v.parser: improve the unused import warning message (add fixing alternatives) (#25880)

spytheman · web-flow · commit e3d328a92b0f · 2025-12-03T10:18:35.000+02:00
diff --git a/vlib/v/checker/tests/decompose_interface_err.out b/vlib/v/checker/tests/decompose_interface_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/decompose_interface_err.vv:3:8: warning: module 'arrays' is imported but never used
+vlib/v/checker/tests/decompose_interface_err.vv:3:8: warning: module 'arrays' is imported but never used. Use `import arrays as _`, to silence this warning, or just remove the unused import line
     1 | module main
     2 | 
     3 | import arrays
diff --git a/vlib/v/checker/tests/fn_param_import_sym_conflict.out b/vlib/v/checker/tests/fn_param_import_sym_conflict.out
@@ -1,15 +1,15 @@
-vlib/v/checker/tests/fn_param_import_sym_conflict.vv:1:8: warning: module 'arrays' is imported but never used
+vlib/v/checker/tests/fn_param_import_sym_conflict.vv:1:8: warning: module 'arrays' is imported but never used. Use `import arrays as _`, to silence this warning, or just remove the unused import line
     1 | import arrays
       |        ~~~~~~
     2 | import maps
     3 | import strings as strs
-vlib/v/checker/tests/fn_param_import_sym_conflict.vv:2:8: warning: module 'maps' is imported but never used
+vlib/v/checker/tests/fn_param_import_sym_conflict.vv:2:8: warning: module 'maps' is imported but never used. Use `import maps as _`, to silence this warning, or just remove the unused import line
     1 | import arrays
     2 | import maps
       |        ~~~~
     3 | import strings as strs
     4 |
-vlib/v/checker/tests/fn_param_import_sym_conflict.vv:3:8: warning: module 'strs (strings)' is imported but never used
+vlib/v/checker/tests/fn_param_import_sym_conflict.vv:3:8: warning: module 'strs (strings)' is imported but never used. Use `import strs (strings) as _`, to silence this warning, or just remove the unused import line
     1 | import arrays
     2 | import maps
     3 | import strings as strs
diff --git a/vlib/v/checker/tests/import_symbol_fn_err.out b/vlib/v/checker/tests/import_symbol_fn_err.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/import_symbol_fn_err.vv:1:8: warning: module 'crypto' is imported but never used
+vlib/v/checker/tests/import_symbol_fn_err.vv:1:8: warning: module 'crypto' is imported but never used. Use `import crypto as _`, to silence this warning, or just remove the unused import line
     1 | import crypto { userper }
       |        ~~~~~~
     2 | fn main() {
diff --git a/vlib/v/checker/tests/import_unused_warning.out b/vlib/v/checker/tests/import_unused_warning.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/import_unused_warning.vv:2:8: warning: module 'time' is imported but never used
+vlib/v/checker/tests/import_unused_warning.vv:2:8: warning: module 'time' is imported but never used. Use `import time as _`, to silence this warning, or just remove the unused import line
     1 | import os as _
     2 | import time
       |        ~~~~
diff --git a/vlib/v/checker/tests/incorrect_name_module.out b/vlib/v/checker/tests/incorrect_name_module.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/incorrect_name_module.vv:4:8: warning: module 'os' is imported but never used
+vlib/v/checker/tests/incorrect_name_module.vv:4:8: warning: module 'os' is imported but never used. Use `import os as _`, to silence this warning, or just remove the unused import line
     2 | 
     3 | import math as _
     4 | import os
