From 80062eb94959467fb0c27b988b87ac08dada4bd8 Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Thu, 2 May 2019 00:40:01 +0100 Subject: gdb/rust: Handle printing structures containing strings When printing a rust structure that contains a string GDB can currently fail to read the fields that define the string. This is because GDB mistakenly treats a value that is the parent structure as though it is the structure that defines the string, and then fails to find the fields needed to extract a string. The solution is to create a new value to represent the string field of the parent value. gdb/ChangeLog: * rust-lang.c (val_print_struct): Handle printing structures containing strings. gdb/testsuite/ChangeLog: * gdb.rust/simple.exp: Add new test case. * gdb.rust/simple.rs (struct StringAtOffset): New struct. (main): Initialise an instance of the new struct. --- gdb/rust-lang.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'gdb/rust-lang.c') diff --git a/gdb/rust-lang.c b/gdb/rust-lang.c index 2fada46..79f1331 100644 --- a/gdb/rust-lang.c +++ b/gdb/rust-lang.c @@ -378,6 +378,14 @@ val_print_struct (struct type *type, int embedded_offset, if (rust_slice_type_p (type) && strcmp (TYPE_NAME (type), "&str") == 0) { + /* If what we are printing here is actually a string within a + structure then VAL will be the original parent value, while TYPE + will be the type of the structure representing the string we want + to print. + However, RUST_VAL_PRINT_STR looks up the fields of the string + inside VAL, assuming that VAL is the string. + So, recreate VAL as a value representing just the string. */ + val = value_at_lazy (type, value_address (val) + embedded_offset); rust_val_print_str (stream, val, options); return; } -- cgit v1.1