Sometimes a user may want to have a command which takes an optional
parameter. For commands with an optional constant string, this is no
issue, as it can be configured as two separate commands, e.g.
start
start tx_first.
However, if we want to have a variable parameter on the command, we hit
issues, because variable tokens do not form part of the generated
command names used for function and result-struct naming. To avoid
duplicate name issues, we add a special syntax to allow the user to
indicate that a particular variable parameter should be included in the
name. Any leading variable names starting with a "__" will be included
in command naming.
This then allows us to have:
start
start tx_first
start tx_first <UINT16>__n
without hitting any naming conflicts.
Signed-off-by: Bruce Richardson <bruce.richard...@intel.com>
---
buildtools/dpdk-cmdline-gen.py | 9 ++++++++-
doc/guides/prog_guide/cmdline.rst | 13 +++++++++++++
2 files changed, 21 insertions(+), 1 deletion(-)
diff --git a/buildtools/dpdk-cmdline-gen.py b/buildtools/dpdk-cmdline-gen.py
index bf1253d949..faee4ffca7 100755
--- a/buildtools/dpdk-cmdline-gen.py
+++ b/buildtools/dpdk-cmdline-gen.py
@@ -40,7 +40,12 @@ def process_command(lineno, tokens, comment):
name_tokens = []
for t in tokens:
if t.startswith("<"):
- break
+ # stop processing the name building at a variable token,
+ # UNLESS the token name starts with "__"
+ t_type, t_name = t[1:].split(">")
+ if not t_name.startswith("__"):
+ break
+ t = t_name[2:] # strip off the leading '__'
name_tokens.append(t)
name = "_".join(name_tokens)
@@ -51,6 +56,8 @@ def process_command(lineno, tokens, comment):
if t.startswith("<"):
t_type, t_name = t[1:].split(">")
t_val = "NULL"
+ if t_name.startswith("__"):
+ t_name = t_name[2:]
else:
t_type = "STRING"
t_name = t
diff --git a/doc/guides/prog_guide/cmdline.rst
b/doc/guides/prog_guide/cmdline.rst
index b804d7a328..fc32d727dc 100644
--- a/doc/guides/prog_guide/cmdline.rst
+++ b/doc/guides/prog_guide/cmdline.rst
@@ -155,6 +155,19 @@ To get at the results structure for each command above,
the ``parsed_result`` parameter should be cast to ``struct cmd_quit_result``
or ``struct cmd_show_port_stats_result`` respectively.
+.. note::
+
+ In some cases, the user may want to have an optional variable parameter at
the end of a command.
+ Such a variable parameter would not normally be included in the
``<cmdname>`` string,
+ leading to duplicate definition errors.
+ To work around this,
+ any variable token with a name prefixed by ``'__'`` will be included in the
cmdname string,
+ with the prefix removed.
+ Using this, it is possible to have commands, such as:
+ ``start tx_first`` and ``start tx_first <UINT16>__n``, without them
conflicting.
+ The resulting code generated will expect functions called
``cmd_start_tx_first_parsed``
+ and ``cmd_start_tx_first_n_parsed`` respectively.
+
Integrating with the Application
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
2.40.1
