c++: Quoting in -fmodules-mapper

Users might be using a space in their build directory path. To allow
specifying such a root for the module mapper started by GCC, we need the
command to allow quotes. Previously quoting a path passed to the module
mapper was not possible, so replace the custom argv parsing with
the argv parsing logic from libiberty, that supports fairly standard
shell quoting using single and double quotes.

The primary purpose of this patch is to allow passing paths with spaces
to the --root parameter of the module mapper.

No test is included as spaces in build directories are tricky cross
platform. The patch was tested manually on my system.

gcc/cp/ChangeLog:

	* mapper-client.cc (spawn_mapper_program): change argv parsing

Signed-off-by: Nicolas Werner <nicolas.werner@hotmail.de>

1 files changed, 14 insertions, 32 deletions

diff --git a/gcc/cp/mapper-client.cc b/gcc/cp/mapper-client.cc
index 9477fee..ac414f0 100644
--- a/gcc/cp/mapper-client.cc
+++ b/gcc/cp/mapper-client.cc
@@ -28,6 +28,7 @@ along with GCC; see the file COPYING3.  If not see
 #define INCLUDE_VECTOR
 #define INCLUDE_MAP
 #include "system.h"
+#include "libiberty.h"
 
 #include "line-map.h"
 #include "rich-location.h"
@@ -51,37 +52,18 @@ static module_client *
 spawn_mapper_program (char const **errmsg, std::string &name,
 		      char const *full_program_name)
 {
-  /* Split writable at white-space.  No space-containing args for
-     you!  */
-  // At most every other char could be an argument
-  char **argv = new char *[name.size () / 2 + 2];
-  unsigned arg_no = 0;
-  char *str = new char[name.size ()];
-  memcpy (str, name.c_str () + 1, name.size ());
-
-  for (auto ptr = str; ; ++ptr)
-    {
-      while (*ptr == ' ')
-	ptr++;
-      if (!*ptr)
-	break;
-
-      if (!arg_no)
-	{
-	  /* @name means look in the compiler's install dir.  */
-	  if (ptr[0] == '@')
-	    ptr++;
-	  else
-	    full_program_name = nullptr;
-	}
-
-      argv[arg_no++] = ptr;
-      while (*ptr && *ptr != ' ')
-	ptr++;
-      if (!*ptr)
-	break;
-      *ptr = 0;
-    }
+  // Split mapper argument into parameters.
+  char** original_argv = buildargv (name.c_str () + 1);
+  int arg_no = countargv (original_argv);
+  char **argv = new char *[arg_no + 1];
+  for (int i = 0; i < arg_no; i++)
+    argv[i] = original_argv[i];
+
+  /* @name means look in the compiler's install dir.  */
+  if (arg_no && argv[0][0] == '@')
+    argv[0] = argv[0] + 1;
+  else
+    full_program_name = nullptr;
   argv[arg_no] = nullptr;
 
   auto *pex = pex_init (PEX_USE_PIPES, progname, NULL);
@@ -108,8 +90,8 @@ spawn_mapper_program (char const **errmsg, std::string &name,
       int err;
       *errmsg = pex_run (pex, flags, argv[0], argv, NULL, NULL, &err);
     }
-  delete[] str;
   delete[] argv;
+  freeargv (original_argv);
 
   int fd_from = -1, fd_to = -1;
   if (!*errmsg)