preprocessor: Replace some flags with a single enum

_cpp_find_file has 3 bool arguments, at most one of which is ever set.
Ripe for replacing with a 4-state enum.  Also, this is C++, so
'typedef struct Foo Foo' is unnecessary.

	* internal.h (typedef _cpp_file): Delete, unnecessary in C++.
	(enum _cpp_find_file_kind): New.
	(_cpp_find_file): Use it, not 3 bools.
	* files.c (_cpp_find_file): Use _cpp_find_file_kind enum, not
	bools.
	(cpp_make_system_header): Break overly long line.
	(_cpp_stack_include, _cpp_fake_include)
	(_cpp_do_file_change, _cpp_compare_file_date, _cpp_has_header): Adjust.
	* init.c (cpp_read_main): Adjust _cpp_find_file call.

4 files changed, 36 insertions, 35 deletions

diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index 040de527b72..622260391da 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,3 +1,15 @@
+2020-05-20  Nathan Sidwell  <nathan@acm.org>
+
+	* internal.h (typedef _cpp_file): Delete, unnecessary in C++.
+	(enum _cpp_find_file_kind): New.
+	(_cpp_find_file): Use it, not 3 bools.
+	* files.c (_cpp_find_file): Use _cpp_find_file_kind enum, not
+	bools.
+	(cpp_make_system_header): Break overly long line.
+	(_cpp_stack_include, _cpp_fake_include)
+	(_cpp_do_file_change, _cpp_compare_file_date, _cpp_has_header): Adjust.
+	* init.c (cpp_read_main): Adjust _cpp_find_file call.
+
 2020-05-18  Nathan Sidwell  <nathan@acm.org>
 
 	* include/cpplib.h (cpp_get_otions, cpp_get_callbacks)
diff --git a/libcpp/files.c b/libcpp/files.c
index f25b58dc394..85c79a1ef93 100644
--- a/libcpp/files.c
+++ b/libcpp/files.c
@@ -496,21 +496,16 @@ _cpp_find_failed (_cpp_file *file)
    had previously been closed.  To open it again pass the return value
    to open_file().
 
-   If IMPLICIT_PREINCLUDE then it is OK for the file to be missing.
-   If present, it is OK for a precompiled header to be included after
-   it.
+   If KIND is _cpp_FFK_PRE_INCLUDE then it is OK for the file to be
+   missing.  If present, it is OK for a precompiled header to be
+   included after it.
 
    Use LOC as the location for any errors.  */
 
 _cpp_file *
 _cpp_find_file (cpp_reader *pfile, const char *fname, cpp_dir *start_dir,
-		int angle_brackets,
-		bool fake, bool implicit_preinclude, bool has_include,
-		location_t loc)
+		int angle_brackets, _cpp_find_file_kind kind, location_t loc)
 {
-  struct cpp_file_hash_entry *entry;
-  void **hash_slot;
-  _cpp_file *file;
   bool invalid_pch = false;
   bool saw_bracket_include = false;
   bool saw_quote_include = false;
@@ -520,22 +515,22 @@ _cpp_find_file (cpp_reader *pfile, const char *fname, cpp_dir *start_dir,
   if (start_dir == NULL)
     cpp_error_at (pfile, CPP_DL_ICE, loc, "NULL directory in find_file");
 
-  hash_slot
+  void **hash_slot
     = htab_find_slot_with_hash (pfile->file_hash, fname,
 				htab_hash_string (fname), INSERT);
 
   /* First check the cache before we resort to memory allocation.  */
-  entry = search_cache ((struct cpp_file_hash_entry *) *hash_slot, start_dir);
+  cpp_file_hash_entry *entry
+    = search_cache ((struct cpp_file_hash_entry *) *hash_slot, start_dir);
   if (entry)
     return entry->u.file;
 
-  file = make_cpp_file (pfile, start_dir, fname);
+  _cpp_file *file = make_cpp_file (pfile, start_dir, fname);
   file->implicit_preinclude
-    = (implicit_preinclude
-       || (pfile->buffer
-	   && pfile->buffer->file->implicit_preinclude));
+    = (kind == _cpp_FFK_PRE_INCLUDE
+       || (pfile->buffer && pfile->buffer->file->implicit_preinclude));
 
-  if (!fake)
+  if (kind != _cpp_FFK_FAKE)
     /* Try each path in the include chain.  */
     for (;;)
       {
@@ -580,7 +575,7 @@ _cpp_find_file (cpp_reader *pfile, const char *fname, cpp_dir *start_dir,
 			     "use -Winvalid-pch for more information");
 	      }
 
-	    if (implicit_preinclude)
+	    if (kind == _cpp_FFK_PRE_INCLUDE)
 	      {
 		free ((char *) file->name);
 		free (file);
@@ -593,7 +588,7 @@ _cpp_find_file (cpp_reader *pfile, const char *fname, cpp_dir *start_dir,
 		return NULL;
 	      }
 
