[PATCH v5 2/9] gdbsupport: Adapt construct_inferior_arguments

Michael Weghorn
2020-05-20T16:21:35Z

Allow construct_inferior_arguments to handle zero args
and have it return a std::string, similar to how
stringify_argv in gdbsupport/common-utils does.

Also, add a const qualifier for the second parameter,
since it is only read, not written to.

The intention is to replace existing uses of
stringify_argv by construct_inferior_arguments
in a subsequent step, since construct_inferior_arguments
properly handles special characters, while stringify_argv
doesn't.

2020-05-13 Michael Weghorn <m.weghorn@posteo.de>

* common-inferior.cc, common-inferior.h (construct_inferior_arguments):
Adapt to handle zero args and return a std::string.
Adapt call site.
---
gdb/infcmd.c | 9 ++---
gdbsupport/common-inferior.cc | 65 ++++++++++++-----------------------
gdbsupport/common-inferior.h | 2 +-
3 files changed, 26 insertions(+), 50 deletions(-)

diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index cf6e540e79..ffcc364f64 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -151,12 +151,9 @@ get_inferior_args (void)
{
if (current_inferior ()->argc != 0)
{
- char *n;
-
- n = construct_inferior_arguments (current_inferior ()->argc,
- current_inferior ()->argv);
- set_inferior_args (n);
- xfree (n);
+ std::string n = construct_inferior_arguments (current_inferior ()->argc,
+ current_inferior ()->argv);
+ set_inferior_args (n.c_str ());
}

if (current_inferior ()->args == NULL)
diff --git a/gdbsupport/common-inferior.cc b/gdbsupport/common-inferior.cc
index a7d631f357..aa8be14c74 100644
--- a/gdbsupport/common-inferior.cc
+++ b/gdbsupport/common-inferior.cc
@@ -27,15 +27,12 @@ bool startup_with_shell = true;

/* See common-inferior.h. */

-char *
-construct_inferior_arguments (int argc, char **argv)
+std::string
+construct_inferior_arguments (int argc, char * const *argv)
{
- char *result;
+ gdb_assert (argc >= 0);

- /* ARGC should always be at least 1, but we double check this
- here. This is also needed to silence -Werror-stringop
- warnings. */
- gdb_assert (argc > 0);
+ std::string result;

if (startup_with_shell)
{
@@ -51,49 +48,38 @@ construct_inferior_arguments (int argc, char **argv)
static const char special[] = "\"!#$&*()\\|[]{}<>?'`~^; \t\n";
static const char quote = '\'';
#endif
- int i;
- int length = 0;
- char *out, *cp;
-
- /* We over-compute the size. It shouldn't matter. */
- for (i = 0; i < argc; ++i)
- length += 3 * strlen (argv[i]) + 1 + 2 * (argv[i][0] == '\0');
-
- result = (char *) xmalloc (length);
- out = result;
-
- for (i = 0; i < argc; ++i)
+ for (int i = 0; i < argc; ++i)
{
if (i > 0)
- *out++ = ' ';
+ result += ' ';

/* Need to handle empty arguments specially. */
if (argv[i][0] == '\0')
{
- *out++ = quote;
- *out++ = quote;
+ result += quote;
+ result += quote;
}
else
{
#ifdef __MINGW32__
- int quoted = 0;
+ bool quoted = false;

if (strpbrk (argv[i], special))
{
- quoted = 1;
- *out++ = quote;
+ quoted = true;
+ result += quote;
}
#endif
- for (cp = argv[i]; *cp; ++cp)
+ for (char *cp = argv[i]; *cp; ++cp)
{
if (*cp == '\n')
{
/* A newline cannot be quoted with a backslash (it
just disappears), only by putting it inside
quotes. */
- *out++ = quote;
- *out++ = '\n';
- *out++ = quote;
+ result += quote;
+ result += '\n';
+ result += quote;
}
else
{
@@ -102,26 +88,22 @@ construct_inferior_arguments (int argc, char **argv)
#else
if (strchr (special, *cp) != NULL)
#endif
- *out++ = '\\';
- *out++ = *cp;
+ result += '\\';
+ result += *cp;
}
}
#ifdef __MINGW32__
if (quoted)
- *out++ = quote;
+ result += quote;
#endif
}
}
- *out = '\0';
}
else
{
/* In this case we can't handle arguments that contain spaces,
tabs, or newlines -- see breakup_args(). */
- int i;
- int length = 0;
-
- for (i = 0; i < argc; ++i)
+ for (int i = 0; i < argc; ++i)
{
char *cp = strchr (argv[i], ' ');
if (cp == NULL)
@@ -131,16 +113,13 @@ construct_inferior_arguments (int argc, char **argv)
if (cp != NULL)
error (_("can't handle command-line "
"argument containing whitespace"));
- length += strlen (argv[i]) + 1;
}

- result = (char *) xmalloc (length);
- result[0] = '\0';
- for (i = 0; i < argc; ++i)
+ for (int i = 0; i < argc; ++i)
{
if (i > 0)
- strcat (result, " ");
- strcat (result, argv[i]);
+ result += " ";
+ result += argv[i];
}
}

diff --git a/gdbsupport/common-inferior.h b/gdbsupport/common-inferior.h
index ee87bc75a3..5e9fc8b0b9 100644
--- a/gdbsupport/common-inferior.h
+++ b/gdbsupport/common-inferior.h
@@ -60,6 +60,6 @@ extern bool startup_with_shell;

/* Compute command-line string given argument vector. This does the
same shell processing as fork_inferior. */
-extern char *construct_inferior_arguments (int, char **);
+extern std::string construct_inferior_arguments (int, char * const *);

#endif /* COMMON_COMMON_INFERIOR_H */
--
2.26.2