1 files changed, 549 insertions, 0 deletions
diff --git a/libcpp/mkdeps.cc b/libcpp/mkdeps.cc
new file mode 100644
index 0000000..30e87d8
--- /dev/null
+++ b/libcpp/mkdeps.cc
@@ -0,0 +1,549 @@
+/* Dependency generator for Makefile fragments.
+   Copyright (C) 2000-2022 Free Software Foundation, Inc.
+   Contributed by Zack Weinberg, Mar 2000
+
+This program is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 3, or (at your option) any
+later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.
+
+ In other words, you are welcome to use, share and improve this program.
+ You are forbidden to forbid anyone else to use, share and improve
+ what you give them.   Help stamp out software-hoarding!  */
+
+#include "config.h"
+#include "system.h"
+#include "mkdeps.h"
+#include "internal.h"
+
+/* Not set up to just include std::vector et al, here's a simple
+   implementation.  */
+
+/* Keep this structure local to this file, so clients don't find it
+   easy to start making assumptions.  */
+class mkdeps
+{
+public:
+  /* T has trivial cctor & dtor.  */
+  template <typename T>
+  class vec
+  {
+  private:
+    T *ary;
+    unsigned num;
+    unsigned alloc;
+
+  public:
+    vec ()
+      : ary (NULL), num (0), alloc (0)
+      {}
+    ~vec ()
+      {
+	XDELETEVEC (ary);
+      }
+
+  public:
+    unsigned size () const
+    {
+      return num;
+    }
+    const T &operator[] (unsigned ix) const
+    {
+      return ary[ix];
+    }
+    T &operator[] (unsigned ix)
+    {
+      return ary[ix];
+    }
+    void push (const T &elt)
+    {
+      if (num == alloc)
+	{
+	  alloc = alloc ? alloc * 2 : 16;
+	  ary = XRESIZEVEC (T, ary, alloc);
+	}
+      ary[num++] = elt;
+    }
+  };
+  struct velt
+  {
+    const char *str;
+    size_t len;
+  };
+
+  mkdeps ()
+    : module_name (NULL), cmi_name (NULL), is_header_unit (false), quote_lwm (0)
+  {
+  }
+  ~mkdeps ()
+  {
+    unsigned int i;
+
+    for (i = targets.size (); i--;)
+      free (const_cast <char *> (targets[i]));
+    for (i = deps.size (); i--;)
+      free (const_cast <char *> (deps[i]));
+    for (i = vpath.size (); i--;)
+      XDELETEVEC (vpath[i].str);
+    for (i = modules.size (); i--;)
+      XDELETEVEC (modules[i]);
+    XDELETEVEC (module_name);
+    free (const_cast <char *> (cmi_name));
+  }
+
+public:
+  vec<const char *> targets;
+  vec<const char *> deps;
+  vec<velt> vpath;
+  vec<const char *> modules;
+
+public:
+  const char *module_name;
+  const char *cmi_name;
+  bool is_header_unit;
+  unsigned short quote_lwm;
+};
+
+/* Apply Make quoting to STR, TRAIL.  Note that it's not possible to
+   quote all such characters - e.g. \n, %, *, ?, [, \ (in some
+   contexts), and ~ are not properly handled.  It isn't possible to
+   get this right in any current version of Make.  (??? Still true?
+   Old comment referred to 3.76.1.)  */
+
+static const char *
+munge (const char *str, const char *trail = nullptr)
+{
+  static unsigned alloc;
+  static char *buf;
+  unsigned dst = 0;
+
+  for (; str; str = trail, trail = nullptr)
+    {
+      unsigned slashes = 0;
+      char c;
+      for (const char *probe = str; (c = *probe++);)
+	{
+	  if (alloc < dst + 4 + slashes)
+	    {
+	      alloc = alloc * 2 + 32;
+	      buf = XRESIZEVEC (char, buf, alloc);
+	    }
+
+	  switch (c)
+	    {
+	    case '\\':
+	      slashes++;
+	      break;
+
+	    case '$':
+	      buf[dst++] = '$';
+	      goto def;
+
+	    case ' ':
+	    case '\t':
+	      /* GNU make uses a weird quoting scheme for white space.
