Expand preprocessor macros in C expressions.
* c-lang.h: #include "macroexp.h", for macro_lookup_ftype.
(scan_macro_expansion, scanning_macro_expansion,
finished_macro_expansion): New function declarations.
(expression_macro_lookup_func, expression_macro_lookup_baton): New
variable declarations.
* parser-defs.h (expression_context_pc): New declaration.
* parse.c (expression_context_pc): New variable.
(parse_exp_1): Set expression_context_pc, as well as
expression_context_block.
* c-exp.y (yylex): If we're not already reading the result of a
macro expansion, try to macro-expand the next token. When we're
done scanning a macro expansion, switch back to the mainline text.
Commas and `if's in a macro's expansion don't terminate the input.
* c-lang.c: #include "macroscope.h" and "gdb_assert.h".
(macro_original_text, macro_expanded_text,
expression_macro_lookup_func, expression_macro_lookup_baton): New
variables.
(scan_macro_expansion, scanning_macro_expansion,
finished_macro_expansion, scan_macro_cleanup, null_macro_lookup,
c_preprocess_and_parse): New functions.
(c_language_defn, cplus_language_defn, asm_language_defn): Call
c_preprocess_and_parse, instead of c_parse.
* Makefile.in (c_lang_h): Note that this #includes macroexp.h.
(c-lang.o): Note dependency on macroscope.h and gdb_assert.h.
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 03a7bcd..20dfcbc 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,31 @@
+2002-05-10 Jim Blandy <jimb@redhat.com>
+
+ Expand preprocessor macros in C expressions.
+ * c-lang.h: #include "macroexp.h", for macro_lookup_ftype.
+ (scan_macro_expansion, scanning_macro_expansion,
+ finished_macro_expansion): New function declarations.
+ (expression_macro_lookup_func, expression_macro_lookup_baton): New
+ variable declarations.
+ * parser-defs.h (expression_context_pc): New declaration.
+ * parse.c (expression_context_pc): New variable.
+ (parse_exp_1): Set expression_context_pc, as well as
+ expression_context_block.
+ * c-exp.y (yylex): If we're not already reading the result of a
+ macro expansion, try to macro-expand the next token. When we're
+ done scanning a macro expansion, switch back to the mainline text.
+ Commas and `if's in a macro's expansion don't terminate the input.
+ * c-lang.c: #include "macroscope.h" and "gdb_assert.h".
+ (macro_original_text, macro_expanded_text,
+ expression_macro_lookup_func, expression_macro_lookup_baton): New
+ variables.
+ (scan_macro_expansion, scanning_macro_expansion,
+ finished_macro_expansion, scan_macro_cleanup, null_macro_lookup,
+ c_preprocess_and_parse): New functions.
+ (c_language_defn, cplus_language_defn, asm_language_defn): Call
+ c_preprocess_and_parse, instead of c_parse.
+ * Makefile.in (c_lang_h): Note that this #includes macroexp.h.
+ (c-lang.o): Note dependency on macroscope.h and gdb_assert.h.
+
2002-05-09 Jim Blandy <jimb@redhat.com>
Add commands for manually expanding macros and showing their
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 26afec5..5aa1412 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -599,7 +599,7 @@
builtin_regs_h = builtin-regs.h
breakpoint_h = breakpoint.h $(frame_h) $(value_h)
buildsym_h = buildsym.h
-c_lang_h = c-lang.h $(value_h)
+c_lang_h = c-lang.h $(value_h) $(macroexp_h)
call_cmds_h = call-cmds.h
cli_cmds_h = $(srcdir)/cli/cli-cmds.h
cli_decode_h = $(srcdir)/cli/cli-decode.h $(command_h)
@@ -1311,7 +1311,8 @@
$(gdb_string_h) $(value_h) $(frame_h)
c-lang.o: c-lang.c $(c_lang_h) $(defs_h) $(expression_h) $(gdbtypes_h) \
- $(language_h) $(parser_defs_h) $(symtab_h)
+ $(language_h) $(parser_defs_h) $(symtab_h) $(macroscope_h) \
+ gdb_assert.h
c-typeprint.o: c-typeprint.c $(c_lang_h) $(defs_h) $(expression_h) \
$(gdbcmd_h) $(gdbcore_h) $(gdbtypes_h) $(language_h) $(symtab_h) \
diff --git a/gdb/c-exp.y b/gdb/c-exp.y
index a15a445..f555518 100644
--- a/gdb/c-exp.y
+++ b/gdb/c-exp.y
@@ -1246,6 +1246,17 @@
retry:
+ /* Check if this is a macro invocation that we need to expand. */
+ if (! scanning_macro_expansion ())
+ {
+ char *expanded = macro_expand_next (&lexptr,
+ expression_macro_lookup_func,
+ expression_macro_lookup_baton);
+
+ if (expanded)
+ scan_macro_expansion (expanded);
+ }
+
prev_lexptr = lexptr;
unquoted_expr = 1;
@@ -1271,7 +1282,17 @@
switch (c = *tokstart)
{
case 0:
- return 0;
+ /* If we were just scanning the result of a macro expansion,
+ then we need to resume scanning the original text.
