From 921da19854e9f9dba416dc68c57379231c6ca52b Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Fri, 27 Nov 2015 14:48:21 +0000 Subject: [PATCH] PR other/61321 - demangler crash on casts in template parameters The fix for bug 59195: [C++ demangler handles conversion operator incorrectly] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59195 unfortunately makes the demangler crash due to infinite recursion, in case of casts in template parameters. For example, with: template struct A {}; template void function_temp(A) {} template void function_temp(A); The 'function_temp' instantiation above mangles to: _Z13function_tempIiEv1AIXszcvT_Li999EEE The demangler parses this as: typed name template name 'function_temp' template argument list builtin type int function type builtin type void argument list template (*) name 'A' template argument list unary operator operator sizeof unary operator cast template parameter 0 (**) literal builtin type int name '999' And after the fix for 59195, due to: static void d_print_cast (struct d_print_info *dpi, int options, const struct demangle_component *dc) { ... /* For a cast operator, we need the template parameters from the enclosing template in scope for processing the type. */ if (dpi->current_template != NULL) { dpt.next = dpi->templates; dpi->templates = &dpt; dpt.template_decl = dpi->current_template; } when printing the template argument list of A (what should be ""), the template parameter 0 (that is, "T_", the '**' above) now refers to the first parameter of the the template argument list of the 'A' template (the '*' above), exactly what we were already trying to print. This leads to infinite recursion, and stack exaustion. The template parameter 0 should actually refer to the first parameter of the 'function_temp' template. Where it reads "for the cast operator" in the comment in d_print_cast (above), it's really talking about a conversion operator, like: struct A { template explicit operator U(); }; We don't want to inject the template parameters from the enclosing template in scope when processing a cast _expression_, only when handling a conversion operator. The problem is that DEMANGLE_COMPONENT_CAST is currently ambiguous, and means _both_ 'conversion operator' and 'cast expression'. Fix this by adding a new DEMANGLE_COMPONENT_CONVERSION component type, which does what DEMANGLE_COMPONENT_CAST does today, and making DEMANGLE_COMPONENT_CAST just simply print its component subtree. I think we could instead reuse DEMANGLE_COMPONENT_CAST and in d_print_comp_inner still do: @@ -5001,9 +5013,9 @@ d_print_comp_inner (struct d_print_info *dpi, int options, d_print_comp (dpi, options, dc->u.s_extended_operator.name); return; case DEMANGLE_COMPONENT_CAST: d_append_string (dpi, "operator "); - d_print_cast (dpi, options, dc); + d_print_conversion (dpi, options, dc); return; leaving the unary cast case below calling d_print_cast, but seems to me that spliting the component types makes it easier to reason about the code. g++'s testsuite actually generates three symbols that crash the demangler in the same way. I've added those as tests in the demangler testsuite as well. And then this fixes PR other/61233 too, which happens to be a demangler crash originally reported to GDB, at: https://sourceware.org/bugzilla/show_bug.cgi?id=16957 Bootstrapped and regtested on x86_64 Fedora 20. Also ran this through GDB's testsuite. GDB will require a small update to use DEMANGLE_COMPONENT_CONVERSION in one place it's using DEMANGLE_COMPONENT_CAST in its sources. libiberty/ 2015-11-27 Pedro Alves PR other/61321 PR other/61233 * demangle.h (enum demangle_component_type) : New value. * cp-demangle.c (d_demangle_callback, d_make_comp): Handle DEMANGLE_COMPONENT_CONVERSION. (is_ctor_dtor_or_conversion): Handle DEMANGLE_COMPONENT_CONVERSION instead of DEMANGLE_COMPONENT_CAST. (d_operator_name): Return a DEMANGLE_COMPONENT_CONVERSION component if handling