[parser] Force func decl allocation for non-block code coverage

In addition to the previous change enabling forced FunctionDeclaration
allocation when block code coverage is enabled, enable it now for all
(non-best-effort) code coverage by reading off the coverage mode from
the isolate (rather than relying on the presence of a source range map).

Bug: chromium:927464
Change-Id: I26f86c9fbebc0df52d5cdeff3ca1095215a6d912
Reviewed-on: https://chromium-review.googlesource.com/c/1456041
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59626}

src/parsing/parse-info.cc

@@ -51,6 +51,7 @@ ParseInfo::ParseInfo(Isolate* isolate, AccountingAllocator* zone_allocator)
   set_ast_string_constants(isolate->ast_string_constants());
   set_collect_source_positions(!FLAG_enable_lazy_source_positions ||
                                isolate->NeedsDetailedOptimizedCodeLineInfo());
+  if (!isolate->is_best_effort_code_coverage()) set_coverage_enabled();
   if (isolate->is_block_code_coverage()) set_block_coverage_enabled();
   if (isolate->is_collecting_type_profile()) set_collect_type_profile();
   if (isolate->compiler_dispatcher()->IsEnabled()) {

src/parsing/parse-info.h

@@ -84,6 +84,7 @@ class V8_EXPORT_PRIVATE ParseInfo {
   FLAG_ACCESSOR(kIsAsmWasmBroken, is_asm_wasm_broken, set_asm_wasm_broken)
   FLAG_ACCESSOR(kContainsAsmModule, contains_asm_module,
                 set_contains_asm_module)
+  FLAG_ACCESSOR(kCoverageEnabled, coverage_enabled, set_coverage_enabled)
   FLAG_ACCESSOR(kBlockCoverageEnabled, block_coverage_enabled,
                 set_block_coverage_enabled)
   FLAG_ACCESSOR(kOnBackgroundThread, on_background_thread,
@@ -296,26 +297,27 @@ class V8_EXPORT_PRIVATE ParseInfo {
     kIsNamedExpression = 1 << 8,
     kLazyCompile = 1 << 9,
     kCollectTypeProfile = 1 << 10,
-    kBlockCoverageEnabled = 1 << 11,
-    kIsAsmWasmBroken = 1 << 12,
-    kOnBackgroundThread = 1 << 13,
-    kWrappedAsFunction = 1 << 14,  // Implicitly wrapped as function.
-    kAllowEvalCache = 1 << 15,
-    kIsDeclaration = 1 << 16,
-    kRequiresInstanceMembersInitializer = 1 << 17,
-    kContainsAsmModule = 1 << 18,
-    kMightAlwaysOpt = 1 << 19,
-    kAllowLazyCompile = 1 << 20,
-    kAllowNativeSyntax = 1 << 21,
-    kAllowHarmonyPublicFields = 1 << 22,
-    kAllowHarmonyStaticFields = 1 << 23,
-    kAllowHarmonyDynamicImport = 1 << 24,
-    kAllowHarmonyImportMeta = 1 << 25,
-    kAllowHarmonyNumericSeparator = 1 << 26,
-    kAllowHarmonyPrivateFields = 1 << 27,
-    kAllowHarmonyPrivateMethods = 1 << 28,
-    kIsOneshotIIFE = 1 << 29,
-    kCollectSourcePositions = 1 << 30,
+    kCoverageEnabled = 1 << 11,
+    kBlockCoverageEnabled = 1 << 12,
+    kIsAsmWasmBroken = 1 << 13,
+    kOnBackgroundThread = 1 << 14,
+    kWrappedAsFunction = 1 << 15,  // Implicitly wrapped as function.
+    kAllowEvalCache = 1 << 16,
+    kIsDeclaration = 1 << 17,
+    kRequiresInstanceMembersInitializer = 1 << 18,
+    kContainsAsmModule = 1 << 19,
+    kMightAlwaysOpt = 1 << 20,
+    kAllowLazyCompile = 1 << 21,
+    kAllowNativeSyntax = 1 << 22,
+    kAllowHarmonyPublicFields = 1 << 23,
+    kAllowHarmonyStaticFields = 1 << 24,
+    kAllowHarmonyDynamicImport = 1 << 25,
+    kAllowHarmonyImportMeta = 1 << 26,
+    kAllowHarmonyNumericSeparator = 1 << 27,
+    kAllowHarmonyPrivateFields = 1 << 28,
+    kAllowHarmonyPrivateMethods = 1 << 29,
+    kIsOneshotIIFE = 1 << 30,
+    kCollectSourcePositions = 1 << 31,
   };
 
   //------------- Inputs to parsing and scope analysis -----------------------

src/parsing/parser.cc

@@ -1447,7 +1447,7 @@ Statement* Parser::DeclareFunction(const AstRawString* variable_name,
   bool was_added;
   Declare(declaration, variable_name, kind, mode, kCreatedInitialized, scope(),
           &was_added, beg_pos);
-  if (source_range_map_ != nullptr) {
+  if (info()->coverage_enabled()) {
     // Force the function to be allocated when collecting source coverage, so
     // that even dead functions get source coverage data.
     declaration->var()->set_is_used();

test/inspector/cpu-profiler/coverage-expected.txt

@@ -753,6 +753,17 @@ Running test: testPreciseCountCoveragePartial
                             }
                         ]
                     }
+                    [6] : {
+                        functionName : nested_4
+                        isBlockCoverage : false
+                        ranges : [
+                            [0] : {
+                                count : 0
+                                endOffset : 201
+                                startOffset : 179
+                            }
+                        ]
+                    }
                 ]
                 scriptId : <scriptId>
                 url : testPreciseCountCoveragePartial

test/mjsunit/code-coverage-ad-hoc.js

@@ -57,3 +57,19 @@ fib(5);
 [{"start":0,"end":80,"count":1},
  {"start":0,"end":72,"count":1}]
 );
+
+TestCoverageNoGC(
+"https://crbug.com/927464",
+`
+!function f() {                           // 0000
+  function unused() { nop(); }            // 0100
+  nop();                                  // 0150
+}();                                      // 0200
+`,
+[{"start":0,"end":199,"count":1},
+ {"start":1,"end":151,"count":1}
+ // The unused function is unfortunately not marked as unused in best-effort
+ // code coverage, as the information about its source range is discarded
+ // entirely.
+]
+);

test/mjsunit/code-coverage-precise.js

@@ -50,4 +50,17 @@ for (var i = 0; i < 10; i++) {
 [{"start":0,"end":63,"count":1},{"start":41,"end":48,"count":5}]
 );
 
+TestCoverage(
+"https://crbug.com/927464",
+`
+!function f() {                           // 0000
+  function unused() { nop(); }            // 0100
+  nop();                                  // 0150
+}();                                      // 0200
+`,
+[{"start":0,"end":199,"count":1},
+ {"start":1,"end":151,"count":1},
+ {"start":52,"end":80,"count":0}]
+);
+
 %DebugTogglePreciseCoverage(false);