Auto merge of #127419 - trevyn:issue-125446, r=fee1-dead

Add suggestions for possible missing `fn`, `struct`, or `enum` keywords

Closes #125446
Closes #65381

16 files changed, 129 insertions, 4 deletions

diff --git a/tests/ui/parser/extern-no-fn.rs b/tests/ui/parser/extern-no-fn.rs
index 73568609cdf..e965b390f07 100644
--- a/tests/ui/parser/extern-no-fn.rs
+++ b/tests/ui/parser/extern-no-fn.rs
@@ -1,5 +1,7 @@
 extern "C" {
-    f(); //~ ERROR expected one of `!` or `::`, found `(`
+    f();
+    //~^ ERROR missing `fn` or `struct` for function or struct definition
+    //~| HELP if you meant to call a macro, try
 }
 
 fn main() {
diff --git a/tests/ui/parser/extern-no-fn.stderr b/tests/ui/parser/extern-no-fn.stderr
index 2e434afb218..03826e4a93b 100644
--- a/tests/ui/parser/extern-no-fn.stderr
+++ b/tests/ui/parser/extern-no-fn.stderr
@@ -1,12 +1,18 @@
-error: expected one of `!` or `::`, found `(`
-  --> $DIR/extern-no-fn.rs:2:6
+error: missing `fn` or `struct` for function or struct definition
+  --> $DIR/extern-no-fn.rs:2:5
    |
 LL | extern "C" {
    |            - while parsing this item list starting here
 LL |     f();
-   |      ^ expected one of `!` or `::`
+   |     ^
+...
 LL | }
    | - the item list ends here
+   |
+help: if you meant to call a macro, try
+   |
+LL |     f!();
+   |     ~~
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/parser/missing-enum-issue-125446.rs b/tests/ui/parser/missing-enum-issue-125446.rs
new file mode 100644
index 00000000000..8d2cdb0dc40
--- /dev/null
+++ b/tests/ui/parser/missing-enum-issue-125446.rs
@@ -0,0 +1,6 @@
+Whoops {
+//~^ ERROR missing `enum` for enum definition
+//~| HELP add `enum` here to parse `Whoops` as an enum
+    OptionA,
+    OptionB,
+}
diff --git a/tests/ui/parser/missing-enum-issue-125446.stderr b/tests/ui/parser/missing-enum-issue-125446.stderr
new file mode 100644
index 00000000000..113b147473c
--- /dev/null
+++ b/tests/ui/parser/missing-enum-issue-125446.stderr
@@ -0,0 +1,13 @@
+error: missing `enum` for enum definition
+  --> $DIR/missing-enum-issue-125446.rs:1:1
+   |
+LL | Whoops {
+   | ^^^^^^
+   |
+help: add `enum` here to parse `Whoops` as an enum
+   |
+LL | enum Whoops {
+   | ++++
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/parser/missing-enum-or-struct-issue-125446.rs b/tests/ui/parser/missing-enum-or-struct-issue-125446.rs
new file mode 100644
index 00000000000..c817ffaf859
--- /dev/null
+++ b/tests/ui/parser/missing-enum-or-struct-issue-125446.rs
@@ -0,0 +1,2 @@
+Whoops {}
+//~^ ERROR missing `enum` or `struct` for enum or struct definition
diff --git a/tests/ui/parser/missing-enum-or-struct-issue-125446.stderr b/tests/ui/parser/missing-enum-or-struct-issue-125446.stderr
new file mode 100644
index 00000000000..15916cebf45
--- /dev/null
+++ b/tests/ui/parser/missing-enum-or-struct-issue-125446.stderr
@@ -0,0 +1,8 @@
+error: missing `enum` or `struct` for enum or struct definition
+  --> $DIR/missing-enum-or-struct-issue-125446.rs:1:1
+   |
+LL | Whoops {}
+   | ^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/parser/missing-fn-issue-125446.rs b/tests/ui/parser/missing-fn-issue-125446.rs
new file mode 100644
index 00000000000..73c9c3a60e1
--- /dev/null
+++ b/tests/ui/parser/missing-fn-issue-125446.rs
@@ -0,0 +1,7 @@
+whoops() {}
+//~^ ERROR missing `fn` for function definition
+//~| HELP add `fn` here to parse `whoops` as a function
+
+fn main() {
+    whoops();
+}
diff --git a/tests/ui/parser/missing-fn-issue-125446.stderr b/tests/ui/parser/missing-fn-issue-125446.stderr
new file mode 100644
index 00000000000..2a92e0062cb
--- /dev/null
+++ b/tests/ui/parser/missing-fn-issue-125446.stderr
@@ -0,0 +1,13 @@
+error: missing `fn` for function definition
+  --> $DIR/missing-fn-issue-125446.rs:1:1
