-  override lookupGenericType(name: string): Type | null {
-    let contextualTypeArguments = this.contextualTypeArguments;
-    if (contextualTypeArguments && contextualTypeArguments.has(name)) {
-      return assert(contextualTypeArguments.get(name));
-    }
-    return this.parent.lookupGenericType(name);
-  }
-
   /** Sets the base class. */
   setBase(base: Class): void {
     assert(!this.base);
diff --git a/src/resolver.ts b/src/resolver.ts
index fb61c38963..5a19f8e152 100644
--- a/src/resolver.ts
+++ b/src/resolver.ts
@@ -188,13 +188,8 @@ export class Resolver extends DiagnosticEmitter {
     // Look up in contextual types if a simple type
     if (isSimpleType) {
       let simpleName = nameNode.identifier.text;
-      let type: Type | null = null;
       if (ctxTypes && ctxTypes.has(simpleName)) {
-        type = assert(ctxTypes.get(simpleName));
-      } else {
-        type = ctxElement.lookupGenericType(simpleName);
-      }
-      if (type) {
+        let type = assert(ctxTypes.get(simpleName));
         if (typeArgumentNodes && typeArgumentNodes.length > 0) {
           if (reportMode == ReportMode.REPORT) {
             this.error(
@@ -768,7 +763,7 @@ export class Resolver extends DiagnosticEmitter {
           }
           let defaultType = typeParameterNode.defaultType;
           if (defaultType) {
-            let resolvedDefaultType = this.resolveType(defaultType, prototype, contextualTypeArguments, reportMode);
+            let resolvedDefaultType = this.resolveType(defaultType, ctxFlow.actualFunction, contextualTypeArguments, reportMode);
             if (!resolvedDefaultType) return null;
             resolvedTypeArguments[i] = resolvedDefaultType;
             continue;

From 2ebefe597210703a002851aa638530dbc5f682ed Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907@163.com>
Date: Sun, 21 Aug 2022 08:00:46 +0800
Subject: [PATCH 6/9] use callee ctx to infer default type

---
 src/resolver.ts | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/resolver.ts b/src/resolver.ts
index 5a19f8e152..159e200a77 100644
--- a/src/resolver.ts
+++ b/src/resolver.ts
@@ -763,7 +763,13 @@ export class Resolver extends DiagnosticEmitter {
           }
           let defaultType = typeParameterNode.defaultType;
           if (defaultType) {
-            let resolvedDefaultType = this.resolveType(defaultType, ctxFlow.actualFunction, contextualTypeArguments, reportMode);
+            let defaultTypeContextualTypeArguments: Map<string, Type> | null = null;
+            if (prototype.parent.kind == ElementKind.CLASS) {
+              defaultTypeContextualTypeArguments = (<Class>prototype.parent).contextualTypeArguments;
+            } else if (prototype.parent.kind == ElementKind.FUNCTION) {
+              defaultTypeContextualTypeArguments = (<Function>prototype.parent).contextualTypeArguments;
+            } 
+            let resolvedDefaultType = this.resolveType(defaultType, prototype, defaultTypeContextualTypeArguments, reportMode);
             if (!resolvedDefaultType) return null;
             resolvedTypeArguments[i] = resolvedDefaultType;
             continue;

From 277318d5d1e3422e1b7e9eca6b564ac819240094 Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907@163.com>
Date: Sun, 21 Aug 2022 08:22:44 +0800
Subject: [PATCH 7/9] add testcase

---
 .../optional-typeparameters.debug.wat         | 120 +++++++++----
 .../optional-typeparameters.release.wat       | 161 +++++++++++-------