diff --git a/vlib/v/checker/tests/os_prefix.out b/vlib/v/checker/tests/os_prefix.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/os_prefix.vv:1:8: warning: module 'os' is imported but never used
+vlib/v/checker/tests/os_prefix.vv:1:8: warning: module 'os' is imported but never used. Use `import os as _`, to silence this warning, or just remove the unused import line
     1 | import os
       |        ~~
     2 | 
diff --git a/vlib/v/checker/tests/selective_const_import.out b/vlib/v/checker/tests/selective_const_import.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/selective_const_import.vv:1:8: warning: module 'time' is imported but never used
+vlib/v/checker/tests/selective_const_import.vv:1:8: warning: module 'time' is imported but never used. Use `import time as _`, to silence this warning, or just remove the unused import line
     1 | import time { second }
       |        ~~~~
 vlib/v/checker/tests/selective_const_import.vv:1:15: error: cannot selectively import constant `second` from `time`, import `time` and use `time.second` instead
diff --git a/vlib/v/checker/tests/unused_import_err.out b/vlib/v/checker/tests/unused_import_err.out
@@ -1,8 +1,8 @@
-vlib/v/checker/tests/unused_import_err.vv:1:8: warning: module 'te (term)' is imported but never used
+vlib/v/checker/tests/unused_import_err.vv:1:8: warning: module 'te (term)' is imported but never used. Use `import te (term) as _`, to silence this warning, or just remove the unused import line
     1 | import term as te
       |        ~~~~
     2 | import te.ui
-vlib/v/checker/tests/unused_import_err.vv:2:8: warning: module 'ui (te.ui)' is imported but never used
+vlib/v/checker/tests/unused_import_err.vv:2:8: warning: module 'ui (te.ui)' is imported but never used. Use `import ui (te.ui) as _`, to silence this warning, or just remove the unused import line
     1 | import term as te
     2 | import te.ui
       |        ~~~~~
diff --git a/vlib/v/checker/tests/var_decl_import_sym_conflict.out b/vlib/v/checker/tests/var_decl_import_sym_conflict.out
@@ -1,4 +1,4 @@
-vlib/v/checker/tests/var_decl_import_sym_conflict.vv:1:8: warning: module 'arrays' is imported but never used
+vlib/v/checker/tests/var_decl_import_sym_conflict.vv:1:8: warning: module 'arrays' is imported but never used. Use `import arrays as _`, to silence this warning, or just remove the unused import line
     1 | import arrays
       |        ~~~~~~
     2 | 
diff --git a/vlib/v/parser/module.v b/vlib/v/parser/module.v
@@ -89,7 +89,8 @@ fn (mut p Parser) check_unused_imports() {
 		if !(alias.len == 1 && alias[0] == `_`) && !p.is_used_import(alias)
 			&& alias !in p.auto_imports {
 			mod_alias := if alias == mod { alias } else { '${alias} (${mod})' }
-			p.warn_with_pos("module '${mod_alias}' is imported but never used", import_m.mod_pos)
+			p.warn_with_pos("module '${mod_alias}' is imported but never used. Use `import ${mod_alias} as _`, to silence this warning, or just remove the unused import line",
+				import_m.mod_pos)
 		}
 	}
 }
diff --git a/vlib/v/parser/tests/import_sym_fn_unused_warning_err.out b/vlib/v/parser/tests/import_sym_fn_unused_warning_err.out
@@ -1,4 +1,4 @@
-vlib/v/parser/tests/import_sym_fn_unused_warning_err.vv:1:8: warning: module 'math' is imported but never used
+vlib/v/parser/tests/import_sym_fn_unused_warning_err.vv:1:8: warning: module 'math' is imported but never used. Use `import math as _`, to silence this warning, or just remove the unused import line
     1 | import math { sin, cos }
       |        ~~~~
     2 | 
diff --git a/vlib/v/tests/modules/sub/foo.c.v b/vlib/v/tests/modules/sub/foo.c.v
@@ -1,15 +1,10 @@
 module sub
 
