gcc/:
	PR c/37303
	* c-decl.c (build_compound_literal): Make the decl readonly if it
	an array of a readonly type.
	* gimplify.c (gimplify_compound_literal_expr): Add fallback
	parameter.  Change all callers.  If the decl is not addressable
	and is not an l-value, make it readonly.
gcc/testsuite:
	PR c/37303
	* gcc.dg/pr37303.c: New test.

From-SVN: r187027

2012-05-01  François Dumont  <fdumont@gcc.gnu.org>

	PR libstdc++/53115
	* include/bits/hashtable.h
	(_Hashtable<>::_M_rehash_aux(size_type, false_type)): Fix buckets
	after insertion of several equivalent elements.
	* testsuite/23_containers/unordered_multiset/insert/53115.cc: New.
	* testsuite/23_containers/unordered_multimap/insert/53115.cc: New.

From-SVN: r187025

	* ira.c (allocated_reg_info_size): New static variable.
	(expand_reg_info): Manage it. Call
	setup_preferred_alternate_classes_for_new_pseudos.
	(ira): Don't do it here.  Remove local allocated_reg_info_size,
	set the global before calling find_moveable_pseudos.
	(find_moveable_pseudos): Call expand_reg_info rather than
	resize_reg_info.

From-SVN: r187019

From-SVN: r187018

        * common.opt (fsync-libcalls): New.
        * doc/invoke.texi: Document it.
        * optabs.c (init_sync_libfuncs): Honor it.

From-SVN: r187017

        (check_effective_target_sync_long_long_runtime): True for
        check_effective_target_powerpc64.

From-SVN: r187016

gcc/
2012-03-31  Kenneth Zadeck  <zadeck@naturalbridge.com>
	    Richard Sandiford  <r.sandiford@uk.ibm.com>

	* Makefile.in (lower-subreg.o, target-globals.o): Depend on
	lower-subreg.h.
	* lower-subreg.h: New file.
	* target-globals.h (this_target_lower_subreg): Declare.
	(target_globals): Add lower_subreg;
	(restore_target_globals): Restore this_target_lower_subreg.
	* target-globals.c: Include it.
	(default_target_globals): Add default_target_lower_subreg.
	(save_target_globals): Initialize target_lower_subreg.
	* rtl.h (init_lower_subreg): Added declaration.
	* toplev.c (backend_init_target): Call initializer for lower-subreg
	pass.
	* lower-subreg.c (LOG_COSTS, FORCE_LOWERING): New macros.
	(default_target_lower_subreg): New variable.
	(this_target_lower_subreg): Likewise.
	(twice_word_mode, choices): New macros.
	(shift_cost, compute_splitting_shift, compute_costs)
	(init_lower_subreg): New functions.
	(resolve_simple_move): Add speed_p argument.  Check choices.
	(find_pseudo_copy): Don't check the mode size here.
	(resolve_simple_move): Assert the mode size.
	(find_decomposable_shift_zext): Add speed_p argument and return
	a bool.  Check choices.
	(resolve_shift_zext): Add comment.
	(dump_shift_choices, dump_choices): New functions.
	(decompose_multiword_subregs): Dump list of profitable
	transformations.  Add code to skip non profitable transformations.
	Update calls to simple_move and find_decomposable_shift_zext.

Co-Authored-By: Richard Sandiford <r.sandiford@uk.ibm.com>

From-SVN: r187015

2012-05-01  Ian Bolton  <ian.bolton@arm.com>
            Sameera Deshpande  <sameera.deshpande@arm.com>
            Greta Yorsh  <greta.yorsh@arm.com>

	* config/arm/arm-protos.h (thumb_unexpanded_epilogue): Rename to...
        (thumb1_unexpanded_epilogue): ...this.
	* config/arm/arm.c (thumb_unexpanded_epilogue): Rename to...
        (thumb1_unexpanded_epilogue): ...this.
	* config/arm/arm.md (thumb_unexpanded_epilogue): Rename to...
        (thumb1_unexpanded_epilogue): ...this.