+   |
+LL | whoops() {}
+   | ^^^^^^
+   |
+help: add `fn` here to parse `whoops` as a function
+   |
+LL | fn whoops() {}
+   | ++
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/parser/missing-fn-issue-65381-1.rs b/tests/ui/parser/missing-fn-issue-65381-1.rs
new file mode 100644
index 00000000000..ac0299ae37b
--- /dev/null
+++ b/tests/ui/parser/missing-fn-issue-65381-1.rs
@@ -0,0 +1,4 @@
+main() {
+//~^ ERROR missing `fn` for function definition
+//~| HELP add `fn` here to parse `main` as a function
+}
diff --git a/tests/ui/parser/missing-fn-issue-65381-1.stderr b/tests/ui/parser/missing-fn-issue-65381-1.stderr
new file mode 100644
index 00000000000..95ccd8518ee
--- /dev/null
+++ b/tests/ui/parser/missing-fn-issue-65381-1.stderr
@@ -0,0 +1,13 @@
+error: missing `fn` for function definition
+  --> $DIR/missing-fn-issue-65381-1.rs:1:1
+   |
+LL | main() {
+   | ^^^^
+   |
+help: add `fn` here to parse `main` as a function
+   |
+LL | fn main() {
+   | ++
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/parser/missing-fn-issue-65381-2.rs b/tests/ui/parser/missing-fn-issue-65381-2.rs
new file mode 100644
index 00000000000..e8c214a58b6
--- /dev/null
+++ b/tests/ui/parser/missing-fn-issue-65381-2.rs
@@ -0,0 +1,3 @@
+main();
+//~^ ERROR missing `fn` or `struct` for function or struct definition
+//~| HELP if you meant to call a macro, try
diff --git a/tests/ui/parser/missing-fn-issue-65381-2.stderr b/tests/ui/parser/missing-fn-issue-65381-2.stderr
new file mode 100644
index 00000000000..e13d395d70d
--- /dev/null
+++ b/tests/ui/parser/missing-fn-issue-65381-2.stderr
@@ -0,0 +1,13 @@
+error: missing `fn` or `struct` for function or struct definition
+  --> $DIR/missing-fn-issue-65381-2.rs:1:1
+   |
+LL | main();
+   | ^^^^
+   |
+help: if you meant to call a macro, try
+   |
+LL | main!();
+   | ~~~~~
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/parser/missing-fn-issue-65381-3.rs b/tests/ui/parser/missing-fn-issue-65381-3.rs
new file mode 100644
index 00000000000..28e5b5aa430
--- /dev/null
+++ b/tests/ui/parser/missing-fn-issue-65381-3.rs
@@ -0,0 +1,4 @@
+pub const initial_value() -> Self {
+//~^ ERROR missing `fn` for function definition
+//~| HELP add `fn` here to parse `initial_value` as a function
+}
diff --git a/tests/ui/parser/missing-fn-issue-65381-3.stderr b/tests/ui/parser/missing-fn-issue-65381-3.stderr
new file mode 100644
index 00000000000..883295baede
--- /dev/null
+++ b/tests/ui/parser/missing-fn-issue-65381-3.stderr
@@ -0,0 +1,13 @@
+error: missing `fn` for function definition
+  --> $DIR/missing-fn-issue-65381-3.rs:1:11
+   |
+LL | pub const initial_value() -> Self {
+   |           ^^^^^^^^^^^^^
+   |
+help: add `fn` here to parse `initial_value` as a function
+   |
+LL | pub const fn initial_value() -> Self {
+   |           ++
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/parser/missing-struct-issue-125446.rs b/tests/ui/parser/missing-struct-issue-125446.rs
new file mode 100644
index 00000000000..439087aeec9
--- /dev/null
+++ b/tests/ui/parser/missing-struct-issue-125446.rs
@@ -0,0 +1,5 @@
+Whoops {
+//~^ ERROR missing `struct` for struct definition
+//~| HELP add `struct` here to parse `Whoops` as a struct
+    value: u64,
+}
diff --git a/tests/ui/parser/missing-struct-issue-125446.stderr b/tests/ui/parser/missing-struct-issue-125446.stderr
new file mode 100644
index 00000000000..ff3135b2357
--- /dev/null
+++ b/tests/ui/parser/missing-struct-issue-125446.stderr
@@ -0,0 +1,13 @@
+error: missing `struct` for struct definition
+  --> $DIR/missing-struct-issue-125446.rs:1:1
+   |
+LL | Whoops {
+   | ^^^^^^
+   |
+help: add `struct` here to parse `Whoops` as a struct
+   |
+LL | struct Whoops {
+   | ++++++
+
+error: aborting due to 1 previous error
+