+		 A space or tab preceded by 2N+1 backslashes
+		 represents N backslashes followed by space; a space
+		 or tab preceded by 2N backslashes represents N
+		 backslashes at the end of a file name; and
+		 backslashes in other contexts should not be
+		 doubled.  */
+	      while (slashes--)
+		buf[dst++] = '\\';
+	      /* FALLTHROUGH  */
+
+	    case '#':
+	      buf[dst++] = '\\';
+	      /* FALLTHROUGH  */
+
+	    default:
+	    def:
+	      slashes = 0;
+	      break;
+	    }
+
+	  buf[dst++] = c;
+	}
+    }
+
+  buf[dst] = 0;
+  return buf;
+}
+
+/* If T begins with any of the partial pathnames listed in d->vpathv,
+   then advance T to point beyond that pathname.  */
+static const char *
+apply_vpath (class mkdeps *d, const char *t)
+{
+  if (unsigned len = d->vpath.size ())
+    for (unsigned i = len; i--;)
+      {
+	if (!filename_ncmp (d->vpath[i].str, t, d->vpath[i].len))
+	  {
+	    const char *p = t + d->vpath[i].len;
+	    if (!IS_DIR_SEPARATOR (*p))
+	      goto not_this_one;
+
+	    /* Do not simplify $(vpath)/../whatever.  ??? Might not
+	       be necessary. */
+	    if (p[1] == '.' && p[2] == '.' && IS_DIR_SEPARATOR (p[3]))
+	      goto not_this_one;
+
+	    /* found a match */
+	    t = t + d->vpath[i].len + 1;
+	    break;
+	  }
+      not_this_one:;
+      }
+
+  /* Remove leading ./ in any case.  */
+  while (t[0] == '.' && IS_DIR_SEPARATOR (t[1]))
+    {
+      t += 2;
+      /* If we removed a leading ./, then also remove any /s after the
+	 first.  */
+      while (IS_DIR_SEPARATOR (t[0]))
+	++t;
+    }
+
+  return t;
+}
+
+/* Public routines.  */
+
+class mkdeps *
+deps_init (void)
+{
+  return new mkdeps ();
+}
+
+void
+deps_free (class mkdeps *d)
+{
+  delete d;
+}
+
+/* Adds a target T.  We make a copy, so it need not be a permanent
+   string.  QUOTE is true if the string should be quoted.  */
+void
+deps_add_target (class mkdeps *d, const char *t, int quote)
+{
+  t = xstrdup (apply_vpath (d, t));
+
+  if (!quote)
+    {
+      /* Sometimes unquoted items are added after quoted ones.
+	 Swap out the lowest quoted.  */
+      if (d->quote_lwm != d->targets.size ())
+	{
+	  const char *lowest = d->targets[d->quote_lwm];
+	  d->targets[d->quote_lwm] = t;
+	  t = lowest;
+	}
+      d->quote_lwm++;
+    }
+
+  d->targets.push (t);
+}
+
+/* Sets the default target if none has been given already.  An empty
+   string as the default target in interpreted as stdin.  The string
+   is quoted for MAKE.  */
+void
+deps_add_default_target (class mkdeps *d, const char *tgt)
+{
+  /* Only if we have no targets.  */
+  if (d->targets.size ())
+    return;
+
+  if (tgt[0] == '\0')
+    d->targets.push (xstrdup ("-"));
+  else
+    {
+#ifndef TARGET_OBJECT_SUFFIX
+# define TARGET_OBJECT_SUFFIX ".o"
+#endif
+      const char *start = lbasename (tgt);
+      char *o = (char *) alloca (strlen (start)
+                                 + strlen (TARGET_OBJECT_SUFFIX) + 1);
+      char *suffix;
+
+      strcpy (o, start);
+
+      suffix = strrchr (o, '.');
+      if (!suffix)
+        suffix = o + strlen (o);
+      strcpy (suffix, TARGET_OBJECT_SUFFIX);
+
+      deps_add_target (d, o, 1);
+    }
+}
+
+void
+deps_add_dep (class mkdeps *d, const char *t)
+{
+  gcc_assert (*t);
+
+  t = apply_vpath (d, t);
+
+  d->deps.push (xstrdup (t));
+}
+
+void
+deps_add_vpath (class mkdeps *d, const char *vpath)
+{
+  const char *elem, *p;
+
+  for (elem = vpath; *elem; elem = p)
+    {
+      for (p = elem; *p && *p != ':'; p++)
+	continue;
+      mkdeps::velt elt;