 tests/compiler/optional-typeparameters.ts     |  11 +-
 3 files changed, 201 insertions(+), 91 deletions(-)

diff --git a/tests/compiler/optional-typeparameters.debug.wat b/tests/compiler/optional-typeparameters.debug.wat
index 5c85c6f73d..fc9f68cd86 100644
--- a/tests/compiler/optional-typeparameters.debug.wat
+++ b/tests/compiler/optional-typeparameters.debug.wat
@@ -27,10 +27,11 @@
  (global $optional-typeparameters/tConcrete (mut i32) (i32.const 0))
  (global $optional-typeparameters/tDerived (mut i32) (i32.const 0))
  (global $optional-typeparameters/tMethodDerived (mut i32) (i32.const 0))
+ (global $optional-typeparameters/tMethodDerived2 (mut i32) (i32.const 0))
  (global $~lib/rt/__rtti_base i32 (i32.const 416))
- (global $~lib/memory/__data_end i32 (i32.const 476))
- (global $~lib/memory/__stack_pointer (mut i32) (i32.const 16860))
- (global $~lib/memory/__heap_base i32 (i32.const 16860))
+ (global $~lib/memory/__data_end i32 (i32.const 484))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 16868))
+ (global $~lib/memory/__heap_base i32 (i32.const 16868))
  (memory $0 1)
  (data (i32.const 12) "<\00\00\00\00\00\00\00\00\00\00\00\01\00\00\00(\00\00\00A\00l\00l\00o\00c\00a\00t\00i\00o\00n\00 \00t\00o\00o\00 \00l\00a\00r\00g\00e\00\00\00\00\00")
  (data (i32.const 76) "<\00\00\00\00\00\00\00\00\00\00\00\01\00\00\00 \00\00\00~\00l\00i\00b\00/\00r\00t\00/\00i\00t\00c\00m\00s\00.\00t\00s\00\00\00\00\00\00\00\00\00\00\00\00\00")
@@ -40,7 +41,7 @@
  (data (i32.const 268) ",\00\00\00\00\00\00\00\00\00\00\00\01\00\00\00\14\00\00\00~\00l\00i\00b\00/\00r\00t\00.\00t\00s\00\00\00\00\00\00\00\00\00")
  (data (i32.const 320) "\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
  (data (i32.const 348) "<\00\00\00\00\00\00\00\00\00\00\00\01\00\00\00\1e\00\00\00~\00l\00i\00b\00/\00r\00t\00/\00t\00l\00s\00f\00.\00t\00s\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
- (data (i32.const 416) "\07\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\00\00\00\00\00\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\02A\00\00\00\00\00\00")
+ (data (i32.const 416) "\08\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\00\00\00\00\00\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\02A\00\00\00\00\00\00 \00\00\00\00\00\00\00")
  (table $0 1 1 funcref)
  (elem $0 (i32.const 1))
  (export "memory" (memory $0))
@@ -2134,7 +2135,14 @@
   f64.add
  )
  (func $optional-typeparameters/TestMethodDerived<~lib/string/String>#test<~lib/array/Array<~lib/string/String>> (param $0 i32)
-  nop
+  i32.const 6
+  i32.const 6
+  i32.eq
+  drop
+ )
+ (func $optional-typeparameters/TestMethodDerived2<f64>#foo (param $0 i32) (param $1 i32)
+  local.get $1
+  call $optional-typeparameters/TestMethodDerived<~lib/string/String>#test<~lib/array/Array<~lib/string/String>>
  )
  (func $~lib/rt/__visit_globals (param $0 i32)
   (local $1 i32)
@@ -2159,6 +2167,13 @@
    local.get $0
    call $~lib/rt/itcms/__visit
   end
+  global.get $optional-typeparameters/tMethodDerived2
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
   i32.const 224
   local.get $0
   call $~lib/rt/itcms/__visit
@@ -2229,37 +2244,40 @@
  )
  (func $~lib/rt/__visit_members (param $0 i32) (param $1 i32)
   block $invalid
-   block $~lib/array/Array<~lib/string/String>
-    block $optional-typeparameters/TestMethodDerived<~lib/string/String>
-     block $optional-typeparameters/TestDerived<f64,f64>
-      block $optional-typeparameters/TestConcrete<i32,i32>