Co-Authored-By: Greta Yorsh <greta.yorsh@arm.com>
Co-Authored-By: Sameera Deshpande <sameera.deshpande@arm.com>

From-SVN: r187014

2012-05-01  Greta Yorsh  <Greta.Yorsh@arm.com>

	* MAINTAINERS (Write After Approval): Add myself.

From-SVN: r187013

	* arm/linux-eabi.h (GLIBC_DYNAMIC_LINKER_DEFAULT): Avoid ifdef
	comparing enumeration values.  Update comments.

From-SVN: r187012

	PR target/53038
	* config/rs6000/rs6000.c (load_lr_save, restore_saved_lr,
	load_cr_save, add_crlr_cfa_restore): New functions.
	(rs6000_restore_saved_cr): Rename to..
	(restore_saved_cr): ..this.  Add cfa_restore notes for cr.
	(rs6000_emit_epilogue): Use new functions.  Adjust condition
	for emitting lr and cr cfa_restore.  Emit cfa_restores for fp
	regs when using out-of-line restore only when shrink wrapping.

From-SVN: r187010

From-SVN: r187007

re PR middle-end/53136 (Use after free in ipa_make_edge_direct_to_target, cxx_printable_name_internal problem)

	PR middle-end/53136
	* ipa-prop.c (ipa_print_node_jump_functions): Wrap multiple
	calls to cgraph_node_name in xstrdup.
	(ipa_make_edge_direct_to_target): Ditto.
	* cgraph.c (dump_cgraph_node): Ditto.
	* tree-sra.c (convert_callers_for_node): Ditto.
	* lto-symtab.c (lto_cgraph_replace_node): Ditto.
	* ipa-cp.c (perhaps_add_new_callers): Ditto.
	* cgraphunit.c (cgraph_redirect_edge_call_stmt_to_callee): Ditto.
	(cgraph_materialize_all_clones): Ditto.
	* ipa-inline.c (report_inline_failed_reason): Ditto.
	(want_early_inline_function_p): Ditto.
	(edge_badness): Ditto.
	(update_edge_key): Ditto.
	(flatten_function): Ditto.
	(ipa_inline): Ditto.
	(inlinw_always_inline_functions): Ditto.
	(early_inline_small_functions): Ditto.

From-SVN: r187001

	PR target/53141
	* config/i386/i386.md (*umul<mode><dwi>3_1): Switch places of
	constraints 0 and 1.

