Merge pull request bytecodealliance#11 from dhil/wasmfx-merge

Merge with upstream

crates/wasm-compose/README.md

@@ -75,7 +75,7 @@ of composing WebAssembly components together.
 ## License
 
 This project is licensed under the Apache 2.0 license with the LLVM exception.
-See [LICENSE](LICENSE) for more details.
+See [LICENSE](../../LICENSE) for more details.
 
 ### Contribution
 

crates/wasm-mutate/README.md

@@ -138,7 +138,7 @@ wasm-tools mutate original.wasm --seed 0 -o out.wasm --preserve-semantics
 # License
 
 This project is licensed under the Apache 2.0 license with the LLVM exception.
-See [LICENSE](LICENSE) for more details.
+See [LICENSE](../../LICENSE) for more details.
 
 ### Contribution
 

crates/wasm-smith/README.md

@@ -5,7 +5,6 @@
 [![](https://docs.rs/wasm-smith/badge.svg)](https://docs.rs/wasm-smith/)
 [![](https://img.shields.io/crates/v/wasm-smith.svg)](https://crates.io/crates/wasm-smith)
 [![](https://img.shields.io/crates/d/wasm-smith.svg)](https://crates.io/crates/wasm-smith)
-![Rust](https://github.com/fitzgen/wasm-smith/workflows/Rust/badge.svg)
 