-	    if (!has_include)
+	    if (kind != _cpp_FFK_HAS_INCLUDE)
 	      open_file_failed (pfile, file, angle_brackets, loc);
 	    break;
 	  }
@@ -1049,7 +1044,8 @@ _cpp_stack_include (cpp_reader *pfile, const char *fname, int angle_brackets,
     return false;
 
   _cpp_file *file = _cpp_find_file (pfile, fname, dir, angle_brackets,
-				    false, type == IT_DEFAULT, false, loc);
+				    type == IT_DEFAULT ? _cpp_FFK_PRE_INCLUDE
+				    : _cpp_FFK_NORMAL, loc);
   if (type == IT_DEFAULT && file == NULL)
     return false;
 
@@ -1342,8 +1338,7 @@ cpp_clear_file_cache (cpp_reader *pfile)
 void
 _cpp_fake_include (cpp_reader *pfile, const char *fname)
 {
-  _cpp_find_file (pfile, fname, pfile->buffer->file->dir,
-		  0, true, false, false, 0);
+  _cpp_find_file (pfile, fname, pfile->buffer->file->dir, 0, _cpp_FFK_FAKE, 0);
 }
 
 /* Not everyone who wants to set system-header-ness on a buffer can
@@ -1360,7 +1355,8 @@ cpp_make_system_header (cpp_reader *pfile, int syshdr, int externc)
     flags = 1 + (externc != 0);
   pfile->buffer->sysp = flags;
   _cpp_do_file_change (pfile, LC_RENAME, ORDINARY_MAP_FILE_NAME (map),
-		       SOURCE_LINE (map, pfile->line_table->highest_line), flags);
+		       SOURCE_LINE (map, pfile->line_table->highest_line),
+		       flags);
 }
 
 /* Allow the client to change the current file.  Used by the front end
@@ -1461,8 +1457,7 @@ _cpp_compare_file_date (cpp_reader *pfile, const char *fname,
   if (!dir)
     return -1;
 
-  file = _cpp_find_file (pfile, fname, dir, angle_brackets,
-			 false, false, false, 0);
+  file = _cpp_find_file (pfile, fname, dir, angle_brackets, _cpp_FFK_NORMAL, 0);
   if (file->err_no)
     return -1;
 
@@ -2006,10 +2001,7 @@ _cpp_has_header (cpp_reader *pfile, const char *fname, int angle_brackets,
 {
   cpp_dir *start_dir = search_path_head (pfile, fname, angle_brackets, type);
   _cpp_file *file = _cpp_find_file (pfile, fname, start_dir, angle_brackets,
-				    /*fake=*/false,
-				    /*implicit_preinclude=*/false,
-				    /*has_include=*/true,
-				    0);
+				    _cpp_FFK_HAS_INCLUDE, 0);
   return file->err_no != ENOENT;
 }
 
diff --git a/libcpp/init.c b/libcpp/init.c
index 1f8996af47f..63124c8161e 100644
--- a/libcpp/init.c
+++ b/libcpp/init.c
@@ -662,8 +662,6 @@ cpp_post_options (cpp_reader *pfile)
 const char *
 cpp_read_main_file (cpp_reader *pfile, const char *fname)
 {
-  const location_t loc = 0;
-
   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
     {
       if (!pfile->deps)
@@ -675,8 +673,7 @@ cpp_read_main_file (cpp_reader *pfile, const char *fname)
 
   pfile->main_file
     = _cpp_find_file (pfile, fname, &pfile->no_search_path, /*angle=*/0,
-		      /*fake=*/false, /*preinclude=*/false, /*hasinclude=*/false,
-		      loc);
+		      _cpp_FFK_NORMAL, 0);
   if (_cpp_find_failed (pfile->main_file))
     return NULL;
 
diff --git a/libcpp/internal.h b/libcpp/internal.h
index 765ff9d8206..049ee175317 100644
--- a/libcpp/internal.h
+++ b/libcpp/internal.h
@@ -677,10 +677,10 @@ extern void _cpp_init_hashtable (cpp_reader *, cpp_hash_table *);
 extern void _cpp_destroy_hashtable (cpp_reader *);
 
 /* In files.c */
-typedef struct _cpp_file _cpp_file;
+enum _cpp_find_file_kind
+  { _cpp_FFK_NORMAL, _cpp_FFK_FAKE, _cpp_FFK_PRE_INCLUDE, _cpp_FFK_HAS_INCLUDE };
 extern _cpp_file *_cpp_find_file (cpp_reader *, const char *, cpp_dir *,
-				  int angle, bool fake, bool preinclude,
-				  bool has_include, location_t);
+				  int angle, _cpp_find_file_kind, location_t);
 extern bool _cpp_find_failed (_cpp_file *);
 extern void _cpp_mark_file_once_only (cpp_reader *, struct _cpp_file *);
 extern void _cpp_fake_include (cpp_reader *, const char *);