From-SVN: r187000

	* cgraph.c (ld_plugin_symbol_resolution_names): Move to symtab.c
	(cgraph_asm_nodes, cgraph_asm_last_node): Move to cgraphunit.c
	(cgraph_add_to_same_comdat_group): Remove.
	(cgraph_add_asm_node): Move to cgraphunit.c.
	(cgraph_make_decl_local): Move to symtab.c
	(cgraph_make_node_local_1): Update.
	(cgraph_can_remove_if_no_direct_calls_and): Update.
	(used_from_object_file_p): Update.
	(resolution_used_from_other_file_p): Move to symtab.c
	(cgraph_used_from_object_file_p): move to symtab.c
	(verify_cgraph_node): Verify same comdat groups.
	* cgraph.h (cgraph_asm_node): Rename to ...
	(asm_node): ... this one.
	(cgraph_asm_nodes): Rename to ...
	(asm_nodes): ... this one.
	(symtab_add_to_same_comdat_group): New function.
	(symtab_dissolve_same_comdat_group_list): New function.
	(symtab_used_from_object_file_p): Declare.
	(symtab_make_decl_local): Declare.
	(cgraph_add_to_same_comdat_group): Remove.
	(cgraph_add_asm_node): Remove.
	(cgraph_used_from_object_file_p, varpool_used_from_object_file_p):
	Remove.
	(cgraph_finalize_compilation_unit): Rename to ...
	(finalize_compilation_unit): ... this one.
	(cgraph_optimize): Rename to ....
	(compile): ... this one.
	(add_asm_node): Declare.
	(fixup_same_cpp_alias_visibility): Declare.
	(cgraph_make_decl_local): Remove.
	(varpool_assemble_pending_decls): Rename to ...
	(varpool_output_variables): ... this one.
	(varpool_remove_unreferenced_decls): Remove.
	* ipa-inline-transform.c (clone_inlined_nodes): Dissolve comdat groups.
	(preserve_function_body_p): Make static.
	* toplev.c (compile_file): Update comments;
	update.
	* cgraphunit.c: Update comments.
	(cgraph_expand_all_functions): Rename to ...
	(expand_all_functions): ... this one; update.
	(cgraph_mark_functions_to_output): Rename to ...
	(mark_functions_to_output): ... this one; cleanup.
	(cgraph_output_pending_asms): Remove prototype.
	(asm_nodes, asm_last_node): New static vars.
	(cgraph_process_new_functions): Update.
	(cgraph_reset_node): Cleanup; add comment.
	(cgraph_add_new_function): Update.
	(cgraph_output_pending_asms): Rename to ...
	(output_asm_statements): ... this one.
	(add_asm_node): New function.
	(fixup_same_cpp_alias_visibility): New function based on code
	in cgraph_analyze_function.
	(cgraph_analyze_function): Use it.
	(cgraph_order_sort): Update.
	(cgraph_output_in_order): Update.
	(cgraph_function_versioning): Update.
	(cgraph_optimize): Rename to ...
	(compile): ... this one; initialize streamer hooks here.
	(cgraph_finalize_compilation_unit): Rename to ...
	(finalize_compilation_unit): ... this one; do not initialize streamer
	hook here.
	* lto-streamer-out.c (lto_output_toplevel_asms): Update.
	* dwarf2out.c: Update ocmment.
	* optimize.c (maybe_clone_body): Use symtab_add_to_same_comdat_group.
	* method.c (use_thunk): Likewise.
	* semantics.c (maybe_add_lambda_conv_op): Likewise.
	* decl2.c (maybe_emit_vtables): Likewise.	
	(cp_write_global_declarations): Use finalize_compilation_unit.
	* parser.c (cp_parser_asm_definition): Use add_asm_node.
	* lto-streamer-in.c (lto_input_toplevel_asms): Use add_asm_node
	* c-decl.c (c_write_global_declarations): Use finalize_compilation_unit.
	* langhooks.c (write_global_declarations): Update.
	* ipa.c (cgraph_externally_visible_p): Update.
	(dissolve_same_comdat_group_list): Remove.
	(function_and_variable_visibility): Update.
	* symtab.c: Inlcude lto-streamer.h and rtl.h
	(ld_plugin_symbol_resolution_names): New.
	(symtab_add_to_same_comdat_group): New.
	(symtab_dissolve_same_comdat_group_list): New.
	(resolution_used_from_other_file_p): Move here from cgraph.c
	(symtab_used_from_object_file_p): New.
	(symtab_make_decl_local): New.
	* passes.c (register_pass): Update comments.
	* c-parser.c (c_parser_asm_definition): Update.
	* varpool.c (varpool_analyze_node): Use fixup_same_cpp_alias_visibility.
	(varpool_remove_unreferenced_decls): Make static.
	(varpool_assemble_pending_decls): Rename to ...
	(varpool_output_variables): ... this one; call
	varpool_remove_unreferenced_decls.
	(varpool_used_from_object_file_p): Remove.

	* gogo-tree.cc (Gogo::write_globals): Use finalize_compilation_unit.

	* gcc-interface/utils.c (rest_of_subprog_body_compilation): Update
	comment.
	(gnat_write_global_declarations): Use finalize_compilation_unit.

	* f95-lang.c (gfc_finish): Update comments.

	* lto.c (lto_main): Use compile ().
	* lto-partition.c (partition_cgraph_node_p): Use symtab_used_from_object_file_p.
	(partition_varpool_node_p): Likewise.

