From 403cb6b138c38faf72f7abc034db3505b9bdb82f Mon Sep 17 00:00:00 2001 From: Joel Brobecker Date: Mon, 11 Nov 2013 09:21:44 +0400 Subject: GDB/MI: Add new "--language LANG" command option. Frontend sometimes need to evaluate expressions that are language-specific. For instance, Eclipse uses the following expression to determine the size of an address on the target: -data-evaluate-expression "sizeof (void*)" Unfortunately, if the main of the program being debugged is not C, this may not work. For instance, if the main is in Ada, you get... -data-evaluate-expression "sizeof (void*)" ^error,msg="No definition of \"sizeof\" in current context." ... and apparently decides to stop the debugging session as a result. The recommendation sent was to specifically set the language to C before trying to evaluate the expression. Something such as: 1. save current language 2. set language c 3. -data-evaluate-expression "sizeof (void*)" 4. Restore language This has the same disadvantages as the ones outlined in the "Context Management" section of the GDB/MI documentation regarding setting the current thread or the current frame, thus recommending the use of general command-line switches such as --frame, or --thread instead. This patch follows the same steps for the language, adding a similar new command option: --language LANG. Example of use: -data-evaluate-expression --language c "sizeof (void*)" ^done,value="4" gdb/ChangeLog: * mi/mi-parse.h (struct mi_parse) : New field. * mi/mi-main.c (mi_cmd_execute): Temporarily set language to PARSE->LANGUAGE during command execution, if set. * mi/mi-parse.c: Add "language.h" #include. (mi_parse): Add parsing of "--language" command option. * NEWS: Add entry mentioning the new "--language" command option. gdb/testsuite/ChangeLog: * gdb.mi/mi-language.exp: New file. gdb/doc/ChangeLog: * gdb.texinfo (Show): Add xref anchor for "show language" command. (Context management): Place current subsection text into its own subsubsection. Add new subsubsection describing the "--language" command option. --- gdb/mi/mi-main.c | 7 +++++++ gdb/mi/mi-parse.c | 25 ++++++++++++++++++++++++- gdb/mi/mi-parse.h | 4 ++++ 3 files changed, 35 insertions(+), 1 deletion(-) (limited to 'gdb/mi') diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c index c3f7221..bbf944a 100644 --- a/gdb/mi/mi-main.c +++ b/gdb/mi/mi-main.c @@ -2122,6 +2122,7 @@ static void mi_cmd_execute (struct mi_parse *parse) { struct cleanup *cleanup; + enum language saved_language; cleanup = prepare_execute_command (); @@ -2183,6 +2184,12 @@ mi_cmd_execute (struct mi_parse *parse) error (_("Invalid frame id: %d"), frame); } + if (parse->language != language_unknown) + { + make_cleanup_restore_current_language (); + set_language (parse->language); + } + current_context = parse; if (parse->cmd->suppress_notification != NULL) diff --git a/gdb/mi/mi-parse.c b/gdb/mi/mi-parse.c index a3c1849..9994307 100644 --- a/gdb/mi/mi-parse.c +++ b/gdb/mi/mi-parse.c @@ -27,6 +27,7 @@ #include #include "gdb_string.h" #include "cli/cli-utils.h" +#include "language.h" static const char mi_no_values[] = "--no-values"; static const char mi_simple_values[] = "--simple-values"; @@ -244,6 +245,7 @@ mi_parse (const char *cmd, char **token) parse->thread_group = -1; parse->thread = -1; parse->frame = -1; + parse->language = language_unknown; cleanup = make_cleanup (mi_parse_cleanup, parse); @@ -292,7 +294,10 @@ mi_parse (const char *cmd, char **token) some important commands, like '-break-*' are implemented by forwarding to the CLI layer directly. We want to parse --thread and --frame here, so as not to leave those option in the string - that will be passed to CLI. */ + that will be passed to CLI. + + Same for the --language option. */ + for (;;) { const char *option; @@ -300,6 +305,7 @@ mi_parse (const char *cmd, char **token) size_t tgs = sizeof ("--thread-group ") - 1; size_t ts = sizeof ("--thread ") - 1; size_t fs = sizeof ("--frame ") - 1; + size_t ls = sizeof ("--language ") - 1; if (strncmp (chp, "--all ", as) == 0) { @@ -348,6 +354,23 @@ mi_parse (const char *cmd, char **token) parse->frame = strtol (chp, &endp, 10); chp = endp; } + else if (strncmp (chp, "--language ", ls) == 0) + { + char *lang_name; + struct cleanup *old_chain; + + option = "--language"; + chp += ls; + lang_name = extract_arg_const (&chp); + old_chain = make_cleanup (xfree, lang_name); + + parse->language = language_enum (lang_name); + if (parse->language == language_unknown + || parse->language == language_auto) + error (_("Invalid --language argument: %s"), lang_name); + + do_cleanups (old_chain); + } else break; diff --git a/gdb/mi/mi-parse.h b/gdb/mi/mi-parse.h index b20a389..325c1e1 100644 --- a/gdb/mi/mi-parse.h +++ b/gdb/mi/mi-parse.h @@ -50,6 +50,10 @@ struct mi_parse int thread_group; /* At present, the same as inferior number. */ int thread; int frame; + + /* The language that should be used to evaluate the MI command. + Ignored if set to language_unknown. */ + enum language language; }; /* Attempts to parse CMD returning a ``struct mi_parse''. If CMD is -- cgit v1.1