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[PATCH] Print void types correctly in Rust
- From: Manish Goregaokar <manish at mozilla dot com>
- To: gdb-patches at sourceware dot org, Tom Tromey <tom at tromey dot com>
- Date: Mon, 27 Jun 2016 21:22:33 +0530
- Subject: [PATCH] Print void types correctly in Rust
- Authentication-results: sourceware.org; auth=none
Rust prefers to not specify the return type of a function when it is unit
(`()`). The type is also referred to as "void" in debuginfo but not in actual
usage, so we should never be printing "void" when the language is Rust.
gdb/ChangeLog:
* rust-lang.c: Print unit types as "()"
* rust-lang.c: Omit return type for functions returning unit
gdb/testsuite/ChangeLog:
2016-06-27 Manish Goregaokar <manish@mozilla.com>
* gdb.rust/simple.rs: Add test for returning unit in a function
* gdb.rust/simple.exp: Add expectation for functions returning unit
---
gdb/rust-lang.c | 22 ++++++++++++++++++----
gdb/testsuite/gdb.rust/simple.exp | 1 +
gdb/testsuite/gdb.rust/simple.rs | 7 +++++++
3 files changed, 26 insertions(+), 4 deletions(-)
diff --git a/gdb/rust-lang.c b/gdb/rust-lang.c
index 0c56a0f..2b115ee 100644
--- a/gdb/rust-lang.c
+++ b/gdb/rust-lang.c
@@ -446,7 +446,7 @@ static const struct generic_val_print_decorations
rust_decorations =
" * I",
"true",
"false",
- "void",
+ "()",
"[",
"]"
};
@@ -729,13 +729,22 @@ rust_print_type (struct type *type, const char *varstring,
if (show <= 0
&& TYPE_NAME (type) != NULL)
{
- fputs_filtered (TYPE_NAME (type), stream);
+ /* Rust calls the unit type "void" in its debuginfo,
+ but we don't want to print it as that. */
+ if (TYPE_CODE (type) == TYPE_CODE_VOID)
+ fputs_filtered ("()", stream);
+ else
+ fputs_filtered (TYPE_NAME (type), stream);
return;
}
type = check_typedef (type);
switch (TYPE_CODE (type))
{
+ case TYPE_CODE_VOID:
+ fputs_filtered ("()", stream);
+ break;
+
case TYPE_CODE_FUNC:
/* Delegate varargs to the C printer. */
if (TYPE_VARARGS (type))
@@ -753,8 +762,13 @@ rust_print_type (struct type *type, const char *varstring,
rust_print_type (TYPE_FIELD_TYPE (type, i), "", stream, -1, 0,
flags);
}
- fputs_filtered (") -> ", stream);
- rust_print_type (TYPE_TARGET_TYPE (type), "", stream, -1, 0, flags);
+ fputs_filtered (")", stream);
+ /* If it returns unit, we can omit the return type. */
+ if (TYPE_CODE (TYPE_TARGET_TYPE (type)) != TYPE_CODE_VOID)
+ {
+ fputs_filtered (" -> ", stream);
+ rust_print_type (TYPE_TARGET_TYPE (type), "", stream, -1, 0, flags);
+ }
break;
case TYPE_CODE_ARRAY:
diff --git a/gdb/testsuite/gdb.rust/simple.exp
b/gdb/testsuite/gdb.rust/simple.exp
index 88f1c89..4622f75 100644
--- a/gdb/testsuite/gdb.rust/simple.exp
+++ b/gdb/testsuite/gdb.rust/simple.exp
@@ -149,6 +149,7 @@ gdb_test "print self::diff2(8, 9)" " = -1"
gdb_test "print ::diff2(23, -23)" " = 46"
gdb_test "ptype diff2" "fn \\(i32, i32\\) -> i32"
+gdb_test "ptype empty" "fn \\(\\)"
gdb_test "print (diff2 as fn(i32, i32) -> i32)(19, -2)" " = 21"
diff --git a/gdb/testsuite/gdb.rust/simple.rs b/gdb/testsuite/gdb.rust/simple.rs
index 32da580..3d28e27 100644
--- a/gdb/testsuite/gdb.rust/simple.rs
+++ b/gdb/testsuite/gdb.rust/simple.rs
@@ -48,6 +48,12 @@ fn diff2(x: i32, y: i32) -> i32 {
x - y
}
+// Empty function, should not have "void"
+// or "()" in its return type
+fn empty() {
+
+}
+
pub struct Unit;
// This triggers the non-zero optimization that yields a different
@@ -111,4 +117,5 @@ fn main () {
println!("{}, {}", x.0, x.1); // set breakpoint here
println!("{}", diff2(92, 45));
+ empty();
}
--
2.8.3