[PATCH v7 1/4] spec: add a spec function to join arguments

[Ben Boeckel <ben.boeckel@kitware.com>]

When passing `-o` flags to other options, the typical `-o foo` spelling
leaves a leading whitespace when replacing elsewhere. This ends up
creating flags spelled as `-some-option-with-arg= foo.ext` which doesn't
parse properly. When attempting to make a spec function to just remove
the leading whitespace, the argument splitting ends up masking the
whitespace. However, the intended extension *also* ends up being its own
argument. To perform the desired behavior, the arguments need to be
concatenated together.

gcc/:

	* gcc.cc (join_spec_func): Add a spec function to join all
	arguments.

Signed-off-by: Ben Boeckel <ben.boeckel@kitware.com>
---
 gcc/gcc.cc | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/gcc/gcc.cc b/gcc/gcc.cc
index fdfac0b4fe4..44433b80d61 100644
--- a/gcc/gcc.cc
+++ b/gcc/gcc.cc
@@ -447,6 +447,7 @@ static const char *greater_than_spec_func (int, const char **);
 static const char *debug_level_greater_than_spec_func (int, const char **);
 static const char *dwarf_version_greater_than_spec_func (int, const char **);
 static const char *find_fortran_preinclude_file (int, const char **);
+static const char *join_spec_func (int, const char **);
 static char *convert_white_space (char *);
 static char *quote_spec (char *);
 static char *quote_spec_arg (char *);
@@ -1772,6 +1773,7 @@ static const struct spec_function static_spec_functions[] =
   { "debug-level-gt",		debug_level_greater_than_spec_func },
   { "dwarf-version-gt",		dwarf_version_greater_than_spec_func },
   { "fortran-preinclude-file",	find_fortran_preinclude_file},
+  { "join",			join_spec_func},
 #ifdef EXTRA_SPEC_FUNCTIONS
   EXTRA_SPEC_FUNCTIONS
 #endif
@@ -10975,6 +10977,19 @@ find_fortran_preinclude_file (int argc, const char **argv)
   return result;
 }
 
+/* The function takes any number of arguments and joins them together.  */
+
+static const char *
+join_spec_func (int argc, const char **argv)
+{
+  char *result = NULL;
+
+  for (int i = 0; i < argc; ++i)
+    result = reconcat(result, result ? result : "", argv[i], NULL);
+
+  return result;
+}
+
 /* If any character in ORIG fits QUOTE_P (_, P), reallocate the string
    so as to precede every one of them with a backslash.  Return the
    original string or the reallocated one.  */
-- 
2.40.1