Introduce a command line option to enable statement frontiers, enabled
by default in optimized builds with DWARF2+ debug information.
This patch depends on an earlier patch that completed the
infrastructure for debug markers, and on another patch that turns -g
into a negatable option prefix.
gcc/ChangeLog
* common.opt (gstatement-frontiers): New, setting
debug_nonbind_markers_p.
* rtl.h (MAY_HAVE_DEBUG_MARKER_INSNS): Activate.
* toplev.c (process_options): Autodetect value for debug statement
frontiers option.
* tree.h (MAY_HAVE_DEBUG_MARKER_STMTS): Activate.
* doc/invoke.texi (gstatement-frontiers, gno-statement-frontiers): New.
---
gcc/common.opt | 4 ++++
gcc/doc/invoke.texi | 12 ++++++++++++
gcc/rtl.h | 2 +-
gcc/toplev.c | 4 ++++
gcc/tree.h | 2 +-
5 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/gcc/common.opt b/gcc/common.opt
index dfde6ad..a12c11c 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2889,6 +2889,10 @@ gstabs+
Common Driver JoinedOrMissing Negative(gvms)
Generate debug information in extended STABS format.
+gstatement-frontiers
+Common Driver Var(debug_nonbind_markers_p) Init(2)
+Emit progressive recommended breakpoint locations.
+
gstrict-dwarf
Common Driver Report Var(dwarf_strict) Init(0)
Don't emit DWARF additions beyond selected version.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 108d730..85e41e4 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -346,6 +346,7 @@ Objective-C and Objective-C++ Dialects}.
-ggdb -grecord-gcc-switches -gno-record-gcc-switches @gol
-gstabs -gstabs+ -gstrict-dwarf -gno-strict-dwarf @gol
-gcolumn-info -gno-column-info @gol
+-gstatement-frontiers -gno-statement-frontiers @gol
-gvms -gxcoff -gxcoff+ -gz@r{[}=@var{type}@r{]} @gol
-fdebug-prefix-map=@var{old}=@var{new} -fdebug-types-section @gol
-fno-eliminate-unused-debug-types @gol
@@ -7040,6 +7041,17 @@ Emit location column information into DWARF debugging
information, rather
than just file and line.
This option is disabled by default.
+@item -gstatement-frontiers
+@item -gno-statement-frontiers
+@opindex gstatement-frontiers
+@opindex gno-statement-frontiers
+This option causes GCC to create markers in the internal representation
+at the beginning of statements, and to keep them roughly in place
+throughout compilation, using them to guide the output of @code{is_stmt}
+markers in the line number table. This is enabled by default when
+compiling with optimization (@option{-Os}, @option{-O}, @option{-O2},
+@dots{}), and outputting DWARF 2 debug information at the normal level.
+
@item -gz@r{[}=@var{type}@r{]}
@opindex gz
Produce compressed debug sections in DWARF format, if that is supported.
diff --git a/gcc/rtl.h b/gcc/rtl.h
index c79a277..a0c27fc 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -816,7 +816,7 @@ struct GTY(()) rtvec_def {
#define NONDEBUG_INSN_P(X) (INSN_P (X) && !DEBUG_INSN_P (X))
/* Nonzero if DEBUG_MARKER_INSN_P may possibly hold. */
-#define MAY_HAVE_DEBUG_MARKER_INSNS 0 /* debug_nonbind_markers_p */
+#define MAY_HAVE_DEBUG_MARKER_INSNS debug_nonbind_markers_p
/* Nonzero if DEBUG_BIND_INSN_P may possibly hold. */
#define MAY_HAVE_DEBUG_BIND_INSNS flag_var_tracking_assignments
/* Nonzero if DEBUG_INSN_P may possibly hold. */
diff --git a/gcc/toplev.c b/gcc/toplev.c
index bee79d3..0ef46da 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -1514,6 +1514,10 @@ process_options (void)
warning_at (UNKNOWN_LOCATION, 0,
"var-tracking-assignments changes selective scheduling");
+ if (debug_nonbind_markers_p == AUTODETECT_VALUE)
+ debug_nonbind_markers_p = optimize && debug_info_level >=
DINFO_LEVEL_NORMAL
+ && (write_symbols == DWARF2_DEBUG || write_symbols ==
VMS_AND_DWARF2_DEBUG);
+
if (flag_tree_cselim == AUTODETECT_VALUE)
{
if (HAVE_conditional_move)
diff --git a/gcc/tree.h b/gcc/tree.h
index 62a85ea..8c3bda1 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -1127,7 +1127,7 @@ extern void omp_clause_range_check_failed (const_tree,
const char *, int,
((int)TREE_INT_CST_LOW (VL_EXP_CHECK (NODE)->exp.operands[0]))
/* Nonzero if gimple_debug_nonbind_marker_p() may possibly hold. */
-#define MAY_HAVE_DEBUG_MARKER_STMTS 0 /* debug_nonbind_markers_p */
+#define MAY_HAVE_DEBUG_MARKER_STMTS debug_nonbind_markers_p
/* Nonzero if gimple_debug_bind_p() (and thus
gimple_debug_source_bind_p()) may possibly hold. */
#define MAY_HAVE_DEBUG_BIND_STMTS flag_var_tracking_assignments
--
2.9.5
