Less verbose fix-it hints for missing header files (PR 87091)

This patch tweaks maybe_add_include_fixit so that if we're emitting a note
about adding the header file, the note's primary location will be replaced
by that of the fix-it hint, to avoid repeating a location we've already
emitted (or one close to it).

For example, this simplifies:

  ../x86_64-pc-linux-gnu/libstdc++-v3/include/vector:87:27: error: msg 1
  87 |       using vector = std::vector<_Tp, polymorphic_allocator<_Tp>>;
     |                           ^~~~~~
  ../x86_64-pc-linux-gnu/libstdc++-v3/include/vector:87:22: note: msg 2
   73 | # include <debug/vector>
  +++ |+#include <vector>
   74 | #endif
  ....
   87 |       using vector = std::vector<_Tp, polymorphic_allocator<_Tp>>;
      |                      ^~~

to:

  ../x86_64-pc-linux-gnu/libstdc++-v3/include/vector:87:27: error: msg 1
  87 |       using vector = std::vector<_Tp, polymorphic_allocator<_Tp>>;
     |                           ^~~~~~
  ../x86_64-pc-linux-gnu/libstdc++-v3/include/vector:74:1: note: msg 2
   73 | # include <debug/vector>
  +++ |+#include <vector>
   74 | #endif

eliminating the repetition of line 87 in the note.

Doing so requires converting show_caret_p to a tri-state, to avoid
meaninglessly printing a caret for the first column in the next line
(and colorizing it):

  ../x86_64-pc-linux-gnu/libstdc++-v3/include/vector:74:1: note: msg 2
   73 | # include <debug/vector>
  +++ |+#include <vector>
   74 | #endif
      | ^

gcc/c-family/ChangeLog:
	PR 87091
	* c-common.c (c_cpp_error): Update for conversion of show_caret_p
	to a tri-state.
	(maybe_suggest_missing_token_insertion): Likewise.
	(maybe_add_include_fixit): Add param "override_location".  If set,
	and source-printing is enabled, then override the rich_location's
	primary location with that of the insertion point for the fix-it
	hint, marking it with SHOW_LINES_WITHOUT_RANGE.
	* c-common.h (extern void maybe_add_include_fixit): Add bool
	param.
	* c-format.c (selftest::test_type_mismatch_range_labels): Update
	for conversion of show_caret_p to a tri-state.
	* c-warn.c (warn_for_restrict): Likewise.
	* known-headers.cc
	(suggest_missing_header::~suggest_missing_header): Update call to
	maybe_add_include_fixit to suggest overriding the location, as it
	is for a note.

gcc/c/ChangeLog:
	PR 87091
	* c-decl.c (implicitly_declare): Update call to
	maybe_add_include_fixit to suggest overriding the location, as it
	is for a note.
	* c-objc-common.c (c_tree_printer): Update for conversion of
	show_caret_p to a tri-state.

gcc/cp/ChangeLog:
	PR 87091
	* decl.c (grokdeclarator): Update for conversion of show_caret_p
	to a tri-state.
	* error.c (cp_printer): Likewise.
	* name-lookup.c (maybe_suggest_missing_std_header): Update call to
	maybe_add_include_fixit to suggest overriding the location, as it
	is for a note.
	* parser.c (cp_parser_string_literal): Update for conversion of
	show_caret_p to a tri-state.
	(cp_parser_elaborated_type_specifier): Likewise.
	(set_and_check_decl_spec_loc): Likewise.
	* pt.c (listify): Update call to maybe_add_include_fixit to not
	override the location, as it is for an error.
	* rtti.c (typeid_ok_p): Likewise.

gcc/ChangeLog:
	PR 87091
	* diagnostic-show-locus.c (class layout_range): Update for
	conversion of show_caret_p to a tri-state.
	(layout_range::layout_range): Likewise.
	(make_range): Likewise.
	(layout::maybe_add_location_range): Likewise.
	(layout::should_print_annotation_line_p): Don't show annotation
	lines for ranges that are SHOW_LINES_WITHOUT_RANGE.
	(layout::get_state_at_point): Update for conversion of
	show_caret_p to a tri-state.  Bail out early for
	SHOW_LINES_WITHOUT_RANGE, so that such ranges don't affect
	underlining or source colorization.
	(gcc_rich_location::add_location_if_nearby): Update for conversion
	of show_caret_p to a tri-state.
	(selftest::test_one_liner_multiple_carets_and_ranges): Likewise.
	(selftest::test_one_liner_fixit_replace_equal_secondary_range):
	Likewise.
	(selftest::test_one_liner_labels): Likewise.
	* gcc-rich-location.c (gcc_rich_location::add_expr): Update for
	conversion of show_caret_p to a tri-state.
	* pretty-print.c (text_info::set_location): Likewise.
	* pretty-print.h (text_info::set_location): Likewise.
	* substring-locations.c (format_warning_n_va): Likewise.
	* tree-diagnostic.c (default_tree_printer): Likewise.
	* tree-pretty-print.c (newline_and_indent): Likewise.

