diff options
Diffstat (limited to 'PR82155.patch')
| -rw-r--r-- | PR82155.patch | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/PR82155.patch b/PR82155.patch new file mode 100644 index 000000000000..f55bb934c0b0 --- /dev/null +++ b/PR82155.patch @@ -0,0 +1,119 @@ +From: Pierre-Marie de Rodat <derodat at adacore dot com> +To: gcc-patches at gcc dot gnu dot org +Cc: Pierre-Marie de Rodat <derodat at adacore dot com> +Subject: [PATCH] [PR82155] Fix crash in dwarf2out_abstract_function +Date: Tue, 12 Sep 2017 08:00:03 +0200 +Message-Id: <20170912060003.32378-1-derodat@adacore.com> +X-IsSubscribed: yes + +Hello, + +This patch is an attempt to fix the crash reported in PR82155. + +When generating a C++ class method for a class that is itself nested in +a class method, dwarf2out_early_global_decl currently leaves the +existing context DIE as it is if it already exists. However, it is +possible that this call happens at a point where this context DIE is +just a declaration that is itself not located in its own context. + +>From there, if dwarf2out_early_global_decl is not called on any of the +FUNCTION_DECL in the context chain, DIEs will be left badly scoped and +some (such as the nested method) will be removed by the type pruning +machinery. As a consequence, dwarf2out_abstract_function will will +crash when called on the corresponding DECL because it asserts that the +DECL has a DIE. + +This patch fixes this crash making dwarf2out_early_global_decl process +context DIEs the same way we process abstract origins for FUNCTION_DECL: +if the corresponding DIE exists but is only a declaration, call +dwarf2out_decl anyway on it so that it is turned into a more complete +DIE and so that it is relocated in the proper context. + +Bootstrapped and regtested on x86_64-linux. The crash this addresses is +present both on trunk and on the gcc-7 branch: I suggest we commit this +patch on both branches. Ok to commit? Thank you in advance! + +gcc/ + + PR debug/82155 + * dwarf2out.c (dwarf2out_early_global_decl): Call dwarf2out_decl + on the FUNCTION_DECL function context if it has a DIE that is a + declaration. + +gcc/testsuite/ + + * g++.dg/pr82155.C: New testcase. +--- + gcc/dwarf2out.c | 10 ++++++++-- + gcc/testsuite/g++.dg/pr82155.C | 36 ++++++++++++++++++++++++++++++++++++ + 2 files changed, 44 insertions(+), 2 deletions(-) + create mode 100644 gcc/testsuite/g++.dg/pr82155.C + +diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c +index 00d6d951ba3..4cfc9c186af 100644 +--- a/gcc/dwarf2out.c ++++ b/gcc/dwarf2out.c +@@ -25500,10 +25500,16 @@ dwarf2out_early_global_decl (tree decl) + so that all nested DIEs are generated at the proper scope in the + first shot. */ + tree context = decl_function_context (decl); +- if (context != NULL && lookup_decl_die (context) == NULL) ++ if (context != NULL) + { ++ dw_die_ref context_die = lookup_decl_die (context); + current_function_decl = context; +- dwarf2out_decl (context); ++ ++ /* Avoid emitting DIEs multiple times, but still process CONTEXT ++ enough so that it lands in its own context. This avoids type ++ pruning issues later on. */ ++ if (context_die == NULL || is_declaration_die (context_die)) ++ dwarf2out_decl (context); + } + + /* Emit an abstract origin of a function first. This happens +diff --git a/gcc/testsuite/g++.dg/pr82155.C b/gcc/testsuite/g++.dg/pr82155.C +new file mode 100644 +index 00000000000..75d9b615f39 +--- /dev/null ++++ b/gcc/testsuite/g++.dg/pr82155.C +@@ -0,0 +1,36 @@ ++/* { dg-do compile { target c++11 } } */ ++/* { dg-options "-g -O2" } */ ++ ++template <typename a> struct b { a c; }; ++template <typename d> struct e { d *operator->(); }; ++template <typename d> class h { ++public: ++ typedef e<d> ag; ++}; ++class i { ++protected: ++ i(int); ++}; ++class j { ++ virtual void k(int) = 0; ++ ++public: ++ int f; ++ void l() { k(f); } ++}; ++struct m : i { ++ int cn; ++ m() : i(cn) { ++ struct n : j { ++ n() {} ++ void k(int) {} ++ }; ++ } ++}; ++struct o { ++ o() { ++ for (h<b<b<j *>>>::ag g;;) ++ g->c.c->l(); ++ } ++}; ++void fn1() { o(); } +-- +2.14.1 + |