compile.c: add a RUBY_EVENT_COVERAGE_LINE event for line coverage

2.5's line coverage measurement was about two times slower than 2.4
because of two reasons; (1) vm_trace uses rb_iseq_event_flags (which
takes O(n) currently where n is the length of iseq) to get an event
type, and (2) RUBY_EVENT_LINE uses setjmp to call an event hook.

This change adds a special event for line coverage,
RUBY_EVENT_COVERAGE_LINE, and adds `tracecoverage` instructions where
the event occurs in iseq.
`tracecoverage` instruction calls an event hook without vm_trace.
And, RUBY_EVENT_COVERAGE_LINE is an internal event which does not
use setjmp.

This change also cancells lineno change due to the deletion of trace
instructions [Feature #14104].  So fixes [Bug #14191].

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61350 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 12 insertions, 1 deletions

diff --git a/compile.c b/compile.c
index 574a589dc8..4ca855b002 100644
--- a/compile.c
+++ b/compile.c
@@ -250,6 +250,16 @@ struct iseq_compile_data_ensure_node_stack {
 
 #define ADD_TRACE(seq, event) \
   ADD_ELEM((seq), (LINK_ELEMENT *)new_trace_body(iseq, (event)))
+#define ADD_TRACE_LINE_COVERAGE(seq, line) \
+  do { \
+      if (ISEQ_COVERAGE(iseq) && \
+	  ISEQ_LINE_COVERAGE(iseq) && \
+	  (line) > 0) { \
+	  RARRAY_ASET(ISEQ_LINE_COVERAGE(iseq), (line) - 1, INT2FIX(0)); \
+	  ADD_INSN2((seq), (line), tracecoverage, INT2FIX(RUBY_EVENT_COVERAGE_LINE), INT2FIX(line)); \
+      } \
+  } while (0)
+
 
 #define DECL_BRANCH_BASE(branches, first_line, first_column, last_line, last_column, type) \
   do { \
@@ -280,7 +290,7 @@ struct iseq_compile_data_ensure_node_stack {
 	  rb_ary_push(branches, INT2FIX(last_line)); \
 	  rb_ary_push(branches, INT2FIX(last_column)); \
 	  rb_ary_push(branches, INT2FIX(counter_idx)); \
-	  ADD_INSN2((seq), (first_line), tracebranch, INT2FIX(RUBY_EVENT_COVERAGE_BRANCH), INT2FIX(counter_idx)); \
+	  ADD_INSN2((seq), (first_line), tracecoverage, INT2FIX(RUBY_EVENT_COVERAGE_BRANCH), INT2FIX(counter_idx)); \
       } \
   } while (0)
 
@@ -5421,6 +5431,7 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, in
     else {
 	if (node->flags & NODE_FL_NEWLINE) {
 	    ISEQ_COMPILE_DATA(iseq)->last_line = line;
+	    ADD_TRACE_LINE_COVERAGE(ret, line);
 	    ADD_TRACE(ret, RUBY_EVENT_LINE);
 	}
     }