gcc/fortran/ChangeLog:
	PR 87091
	* error.c (gfc_format_decoder): Update for conversion of
	show_caret_p to a tri-state.

gcc/testsuite/ChangeLog:
	PR 87091
	* gcc.dg/empty.h: New file.
	* gcc.dg/fixits-pr84852-1.c: Update for move of fix-it hint to
	top of file and removal of redundant second printing of warning
	location.
	* gcc.dg/fixits-pr84852-2.c: Likewise.
	* gcc.dg/missing-header-fixit-3.c: Likewise.
	* gcc.dg/missing-header-fixit-4.c: New test.
	* gcc.dg/plugin/diagnostic_plugin_test_show_locus.c: Update for
	conversion of show_caret_p to a tri-state.

libcpp/ChangeLog:
	PR 87091
	* include/line-map.h (enum range_display_kind): New enum.
	(struct location_range): Replace field "m_show_caret_p" with
	"m_range_display_kind", converting from bool to the new enum.
	(class rich_location): Add example of line insertion fix-it hint.
	(rich_location::add_range): Convert param "show_caret_p" from bool
	to enum range_display_kind and rename to "range_display_kind",
	giving it a default of SHOW_RANGE_WITHOUT_CARET.
	(rich_location::set_range): Likewise, albeit without a default.
	* line-map.c (rich_location::rich_location): Update for conversion
	of show_caret_p to tri-state enum.
	(rich_location::add_range): Likewise.
	(rich_location::set_range): Likewise.

From-SVN: r263885

7 files changed, 29 insertions, 12 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index e6d6208..a05049c 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,20 @@
+2018-08-27  David Malcolm  <dmalcolm@redhat.com>
+
+	PR 87091
+	* decl.c (grokdeclarator): Update for conversion of show_caret_p
+	to a tri-state.
+	* error.c (cp_printer): Likewise.
+	* name-lookup.c (maybe_suggest_missing_std_header): Update call to
+	maybe_add_include_fixit to suggest overriding the location, as it
+	is for a note.
+	* parser.c (cp_parser_string_literal): Update for conversion of
+	show_caret_p to a tri-state.
+	(cp_parser_elaborated_type_specifier): Likewise.
+	(set_and_check_decl_spec_loc): Likewise.
+	* pt.c (listify): Update call to maybe_add_include_fixit to not
+	override the location, as it is for an error.
+	* rtti.c (typeid_ok_p): Likewise.
+
 2018-08-27  Martin Liska  <mliska@suse.cz>
 
 	* call.c (build_call_a): Use new function
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index c9c5fa6..d9f4d34 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -10737,14 +10737,14 @@ grokdeclarator (const cp_declarator *declarator,
       if (signed_p && unsigned_p)
 	{
 	  gcc_rich_location richloc (declspecs->locations[ds_signed]);
-	  richloc.add_range (declspecs->locations[ds_unsigned], false);
+	  richloc.add_range (declspecs->locations[ds_unsigned]);
 	  error_at (&richloc,
 		    "%<signed%> and %<unsigned%> specified together");
 	}
       else if (long_p && short_p)
 	{
 	  gcc_rich_location richloc (declspecs->locations[ds_long]);
-	  richloc.add_range (declspecs->locations[ds_short], false);
+	  richloc.add_range (declspecs->locations[ds_short]);
 	  error_at (&richloc, "%<long%> and %<short%> specified together");
 	}
       else if (TREE_CODE (type) != INTEGER_TYPE
@@ -10888,7 +10888,7 @@ grokdeclarator (const cp_declarator *declarator,
       if (staticp == 2)
 	{
 	  gcc_rich_location richloc (declspecs->locations[ds_virtual]);
-	  richloc.add_range (declspecs->locations[ds_storage_class], false);
+	  richloc.add_range (declspecs->locations[ds_storage_class]);
 	  error_at (&richloc, "member %qD cannot be declared both %<virtual%> "
 		    "and %<static%>", dname);
 	  storage_class = sc_none;
@@ -10897,7 +10897,7 @@ grokdeclarator (const cp_declarator *declarator,
       if (constexpr_p)
 	{
 	  gcc_rich_location richloc (declspecs->locations[ds_virtual]);
-	  richloc.add_range (declspecs->locations[ds_constexpr], false);
+	  richloc.add_range (declspecs->locations[ds_constexpr]);
 	  error_at (&richloc, "member %qD cannot be declared both %<virtual%> "
 		    "and %<constexpr%>", dname);
 	}
@@ -11448,7 +11448,7 @@ grokdeclarator (const cp_declarator *declarator,
 		  {
 		    /* Cannot be both friend and virtual.  */
 		    gcc_rich_location richloc (declspecs->locations[ds_virtual]);
-		    richloc.add_range (declspecs->locations[ds_friend], false);
+		    richloc.add_range (declspecs->locations[ds_friend]);
 		    error_at (&richloc, "virtual functions cannot be friends");
 		    friendp = 0;
 		  }
diff --git a/gcc/cp/error.c b/gcc/cp/error.c
index 452ecb9..5bab3f3 100644
--- a/gcc/cp/error.c
+++ b/gcc/cp/error.c
@@ -4119,7 +4119,7 @@ cp_printer (pretty_printer *pp, text_info *text, const char *spec,
 