a conversion. (d_count_templates_scopes, d_print_comp_inner): Handle DEMANGLE_COMPONENT_CONVERSION. (d_print_comp_inner): Handle DEMANGLE_COMPONENT_CONVERSION instead of DEMANGLE_COMPONENT_CAST. (d_print_cast): Rename as ... (d_print_conversion): ... this. Adjust comments. (d_print_cast): Rewrite - simply print the left subcomponent. * cp-demint.c (cplus_demangle_fill_component): Handle DEMANGLE_COMPONENT_CONVERSION. * testsuite/demangle-expected: Add tests. From-SVN: r231020 --- include/demangle.h | 4 +++ libiberty/ChangeLog | 24 +++++++++++++++++ libiberty/cp-demangle.c | 37 +++++++++++++++++++++------ libiberty/cp-demint.c | 1 + libiberty/testsuite/demangle-expected | 23 +++++++++++++++++ 5 files changed, 81 insertions(+), 8 deletions(-) diff --git a/include/demangle.h b/include/demangle.h index f4c41218e7f..1d7cadf4b71 100644 --- a/include/demangle.h +++ b/include/demangle.h @@ -379,6 +379,10 @@ enum demangle_component_type /* A typecast, represented as a unary operator. The one subtree is the type to which the argument should be cast. */ DEMANGLE_COMPONENT_CAST, + /* A conversion operator, represented as a unary operator. The one + subtree is the type to which the argument should be converted + to. */ + DEMANGLE_COMPONENT_CONVERSION, /* A nullary expression. The left subtree is the operator. */ DEMANGLE_COMPONENT_NULLARY, /* A unary expression. The left subtree is the operator, and the diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog index de47a87d10d..673123c8e05 100644 --- a/libiberty/ChangeLog +++ b/libiberty/ChangeLog @@ -1,3 +1,27 @@ +2015-11-27 Pedro Alves + + PR other/61321 + PR other/61233 + * demangle.h (enum demangle_component_type) + : New value. + * cp-demangle.c (d_demangle_callback, d_make_comp): Handle + DEMANGLE_COMPONENT_CONVERSION. + (is_ctor_dtor_or_conversion): Handle DEMANGLE_COMPONENT_CONVERSION + instead of DEMANGLE_COMPONENT_CAST. + (d_operator_name): Return a DEMANGLE_COMPONENT_CONVERSION + component if handling a conversion. + (d_count_templates_scopes, d_print_comp_inner): Handle + DEMANGLE_COMPONENT_CONVERSION. + (d_print_comp_inner): Handle DEMANGLE_COMPONENT_CONVERSION instead + of DEMANGLE_COMPONENT_CAST. + (d_print_cast): Rename as ... + (d_print_conversion): ... this. Adjust comments. + (d_print_cast): Rewrite - simply print the left subcomponent. + * cp-demint.c (cplus_demangle_fill_component): Handle + DEMANGLE_COMPONENT_CONVERSION. + + * testsuite/demangle-expected: Add tests. + 2015-11-12 Mike Stump * Makefile.in (etags tags TAGS): Use && instead of ;. diff --git a/libiberty/cp-demangle.c b/libiberty/cp-demangle.c index ff608a36d67..bd64bef8cf7 100644 --- a/libiberty/cp-demangle.c +++ b/libiberty/cp-demangle.c @@ -542,8 +542,10 @@ d_print_array_type (struct d_print_info *, int, static void d_print_expr_op (struct d_print_info *, int, const struct demangle_component *); -static void -d_print_cast (struct d_print_info *, int, const struct demangle_component *); +static void d_print_cast (struct d_print_info *, int, + const struct demangle_component *); +static void d_print_conversion (struct d_print_info *, int, + const struct demangle_component *); static int d_demangle_callback (const char *, int, demangle_callbackref, void *); @@ -736,6 +738,9 @@ d_dump (struct demangle_component *dc, int indent) case DEMANGLE_COMPONENT_CAST: printf ("cast\n"); break; + case DEMANGLE_COMPONENT_CONVERSION: + printf ("conversion operator\n"); + break; case DEMANGLE_COMPONENT_NULLARY: printf ("nullary operator\n"); break; @@ -945,6 +950,7 @@ d_make_comp (struct d_info *di, enum demangle_component_type type, case DEMANGLE_COMPONENT_IMAGINARY: case DEMANGLE_COMPONENT_VENDOR_TYPE: case DEMANGLE_COMPONENT_CAST: + case DEMANGLE_COMPONENT_CONVERSION: case DEMANGLE_COMPONENT_JAVA_RESOURCE: case DEMANGLE_COMPONENT_DECLTYPE: case DEMANGLE_COMPONENT_PACK_EXPANSION: @@ -1238,7 +1244,7 @@ is_ctor_dtor_or_conversion (struct demangle_component *dc) return