From bfe40565753295a4cf8403f4124710acd2827d21 Mon Sep 17 00:00:00 2001
From: Phillip Lord <phillip.lord@russet.org.uk>
Date: Thu, 23 Apr 2020 10:17:15 +0100
Subject: Re-implement rust-in-macro for performance

rust-in-macro could cause significant performance problems resulting
in a very choppy user experience. Reimplement rust-in macro in a
somewhat simpler manner and in way which allows both allows
restriction to parts of the buffer and caching of buffer analysis.
Optimize rust-syntax-propertize to use this caching mechanism.

Fixes #208
Fixes #288
---
 rust-mode-tests.el | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 108 insertions(+), 2 deletions(-)

(limited to 'rust-mode-tests.el')

diff --git a/rust-mode-tests.el b/rust-mode-tests.el
index 4860941..b6a23e5 100644
--- a/rust-mode-tests.el
+++ b/rust-mode-tests.el
@@ -2139,8 +2139,8 @@ fn main() {
         (should (equal (scan-sexps (+ 1 close-pos) -1) open-pos))))
     (dolist (nonpar-pos nonparen-positions)
       (let ((nonpar-syntax-class (syntax-class (syntax-after nonpar-pos))))
-        (should (not (equal 4 nonpar-syntax-class)))
-        (should (not (equal 5 nonpar-syntax-class)))))))
+        (should-not (equal 4 nonpar-syntax-class))
+        (should-not (equal 5 nonpar-syntax-class))))))
 
 (ert-deftest rust-test-unmatched-single-quote-in-comment-paren-matching ()
   ;; This was a bug from the char quote handling that affected the paren
@@ -2923,6 +2923,112 @@ macro_c!{
      125 ;; macro_d >
      )))
 
+(ert-deftest rust-test-paren-matching-no-angle-brackets-in-macro-rules ()
+  (rust-test-matching-parens
+   "
+fn foo<A>(a:A) {
+    macro_rules! foo ( foo::<ignore the bracets> );
+    macro_rules! bar [ foo as Option<B> ];
+}
+
+macro_c!{
+    struct Boo<D> {}
+}"
+   '((8 10))
+   ;; Inside macros, it should not find any angle brackets, even if it normally
+   ;; would
+   '(47 ;; foo <
+     62 ;; foo >
+     107 ;; bar <
+     109 ;; bar >
+     141 ;; macro_c <
+     143 ;; macro_c >
+     )))
+
+(ert-deftest rust-test-in-macro-do-not-fail-on-unbalance ()
+  (should
+   ;; We don't care about the results here, so long as they do not error
+   (with-temp-buffer
+     (insert
+      "fn foo<A>(a:A) {
+    macro_c!{
+        struct Boo<D> {}
+")
+     (rust-mode)
+     (goto-char (point-max))
+     (syntax-ppss))))
+
+
+(ert-deftest rust-test-in-macro-no-caching ()
+  (should-not
+   (with-temp-buffer
+     (insert
+      "fn foo<A>(a:A) {
+    macro_c!{
+        struct Boo<D> {}
+")
+     (rust-mode)
+     (search-backward "macro")
+     ;; do not use the cache
+     (let ((rust-macro-scopes nil))
+       (rust-in-macro)))))
+
+(ert-deftest rust-test-in-macro-fake-cache ()
+  (should
+   (with-temp-buffer
+     (insert
+      "fn foo<A>(a:A) {
+    macro_c!{
+        struct Boo<D> {}
+")
+     (rust-mode)
+     (search-backward "macro")
+     ;; make the cache lie to make the whole buffer in scope
+     ;; we need to be at paren level 1 for this to work
+     (let ((rust-macro-scopes `((,(point-min) ,(point-max)))))
+       (rust-in-macro)))))
+
+(ert-deftest rust-test-in-macro-broken-cache ()
+  (should-error
+   (with-temp-buffer
+     (insert
+      "fn foo<A>(a:A) {
+    macro_c!{
+        struct Boo<D> {}
+")
+     (rust-mode)
+     (search-backward "Boo")
+     ;; do we use the cache at all
+     (let ((rust-macro-scopes '(I should break)))
+       (rust-in-macro)))))
+
+(ert-deftest rust-test-in-macro-nested ()
+  (should
+   (equal
+    (with-temp-buffer
+      (insert
+       "macro_rules! outer {
+    () => { vec![] };
+}")
+      (rust-mode)
+      (rust-macro-scope (point-min) (point-max)))
+    '((38 40) (20 45)))))
+
+(ert-deftest rust-test-in-macro-not-with-space ()
+  (should
+   (equal
+    (with-temp-buffer
+      (insert
+       "fn foo<T>() {
+    if !(mem::size_of::<T>() > 8) {
+        bar()
+    }
+}")
+      (rust-mode)
+      (rust-macro-scope (point-min) (point-max)))
+    'empty)))
+
+
 (ert-deftest rust-test-paren-matching-type-with-module-name ()
   (rust-test-matching-parens
    "
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