From aa7e63a4ffe62cf7787260bdda20d0793bc4ef68 Mon Sep 17 00:00:00 2001
From: sandeepgupta12 <sandeep.gupta12@ibm.com>
Date: Wed, 13 Aug 2025 16:47:02 +0530
Subject: [PATCH] base: add musl + ppc64le fallback for
 UnscaledCycleClock::Frequency

Fixes build failures on ppc64le with musl libc, where
UnscaledCycleClock::Frequency() had no implementation.

This patch adds a fallback for __linux__ + __powerpc64__ when
glibc is not present, using a constant 512 MHz timebase frequency.
This matches the existing AIX implementation and unblocks
projects like Node.js/V8 from building on Alpine Linux (musl).

Tested by building Node.js 24.x on ppc64le + musl.
---
 absl/base/internal/unscaledcycleclock.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/absl/base/internal/unscaledcycleclock.cc b/absl/base/internal/unscaledcycleclock.cc
index 68f92730..77b04317 100644
--- a/absl/base/internal/unscaledcycleclock.cc
+++ b/absl/base/internal/unscaledcycleclock.cc
@@ -85,6 +85,9 @@ int64_t UnscaledCycleClock::Now() {
 double UnscaledCycleClock::Frequency() {
 #ifdef __GLIBC__
   return __ppc_get_timebase_freq();
+#elif defined(__linux__) && (defined(__powerpc__) || defined(__ppc__))
+  // Fallback for musl + ppc64le: use constant timebase frequency (512 MHz)
+  return static_cast<double>(512000000);
 #elif defined(_AIX)
   // This is the same constant value as returned by
   // __ppc_get_timebase_freq().