is_ctor_dtor_or_conversion (d_right (dc)); case DEMANGLE_COMPONENT_CTOR: case DEMANGLE_COMPONENT_DTOR: - case DEMANGLE_COMPONENT_CAST: + case DEMANGLE_COMPONENT_CONVERSION: return 1; } } @@ -1804,11 +1810,16 @@ d_operator_name (struct d_info *di) { struct demangle_component *type; int was_conversion = di->is_conversion; + struct demangle_component *res; di->is_conversion = ! di->is_expression; type = cplus_demangle_type (di); + if (di->is_conversion) + res = d_make_comp (di, DEMANGLE_COMPONENT_CONVERSION, type, NULL); + else + res = d_make_comp (di, DEMANGLE_COMPONENT_CAST, type, NULL); di->is_conversion = was_conversion; - return d_make_comp (di, DEMANGLE_COMPONENT_CAST, type, NULL); + return res; } else { @@ -3928,6 +3939,7 @@ d_count_templates_scopes (int *num_templates, int *num_scopes, case DEMANGLE_COMPONENT_TEMPLATE_ARGLIST: case DEMANGLE_COMPONENT_INITIALIZER_LIST: case DEMANGLE_COMPONENT_CAST: + case DEMANGLE_COMPONENT_CONVERSION: case DEMANGLE_COMPONENT_NULLARY: case DEMANGLE_COMPONENT_UNARY: case DEMANGLE_COMPONENT_BINARY: @@ -5064,9 +5076,9 @@ d_print_comp_inner (struct d_print_info *dpi, int options, d_print_comp (dpi, options, dc->u.s_extended_operator.name); return; - case DEMANGLE_COMPONENT_CAST: + case DEMANGLE_COMPONENT_CONVERSION: d_append_string (dpi, "operator "); - d_print_cast (dpi, options, dc); + d_print_conversion (dpi, options, dc); return; case DEMANGLE_COMPONENT_NULLARY: @@ -5805,11 +5817,20 @@ d_print_expr_op (struct d_print_info *dpi, int options, static void d_print_cast (struct d_print_info *dpi, int options, - const struct demangle_component *dc) + const struct demangle_component *dc) +{ + d_print_comp (dpi, options, d_left (dc)); +} + +/* Print a conversion operator. */ + +static void +d_print_conversion (struct d_print_info *dpi, int options, + const struct demangle_component *dc) { struct d_print_template dpt; - /* For a cast operator, we need the template parameters from + /* For a conversion operator, we need the template parameters from the enclosing template in scope for processing the type. */ if (dpi->current_template != NULL) { diff --git a/libiberty/cp-demint.c b/libiberty/cp-demint.c index 1d1a77af748..efcc5b7f5c0 100644 --- a/libiberty/cp-demint.c +++ b/libiberty/cp-demint.c @@ -110,6 +110,7 @@ cplus_demangle_fill_component (struct demangle_component *p, case DEMANGLE_COMPONENT_IMAGINARY: case DEMANGLE_COMPONENT_VENDOR_TYPE: case DEMANGLE_COMPONENT_CAST: + case DEMANGLE_COMPONENT_CONVERSION: if (right != NULL) return 0; break; diff --git a/libiberty/testsuite/demangle-expected b/libiberty/testsuite/demangle-expected index 041b113d63f..aebf01b3add 100644 --- a/libiberty/testsuite/demangle-expected +++ b/libiberty/testsuite/demangle-expected @@ -4398,3 +4398,26 @@ std::ios_base::failure[abi:cxx11]::failure --format=gnu-v3 _Z1fPDxFvvES0_ f(void (*)() transaction_safe, void (*)() transaction_safe) +# +# These two are from gcc PR61321, and gcc PR61233 / gdb PR16957 +# +--format=gnu-v3 +_Z13function_tempIiEv1AIXszcvT_Li999EEE +void function_temp(A) +# +--format=gnu-v3 +_Z7ZipWithI7QStringS0_5QListZN4oral6detail16AdaptCreateTableI7AccountEES0_RKNS3_16CachedFieldsDataEEUlRKS0_SA_E_ET1_IDTclfp1_cvT__EcvT0__EEEERKT1_ISC_ERKT1_ISD_ET2_ +QList ZipWith(oral::detail::CachedFieldsData const&)::{lambda(QString const&, QString const&)#1}>(QList(oral::detail::CachedFieldsData const&)::{lambda(QString const&, QString const&)#1}> const&, QList const&, QString oral::detail::AdaptCreateTable(oral::detail::CachedFieldsData const&)::{lambda(QString const&, QString const&)#1}) +# +# These three are symbols generated by g++'s testsuite, which triggered the same bug as above. +--format=gnu-v3 +_Z14int_if_addableI1YERiP1AIXszpldecvPT_Li0EdecvS4_Li0EEE +int& int_if_addable(A*) +# +--format=gnu-v3 +_Z3bazIiEvP1AIXszcl3foocvT__ELCf00000000_00000000EEEE +void baz(A*) +# +--format=gnu-v3 +_Z3fooI1FEN1XIXszdtcl1PclcvT__EEE5arrayEE4TypeEv +X::Type foo() -- 2.30.2