From-SVN: r186998

	PR c++/51033
gcc/
	* c-typeck.c (build_array_ref): Call
	convert_vector_to_pointer_for_subscript.
gcc/c-family
	* c-common.c (convert_vector_to_pointer_for_subscript): New function.
	* c-common.h (convert_vector_to_pointer_for_subscript): Declare it.
gcc/cp/
	* typeck.c (cp_build_array_ref): Handle VECTOR_TYPE.
	* decl2.c (grok_array_decl): Likewise.

From-SVN: r186994

i386.md (and<mode>3): Change runtime operand mode checks to compile-time "mode == <MODE>mode" checks.

	* config/i386/i386.md (and<mode>3): Change runtime operand mode checks
	to compile-time "mode == <MODE>mode" checks.
	(and splitter): Ditto.

From-SVN: r186993

From-SVN: r186992

2012-04-30  Manuel López-Ibáñez  <manu@gcc.gnu.org>
	    Dodji Seketeli  <dodji@seketeli.org>

	PR c++/52974
	* libcpp/files.c (maybe_shorter_path): New.
	(find_file_in_dir): Use it.

Co-Authored-By: Dodji Seketeli <dodji@seketeli.org>

From-SVN: r186991

        * config/arm/arm.md (UNSPEC_LL): New.
        * config/arm/sync.md (atomic_loaddi, atomic_loaddi_1): New.
        (arm_load_exclusivedi): Use %H0.

From-SVN: r186990

	* dwarf2out.c (comdat_symbol_id): Add const.
	(union die_symbol_or_type_node): Add const to die_symbol.
	(output_die_symbol, output_die, output_comp_unit): Adjust.

From-SVN: r186989

	PR c++/51314
	* parser.c (cp_parser_sizeof_operand): Require parentheses for
	sizeof...

From-SVN: r186988

re PR go/52586 (libgo fails to build for mips*64-linux-gnu (reference to undefined name 'SYS_GETDENTS64'))

	PR go/52586
mksysinfo, syscall: Make sure SYS_GETDENTS64 is defined.

Fixes build on MIPS GNU/Linux.

From-SVN: r186986

dg-warning and dg-options.

From-SVN: r186985

2012-04-30  Andrew Stubbs  <ams@codesourcery.com>

	* config/arm/arm.md (negdi2): Use gen_negdi2_neon.
	* config/arm/neon.md (negdi2_neon): New insn.
	Also add splitters for core and NEON registers.

From-SVN: r186984

2012-04-30  Andrew Stubbs  <ams@codesourcery.com>

	* config/arm/arm.c (neon_valid_immediate): Allow const_int.
	(arm_print_operand): Add 'x' format.
	* config/arm/constraints.md (Dn): Allow const_int.
	* config/arm/neon.md (neon_mov<mode>): Use VDX to allow DImode.
	Use 'x' format to print constants.
	* config/arm/predicates.md (imm_for_neon_mov_operand): Allow const_int.
	* config/arm/vfp.md (movdi_vfp): Disable for const_int when neon
	is enabled.
	(movdi_vfp_cortexa8): Likewise.

From-SVN: r186983

From-SVN: r186982

2012-04-24  Ian Bolton  <ian.bolton at arm.com>
            Sameera Deshpande  <sameera.deshpande at arm.com>
            Greta Yorsh  <greta.yorsh at arm.com>

        * config/arm/arm-protos.h (ldm_stm_operation_p): New parameters.
        * config/arm/arm.c (ldm_stm_operation_p): New parameters.
        * config/arm/predicates.md (load_multiple_operation): Add arguments.
        (store_multiple_operation): Likewise.

Co-Authored-By: Greta Yorsh <greta.yorsh@arm.com>
Co-Authored-By: Sameera Deshpande <sameera.deshpande@arm.com>

From-SVN: r186981

2012-04-30  Ian Bolton	<ian.bolton at arm.com>
	    Sameera Deshpande  <sameera.deshpande at arm.com>
	    Greta Yorsh	 <greta.yorsh at arm.com>

	* config/arm/arm-protos.h (ldm_stm_operation_p): New declaration.
	* config/arm/arm.c (ldm_stm_operation_p): New function.
	* config/arm/predicates.md (load_multiple_operation): Update predicate.
	(store_multiple_operation): Likewise.

