Add file and line number reporting for some lowering errors (JuliaLan…

…g#35105)

* Add file and line number reporting for desugaring errors

* Cleanup: use globals jl_filename jl_lineno less
  The various code paths that these globals can be set on are quite
  confusing and the globals can leak between unrelated evaluation
  contexts. Reduce this by using them less.

src/ast.c

@@ -863,6 +863,7 @@ jl_value_t *jl_parse_eval_all(const char *fname,
  int last_lineno = jl_lineno;
  const char *last_filename = jl_filename;
  size_t last_age = jl_get_ptls_states()->world_age;
+ int lineno = 0;
  jl_lineno = 0;
  jl_filename = fname;
  jl_module_t *old_module = ctx->module;
@@ -894,17 +895,20 @@ jl_value_t *jl_parse_eval_all(const char *fname,
  expression =
  fl_applyn(fl_ctx, 4,
  symbol_value(symbol(fl_ctx, "jl-expand-to-thunk-warn")),
- expression, symbol(fl_ctx, jl_filename), fixnum(jl_lineno),
+ expression, symbol(fl_ctx, fname), fixnum(lineno),
  iscons(cdr_(ast)) ? fl_ctx->T : fl_ctx->F);
  }
  jl_get_ptls_states()->world_age = jl_world_counter;
  form = scm_to_julia(fl_ctx, expression, inmodule);
  JL_SIGATOMIC_END();
  jl_get_ptls_states()->world_age = jl_world_counter;
- if (jl_is_linenode(form))
- jl_lineno = jl_linenode_line(form);
- else
+ if (jl_is_linenode(form)) {
+ lineno = jl_linenode_line(form);
+ jl_lineno = lineno;
+ }
+ else {
  result = jl_toplevel_eval_flex(inmodule, form, 1, 1);
+ }
  JL_SIGATOMIC_BEGIN();
  ast = cdr_(ast);
  }

src/jlfrontend.scm

@@ -94,7 +94,7 @@
  (let ((ex0 (julia-expand-macroscope e)))
  (if (toplevel-only-expr? ex0)
  ex0
- (let* ((ex (julia-expand0 ex0))
+ (let* ((ex (julia-expand0 ex0 file line))
  (th (julia-expand1
  `(lambda () ()
  (scope-block

src/julia-syntax.scm

@@ -1837,7 +1837,7 @@
  `(= ,lhs ,rhs)))
 
 (define (expand-forms e)
- (if (or (atom? e) (memq (car e) '(quote inert top core globalref outerref line module toplevel ssavalue null true false meta using import export)))
+ (if (or (atom? e) (memq (car e) '(quote inert top core globalref outerref module toplevel ssavalue null true false meta using import export)))
  e
  (let ((ex (get expand-table (car e) #f)))
  (if ex
@@ -2334,6 +2334,11 @@
  (= ,r ,(expand-forms (cadr e)))
  (gc_preserve_end ,s)
  ,r)))
+
+ 'line
+ (lambda (e)
+ (set! *current-desugar-loc* e)
+ e)
  ))
 
 (define (has-return? e)
@@ -4368,9 +4373,22 @@ f(x) = yt(x)
  (analyze-variables!
  (resolve-scopes ex)))) file line))
 
-(define julia-expand0 expand-forms)
+(define *current-desugar-loc* #f)
+
+(define (julia-expand0 ex file line)
+ (with-bindings ((*current-desugar-loc* `(line ,line ,file)))
+ (trycatch (expand-forms ex)
+ (lambda (e)
+ (if (and (pair? e) (eq? (car e) 'error))
+ ; Add location for desugaring errors. This is approximate:
+ ; - Line number nodes are sparse in the AST
+ ; - Line number nodes apply to the next statement, so
+ ; tracking by `set!`ing *current-desugar-loc* relies on
+ ; AST traversal being in program order.
+ (error (string (cadr e) (format-loc *current-desugar-loc*))))
+ (raise e)))))
 
 (define (julia-expand ex (file 'none) (line 0))
  (julia-expand1
  (julia-expand0
- (julia-expand-macroscope ex)) file line))
+ (julia-expand-macroscope ex) file line) file line))

src/macroexpand.scm

@@ -115,7 +115,7 @@
  (cons (decl-var (cadar binds)) vars)))
  ((eventually-call? (cadar binds))
  ;; f()=c
- (let ((asgn (cadr (julia-expand0 (car binds)))))
+ (let ((asgn (cadr (julia-expand0 (car binds) 'none 0))))
  (loop (cdr binds)
  (cons (cadr asgn) vars))))
  ((and (pair? (cadar binds))

src/toplevel.c

@@ -829,6 +829,7 @@ JL_DLLEXPORT jl_value_t *jl_toplevel_eval_in(jl_module_t *m, jl_value_t *ex)
  jl_error("eval cannot be used in a generated function");
  jl_value_t *v = NULL;
  int last_lineno = jl_lineno;
+ const char *last_filename = jl_filename;
  if (jl_options.incremental && jl_generating_output()) {
  if (!ptrhash_has(&jl_current_modules, (void*)m)) {
  if (m != jl_main_module) { // TODO: this was grand-fathered in
@@ -843,9 +844,11 @@ JL_DLLEXPORT jl_value_t *jl_toplevel_eval_in(jl_module_t *m, jl_value_t *ex)
  }
  JL_CATCH {
  jl_lineno = last_lineno;
+ jl_filename = last_filename;
  jl_rethrow();
  }
  jl_lineno = last_lineno;
+ jl_filename = last_filename;
  assert(v);
  return v;
 }

test/syntax.jl

@@ -1459,7 +1459,10 @@ end
 @test c27964(8) == (8, 2)
 
 # issue #26739
-@test_throws ErrorException("syntax: invalid syntax \"sin.[1]\"") Core.eval(@__MODULE__, :(sin.[1]))
+let exc = try Core.eval(@__MODULE__, :(sin.[1])) catch exc ; exc end
+ @test exc isa ErrorException
+ @test startswith(exc.msg, "syntax: invalid syntax \"sin.[1]\"")
+end
 
 # issue #26873
 f26873 = 0
@@ -2182,6 +2185,16 @@ end
  end
 end
 
+# Syntax desugaring pass errors contain line numbers
+@test Meta.lower(@__MODULE__, Expr(:block, LineNumberNode(101, :some_file), :(f(x,x)=1))) ==
+ Expr(:error, "function argument names not unique around some_file:101")
+
+# Ensure file names don't leak between `eval`s
+eval(LineNumberNode(11, :incorrect_file))
+let exc = try eval(:(f(x,x)=1)) catch e ; e ; end
+ @test !occursin("incorrect_file", exc.msg)
+end
+
 # issue #34967
 @test_throws LoadError("string", 2, ErrorException("syntax: invalid UTF-8 sequence")) include_string(@__MODULE__,
  "x34967 = 1\n# Halloa\xf5b\nx34967 = 2")