+ Otherwise, we were already scanning the original text, and
+ we're really done. */
+ if (scanning_macro_expansion ())
+ {
+ finished_macro_expansion ();
+ goto retry;
+ }
+ else
+ return 0;
case ' ':
case '\t':
@@ -1324,7 +1345,9 @@
return c;
case ',':
- if (comma_terminates && paren_depth == 0)
+ if (comma_terminates
+ && paren_depth == 0
+ && ! scanning_macro_expansion ())
return 0;
lexptr++;
return c;
@@ -1503,9 +1526,13 @@
c = tokstart[++namelen];
}
- /* The token "if" terminates the expression and is NOT
- removed from the input stream. */
- if (namelen == 2 && tokstart[0] == 'i' && tokstart[1] == 'f')
+ /* The token "if" terminates the expression and is NOT removed from
+ the input stream. It doesn't count if it appears in the
+ expansion of a macro. */
+ if (namelen == 2
+ && tokstart[0] == 'i'
+ && tokstart[1] == 'f'
+ && ! scanning_macro_expansion ())
{
return 0;
}
diff --git a/gdb/c-lang.c b/gdb/c-lang.c
index f98548a..09a2e6a 100644
--- a/gdb/c-lang.c
+++ b/gdb/c-lang.c
@@ -27,6 +27,8 @@
#include "language.h"
#include "c-lang.h"
#include "valprint.h"
+#include "macroscope.h"
+#include "gdb_assert.h"
extern void _initialize_c_language (void);
static void c_emit_char (int c, struct ui_file * stream, int quoter);
@@ -371,7 +373,128 @@
return (type);
}
+/* Preprocessing and parsing C and C++ expressions. */
+
+/* When we find that lexptr (the global var defined in parse.c) is
+ pointing at a macro invocation, we expand the invocation, and call
+ scan_macro_expansion to save the old lexptr here and point lexptr
+ into the expanded text. When we reach the end of that, we call
+ end_macro_expansion to pop back to the value we saved here. The
+ macro expansion code promises to return only fully-expanded text,
+ so we don't need to "push" more than one level.
+
+ This is disgusting, of course. It would be cleaner to do all macro
+ expansion beforehand, and then hand that to lexptr. But we don't
+ really know where the expression ends. Remember, in a command like
+
+ (gdb) break *ADDRESS if CONDITION
+
+ we evaluate ADDRESS in the scope of the current frame, but we
+ evaluate CONDITION in the scope of the breakpoint's location. So
+ it's simply wrong to try to macro-expand the whole thing at once. */
+static char *macro_original_text;
+static char *macro_expanded_text;
+
+
+void
+scan_macro_expansion (char *expansion)
+{
+ /* We'd better not be trying to push the stack twice. */
+ gdb_assert (! macro_original_text);
+ gdb_assert (! macro_expanded_text);
+
+ /* Save the old lexptr value, so we can return to it when we're done
+ parsing the expanded text. */
+ macro_original_text = lexptr;
+ lexptr = expansion;
+
+ /* Save the expanded text, so we can free it when we're finished. */
+ macro_expanded_text = expansion;
+}
+
+
+int
+scanning_macro_expansion ()
+{
+ return macro_original_text != 0;
+}
+
+
+void
+finished_macro_expansion ()
+{
+ /* There'd better be something to pop back to, and we better have
+ saved a pointer to the start of the expanded text. */
+ gdb_assert (macro_original_text);
+ gdb_assert (macro_expanded_text);
+
+ /* Pop back to the original text. */
+ lexptr = macro_original_text;
+ macro_original_text = 0;
+
+ /* Free the expanded text. */
+ xfree (macro_expanded_text);
+ macro_expanded_text = 0;
+}
+
+
+static void
+scan_macro_cleanup (void *dummy)
+{
+ if (macro_original_text)
+ finished_macro_expansion ();
+}
+
+
+/* We set these global variables before calling c_parse, to tell it
+ how it to find macro definitions for the expression at hand. */
+macro_lookup_ftype *expression_macro_lookup_func;