Co-Authored-By: Greta Yorsh <greta.yorsh@arm.com>
Co-Authored-By: Sameera Deshpande <sameera.deshpande@arm.com>

From-SVN: r186980

	* config/i386/i386.md (and<mode>3): Expand masking operations with
	0xff, 0xffff or 0xffffffff immediates to corresponding zero_extend RTX.
	(and splitter): Split to DImode zero_extend RTX for DImode operand[0].

From-SVN: r186979

Several warnings related to questionable usage cases of variadic
function related macros (like va_start) could not be controlled by any
warning-related macro.  Fixed thus, by introducing the -Wvarargs
option.

Tested on x86_64-unknown-linux-gnu against trunk.

gcc/c-family/

	* c.opt (Wvarargs):  Define new option.

gcc/
	* builtins.c (fold_builtin_next_arg):  Use OPT_Wvarargs as an
	argument for the various warning_at calls.

gcc/doc/

	* invoke.texi: Update the documentation.

gcc/testsuite/

	* c-c++-common/Wvarargs.c: New test case.
	* c-c++-common/Wvarargs-2.c: Likewise.

From-SVN: r186978

This switches the compiler to -ftrack-macro-expansion=2 by default.

Tested and bootstrapped on x86_64-unknown-linux-gnu against trunk.

libcpp/

	* init.c (cpp_create_reader): Switch -ftrack-macro-expansion=2 on
	by default.  Add comments.

gcc/docs/

	* cppopts.texi: Adjust for enabling -ftrack-macro-expansion=2 by
	default.

From-SVN: r186977

Even after all the patches I have already submitted, some test cases
where errors happens on tokens that are defined in macros see their
output change in an incompatible way, when you run them with or
without -ftrack-macro-expansion.

I think this is expected, because the (spelling) locus inside the
definition of the macro pointed to with -ftrack-macro-expansion is
different from the locus of the expansion point of the macro pointed
to without -ftrack-macro-expansion.

In those cases this patch either adjusts the test case and forces it
be run either with -ftrack-macro-expansion, or it just forces it to be
run without -ftrack-macro-expansion.

There are so many libstdc++ tests that were failing because of that
benign issue that I preferred to just run them with
-ftrack-macro-expansion diabled, after inspecting each of them to be
sure there was nothing more serious underneath.

Boostrapped on x86_64-unknown-linux-gnu against trunk with and without
-ftrack-macro-expansion turned on.

gcc/testsuite/

	* objc.dg/foreach-7.m: Force the test case to run without
	-ftrack-macro-expansion.
	* c-c++-common/tm/attrib-1.c: Likewise.
	* c-c++-common/warn-ommitted-condop.c: Likewise.
	* gcc.dg/assign-warn-1.c: Likewise.
	* gcc.dg/assign-warn-2.c: Likewise.
	* gcc.dg/attr-alloc_size.c: Likewise.
	* gcc.dg/builtin-stringop-chk-1.c: Likewise.
	* gcc.dg/builtin-stringop-chk-2.c: Likewise.
	* gcc.dg/builtin-strncat-chk-1.c: Likewise.
	* gcc.dg/c90-const-expr-9.c: Likewise.
	* gcc.dg/c99-const-expr-9.c: Likewise.
	* gcc.dg/cpp/direct2.c: Likewise.  Adjust.
	* gcc.dg/cpp/direct2s.c: Likewise.
	* gcc/testsuite/gcc.dg/cpp/pr28709.c: Likewise.
	* gcc.dg/cpp/pragma-diagnostic-1.c: Likewise.
	* gcc.dg/dfp/composite-type.c: Likewise.
	* gcc.dg/uninit-6-O0.c: Adjust the test case and force it to run
	with -ftrack-macro-expansion
	* g++.dg/cpp0x/constexpr-ex3.C: Likewise.
	* g++.dg/cpp0x/constexpr-overflow.C: Likewise.
	* g++.dg/ext/cleanup-1.C: Likewise.
	* g++.dg/ext/gnu-inline-global-reject.C: Likewise.
	* g++.dg/template/sfinae10.C: Likewise.
	* g++.dg/tm/wrap-2.C: Likewise.
	* g++.dg/warn/Wconversion-real-integer.C: Likewise.
	* g++.dg/warn/Wsign-conversion.C: Likewise.
	* g++.dg/warn/multiple-overflow-warn-1.C: Likewise.
	* g++.old-deja/g++.mike/p10769b.C: Likewise.
	* g++.dg/warn/Wdouble-promotion.C: Adjust the test case and force
	it to run with -ftrack-macro-expansion.
	* libstdc++-v3/scripts/testsuite_flags.in: By default, run the
	test cases without -ftrack-macro-expansion.

