when open macro GENERATED_CODE_COVERAGE, fix compiler error and fd leak

src/x64/assembler-x64.cc

Index: src/x64/assembler-x64.cc
diff --git a/src/x64/assembler-x64.cc b/src/x64/assembler-x64.cc
index 6d3750e3109c95426b9af2ef64116902765c274b..58491688ef074cfe3aa80cf74a66941d1a75ed28 100644
--- a/src/x64/assembler-x64.cc
+++ b/src/x64/assembler-x64.cc
@@ -225,6 +225,7 @@ bool Operand::AddressUsesRegister(Register reg) const {
 
 #ifdef GENERATED_CODE_COVERAGE
 static void InitCoverageLog();
+static void DeinitCoverageLog();
 #endif
 
 Assembler::Assembler(Isolate* isolate, void* buffer, int buffer_size)
@@ -248,6 +249,11 @@ Assembler::Assembler(Isolate* isolate, void* buffer, int buffer_size)
 #endif
 }
 
+Assembler::~Assembler() {
+#ifdef GENERATED_CODE_COVERAGE
+  DeinitCoverageLog();
+#endif
+}
 
 void Assembler::GetCode(CodeDesc* desc) {
   // Finalize code (at this point overflow() may be true, but the gap ensures
@@ -2971,6 +2977,36 @@ bool RelocInfo::IsInConstantPool() {
   return false;
 }
 
+#ifdef GENERATED_CODE_COVERAGE
+static FILE* coverage_log = NULL;
+
+
+static void InitCoverageLog() {
+	char* file_name = getenv("V8_GENERATED_CODE_COVERAGE_LOG");
+	if (file_name != NULL && NULL == coverage_log) {
+		coverage_log = fopen(file_name, "aw+");
+	}
+}
+
+static void DeinitCoverageLog() {
+	if (coverage_log != NULL) {
+		fclose(coverage_log);
+		coverage_log = NULL;
+	}
+}
+
+void LogGeneratedCodeCoverage(const char* file_line) {
+	const char* return_address = (&file_line)[-1];
+	char* push_insn = const_cast<char*>(return_address - 12);
+	push_insn[0] = 0xeb;  // Relative branch insn.
+	push_insn[1] = 13;    // Skip over coverage insns.
+	if (coverage_log != NULL) {
+		fprintf(coverage_log, "%s\n", file_line);
+		fflush(coverage_log);
+	}
+}
+
+#endif
 
 } }  // namespace v8::internal