-       block $~lib/arraybuffer/ArrayBufferView
-        block $~lib/string/String
-         block $~lib/arraybuffer/ArrayBuffer
-          local.get $0
-          i32.const 8
-          i32.sub
-          i32.load
-          br_table $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $optional-typeparameters/TestConcrete<i32,i32> $optional-typeparameters/TestDerived<f64,f64> $optional-typeparameters/TestMethodDerived<~lib/string/String> $~lib/array/Array<~lib/string/String> $invalid
+   block $optional-typeparameters/TestMethodDerived2<f64>
+    block $~lib/array/Array<~lib/string/String>
+     block $optional-typeparameters/TestMethodDerived<~lib/string/String>
+      block $optional-typeparameters/TestDerived<f64,f64>
+       block $optional-typeparameters/TestConcrete<i32,i32>
+        block $~lib/arraybuffer/ArrayBufferView
+         block $~lib/string/String
+          block $~lib/arraybuffer/ArrayBuffer
+           local.get $0
+           i32.const 8
+           i32.sub
+           i32.load
+           br_table $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $optional-typeparameters/TestConcrete<i32,i32> $optional-typeparameters/TestDerived<f64,f64> $optional-typeparameters/TestMethodDerived<~lib/string/String> $~lib/array/Array<~lib/string/String> $optional-typeparameters/TestMethodDerived2<f64> $invalid
+          end
+          return
          end
          return
         end
+        local.get $0
+        local.get $1
+        call $~lib/arraybuffer/ArrayBufferView~visit
         return
        end
-       local.get $0
-       local.get $1
-       call $~lib/arraybuffer/ArrayBufferView~visit
        return
       end
       return
      end
      return
     end
+    local.get $0
+    local.get $1
+    call $~lib/array/Array<~lib/string/String>~visit
     return
    end
-   local.get $0
-   local.get $1
-   call $~lib/array/Array<~lib/string/String>~visit
    return
   end
   unreachable
@@ -2272,8 +2290,8 @@
   global.get $~lib/memory/__data_end
   i32.lt_s
   if
-   i32.const 16880
-   i32.const 16928
+   i32.const 16896
+   i32.const 16944
    i32.const 1
    i32.const 1
    call $~lib/builtins/abort
@@ -2283,13 +2301,13 @@
  (func $start:optional-typeparameters
   (local $0 i32)
   global.get $~lib/memory/__stack_pointer
-  i32.const 4
+  i32.const 8
   i32.sub
   global.set $~lib/memory/__stack_pointer
   call $~stack_check
   global.get $~lib/memory/__stack_pointer
-  i32.const 0
-  i32.store
+  i64.const 0
+  i64.store
   i32.const 1
   call $optional-typeparameters/testConcrete<i32,i32>
   drop
@@ -2349,8 +2367,24 @@
   i32.store
   local.get $0
   call $optional-typeparameters/TestMethodDerived<~lib/string/String>#test<~lib/array/Array<~lib/string/String>>
+  i32.const 0
+  call $optional-typeparameters/TestMethodDerived2<f64>#constructor
+  global.set $optional-typeparameters/tMethodDerived2
+  global.get $optional-typeparameters/tMethodDerived2
+  local.set $0
   global.get $~lib/memory/__stack_pointer
-  i32.const 4
+  local.get $0
+  i32.store
+  local.get $0
+  global.get $optional-typeparameters/tMethodDerived
+  local.set $0
+  global.get $~lib/memory/__stack_pointer
+  local.get $0
+  i32.store offset=4
+  local.get $0
+  call $optional-typeparameters/TestMethodDerived2<f64>#foo
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
   i32.add
   global.set $~lib/memory/__stack_pointer
  )
@@ -2438,4 +2472,32 @@
   global.set $~lib/memory/__stack_pointer
   local.get $1
  )