From-SVN: r186976

In gcc/testsuite/gcc.dg/pr30457.c, the first warning was not being
emitted because the relevant location was inside the var_start macro
defined in a system header.  It can even point to a token for a
builtin macro there.  This patch unwinds to the first token in real
source code in that case.

Tested on x86_64-unknown-linux-gnu against trunk.

	* builtins.c (fold_builtin_next_arg): Unwinds to the first
	location in real source code.

From-SVN: r186975

Consider the test case g++.dg/other/offsetof5.C:

    #include <stddef.h>

    struct A
    {
      char c;
      int &i;
    };

    int j = offsetof (A, i);		// { dg-warning "invalid access|offsetof" }

    template <typename T>
    struct S
    {
      T h;
      T &i;
      static const int j = offsetof (S, i);	// { dg-warning "invalid access|offsetof" }
    };

    int k = S<int>::j;			// { dg-message "required from here" }

The second warning (that involves the instantiation of the S template)
is not emitted when -ftrack-macro-expansion is on.

This is because during the instantiation of the member j of S
template, the location that is used for the warning is the one for the
DECL j (set by instantiate_decl).  And that location is inaccurately
set to the locus of 'offsetof', which is a macro defined in a system
header, so it's discarded by the diagnostics machinery.

Note that when we reach the point where we emit the warning in
build_class_member_access_expr offsetof expression has long been
folded, so we cannot use e.g, the location of the ')' token that would
have been in the source code.  So I believe the location of 'j' is the
best we can get at this point.

The patch below sets the location of the DECL for 'j' to what I
believe is its precise location; with that, the test case passes with
and without -ftrack-macro-expansion.  But I had to adjust
g++.dg/template/sfinae6_neg.C for that.

Tested on x86_64-unknown-linux-gnu against trunk.

gcc/cp

	* decl.c (grokdeclarator): Use the location carried by the
	declarator for the DECL of the static class member.

gcc/testsuite/

	* g++.dg/template/sfinae6_neg.C: Adjust.

From-SVN: r186974

Now that diagnostics first point to the spelling location of tokens
coming from macro expansion, the test case
gcc/testsuite/g++.old-deja/g++.other/vaarg3.C shows that when I write
va_args (args, some_type), the location that is recorded for
"some_type" is not correct.  We wrongly record a location that is in
the system header where the va_args macro is defined.

This patch changes that to correctly record the location for the type
operand of the va_arg expression.

With this patch applied, the
gcc/testsuite/g++.old-deja/g++.other/vaarg3.C test PASSes with and
without -ftrack-macro-expansion.

Tested on x86_64-unknown-linux-gnu against trunk.

Note that the bootstrap with -ftrack-macro-expansion exhibits other
separate issues that are addressed in subsequent patches.  This patch
just fixes one class of problems.

The patch does pass bootstrap with -ftrack-macro-expansion turned off,
though.

gcc/cp/

	* cp-tree.h (build_x_va_arg): Take an additional location
	parameter.
	* call.c (build_x_va_arg): Take a loc parameter for the location
	of the type of the va_arg expression.
	* parser.c (cp_parser_primary_expression): Pass the type of the
	type in the va_arg expression to build_x_va_arg.
	* pt.c (tsubst_copy): Adjust calls to build_x_va_arg.