-import sub.foo.c
+import sub.foo.c as _ // imported only for the C declarations
 
 @[typedef]
 pub struct C.sub_foo {
 	a int
 }
 
 pub type Foo = C.sub_foo
-
-// avoiding compiler warnings: module 'c (sub.foo.c)' is imported but never used
-fn bar() {
-	_ = c.used_import
-}
diff --git a/vlib/v/tests/modules/sub/foo/c/foo.v b/vlib/v/tests/modules/sub/foo/c/foo.v
@@ -1,7 +1,5 @@
 module c
 
-pub const used_import = 1
-
 #flag -I @VMODROOT
 
 #include "foo.h"

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-vlib/v/checker/tests/decompose_interface_err.vv:3:8: warning: module 'arrays' is imported but never used`
	`1`	+vlib/v/checker/tests/decompose_interface_err.vv:3:8: warning: module 'arrays' is imported but never used. Use `import arrays as _`, to silence this warning, or just remove the unused import line
`2`	`2`	`1 \| module main`
`3`	`3`	`2 \|`
`4`	`4`	`3 \| import arrays`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-vlib/v/checker/tests/import_symbol_fn_err.vv:1:8: warning: module 'crypto' is imported but never used`
	`1`	+vlib/v/checker/tests/import_symbol_fn_err.vv:1:8: warning: module 'crypto' is imported but never used. Use `import crypto as _`, to silence this warning, or just remove the unused import line
`2`	`2`	`1 \| import crypto { userper }`
`3`	`3`	`\| ~~~~~~`
`4`	`4`	`2 \| fn main() {`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-vlib/v/checker/tests/import_unused_warning.vv:2:8: warning: module 'time' is imported but never used`
	`1`	+vlib/v/checker/tests/import_unused_warning.vv:2:8: warning: module 'time' is imported but never used. Use `import time as _`, to silence this warning, or just remove the unused import line
`2`	`2`	`1 \| import os as _`
`3`	`3`	`2 \| import time`
`4`	`4`	`\| ~~~~`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-vlib/v/checker/tests/incorrect_name_module.vv:4:8: warning: module 'os' is imported but never used`
	`1`	+vlib/v/checker/tests/incorrect_name_module.vv:4:8: warning: module 'os' is imported but never used. Use `import os as _`, to silence this warning, or just remove the unused import line
`2`	`2`	`2 \|`
`3`	`3`	`3 \| import math as _`
`4`	`4`	`4 \| import os`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-vlib/v/checker/tests/os_prefix.vv:1:8: warning: module 'os' is imported but never used`
	`1`	+vlib/v/checker/tests/os_prefix.vv:1:8: warning: module 'os' is imported but never used. Use `import os as _`, to silence this warning, or just remove the unused import line
`2`	`2`	`1 \| import os`
`3`	`3`	`\| ~~`
`4`	`4`	`2 \|`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-vlib/v/checker/tests/selective_const_import.vv:1:8: warning: module 'time' is imported but never used`
	`1`	+vlib/v/checker/tests/selective_const_import.vv:1:8: warning: module 'time' is imported but never used. Use `import time as _`, to silence this warning, or just remove the unused import line
`2`	`2`	`1 \| import time { second }`
`3`	`3`	`\| ~~~~`
`4`	`4`	vlib/v/checker/tests/selective_const_import.vv:1:15: error: cannot selectively import constant `second` from `time`, import `time` and use `time.second` instead
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-vlib/v/checker/tests/var_decl_import_sym_conflict.vv:1:8: warning: module 'arrays' is imported but never used`
	`1`	+vlib/v/checker/tests/var_decl_import_sym_conflict.vv:1:8: warning: module 'arrays' is imported but never used. Use `import arrays as _`, to silence this warning, or just remove the unused import line
`2`	`2`	`1 \| import arrays`
`3`	`3`	`\| ~~~~~~`
`4`	`4`	`2 \|`
Original file line number	Diff line number	Diff line change
`@@ -89,7 +89,8 @@ fn (mut p Parser) check_unused_imports() {`
`89`	`89`	if !(alias.len == 1 && alias[0] == `_`) && !p.is_used_import(alias)
`90`	`90`	`&& alias !in p.auto_imports {`
`91`	`91`	`mod_alias := if alias == mod { alias } else { '${alias} (${mod})' }`
`92`		`- p.warn_with_pos("module '${mod_alias}' is imported but never used", import_m.mod_pos)`
	`92`	+ p.warn_with_pos("module '${mod_alias}' is imported but never used. Use `import ${mod_alias} as _`, to silence this warning, or just remove the unused import line",
	`93`	`+ import_m.mod_pos)`
`93`	`94`	`}`
`94`	`95`	`}`
`95`	`96`	`}`