+ (func $optional-typeparameters/TestMethodDerived2<f64>#constructor (param $0 i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  local.get $0
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 0
+   i32.const 7
+   call $~lib/rt/itcms/__new
+   local.tee $0
+   i32.store
+  end
+  local.get $0
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $1
+ )
 )
diff --git a/tests/compiler/optional-typeparameters.release.wat b/tests/compiler/optional-typeparameters.release.wat
index fa50437e94..f8d4bdf5dd 100644
--- a/tests/compiler/optional-typeparameters.release.wat
+++ b/tests/compiler/optional-typeparameters.release.wat
@@ -20,7 +20,8 @@
  (global $optional-typeparameters/tConcrete (mut i32) (i32.const 0))
  (global $optional-typeparameters/tDerived (mut i32) (i32.const 0))
  (global $optional-typeparameters/tMethodDerived (mut i32) (i32.const 0))
- (global $~lib/memory/__stack_pointer (mut i32) (i32.const 17884))
+ (global $optional-typeparameters/tMethodDerived2 (mut i32) (i32.const 0))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 17892))
  (memory $0 1)
  (data (i32.const 1036) "<")
  (data (i32.const 1048) "\01\00\00\00(\00\00\00A\00l\00l\00o\00c\00a\00t\00i\00o\00n\00 \00t\00o\00o\00 \00l\00a\00r\00g\00e")
@@ -32,8 +33,8 @@
  (data (i32.const 1304) "\01\00\00\00\14\00\00\00~\00l\00i\00b\00/\00r\00t\00.\00t\00s")
  (data (i32.const 1372) "<")
  (data (i32.const 1384) "\01\00\00\00\1e\00\00\00~\00l\00i\00b\00/\00r\00t\00/\00t\00l\00s\00f\00.\00t\00s")
- (data (i32.const 1440) "\07\00\00\00 \00\00\00\00\00\00\00 ")
- (data (i32.const 1468) " \00\00\00\00\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\02A")
+ (data (i32.const 1440) "\08\00\00\00 \00\00\00\00\00\00\00 ")
+ (data (i32.const 1468) " \00\00\00\00\00\00\00 \00\00\00\00\00\00\00 \00\00\00\00\00\00\00\02A\00\00\00\00\00\00 ")
  (export "memory" (memory $0))
  (start $~start)
  (func $~lib/rt/itcms/visitRoots
@@ -57,6 +58,12 @@
    local.get $0
    call $byn-split-outlined-A$~lib/rt/itcms/__visit
   end
+  global.get $optional-typeparameters/tMethodDerived2
+  local.tee $0
+  if
+   local.get $0
+   call $byn-split-outlined-A$~lib/rt/itcms/__visit
+  end
   i32.const 1248
   call $byn-split-outlined-A$~lib/rt/itcms/__visit
   i32.const 1056
@@ -630,10 +637,10 @@
   if
    unreachable
   end
-  i32.const 17888
+  i32.const 17904
   i32.const 0
   i32.store
-  i32.const 19456
+  i32.const 19472
   i32.const 0
   i32.store
   loop $for-loop|0
@@ -644,7 +651,7 @@
     local.get $0
     i32.const 2
     i32.shl
-    i32.const 17888
+    i32.const 17904
     i32.add
     i32.const 0
     i32.store offset=4
@@ -662,7 +669,7 @@
       i32.add
       i32.const 2
       i32.shl
-      i32.const 17888
+      i32.const 17904
       i32.add
       i32.const 0
       i32.store offset=96
@@ -680,13 +687,13 @@
     br $for-loop|0
    end
   end
-  i32.const 17888
-  i32.const 19460
+  i32.const 17904
+  i32.const 19476
   memory.size
   i32.const 16
   i32.shl
   call $~lib/rt/tlsf/addMemory
-  i32.const 17888
+  i32.const 17904
   global.set $~lib/rt/tlsf/ROOT
  )
  (func $~lib/rt/itcms/step (result i32)
@@ -771,7 +778,7 @@
      local.set $0
      loop $while-continue|0
       local.get $0
-      i32.const 17884
+      i32.const 17892
       i32.lt_u
       if
        local.get $0
@@ -871,7 +878,7 @@
      unreachable
     end
     local.get $0
-    i32.const 17884
+    i32.const 17892
     i32.lt_u
     if
      local.get $0
@@ -894,7 +901,7 @@
      i32.const 4
