From e8a36aac8d68d10a89ef45016058a17a3649abeb Mon Sep 17 00:00:00 2001
From: Eugene Tarassov
Date: Wed, 24 Oct 2018 12:20:25 -0700
Subject: TCF Agent: Breakpoints service: when possible, limit line breakpoint
 to beginning of a statement

---
 agent/tcf/services/breakpoints.c       | 28 ++++++++++++++++++++++++++--
 tests/test-dwarf/tcf/backend/backend.c |  5 +++--
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/agent/tcf/services/breakpoints.c b/agent/tcf/services/breakpoints.c
index 83764522..4448f971 100644
--- a/agent/tcf/services/breakpoints.c
+++ b/agent/tcf/services/breakpoints.c
@@ -265,7 +265,11 @@ static int planted_sw_bp_cnt = 0;
 
 static int bp_location_error = 0;
 #if ENABLE_LineNumbers
-static int bp_line_cnt = 0;
+static unsigned bp_line_cnt = 0;
+static unsigned bp_stmt_cnt = 0;
+static unsigned bp_line_addr_cnt = 0;
+static unsigned bp_line_addr_max = 0;
+static ContextAddress * bp_line_addr = NULL;
 #endif
 
 static TCFBroadcastGroup * broadcast_group = NULL;
@@ -1704,7 +1708,17 @@ static void plant_breakpoint_address_iterator(CodeArea * area, void * x) {
         /* Adjust breakpoint address <addr> if needed */
         BREAKPOINT_ADDR_ADJUST;
 #endif
-        plant_breakpoint(args->ctx, args->bp, addr, 1);
+        if ((addr == area->start_address && area->is_statement) || addr == area->next_stmt_address) {
+            plant_breakpoint(args->ctx, args->bp, addr, 1);
+            bp_stmt_cnt++;
+        }
+        else {
+            if (bp_line_addr_cnt >= bp_line_addr_max) {
+                bp_line_addr_max += 256;
+                bp_line_addr = (ContextAddress *)tmp_realloc(bp_line_addr, sizeof(ContextAddress) * bp_line_addr_max);
+            }
+            bp_line_addr[bp_line_addr_cnt++] = addr;
+        }
     }
     else {
         plant_at_address_expression(args->ctx, area->start_address, args->bp);
@@ -1871,12 +1885,22 @@ static void evaluate_bp_location(void * x) {
         if (bp->file != NULL) {
 #if ENABLE_LineNumbers
             bp_line_cnt = 0;
+            bp_stmt_cnt = 0;
+            bp_line_addr_cnt = 0;
+            bp_line_addr_max = 0;
+            bp_line_addr = NULL;
             if (line_to_address(ctx, bp->file, bp->line, bp->column, plant_breakpoint_address_iterator, args) < 0) {
                 bp_location_error = errno;
             }
             else if (bp_line_cnt == 0) {
                 bp_location_error = set_errno(ERR_OTHER, "Unresolved source line information");
             }
+            else if (bp_stmt_cnt == 0) {
+                unsigned i;
+                for (i = 0; i < bp_line_addr_cnt; i++) {
+                    plant_breakpoint(ctx, bp, bp_line_addr[i], 1);
+                }
+            }
 #else
             bp_location_error = set_errno(ERR_UNSUPPORTED, "LineNumbers service not available");
 #endif
diff --git a/tests/test-dwarf/tcf/backend/backend.c b/tests/test-dwarf/tcf/backend/backend.c
index c5221d28..fb7df57b 100644
--- a/tests/test-dwarf/tcf/backend/backend.c
+++ b/tests/test-dwarf/tcf/backend/backend.c
@@ -333,8 +333,9 @@ static void addr_to_line_callback_p1(CodeArea * area, void * args) {
 
 static void line_to_addr_callback(CodeArea * area, void * args) {
     CodeArea * org = (CodeArea *)args;
-    if (area->start_line > org->start_line || (area->start_line == org->start_line && area->start_column > org->start_column) ||
-        area->end_line < org->start_line || (area->end_line == org->start_line && area->end_column <= org->start_column)) {
+    if (area->start_line > org->start_line || area->end_line < org->start_line ||
+        (org->start_column && area->start_line == org->start_line && area->start_column > org->start_column) ||
+        (org->start_column && area->end_line == org->start_line && area->end_column <= org->start_column)) {
         errno = set_errno(ERR_OTHER, "Invalid line area line numbers");
         error("line_to_address");
     }
-- 
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