From 67430cd00afcc270a27e44b10f9ef4249d554e66 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Mon, 16 Mar 2020 15:00:52 -0600 Subject: Fix dwarf2_name caching bug PR gdb/25663 points out that dwarf2_name will cache a value in the bcache and then return a substring. However, this substring return is only done on the branch that caches the value -- so if the function is called twice with the same arguments, it will return different values. This patch fixes this problem. This area is strange. We cache the entire demangled string, but only return the suffix. I looked at caching just the suffix, but it turns out that anonymous_struct_prefix assumes that the entire string is stored. Also weird is that this code is demangling the linkage name and then storing the demangled form back into the linkage name attribute -- that seems bad, because what if some code wants to find the actual linkage name? Fixing these issues was non-trivial, though; and in the meantime this patch seems like an improvement. Regression tested on x86-64 Fedora 30. gdb/ChangeLog 2020-03-16 Tom Tromey PR gdb/25663: * dwarf2/read.c (dwarf2_name): Strip leading namespaces after putting value into bcache. --- gdb/ChangeLog | 6 ++++++ gdb/dwarf2/read.c | 18 ++++++++---------- 2 files changed, 14 insertions(+), 10 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 6cb3cb5..9211708 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2020-03-16 Tom Tromey + + PR gdb/25663: + * dwarf2/read.c (dwarf2_name): Strip leading namespaces after + putting value into bcache. + 2020-03-16 Simon Marchi PR gdb/21500 diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index 1706b96..88a60c1 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -21799,19 +21799,17 @@ dwarf2_name (struct die_info *die, struct dwarf2_cu *cu) if (demangled == nullptr) return nullptr; - const char *base; - DW_STRING (attr) = objfile->intern (demangled.get ()); DW_STRING_IS_CANONICAL (attr) = 1; - - /* Strip any leading namespaces/classes, keep only the base name. - DW_AT_name for named DIEs does not contain the prefixes. */ - base = strrchr (DW_STRING (attr), ':'); - if (base && base > DW_STRING (attr) && base[-1] == ':') - return &base[1]; - else - return DW_STRING (attr); } + + /* Strip any leading namespaces/classes, keep only the base name. + DW_AT_name for named DIEs does not contain the prefixes. */ + const char *base = strrchr (DW_STRING (attr), ':'); + if (base && base > DW_STRING (attr) && base[-1] == ':') + return &base[1]; + else + return DW_STRING (attr); } break; -- cgit v1.1