      i32.add
      local.tee $0
-     i32.const 17884
+     i32.const 17892
      i32.ge_u
      if
       global.get $~lib/rt/tlsf/ROOT
@@ -1252,17 +1259,20 @@
   (local $3 i32)
   block $folding-inner0
    block $invalid
-    block $~lib/array/Array<~lib/string/String>
-     block $optional-typeparameters/TestMethodDerived<~lib/string/String>
-      block $optional-typeparameters/TestDerived<f64,f64>
-       block $optional-typeparameters/TestConcrete<i32,i32>
-        block $~lib/string/String
-         block $~lib/arraybuffer/ArrayBuffer
-          local.get $0
-          i32.const 8
-          i32.sub
-          i32.load
-          br_table $~lib/arraybuffer/ArrayBuffer $~lib/string/String $folding-inner0 $optional-typeparameters/TestConcrete<i32,i32> $optional-typeparameters/TestDerived<f64,f64> $optional-typeparameters/TestMethodDerived<~lib/string/String> $~lib/array/Array<~lib/string/String> $invalid
+    block $optional-typeparameters/TestMethodDerived2<f64>
+     block $~lib/array/Array<~lib/string/String>
+      block $optional-typeparameters/TestMethodDerived<~lib/string/String>
+       block $optional-typeparameters/TestDerived<f64,f64>
+        block $optional-typeparameters/TestConcrete<i32,i32>
+         block $~lib/string/String
+          block $~lib/arraybuffer/ArrayBuffer
+           local.get $0
+           i32.const 8
+           i32.sub
+           i32.load
+           br_table $~lib/arraybuffer/ArrayBuffer $~lib/string/String $folding-inner0 $optional-typeparameters/TestConcrete<i32,i32> $optional-typeparameters/TestDerived<f64,f64> $optional-typeparameters/TestMethodDerived<~lib/string/String> $~lib/array/Array<~lib/string/String> $optional-typeparameters/TestMethodDerived2<f64> $invalid
+          end
+          return
          end
          return
         end
@@ -1272,37 +1282,37 @@
       end
       return
      end
-     return
-    end
-    local.get $0
-    i32.load offset=4
-    local.tee $1
-    local.get $0
-    i32.load offset=12
-    i32.const 2
-    i32.shl
-    i32.add
-    local.set $3
-    loop $while-continue|0
-     local.get $1
-     local.get $3
-     i32.lt_u
-     if
+     local.get $0
+     i32.load offset=4
+     local.tee $1
+     local.get $0
+     i32.load offset=12
+     i32.const 2
+     i32.shl
+     i32.add
+     local.set $3
+     loop $while-continue|0
       local.get $1
-      i32.load
-      local.tee $2
+      local.get $3
+      i32.lt_u
       if
-       local.get $2
-       call $byn-split-outlined-A$~lib/rt/itcms/__visit
+       local.get $1
+       i32.load
+       local.tee $2
+       if
+        local.get $2
+        call $byn-split-outlined-A$~lib/rt/itcms/__visit
+       end
+       local.get $1
+       i32.const 4
+       i32.add
+       local.set $1
+       br $while-continue|0
       end
-      local.get $1
-      i32.const 4
-      i32.add
-      local.set $1
-      br $while-continue|0
      end
+     br $folding-inner0
     end
-    br $folding-inner0
+    return
    end
    unreachable
   end
@@ -1317,22 +1327,22 @@
  (func $~start
   (local $0 i32)
   global.get $~lib/memory/__stack_pointer
-  i32.const 4
+  i32.const 8
   i32.sub
   global.set $~lib/memory/__stack_pointer
   block $folding-inner0
    global.get $~lib/memory/__stack_pointer
-   i32.const 1500
+   i32.const 1508
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
    local.tee $0
-   i32.const 0
-   i32.store
+   i64.const 0
+   i64.store
    memory.size