   pp_string (pp, result);
   if (set_locus && t != NULL)
-    text->set_location (0, location_of (t), true);
+    text->set_location (0, location_of (t), SHOW_RANGE_WITH_CARET);
   return true;
 #undef next_tree
 #undef next_tcode
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index 8e009b2..c0a12d7 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -5630,7 +5630,7 @@ maybe_suggest_missing_std_header (location_t location, tree name)
   if (cxx_dialect >= header_hint->min_dialect)
     {
       const char *header = header_hint->header;
-      maybe_add_include_fixit (&richloc, header);
+      maybe_add_include_fixit (&richloc, header, true);
       inform (&richloc,
 	      "%<std::%s%> is defined in header %qs;"
 	      " did you forget to %<#include %s%>?",
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 49d476b..d8d4301 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -4133,7 +4133,7 @@ cp_parser_string_literal (cp_parser *parser, bool translate, bool wide_ok,
 	      else if (curr_type != CPP_STRING)
 		{
 		  rich_location rich_loc (line_table, tok->location);
-		  rich_loc.add_range (last_tok_loc, false);
+		  rich_loc.add_range (last_tok_loc);
 		  error_at (&rich_loc,
 			    "unsupported non-standard concatenation "
 			    "of string literals");
@@ -17755,7 +17755,7 @@ cp_parser_elaborated_type_specifier (cp_parser* parser,
 	  || cp_parser_is_keyword (token, RID_STRUCT))
 	{
 	  gcc_rich_location richloc (token->location);
-	  richloc.add_range (input_location, false);
+	  richloc.add_range (input_location);
 	  richloc.add_fixit_remove ();
 	  pedwarn (&richloc, 0, "elaborated-type-specifier for "
 		   "a scoped enum must not use the %qD keyword",
@@ -28390,7 +28390,7 @@ set_and_check_decl_spec_loc (cp_decl_specifier_seq *decl_specs,
 	  gcc_rich_location richloc (location);
 	  if (gnu != decl_specs->gnu_thread_keyword_p)
 	    {
-	      richloc.add_range (decl_specs->locations[ds_thread], false);
+	      richloc.add_range (decl_specs->locations[ds_thread]);
 	      error_at (&richloc,
 			"both %<__thread%> and %<thread_local%> specified");
 	    }
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index efed9a1..a7266e3 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -26077,7 +26077,7 @@ listify (tree arg)
   if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
     {    
       gcc_rich_location richloc (input_location);
-      maybe_add_include_fixit (&richloc, "<initializer_list>");
+      maybe_add_include_fixit (&richloc, "<initializer_list>", false);
       error_at (&richloc,
 		"deducing from brace-enclosed initializer list"
 		" requires %<#include <initializer_list>%>");
diff --git a/gcc/cp/rtti.c b/gcc/cp/rtti.c
index 6692fb7..94a9219 100644
--- a/gcc/cp/rtti.c
+++ b/gcc/cp/rtti.c
@@ -317,7 +317,7 @@ typeid_ok_p (void)
   if (!COMPLETE_TYPE_P (const_type_info_type_node))
     {
       gcc_rich_location richloc (input_location);
-      maybe_add_include_fixit (&richloc, "<typeinfo>");
+      maybe_add_include_fixit (&richloc, "<typeinfo>", false);
       error_at (&richloc,
 		"must %<#include <typeinfo>%> before using"
 		" %<typeid%>");