commit 434c7524413a8a47ae40e4b141f5821eabc506b7

Author: iraisr <iraisr@a5019735-40e9-0310-863c-91ae7b9d1cf9>

Date:   Fri Dec 4 13:14:10 2015 +0000

    Dwarf line info reader now correctly interprets 'is_stmt' register

    Line numbers should correctly reflect all instructions belonging to a source line,

    regardless of is_stmt value. Previously only instructions covered by

    'is_stmt = 1' were attributed to a source line.

    Fixes BZ#356044

    git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15741 a5019735-40e9-0310-863c-91ae7b9d1cf9

diff --git a/coregrind/m_debuginfo/readdwarf.c b/coregrind/m_debuginfo/readdwarf.c

index 88d49e9..a95bb3d 100644

--- a/coregrind/m_debuginfo/readdwarf.c

+++ b/coregrind/m_debuginfo/readdwarf.c

@@ -91,7 +91,6 @@ typedef struct

   ULong  li_header_length;

   UChar  li_min_insn_length;

   UChar  li_max_ops_per_insn;

-  UChar  li_default_is_stmt;

   Int    li_line_base;

   UChar  li_line_range;

   UChar  li_opcode_base;

@@ -150,7 +149,6 @@ typedef struct

   UInt  file;

   UInt  line;

   UInt  column;

-  Int   is_stmt;

   Int   basic_block;

   UChar end_sequence;

 } LineSMR;

@@ -230,7 +228,7 @@ ULong read_initial_length_field ( DiCursor p_img, /*OUT*/Bool* is64 )

 static LineSMR state_machine_regs;

 static 

-void reset_state_machine ( Int is_stmt )

+void reset_state_machine ( void )

 {

    if (0) VG_(printf)("smr.a := %p (reset)\n", NULL );

    state_machine_regs.last_address = 0;

@@ -240,7 +238,6 @@ void reset_state_machine ( Int is_stmt )

    state_machine_regs.file = 1;

    state_machine_regs.line = 1;

    state_machine_regs.column = 0;

-   state_machine_regs.is_stmt = is_stmt;

    state_machine_regs.basic_block = 0;

    state_machine_regs.end_sequence = 0;

 }

@@ -253,7 +250,7 @@ void reset_state_machine ( Int is_stmt )

 static 

 void process_extended_line_op( struct _DebugInfo* di,

                                XArray* fndn_ix_xa,

-                               DiCursor* data, Int is_stmt)

+                               DiCursor* data )

 {

    UInt len = step_leb128U(data);

    if (len == 0) {

@@ -275,19 +272,17 @@ void process_extended_line_op( struct _DebugInfo* di,

             reset_state_machine below */

          state_machine_regs.end_sequence = 1; 

-         if (state_machine_regs.is_stmt) {

-            if (state_machine_regs.last_address) {

-               ML_(addLineInfo) (

-                  di,

-                  safe_fndn_ix (fndn_ix_xa,

-                                state_machine_regs.last_file),

-                  di->text_debug_bias + state_machine_regs.last_address, 

-                  di->text_debug_bias + state_machine_regs.address, 

-                  state_machine_regs.last_line, 0

-               );

-            }

+         if (state_machine_regs.last_address) {

+            ML_(addLineInfo)(

+               di,

+               safe_fndn_ix(fndn_ix_xa,

+                            state_machine_regs.last_file),

+               di->text_debug_bias + state_machine_regs.last_address, 

+               di->text_debug_bias + state_machine_regs.address, 

+               state_machine_regs.last_line, 0

+            );

          }

-         reset_state_machine (is_stmt);

+         reset_state_machine();

          if (di->ddump_line)

             VG_(printf)("  Extended opcode %d: End of Sequence\n\n", 

                         (Int)op_code);

@@ -446,29 +441,9 @@ void read_dwarf2_lineblock ( struct _DebugInfo* di,

       info.li_max_ops_per_insn = 1;

    }

-   info.li_default_is_stmt = ML_(cur_step_UChar)(&external);

-   if (di->ddump_line)

-      VG_(printf)("  Initial value of 'is_stmt':  %d\n", 

-                  (Int)info.li_default_is_stmt);

-

-   /* Josef Weidendorfer (20021021) writes:

-

-      It seems to me that the Intel Fortran compiler generates bad

-      DWARF2 line info code: It sets "is_stmt" of the state machine in

-      the line info reader to be always false. Thus, there is never

-      a statement boundary generated and therefore never an instruction

-      range/line number mapping generated for valgrind.

-

-      Please have a look at the DWARF2 specification, Ch. 6.2

-      (x86.ddj.com/ftp/manuals/tools/dwarf.pdf).  Perhaps I understand

-      this wrong, but I don't think so.

-

-      I just had a look at the GDB DWARF2 reader...  They completely

-      ignore "is_stmt" when recording line info ;-) That's the reason

-      "objdump -S" works on files from the intel fortran compiler.