From-SVN: r186973

There are various conversion related warnings that trigger on
potentially dangerous uses of NULL (or __null).  NULL is defined as a
macro in a system header, so calling warning or warning_at on a
virtual location of NULL yields no diagnostic.  So the test
accompanying this patch (as well as others), was failling when run
with -ftrack-macro-expansion.

I think it's necessary to use the location of NULL that is in the main
source code (instead of, e.g, the spelling location that is in the
system header where the macro is defined) in those cases.  Note that
for __null, we don't have the issue.

I have augmented the test of this patch to check that we don't regress
when handling __null.

Tested on x86_64-unknown-linux-gnu against trunk.

Note that the bootstrap with -ftrack-macro-expansion exhibits other
separate issues that are addressed in subsequent patches.  This patch
just fixes one class of problems.

The patch does pass bootstrap with -ftrack-macro-expansion turned off,
though.

gcc/
	* input.h (expansion_point_location_if_in_system_header): Declare
	new function.
	* input.c (expansion_point_location_if_in_system_header): Define it.
gcc/cp/

	* call.c (conversion_null_warnings): Use the new
	expansion_point_location_if_in_system_header.
	* cvt.c (build_expr_type_conversion): Likewise.
	* typeck.c (cp_build_binary_op): Likewise.

gcc/testsuite/

	* g++.dg/warn/Wconversion-null-2.C: Add testing for __null,
	alongside the previous testing for NULL.

From-SVN: r186972

Besides the warning emitted by warn_uninit, this function wants
to hint the user at where the uninitialized variable was declared, for
cases where the declaration location is outside the current function.

Now that expand_location expands to the location that is in the main
source file (even for -ftrack-macro-expansion) the hinting part was
not working well for cases where the variable is declared in a macro
(outside the function), which is then expanded in the function.

So I had to adjust warn_uninit a little bit to make it consider the
spelling location of the variable declaration.

I have fixed the test gcc.dg/cpp/pragma-diagnostic-2.c on which I
believe gcc shouldn't emit any error.

Here is the new output on that test:

=~=
gcc.dg/cpp/pragma-diagnostic-2.c: In function 'g':
gcc.dg/cpp/pragma-diagnostic-2.c:10:5: warning: 'a' is used uninitialized in this function [-Wuninitialized]
gcc.dg/cpp/pragma-diagnostic-2.c:9:7: note: 'a' was declared here
gcc.dg/cpp/pragma-diagnostic-2.c:9:7: note: in expansion of macro 'CODE_WITH_WARNING'
gcc.dg/cpp/pragma-diagnostic-2.c:17:3: note: expanded from here
gcc.dg/cpp/pragma-diagnostic-2.c: In function 'h':
gcc.dg/cpp/pragma-diagnostic-2.c:10:5: warning: 'a' is used uninitialized in this function [-Wuninitialized]
gcc.dg/cpp/pragma-diagnostic-2.c:9:7: note: 'a' was declared here
gcc.dg/cpp/pragma-diagnostic-2.c:9:7: note: in expansion of macro 'CODE_WITH_WARNING'
gcc.dg/cpp/pragma-diagnostic-2.c:27:3: note: expanded from here
=~=

Tested and bootstrapped on x86_64-unknown-linux-gnu against trunk.

Note that the bootstrap with -ftrack-macro-expansion turned on
exhibits other separate issues that are addressed in subsequent
patches.  This patch just fixes one class of problems.

The patch does pass bootstrap with -ftrack-macro-expansion turned off,
though.

gcc/
	* tree-ssa.c (warn_uninit): Use the spelling location of the
	variable declaration.  Use linemap_location_before_p for source
	locations.

gcc/testsuite/

	* gcc.dg/cpp/pragma-diagnostic-2.c:  Fix this.

From-SVN: r186971

Now that diagnostics for tokens coming from macro expansions point to
the spelling location of the relevant token (and then displays the
context of the expansion), some ugly (not so seldom) corner cases can
happen.