    i32.const 16
    i32.shl
-   i32.const 17884
+   i32.const 17892
    i32.sub
    i32.const 1
    i32.shr_u
@@ -1366,7 +1376,7 @@
    i32.sub
    global.set $~lib/memory/__stack_pointer
    global.get $~lib/memory/__stack_pointer
-   i32.const 1500
+   i32.const 1508
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1392,7 +1402,7 @@
    i32.sub
    global.set $~lib/memory/__stack_pointer
    global.get $~lib/memory/__stack_pointer
-   i32.const 1500
+   i32.const 1508
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1418,7 +1428,7 @@
    i32.sub
    global.set $~lib/memory/__stack_pointer
    global.get $~lib/memory/__stack_pointer
-   i32.const 1500
+   i32.const 1508
    i32.lt_s
    br_if $folding-inner0
    global.get $~lib/memory/__stack_pointer
@@ -1441,12 +1451,41 @@
    i32.store
    global.get $~lib/memory/__stack_pointer
    i32.const 4
+   i32.sub
+   global.set $~lib/memory/__stack_pointer
+   global.get $~lib/memory/__stack_pointer
+   i32.const 1508
+   i32.lt_s
+   br_if $folding-inner0
+   global.get $~lib/memory/__stack_pointer
+   local.tee $0
+   i32.const 0
+   i32.store
+   local.get $0
+   i32.const 7
+   call $~lib/rt/itcms/__new
+   local.tee $0
+   i32.store
+   global.get $~lib/memory/__stack_pointer
+   i32.const 4
+   i32.add
+   global.set $~lib/memory/__stack_pointer
+   local.get $0
+   global.set $optional-typeparameters/tMethodDerived2
+   global.get $~lib/memory/__stack_pointer
+   global.get $optional-typeparameters/tMethodDerived2
+   i32.store
+   global.get $~lib/memory/__stack_pointer
+   global.get $optional-typeparameters/tMethodDerived
+   i32.store offset=4
+   global.get $~lib/memory/__stack_pointer
+   i32.const 8
    i32.add
    global.set $~lib/memory/__stack_pointer
    return
   end
-  i32.const 17904
-  i32.const 17952
+  i32.const 17920
+  i32.const 17968
   i32.const 1
   i32.const 1
   call $~lib/builtins/abort
@@ -1495,7 +1534,7 @@
     if
      i32.const 0
      local.get $1
-     i32.const 17884
+     i32.const 17892
      i32.lt_u
      local.get $1
      i32.load offset=8
diff --git a/tests/compiler/optional-typeparameters.ts b/tests/compiler/optional-typeparameters.ts
index 8fbf479197..7ba1699c0e 100644
--- a/tests/compiler/optional-typeparameters.ts
+++ b/tests/compiler/optional-typeparameters.ts
@@ -27,8 +27,17 @@ var tDerived = new TestDerived<f64>();
 tDerived.test<f64>(1, 2);
 
 class TestMethodDerived<T> {
-  test<U = T[]>(): void {}
+  test<U = T[]>(): void {
+    assert(idof<U>() == idof<T[]>());
+  }
+}
+class TestMethodDerived2<T> {
+  foo(v: TestMethodDerived<string>): void {
+    v.test();
+  }
 }
 
 var tMethodDerived = new TestMethodDerived<string>();
 tMethodDerived.test();
+var tMethodDerived2 = new TestMethodDerived2<f64>();
+tMethodDerived2.foo(tMethodDerived);

From 622e4866915dccf140ef2df62896bc43f294d46f Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907@163.com>
Date: Sun, 21 Aug 2022 09:33:58 +0800
Subject: [PATCH 8/9] add docs

---
 src/resolver.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/resolver.ts b/src/resolver.ts
index 159e200a77..6689c88add 100644
--- a/src/resolver.ts
+++ b/src/resolver.ts
@@ -763,12 +763,13 @@ export class Resolver extends DiagnosticEmitter {
           }
           let defaultType = typeParameterNode.defaultType;
           if (defaultType) {
+            // Default parameters are resolved in context of the called function, not the calling function
