>From 6dd5796f04ca249e8e59026208e90e7619534a80 Mon Sep 17 00:00:00 2001
From: Andrei Herman <Andrei_Herman@codesourcery.com>
Date: Sun, 1 Jun 2014 11:13:09 +0300
Subject: [PATCH 1/2]             Add command line option -fforce-dwarf-lexical-blocks.

            * gcc/c-family/c.opt: Add -fforce-dwarf-lexical-blocks flag.
            * gcc/c-family/c-opts.c (c_common_post_options): Limit its use
            to dwarf4.
            * gcc/doc/invoke.texi: Document the new option.

Signed-off-by: Andrei Herman <Andrei_Herman@codesourcery.com>
---
 gcc/c-family/c-opts.c |   13 +++++++++++++
 gcc/c-family/c.opt    |    4 ++++
 gcc/doc/invoke.texi   |   12 ++++++++++++
 3 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/gcc/c-family/c-opts.c b/gcc/c-family/c-opts.c
index 29e9a35..7c9dbfc 100644
--- a/gcc/c-family/c-opts.c
+++ b/gcc/c-family/c-opts.c
@@ -936,6 +936,19 @@ c_common_post_options (const char **pfilename)
 #endif
     }
 
+  /* The -fforce-dwarf-lexical-blocks option is only relevant when debug
+     info is in DWARF4 format */
+  if (flag_force_dwarf_blocks) {
+    if (write_symbols != DWARF2_DEBUG)
+      flag_force_dwarf_blocks = 0;
+    if (write_symbols == DWARF2_DEBUG && dwarf_version < 4) {
+      inform (input_location,
+              "-fforce-dwarf-lexical-blocks is only supported with "
+              "DWARF4 debug format");
+      flag_force_dwarf_blocks = 0;
+    }
+  }
+
   if (flag_preprocess_only)
     {
       /* Open the output now.  We must do so even if flag_no_output is
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index c586e65..b66389e 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -960,6 +960,10 @@ ffor-scope
 C++ ObjC++ Var(flag_new_for_scope) Init(1)
 Scope of for-init-statement variables is local to the loop
 
+fforce-dwarf-lexical-blocks
+C C++ Var(flag_force_dwarf_blocks)
+Force generation of lexical blocks in dwarf output
+
 ffreestanding
 C ObjC C++ ObjC++
 Do not assume that standard C libraries and \"main\" exist
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 9475594..5bf154a 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -333,6 +333,7 @@ Objective-C and Objective-C++ Dialects}.
 -feliminate-unused-debug-symbols -femit-class-debug-always @gol
 -fenable-@var{kind}-@var{pass} @gol
 -fenable-@var{kind}-@var{pass}=@var{range-list} @gol
+-fforce-dwarf-lexical-blocks @gol
 -fdebug-types-section -fmem-report-wpa @gol
 -fmem-report -fpre-ipa-mem-report -fpost-ipa-mem-report -fprofile-arcs @gol
 -fopt-info @gol
@@ -5200,6 +5201,17 @@ normally emits debugging information for classes because using this
 option increases the size of debugging information by as much as a
 factor of two.
 
+@item -fforce-dwarf-lexical-blocks
+Produce debug information (a DW_TAG_lexical_block) for every function
+body, loop body, switch body, case statement, if-then and if-else statement,
+even if the body is a single statement.  Likewise, a lexical block will be
+emitted for the first label of a statement.  This block ends at the end of the
+current lexical scope, or when a break, continue, goto or return statement is
+encountered at the same lexical scope level.  This option is usefull for
+coverage tools that utilize the dwarf debug information.
+This option only applies to C/C++ code and is available when using DWARF
+Version 4 or higher.
+
 @item -fdebug-types-section
 @opindex fdebug-types-section
 @opindex fno-debug-types-section
-- 
1.7.1