Set TARGET_OS_* from GN, falling back to HOST_OS_*.

runtime/vm/dwarf.cc

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/dwarf.h"
 
 #include "vm/code_descriptors.h"
 #include "vm/object_store.h"
 
 namespace dart {
@@ skipping 136 matching lines @@
   stream_->VPrint(format, args);
   va_end(args);
 }
 
 
 void Dwarf::WriteAbbreviations() {
 // Dwarf data mostly takes the form of a tree, whose nodes are called
 // DIEs. Each DIE begins with an abbreviation code, and the abbreviation
 // describes the attributes of that DIE and their representation.
 
-#if defined(HOST_OS_MACOS)
+#if defined(TARGET_OS_MACOS) || TARGET_OS_IOS
   Print(".section __DWARF,__debug_abbrev,regular,debug\n");
+#elif defined(TARGET_OS_LINUX) || defined(TARGET_OS_ANDROID)
+  Print(".section .debug_abbrev,\"\"\n");
 #else
-  Print(".section .debug_abbrev,\"\"\n");
+  UNIMPLEMENTED();
 #endif
 
   uleb128(kCompilationUnit);     // Abbrev code.
   uleb128(DW_TAG_compile_unit);  // Type.
   u1(DW_CHILDREN_yes);
   uleb128(DW_AT_name);  // Start of attributes.
   uleb128(DW_FORM_string);
   uleb128(DW_AT_producer);
   uleb128(DW_FORM_string);
   uleb128(DW_AT_comp_dir);
@@ skipping 49 matching lines @@
   uleb128(0);
   uleb128(0);  // End of attributes.
 
   uleb128(0);  // End of abbreviations.
 }
 
 
 void Dwarf::WriteCompilationUnit() {
 // 7.5.1.1 Compilation Unit Header
 
-#if defined(HOST_OS_MACOS)
+#if defined(TARGET_OS_MACOS) || TARGET_OS_IOS
   Print(".section __DWARF,__debug_info,regular,debug\n");
+#elif defined(TARGET_OS_LINUX) || defined(TARGET_OS_ANDROID)
+  Print(".section .debug_info,\"\"\n");
 #else
-  Print(".section .debug_info,\"\"\n");
+  UNIMPLEMENTED();
 #endif
   Print(".Ldebug_info:\n");
 
   // Unit length. Assignment to temp works around buggy Mac assembler.
   Print("Lcu_size = .Lcu_end - .Lcu_start\n");
   Print(".4byte Lcu_size\n");
   Print(".Lcu_start:\n");
 
   u2(2);              // DWARF version 2
   u4(0);              // debug_abbrev_offset
@@ skipping 204 matching lines @@
   for (InliningNode* child = node->children_head; child != NULL;
        child = child->children_next) {
     WriteInliningNode(child, root_code_index, script);
   }
 
   uleb128(0);  // End of children.
 }
 
 
 void Dwarf::WriteLines() {
-#if defined(HOST_OS_MACOS)
+#if defined(TARGET_OS_MACOS) || TARGET_OS_IOS
   Print(".section __DWARF,__debug_line,regular,debug\n");
+#elif defined(TARGET_OS_LINUX) || defined(TARGET_OS_ANDROID)
+  Print(".section .debug_line,\"\"\n");
 #else
-  Print(".section .debug_line,\"\"\n");
+  UNIMPLEMENTED();
 #endif
 
   // 6.2.4 The Line Number Program Header
 
   // 1. unit_length. This encoding implies 32-bit DWARF.
   Print("Lline_size = .Lline_end - .Lline_start\n");
   Print(".4byte Lline_size\n");
 
   Print(".Lline_start:\n");
 
@@ skipping 162 matching lines @@
   u1(0);  // This is an extended opcode
   u1(1);  // that is 1 byte long
   u1(DW_LNE_end_sequence);
 
   Print(".Lline_end:\n");
 }
 
 #endif  // DART_PRECOMPILER
 
 }  // namespace dart