 * [Features](#features)
 * [Usage](#usage)
@@ -76,7 +75,7 @@ $ cargo fuzz run my_wasm_smith_fuzz_target
 ```
 
 > **Note:** Also check out [the `validate` fuzz
-> target](https://github.com/bytecodealliance/wasm-tools/blob/main/fuzz/fuzz_targets/validate.rs)
+> target](https://github.com/bytecodealliance/wasm-tools/blob/main/fuzz/src/validate.rs)
 > defined in this repository. Using the `wasmparser` crate, it checks that every
 > module generated by `wasm-smith` validates successfully.
 

crates/wast/src/core/expr.rs

@@ -98,18 +98,18 @@ enum Level<'a> {
     TryArm,
 }
 
-/// Possible states of "what should be parsed next?" in an `if` expression.
+/// Possible states of "what is currently being parsed?" in an `if` expression.
 enum If<'a> {
-    /// Only the `if` has been parsed, next thing to parse is the clause, if
-    /// any, of the `if` instruction.
+    /// Only the `if` instructoin has been parsed, next thing to parse is the
+    /// clause, if any, of the `if` instruction.
+    ///
+    /// This parse ends when `(then ...)` is encountered.
     Clause(Instruction<'a>),
-    /// Next thing to parse is the `then` block
-    Then(Instruction<'a>),
-    /// Next thing to parse is the `else` block
+    /// Currently parsing the `then` block, and afterwards a closing paren is
+    /// required or an `(else ...)` expression.
+    Then,
+    /// Parsing the `else` expression, nothing can come after.
     Else,
-    /// This `if` statement has finished parsing and if anything remains it's a
-    /// syntax error.
-    End,
 }
 
 /// Possible state of "what should be parsed next?" in a `try` expression.
@@ -217,9 +217,6 @@ impl<'a> ExpressionParser<'a> {
                     // items in the `if` statement. Otherwise we're just careful
                     // to terminate with an `end` instruction.
                     Level::If(If::Clause(_)) => {
-                        return Err(parser.error("previous `if` had no clause"));
-                    }
-                    Level::If(If::Then(_)) => {
                         return Err(parser.error("previous `if` had no `then`"));
                     }
                     Level::If(_) => {
@@ -282,23 +279,16 @@ impl<'a> ExpressionParser<'a> {
         })
     }
 
-    /// Handles all parsing of an `if` statement.
+    /// State transitions with parsing an `if` statement.
     ///
     /// The syntactical form of an `if` stament looks like:
     ///
     /// ```wat
-    /// (if $clause (then $then) (else $else))
+    /// (if ($clause)... (then $then) (else $else))
     /// ```
     ///
-    /// but it turns out we practically see a few things in the wild:
-    ///
-    /// * inside the `(if ...)` every sub-thing is surrounded by parens
-    /// * The `then` and `else` keywords are optional
-    /// * The `$then` and `$else` blocks don't need to be surrounded by parens
-    ///
-    /// That's all attempted to be handled here. The part about all sub-parts
-    /// being surrounded by `(` and `)` means that we hook into the `LParen`
-    /// parsing above to call this method there unconditionally.
+    /// THis method is called after a `(` is parsed within the `(if ...` block.
+    /// This determines what to do next.
     ///
     /// Returns `true` if the rest of the arm above should be skipped, or
     /// `false` if we should parse the next item as an instruction (because we
@@ -310,53 +300,37 @@ impl<'a> ExpressionParser<'a> {
             _ => return Ok(false),
         };
 
-        // The first thing parsed in an `if` statement is the clause. If the
-        // clause starts with `then`, however, then we know to skip the clause
-        // and fall through to below.
-        if let If::Clause(if_instr) = i {
-            let instr = mem::replace(if_instr, Instruction::End(None));
-            *i = If::Then(instr);
-            if !parser.peek::<kw::then>()? {
-                return Ok(false);
-            }
-        }
-
-        // All `if` statements are required to have a `then`. This is either the
-        // second s-expr (with or without a leading `then`) or the first s-expr
-        // with a leading `then`. The optionality of `then` isn't strictly what
-        // the text spec says but it matches wabt for now.
-        //
-        // Note that when we see the `then`, that's when we actually add the
-        // original `if` instruction to the stream.
-        if let If::Then(if_instr) = i {
-            let instr = mem::replace(if_instr, Instruction::End(None));
-            self.instrs.push(instr);
-            *i = If::Else;
-            if parser.parse::<Option<kw::then>>()?.is_some() {
+        match i {
+            // If the clause is still being parsed then interpret this `(` as a
+            // folded instruction unless it starts with `then`, in which case
+            // this transitions to the `Then` state and a new level has been
+            // reached.
+            If::Clause(if_instr) => {
+                if !parser.peek::<kw::then>()? {
+                    return Ok(false);
+                }
+                parser.parse::<kw::then>()?;
+                let instr = mem::replace(if_instr, Instruction::End(None));
+                self.instrs.push(instr);
+                *i = If::Then;
                 self.stack.push(Level::IfArm);
-                return Ok(true);
+                Ok(true)
             }
-            return Ok(false);
-        }
 
-        // effectively the same as the `then` parsing above
-        if let If::Else = i {
-            self.instrs.push(Instruction::Else(None));
-            if parser.parse::<Option<kw::r#else>>()?.is_some() {
-                if parser.is_empty() {
-                    self.instrs.pop();
-                }
+            // Previously we were parsing the `(then ...)` clause so this next
+            // `(` must be followed by `else`.
+            If::Then => {
+                parser.parse::<kw::r#else>()?;
+                self.instrs.push(Instruction::Else(None));
+                *i = If::Else;
                 self.stack.push(Level::IfArm);
-                return Ok(true);
+                Ok(true)