When the relevant token is a built-in token (which means the location
of that token is BUILTINS_LOCATION) the location prefix displayed to
the user in the diagnostic line is the "<built-in>:0:0" string.  For
instance:

    <built-in>:0:0: warning: conversion to 'float' alters 'int' constant value

For the user, I think this is surprising and useless.

A more user-friendly approach would be to refer to the first location
that (in the reported macro expansion context) is for a location in
real source code, like what is shown in the new test case
gcc/testsuite/g++.dg/warn/Wconversion-real-integer2.C accompanying
this patch.

To do this, I am making the line-map module provide a new
linemap_unwind_to_first_non_reserved_loc function that resolves a
virtual location to the first spelling location that is in real source
code.

I am then using that facility in the diagnostics printing module and
in the macro unwinder to avoid printing diagnostics lines that refer
to the locations for built-ins or more generally for reserved
locations.  Note that when I start the dance of skipping a built-in
location I also skip locations that are in system headers, because it
turned out that a lot of those built-ins are actually used in system
headers (e.g, "#define INT_MAX __INT_MAX__" where __INT_MAX__ is a
built-in).

Besides the user-friendliness gain, this patch allows a number of
regression tests to PASS unchanged with and without
-ftrack-macro-expansion.

Tested and bootstrapped on x86_64-unknown-linux-gnu against trunk.

Note that the bootstrap with -ftrack-macro-expansion exhibits other
separate issues that are addressed in subsequent patches.  This patch
just fixes one class of problems.

The patch does pass bootstrap with -ftrack-macro-expansion turned off,
though.

libcpp/

	* include/line-map.h (linemap_unwind_toward_expansion): Fix typo
	in comment.
	(linemap_unwind_to_first_non_reserved_loc): Declare new function.
	* line-map.c (linemap_unwind_to_first_non_reserved_loc): Define
	new function.

gcc/

	* input.c (expand_location_1): When expanding to spelling location
	in a context of a macro expansion, skip reserved system header
	locations.  Update comments.  * tree-diagnostic.c
	(maybe_unwind_expanded_macro_loc): Likewise.

gcc/testsuite/

	* g++.dg/warn/Wconversion-real-integer2.C: New test.
	* g++.dg/warn/Wconversion-real-integer-3.C: Likewise.
	* g++.dg/warn/conversion-real-integer-3.h: New header used by the
	new test above.

From-SVN: r186970

Apparently, quite some places in the compiler (like the C/C++
preprocessor, the debug info machinery) expect expand_location to
resolve to locations that are in the main source file, even if the
token at stake comes from a macro that was defined in a header
somewhere.  Turning on -ftrack-macro-expansion by default was
triggering a lot of failures (not necessarily related to diagnostics)
because expand_location resolves to spelling locations instead.

So I have changed expand_location to honour the initial expectation.

In addition, I came up with the new expand_location_to_spelling_point
used in diagnostic_build_prefix because the diagnostic system, on the
other hand, wants to point to the location of the token where it was
spelled, and then display the error context involving all the macro
whose expansion led to that spelling point - if we are in the context
of a macro expansion there.

This seems to me like a reasonable balance.

Tested and bootstrapped on x86_64-unknown-linux-gnu against trunk and
whitnessed that a lot more tests were PASSing.

Note that the bootstrap with -ftrack-macro-expansion exhibits other
separate issues that are addressed in subsequent patches.  This patch
just fixes one class of problems.

The patch does pass bootstrap with -ftrack-macro-expansion turned off,
though.

gcc/

	* input.c (expand_location_1): New.  Takes a parameter to choose
	whether to resolve the location to spelling or expansion point.
	Was factorized from ...
	(expand_location): ... here.
	(expand_location_to_spelling_point): New.  Implemented in terms of
	expand_location_1.
	* diagnostic.c (diagnostic_build_prefix): Use the new
	expand_location_to_spelling_point instead of expand_location.

From-SVN: r186969