+      elt.len = p - elem;
+      char *str = XNEWVEC (char, elt.len + 1);
+      elt.str = str;
+      memcpy (str, elem, elt.len);
+      str[elt.len] = '\0';
+      if (*p == ':')
+	p++;
+
+      d->vpath.push (elt);
+    }
+}
+
+/* Add a new module target (there can only be one).  M is the module
+   name.   */
+
+void
+deps_add_module_target (struct mkdeps *d, const char *m,
+			const char *cmi, bool is_header_unit)
+{
+  gcc_assert (!d->module_name);
+  
+  d->module_name = xstrdup (m);
+  d->is_header_unit = is_header_unit;
+  d->cmi_name = xstrdup (cmi);
+}
+
+/* Add a new module dependency.  M is the module name.  */
+
+void
+deps_add_module_dep (struct mkdeps *d, const char *m)
+{
+  d->modules.push (xstrdup (m));
+}
+
+/* Write NAME, with a leading space to FP, a Makefile.  Advance COL as
+   appropriate, wrap at COLMAX, returning new column number.  Iff
+   QUOTE apply quoting.  Append TRAIL.  */
+
+static unsigned
+make_write_name (const char *name, FILE *fp, unsigned col, unsigned colmax,
+		 bool quote = true, const char *trail = NULL)
+{
+  if (quote)
+    name = munge (name, trail);
+  unsigned size = strlen (name);
+
+  if (col)
+    {
+      if (colmax && col + size> colmax)
+	{
+	  fputs (" \\\n", fp);
+	  col = 0;
+	}
+      col++;
+      fputs (" ", fp);
+    }
+
+  col += size;
+  fputs (name, fp);
+
+  return col;
+}
+
+/* Write all the names in VEC via make_write_name.  */
+
+static unsigned
+make_write_vec (const mkdeps::vec<const char *> &vec, FILE *fp,
+		unsigned col, unsigned colmax, unsigned quote_lwm = 0,
+		const char *trail = NULL)
+{
+  for (unsigned ix = 0; ix != vec.size (); ix++)
+    col = make_write_name (vec[ix], fp, col, colmax, ix >= quote_lwm, trail);
+  return col;
+}
+
+/* Write the dependencies to a Makefile.  If PHONY is true, add
+   .PHONY targets for all the dependencies too.  */
+
+static void
+make_write (const cpp_reader *pfile, FILE *fp, unsigned int colmax)
+{
+  const mkdeps *d = pfile->deps;
+
+  unsigned column = 0;
+  if (colmax && colmax < 34)
+    colmax = 34;
+
+  if (d->deps.size ())
+    {
+      column = make_write_vec (d->targets, fp, 0, colmax, d->quote_lwm);
+      if (CPP_OPTION (pfile, deps.modules) && d->cmi_name)
+	column = make_write_name (d->cmi_name, fp, column, colmax);
+      fputs (":", fp);
+      column++;
+      make_write_vec (d->deps, fp, column, colmax);
+      fputs ("\n", fp);
+      if (CPP_OPTION (pfile, deps.phony_targets))
+	for (unsigned i = 1; i < d->deps.size (); i++)
+	  fprintf (fp, "%s:\n", munge (d->deps[i]));
+    }
+
+  if (!CPP_OPTION (pfile, deps.modules))
+    return;
+
+  if (d->modules.size ())
+    {
+      column = make_write_vec (d->targets, fp, 0, colmax, d->quote_lwm);
+      if (d->cmi_name)
+	column = make_write_name (d->cmi_name, fp, column, colmax);
+      fputs (":", fp);
+      column++;
+      column = make_write_vec (d->modules, fp, column, colmax, 0, ".c++m");
+      fputs ("\n", fp);
+    }
+
+  if (d->module_name)
+    {
+      if (d->cmi_name)
+	{
+	  /* module-name : cmi-name */
+	  column = make_write_name (d->module_name, fp, 0, colmax,
+				    true, ".c++m");
+	  fputs (":", fp);
+	  column++;
+	  column = make_write_name (d->cmi_name, fp, column, colmax);
+	  fputs ("\n", fp);
+
+	  column = fprintf (fp, ".PHONY:");
+	  column = make_write_name (d->module_name, fp, column, colmax,
+				    true, ".c++m");
+	  fputs ("\n", fp);
+	}
+
+      if (d->cmi_name && !d->is_header_unit)
+	{
+	  /* An order-only dependency.
