deprecate catch <expression>

NEWS.md

@@ -70,6 +70,9 @@ Language changes
     warning, so that this syntax can be disallowed or given a new meaning in a
     future version ([#5148]).
 
+  * Placing an expression after `catch`, as in `catch f(x)`, is deprecated.
+    Use `catch; f(x)` instead ([#19987]).
+
   * In `for i = ...`, if a local variable `i` already existed it would be overwritten
     during the loop. This behavior is deprecated, and in the future `for` loop variables
     will always be new variables local to the loop ([#22314]).

base/libgit2/callbacks.jl

@@ -17,7 +17,7 @@ function mirror_callback(remote::Ptr{Ptr{Void}}, repo_ptr::Ptr{Void},
     config = GitConfig(GitRepo(repo_ptr,false))
     name_str = unsafe_string(name)
     err= try set!(config, "remote.$name_str.mirror", true)
-         catch -1
+         catch; -1
          finally close(config)
          end
     err != 0 && return Cint(err)

src/julia-parser.scm

@@ -1464,7 +1464,10 @@
                            (var (if nl #f (parse-eq* s)))
                            (var? (and (not nl) (or (and (symbol? var) (not (eq? var 'false))
                                                         (not (eq? var 'true)))
-                                                   (and (length= var 2) (eq? (car var) '$)))))
+                                                   (and (length= var 2) (eq? (car var) '$))
+                                                   (and (syntax-deprecation s (string "catch " (deparse var) "")
+                                                                            (string "catch; " (deparse var) ""))
+                                                        #f))))
                            (catch-block (if (eq? (require-token s) 'finally)
                                             `(block ,(line-number-node s))
                                             (parse-block s))))

test/parse.jl

@@ -565,10 +565,10 @@ add_method_to_glob_fn!()
 @test expand(Main, :(f(d:Int...) = nothing)) == Expr(:error, "\"d:Int\" is not a valid function argument name")
 
 # issue #16517
-@test (try error(); catch 0; end) === 0
-@test (try error(); catch false; end) === false  # false and true are Bool literals, not variables
-@test (try error(); catch true; end) === true
-f16517() = try error(); catch 0; end
+@test (try error(); catch; 0; end) === 0
+@test (try error(); catch; false; end) === false  # false and true are Bool literals, not variables
+@test (try error(); catch; true; end) === true
+f16517() = try error(); catch; 0; end
 @test f16517() === 0
 
 # issue #16671
@@ -592,7 +592,7 @@ end
 
 # issue #16686
 @test parse("try x
-             catch test()
+             catch; test()
                  y
              end") == Expr(:try,
                            Expr(:block,

test/reflection.jl

@@ -46,7 +46,7 @@ test_code_reflections(test_bin_reflection, code_native)
 mktemp() do f, io
     OLDSTDOUT = STDOUT
     redirect_stdout(io)
-    @test try @code_native map(abs, rand(3)); true; catch false; end
+    @test try @code_native map(abs, rand(3)); true; catch; false; end
     redirect_stdout(OLDSTDOUT)
     nothing
 end