             }
-            *i = If::End;
-            return Ok(false);
-        }
 
-        // If we made it this far then we're at `If::End` which means that there
-        // were too many s-expressions inside the `(if)` and we don't want to
-        // parse anything else.
-        Err(parser.error("unexpected token: too many payloads inside of `(if)`"))
+            // If after a `(else ...` clause is parsed there's another `(` then
+            // that's not syntactically allowed.
+            If::Else => Err(parser.error("unexpected token: too many payloads inside of `(if)`")),
+        }
     }
 
     /// Handles parsing of a `try` statement. A `try` statement is simpler

crates/wit-component/tests/components/adapt-inject-stack-with-adapt-realloc/adapt-old.wat

@@ -25,7 +25,7 @@
 
     ;; `wit-component` should have injected a call to a function that allocates
     ;; the stack and sets $allocation_state to 2
-    (if (i32.ne (global.get $allocation_state) (i32.const 2)) (unreachable))
+    (if (i32.ne (global.get $allocation_state) (i32.const 2)) (then (unreachable)))
 
     ;; First, allocate a page using $cabi_realloc and write to it.  This tests
     ;; that we can use the main module's allocator if present (or else a

crates/wit-component/tests/components/adapt-inject-stack-with-realloc/adapt-old.wat

@@ -25,7 +25,7 @@
 
     ;; `wit-component` should have injected a call to a function that allocates
     ;; the stack and sets $allocation_state to 2
-    (if (i32.ne (global.get $allocation_state) (i32.const 2)) (unreachable))
+    (if (i32.ne (global.get $allocation_state) (i32.const 2)) (then (unreachable)))
 
     ;; First, allocate a page using $cabi_realloc and write to it.  This tests
     ;; that we can use the main module's allocator if present (or else a

crates/wit-component/tests/components/adapt-inject-stack-with-reallocing-adapter/adapt-old.wat

@@ -24,7 +24,7 @@
 
     ;; `wit-component` should have injected a call to a function that allocates
     ;; the stack and sets $allocation_state to 2
-    (if (i32.ne (global.get $allocation_state) (i32.const 2)) (unreachable))
+    (if (i32.ne (global.get $allocation_state) (i32.const 2)) (then (unreachable)))
 
     ;; Allocate 8 bytes of stack space for the two u32 return values. The
     ;; original stack pointer is saved in local 0 and the stack frame for this

tests/local/fuzz1.wat

@@ -260,9 +260,9 @@
     (i32.eqz
      (global.get $hangLimit)
     )
-    (return
+    (then (return
      (i64.const 4293531749)
-    )
+    ))
    )
    (global.set $hangLimit
     (i32.sub
@@ -279,8 +279,8 @@
       (local.tee $0
        (if (result i32)
         (i32.const -2147483647)
-        (local.get $0)
-        (block $label$4 (result i32)
+        (then (local.get $0))
+        (else (block $label$4 (result i32)
          (br_if $label$4
           (if (result i32)
            (block $label$5 (result i32)
@@ -293,9 +293,9 @@
                   (i32.eqz
                    (global.get $hangLimit)
                   )
-                  (return
+                  (then (return
                    (i64.const -32766)
-                  )
+                  ))
                  )
                  (global.set $hangLimit
                   (i32.sub
@@ -315,22 +315,22 @@
                 )
                )
               )
-              (block $label$7 (result f32)
+              (then (block $label$7 (result f32)
                (f32.const -nan:0x7fffda)
-              )
-              (f32.const 4294967296)
+              ))
+              (else (f32.const 4294967296))
              )
             )
             (i32.const -2147483648)
            )
-           (i32.const -1073741824)
-           (local.get $0)
+           (then (i32.const -1073741824))
+           (else (local.get $0))
           )
           (i32.eqz
            (global.get $global$0)
           )
          )
-        )
+        ))
        )
       )
      )

tests/local/if-else-parsing.wast

@@ -0,0 +1,42 @@
+(module
+  (func $a1
+    i32.const 0
+    (if (then) (else))
+  )
+  (func $a2
+    (if (i32.const 1) (i32.eqz) (then) (else))
+  )
+  (func $a3
+    (if (i32.const 1) (i32.eqz) (then))
+  )
+  (func $a4
+    (if (i32.const 1) (i32.eqz) (then nop))
+  )
+)
+(assert_invalid
+  (module quote
+    "(func (if))"
+  )
+  "no `then`")
+
+(assert_invalid
+  (module quote
+    "(func (if (else)))"
+  )
+  "no `then`")
+
+(assert_invalid
+  (module quote
+    "(func (if nop (else)))"
+  )
+  "expected `(`")
+(assert_invalid
+  (module quote
+    "(func (if (nop) (else)))"
+  )
+  "no `then`")
+(assert_invalid
+  (module quote
+    "(func (if (nop) nop (then)))"
+  )
+  "expected `(`")

tests/snapshots/local/if-else-parsing.wast/0.print

@@ -0,0 +1,29 @@
+(module
+  (type (;0;) (func))
+  (func $a1 (;0;) (type 0)
+    i32.const 0
+    if ;; label = @1
+    else
+    end
+  )
+  (func $a2 (;1;) (type 0)
+    i32.const 1
+    i32.eqz
+    if ;; label = @1
+    else
+    end
+  )
+  (func $a3 (;2;) (type 0)
+    i32.const 1
+    i32.eqz
+    if ;; label = @1
+    end
+  )
+  (func $a4 (;3;) (type 0)
+    i32.const 1
+    i32.eqz
+    if ;; label = @1
+      nop
+    end
+  )
+)

tests/snapshots/testsuite/if.wast/0.print

@@ -22,12 +22,14 @@
     end
     local.get 0
     if ;; label = @1
+    else
     end
     local.get 0
     if $l ;; label = @1
     end
     local.get 0
     if $l ;; label = @1
+    else
     end
   )
   (func (;2;) (type 5) (param i32) (result i32)

tests/snapshots/testsuite/proposals/function-references/if.wast/0.print

@@ -22,12 +22,14 @@
     end
     local.get 0
     if ;; label = @1
+    else
     end
     local.get 0
     if $l ;; label = @1
     end
     local.get 0
     if $l ;; label = @1
+    else
     end
   )
   (func (;2;) (type 5) (param i32) (result i32)

tests/snapshots/testsuite/proposals/gc/if.wast/0.print

@@ -22,12 +22,14 @@
     end
     local.get 0
     if ;; label = @1
+    else
     end
     local.get 0
     if $l ;; label = @1
     end
     local.get 0
     if $l ;; label = @1
+    else
     end
   )
   (func (;2;) (type 5) (param i32) (result i32)