Fixes to V8 GN build process on aix platform

src/base/debug/stack_trace_posix.cc: suppressed unused function warnings
for functions DemangleSymbols, OutputPointer(in order to compile with
-Werror flag)

test/cctest/test-isolate-independent-builtins.cc: corrections to make
ByteInText test case compatible with aix. (affects aix only)

Change-Id: I49e45e63545404c77aaed3f51b26557f6f03455e
Reviewed-on: https://chromium-review.googlesource.com/927484Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52071}

src/base/debug/stack_trace_posix.cc

@@ -72,6 +72,7 @@ const char kMangledSymbolPrefix[] = "_Z";
 const char kSymbolCharacters[] =
     "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_";
 
+#if HAVE_EXECINFO_H
 // Demangles C++ symbols in the given text. Example:
 //
 // "out/Debug/base_unittests(_ZN10StackTraceC1Ev+0x20) [0x817778c]"
@@ -81,7 +82,6 @@ void DemangleSymbols(std::string* text) {
   // Note: code in this function is NOT async-signal safe (std::string uses
   // malloc internally).
 
-#if HAVE_EXECINFO_H
 
   std::string::size_type search_from = 0;
   while (search_from < text->size()) {
@@ -117,9 +117,8 @@ void DemangleSymbols(std::string* text) {
       search_from = mangled_start + 2;
     }
   }
-
-#endif  // HAVE_EXECINFO_H
 }
+#endif  // HAVE_EXECINFO_H
 
 class BacktraceOutputHandler {
  public:
@@ -129,6 +128,7 @@ class BacktraceOutputHandler {
   virtual ~BacktraceOutputHandler() {}
 };
 
+#if HAVE_EXECINFO_H
 void OutputPointer(void* pointer, BacktraceOutputHandler* handler) {
   // This should be more than enough to store a 64-bit number in hex:
   // 16 hex digits + 1 for null-terminator.
@@ -139,7 +139,6 @@ void OutputPointer(void* pointer, BacktraceOutputHandler* handler) {
   handler->HandleOutput(buf);
 }
 
-#if HAVE_EXECINFO_H
 void ProcessBacktrace(void* const* trace, size_t size,
                       BacktraceOutputHandler* handler) {
   // NOTE: This code MUST be async-signal safe (it's used by in-process

src/snapshot/macros.h

@@ -14,6 +14,11 @@
 #define V8_ASM_RODATA_SECTION ".const_data\n"
 #define V8_ASM_TEXT_SECTION ".text\n"
 #define V8_ASM_DECLARE(NAME) ".private_extern " V8_ASM_MANGLE_LABEL NAME "\n"
+#elif defined(V8_OS_AIX)  // AIX
+#define V8_ASM_RODATA_SECTION ".csect[RO]\n"
+#define V8_ASM_TEXT_SECTION ".csect .text[PR]\n"
+#define V8_ASM_MANGLE_LABEL ""
+#define V8_ASM_DECLARE(NAME) ".globl " V8_ASM_MANGLE_LABEL NAME "\n"
 #elif defined(V8_OS_WIN)  // WIN
 #if defined(V8_TARGET_ARCH_X64)
 #define V8_ASM_MANGLE_LABEL ""
@@ -23,7 +28,7 @@
 #define V8_ASM_RODATA_SECTION ".section .rodata\n"
 #define V8_ASM_TEXT_SECTION ".section .text\n"
 #define V8_ASM_DECLARE(NAME)
-#else  // !MACOSX && !WIN
+#else  // !MACOSX && !WIN && !AIX
 #define V8_ASM_MANGLE_LABEL ""
 #define V8_ASM_RODATA_SECTION ".section .rodata\n"
 #define V8_ASM_TEXT_SECTION ".section .text\n"
@@ -39,6 +44,24 @@
 #define V8_ASM_LABEL(NAME) V8_ASM_MANGLE_LABEL NAME ":\n"
 
 // clang-format off
+#if defined(V8_OS_AIX)
+
+#define V8_EMBEDDED_TEXT_HEADER(LABEL)         \
+  __asm__(V8_ASM_DECLARE(#LABEL)               \
+          ".csect " #LABEL "[DS]\n"            \
+          #LABEL ":\n"                         \
+          ".llong ." #LABEL ", TOC[tc0], 0\n"  \
+          V8_ASM_TEXT_SECTION                  \
+          "." #LABEL ":\n");
+
+#define V8_EMBEDDED_RODATA_HEADER(LABEL)    \
+  __asm__(V8_ASM_RODATA_SECTION             \
+          V8_ASM_DECLARE(#LABEL)            \
+          ".align 5\n"                      \
+          V8_ASM_LABEL(#LABEL));
+
+#else
+
 #define V8_EMBEDDED_TEXT_HEADER(LABEL) \
   __asm__(V8_ASM_TEXT_SECTION          \
           V8_ASM_DECLARE(#LABEL)       \
@@ -50,6 +73,6 @@
           V8_ASM_DECLARE(#LABEL)         \
           V8_ASM_BALIGN32                \
           V8_ASM_LABEL(#LABEL));
-// clang-format off
 
+#endif  // #if defined(V8_OS_AIX)
 #endif  // V8_SNAPSHOT_MACROS_H_

test/cctest/test-isolate-independent-builtins.cc

@@ -236,7 +236,11 @@ TEST(GenerateTestFunctionData) {
 #elif V8_TARGET_ARCH_ARM
 #define FUNCTION_BYTES ".byte 0x01, 0x00, 0x80, 0xe0, 0x0e, 0xf0, 0xa0, 0xe1\n"
 #elif V8_TARGET_ARCH_PPC
+#if defined(V8_OS_AIX)
+#define FUNCTION_BYTES ".byte 0x7c, 0x64, 0x1a, 0x14, 0x4e, 0x80, 0x00, 0x20\n"
+#else
 #define FUNCTION_BYTES ".byte 0x14, 0x22, 0x63, 0x7c, 0x20, 0x00, 0x80, 0x4e\n"
+#endif
 #elif defined(V8_TARGET_ARCH_MIPS) || defined(V8_TARGET_ARCH_MIPS64)
 #if defined(V8_TARGET_BIG_ENDIAN)
 #define FUNCTION_BYTES                               \