-

-      Therefore: */

-   info.li_default_is_stmt = True; 

+   /* Register is_stmt is not tracked as we are interested only

+      in pc -> line info mapping and not other debugger features. */

+   /* default_is_stmt = */ ML_(cur_step_UChar)(&external);

    /* JRS: changed (UInt*) to (UChar*) */

    info.li_line_base = ML_(cur_step_UChar)(&external);

@@ -495,7 +470,7 @@ void read_dwarf2_lineblock ( struct _DebugInfo* di,

    DiCursor end_of_sequence

      = ML_(cur_plus)(data, info.li_length + (is64 ? 12 : 4));

-   reset_state_machine (info.li_default_is_stmt);

+   reset_state_machine();

    /* Read the contents of the Opcodes table.  */

    DiCursor standard_opcodes = external;

@@ -632,55 +607,49 @@ void read_dwarf2_lineblock ( struct _DebugInfo* di,

                         (Int)op_code, advAddr, state_machine_regs.address,

                         (Int)adv, (Int)state_machine_regs.line );

-         if (state_machine_regs.is_stmt) {

-            /* only add a statement if there was a previous boundary */

-            if (state_machine_regs.last_address) {

-               ML_(addLineInfo)(

-                  di,

-                  safe_fndn_ix (fndn_ix_xa,

-                                state_machine_regs.last_file),

-                  di->text_debug_bias + state_machine_regs.last_address, 

-                  di->text_debug_bias + state_machine_regs.address, 

-                  state_machine_regs.last_line, 

-                  0

-               );

-            }

-            state_machine_regs.last_address = state_machine_regs.address;

-            state_machine_regs.last_file = state_machine_regs.file;

-            state_machine_regs.last_line = state_machine_regs.line;

+         /* only add a statement if there was a previous boundary */

+         if (state_machine_regs.last_address) {

+            ML_(addLineInfo)(

+               di,

+               safe_fndn_ix(fndn_ix_xa,

+                            state_machine_regs.last_file),

+               di->text_debug_bias + state_machine_regs.last_address, 

+               di->text_debug_bias + state_machine_regs.address, 

+               state_machine_regs.last_line, 

+               0

+            );

          }

+         state_machine_regs.last_address = state_machine_regs.address;

+         state_machine_regs.last_file = state_machine_regs.file;

+         state_machine_regs.last_line = state_machine_regs.line;

       }

       else { /* ! (op_code >= info.li_opcode_base) */

       switch (op_code) {

          case DW_LNS_extended_op:

-            process_extended_line_op (

-                       di, fndn_ix_xa,

-                       &data, info.li_default_is_stmt);

+            process_extended_line_op(di, fndn_ix_xa, &data);

             break;

          case DW_LNS_copy:

             if (0) VG_(printf)("1002: di->o %#lx, smr.a %#lx\n",

                                (UWord)di->text_debug_bias,

                                state_machine_regs.address );

-            if (state_machine_regs.is_stmt) {

-               /* only add a statement if there was a previous boundary */

-               if (state_machine_regs.last_address) {

-                  ML_(addLineInfo)(

-                     di,

-                     safe_fndn_ix (fndn_ix_xa,

-                                   state_machine_regs.last_file), 

-                     di->text_debug_bias + state_machine_regs.last_address, 

-                     di->text_debug_bias + state_machine_regs.address,

-                     state_machine_regs.last_line, 

-                     0

-                  );

-               }

-               state_machine_regs.last_address = state_machine_regs.address;

-               state_machine_regs.last_file = state_machine_regs.file;

-               state_machine_regs.last_line = state_machine_regs.line;

+            /* only add a statement if there was a previous boundary */

+            if (state_machine_regs.last_address) {

+               ML_(addLineInfo)(

+                  di,

+                  safe_fndn_ix(fndn_ix_xa,

+                               state_machine_regs.last_file), 

+                  di->text_debug_bias + state_machine_regs.last_address, 

+                  di->text_debug_bias + state_machine_regs.address,

+                  state_machine_regs.last_line, 

+                  0

+               );

             }

+            state_machine_regs.last_address = state_machine_regs.address;

+            state_machine_regs.last_file = state_machine_regs.file;

+            state_machine_regs.last_line = state_machine_regs.line;

             state_machine_regs.basic_block = 0; /* JRS added */

             if (di->ddump_line)

                VG_(printf)("  Copy\n");

@@ -719,9 +688,6 @@ void read_dwarf2_lineblock ( struct _DebugInfo* di,

             break;

          }

          case DW_LNS_negate_stmt: {

-            Int adv = state_machine_regs.is_stmt;

-            adv = ! adv;

-            state_machine_regs.is_stmt = adv;

             if (di->ddump_line)

                VG_(printf)("  DWARF2-line: negate_stmt\n");

             break;

diff --git a/coregrind/m_debuginfo/storage.c b/coregrind/m_debuginfo/storage.c

index 7b2e26a..e6a9856 100644

--- a/coregrind/m_debuginfo/storage.c

+++ b/coregrind/m_debuginfo/storage.c

@@ -419,6 +419,21 @@ static void addLoc ( struct _DebugInfo* di, DiLoc* loc, UInt fndn_ix )

    /* Zero-sized locs should have been ignored earlier */

    vg_assert(loc->size > 0);

+   /* Check if the last entry has adjacent range for the same line. */

+   if (di->loctab_used > 0) {

+      DiLoc *previous = &di->loctab[di->loctab_used - 1];

+      if ((previous->lineno == loc->lineno)

+          && (previous->addr + previous->size == loc->addr)) {

+         if (0)

+            VG_(printf)("Merging previous: addr %#lx, size %d, line %d, "

+                        "with current: addr %#lx, size %d, line %d.\n",

+                        previous->addr, previous->size, previous->lineno,

+                        loc->addr, loc->size, loc->lineno);

+         previous->size += loc->size;

+         return;

+      }

+   }

+

    if (di->loctab_used == di->loctab_size) {

       UInt   new_sz;

       DiLoc* new_loctab;