+	      cmi-name :| first-target
+	     We can probably drop this this in favour of Make-4.3's grouped
+	      targets '&:'  */
+	  column = make_write_name (d->cmi_name, fp, 0, colmax);
+	  fputs (":|", fp);
+	  column++;
+	  column = make_write_name (d->targets[0], fp, column, colmax);
+	  fputs ("\n", fp);
+	}
+    }
+  
+  if (d->modules.size ())
+    {
+      column = fprintf (fp, "CXX_IMPORTS +=");
+      make_write_vec (d->modules, fp, column, colmax, 0, ".c++m");
+      fputs ("\n", fp);
+    }
+}
+
+/* Write out dependencies according to the selected format (which is
+   only Make at the moment).  */
+/* Really we should be opening fp here.  */
+
+void
+deps_write (const cpp_reader *pfile, FILE *fp, unsigned int colmax)
+{
+  make_write (pfile, fp, colmax);
+}
+
+/* Write out a deps buffer to a file, in a form that can be read back
+   with deps_restore.  Returns nonzero on error, in which case the
+   error number will be in errno.  */
+
+int
+deps_save (class mkdeps *deps, FILE *f)
+{
+  unsigned int i;
+  size_t size;
+
+  /* The cppreader structure contains makefile dependences.  Write out this
+     structure.  */
+
+  /* The number of dependences.  */
+  size = deps->deps.size ();
+  if (fwrite (&size, sizeof (size), 1, f) != 1)
+    return -1;
+
+  /* The length of each dependence followed by the string.  */
+  for (i = 0; i < deps->deps.size (); i++)
+    {
+      size = strlen (deps->deps[i]);
+      if (fwrite (&size, sizeof (size), 1, f) != 1)
+	return -1;
+      if (fwrite (deps->deps[i], size, 1, f) != 1)
+	return -1;
+    }
+
+  return 0;
+}
+
+/* Read back dependency information written with deps_save into
+   the deps sizefer.  The third argument may be NULL, in which case
+   the dependency information is just skipped, or it may be a filename,
+   in which case that filename is skipped.  */
+
+int
+deps_restore (class mkdeps *deps, FILE *fd, const char *self)
+{
+  size_t size;
+  char *buf = NULL;
+  size_t buf_size = 0;
+
+  /* Number of dependences.  */
+  if (fread (&size, sizeof (size), 1, fd) != 1)
+    return -1;
+
+  /* The length of each dependence string, followed by the string.  */
+  for (unsigned i = size; i--;)
+    {
+      /* Read in # bytes in string.  */
+      if (fread (&size, sizeof (size), 1, fd) != 1)
+	return -1;
+
+      if (size >= buf_size)
+	{
+	  buf_size = size + 512;
+	  buf = XRESIZEVEC (char, buf, buf_size);
+	}
+      if (fread (buf, 1, size, fd) != size)
+	{
+	  XDELETEVEC (buf);
+	  return -1;
+	}
+      buf[size] = 0;
+
+      /* Generate makefile dependencies from .pch if -nopch-deps.  */
+      if (self != NULL && filename_cmp (buf, self) != 0)
+        deps_add_dep (deps, buf);
+    }
+
+  XDELETEVEC (buf);
+  return 0;
+}