+void *expression_macro_lookup_baton;
+
+
+static struct macro_definition *
+null_macro_lookup (const char *name, void *baton)
+{
+ return 0;
+}
+
+
+static int
+c_preprocess_and_parse ()
+{
+ /* Set up a lookup function for the macro expander. */
+ struct macro_scope *scope = 0;
+ struct cleanup *back_to = make_cleanup (free_current_contents, &scope);
+
+ if (expression_context_block)
+ scope = sal_macro_scope (find_pc_line (expression_context_pc, 0));
+ else
+ scope = default_macro_scope ();
+
+ if (scope)
+ {
+ expression_macro_lookup_func = standard_macro_lookup;
+ expression_macro_lookup_baton = (void *) scope;
+ }
+ else
+ {
+ expression_macro_lookup_func = null_macro_lookup;
+ expression_macro_lookup_baton = 0;
+ }
+
+ gdb_assert (! macro_original_text);
+ make_cleanup (scan_macro_cleanup, 0);
+
+ {
+ int result = c_parse ();
+ do_cleanups (back_to);
+ return result;
+ }
+}
+
+
+
/* Table mapping opcodes into strings for printing operators
and precedences of the operators. */
@@ -439,7 +562,7 @@
range_check_off,
type_check_off,
case_sensitive_on,
- c_parse,
+ c_preprocess_and_parse,
c_error,
evaluate_subexp_standard,
c_printchar, /* Print a character constant */
@@ -491,7 +614,7 @@
range_check_off,
type_check_off,
case_sensitive_on,
- c_parse,
+ c_preprocess_and_parse,
c_error,
evaluate_subexp_standard,
c_printchar, /* Print a character constant */
@@ -520,7 +643,7 @@
range_check_off,
type_check_off,
case_sensitive_on,
- c_parse,
+ c_preprocess_and_parse,
c_error,
evaluate_subexp_standard,
c_printchar, /* Print a character constant */
diff --git a/gdb/c-lang.h b/gdb/c-lang.h
index b1925e1..e64d4c6 100644
--- a/gdb/c-lang.h
+++ b/gdb/c-lang.h
@@ -24,6 +24,7 @@
#define C_LANG_H 1
#include "value.h"
+#include "macroexp.h"
extern int c_parse (void); /* Defined in c-exp.y */
@@ -49,6 +50,13 @@
unsigned int length, int width,
int force_ellipses);
+extern void scan_macro_expansion (char *expansion);
+extern int scanning_macro_expansion (void);
+extern void finished_macro_expansion (void);
+
+extern macro_lookup_ftype *expression_macro_lookup_func;
+extern void *expression_macro_lookup_baton;
+
extern struct type *c_create_fundamental_type (struct objfile *, int);
extern struct type **const (c_builtin_types[]);
diff --git a/gdb/parse.c b/gdb/parse.c
index 9c1f3e1..bc81f22 100644
--- a/gdb/parse.c
+++ b/gdb/parse.c
@@ -71,6 +71,7 @@
int expout_size;
int expout_ptr;
struct block *expression_context_block;
+CORE_ADDR expression_context_pc;
struct block *innermost_block;
int arglist_len;
union type_stack_elt *type_stack;
@@ -1140,7 +1141,13 @@
old_chain = make_cleanup (free_funcalls, 0 /*ignore*/);
funcall_chain = 0;
- expression_context_block = block ? block : get_selected_block (0);
+ if (block)
+ {
+ expression_context_block = block;
+ expression_context_pc = block->startaddr;
+ }
+ else
+ expression_context_block = get_selected_block (&expression_context_pc);
namecopy = (char *) alloca (strlen (lexptr) + 1);
expout_size = 10;
diff --git a/gdb/parser-defs.h b/gdb/parser-defs.h
index ece2849..7db1c77e 100644
--- a/gdb/parser-defs.h
+++ b/gdb/parser-defs.h
@@ -37,6 +37,12 @@
extern struct block *expression_context_block;
+/* If expression_context_block is non-zero, then this is the PC within
+ the block that we want to evaluate expressions at. When debugging
+ C or C++ code, we use this to find the exact line we're at, and
+ then look up the macro definitions active at that point. */
+CORE_ADDR expression_context_pc;
+
/* The innermost context required by the stack and register variables
we've encountered so far. */
extern struct block *innermost_block;