             let defaultTypeContextualTypeArguments: Map<string, Type> | null = null;
             if (prototype.parent.kind == ElementKind.CLASS) {
               defaultTypeContextualTypeArguments = (<Class>prototype.parent).contextualTypeArguments;
             } else if (prototype.parent.kind == ElementKind.FUNCTION) {
               defaultTypeContextualTypeArguments = (<Function>prototype.parent).contextualTypeArguments;
-            } 
+            }
             let resolvedDefaultType = this.resolveType(defaultType, prototype, defaultTypeContextualTypeArguments, reportMode);
             if (!resolvedDefaultType) return null;
             resolvedTypeArguments[i] = resolvedDefaultType;

From b6e3ab6cc2d4fb2761337cb405d3ec7b5ac5d10e Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907@163.com>
Date: Sun, 21 Aug 2022 09:56:55 +0800
Subject: [PATCH 9/9] resolve conflict

---
 .../optional-typeparameters.debug.wat         | 52 +++++++++----------
 1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/tests/compiler/optional-typeparameters.debug.wat b/tests/compiler/optional-typeparameters.debug.wat
index e978c512c1..cbe085dc33 100644
--- a/tests/compiler/optional-typeparameters.debug.wat
+++ b/tests/compiler/optional-typeparameters.debug.wat
@@ -2134,14 +2134,14 @@
   local.get $b
   f64.add
  )
- (func $optional-typeparameters/TestMethodDerived<~lib/string/String>#test<~lib/array/Array<~lib/string/String>> (param $0 i32)
+ (func $optional-typeparameters/TestMethodDerived<~lib/string/String>#test<~lib/array/Array<~lib/string/String>> (param $this i32)
   i32.const 6
   i32.const 6
   i32.eq
   drop
  )
- (func $optional-typeparameters/TestMethodDerived2<f64>#foo (param $0 i32) (param $1 i32)
-  local.get $1
+ (func $optional-typeparameters/TestMethodDerived2<f64>#foo (param $this i32) (param $v i32)
+  local.get $v
   call $optional-typeparameters/TestMethodDerived<~lib/string/String>#test<~lib/array/Array<~lib/string/String>>
  )
  (func $~lib/rt/__visit_globals (param $0 i32)
@@ -2192,49 +2192,49 @@
    call $~lib/rt/itcms/__visit
   end
  )
- (func $~lib/array/Array<~lib/string/String>#__visit (param $0 i32) (param $1 i32)
-  (local $2 i32)
-  (local $3 i32)
-  (local $4 i32)
-  (local $5 i32)
+ (func $~lib/array/Array<~lib/string/String>#__visit (param $this i32) (param $cookie i32)
+  (local $var$2 i32)
+  (local $var$3 i32)
+  (local $var$4 i32)
+  (local $val i32)
   i32.const 1
   drop
-  local.get $0
+  local.get $this
   i32.load offset=4
-  local.set $2
-  local.get $2
-  local.get $0
+  local.set $var$2
+  local.get $var$2
+  local.get $this
   i32.load offset=12
   i32.const 2
   i32.shl
   i32.add
-  local.set $3
+  local.set $var$3
   loop $while-continue|0
-   local.get $2
-   local.get $3
+   local.get $var$2
+   local.get $var$3
    i32.lt_u
-   local.set $4
-   local.get $4
+   local.set $var$4
+   local.get $var$4
    if
-    local.get $2
+    local.get $var$2
     i32.load
-    local.set $5
-    local.get $5
+    local.set $val
+    local.get $val
     if
-     local.get $5
-     local.get $1
+     local.get $val
+     local.get $cookie
      call $~lib/rt/itcms/__visit
     end
-    local.get $2
+    local.get $var$2
     i32.const 4
     i32.add
-    local.set $2
+    local.set $var$2
     br $while-continue|0
    end
   end
-  local.get $0
+  local.get $this
   i32.load
-  local.get $1
+  local.get $cookie
   call $~lib/rt/itcms/__visit
  )
  (func $~lib/array/Array<~lib/string/String>~visit (param $0 i32) (param $1 i32)