[PATCH] build: detect backtrace availability

[Thomas Monjalon]

Backtrace dump is available:
	- always on Windows
	- on Linux/BSD if execinfo.h is available (not anymore on Alpine)

The flag RTE_BACKTRACE was set unconditionnaly in rte_config.h.
It is now set only if the feature is available.

Note: Alpine Linux has decided to remove libexecinfo support,
so this change will allow to compile DPDK on recent Alpine Linux.

Signed-off-by: Thomas Monjalon <thomas at monjalon.net>
---
 config/meson.build                | 3 ++-
 config/rte_config.h               | 1 -
 doc/guides/linux_gsg/sys_reqs.rst | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/config/meson.build b/config/meson.build
index 80564eec52..0c4d1f06e5 100644
--- a/config/meson.build
+++ b/config/meson.build
@@ -200,10 +200,11 @@ if fdt_dep.found() and cc.has_header('fdt.h')
 endif
 
 libexecinfo = cc.find_library('libexecinfo', required: false)
-if libexecinfo.found() and cc.has_header('execinfo.h')
+if libexecinfo.found()
     add_project_link_arguments('-lexecinfo', language: 'c')
     dpdk_extra_ldflags += '-lexecinfo'
 endif
+dpdk_conf.set('RTE_BACKTRACE', cc.has_header('execinfo.h') or is_windows)
 
 libarchive = dependency('libarchive', required: false, method: 'pkg-config')
 if libarchive.found()
diff --git a/config/rte_config.h b/config/rte_config.h
index 3c4876d434..7b8c85e948 100644
--- a/config/rte_config.h
+++ b/config/rte_config.h
@@ -37,7 +37,6 @@
 #define RTE_MAX_MEMZONE 2560
 #define RTE_MAX_TAILQ 32
 #define RTE_LOG_DP_LEVEL RTE_LOG_INFO
-#define RTE_BACKTRACE 1
 #define RTE_MAX_VFIO_CONTAINERS 64
 
 /* bsd module defines */
diff --git a/doc/guides/linux_gsg/sys_reqs.rst b/doc/guides/linux_gsg/sys_reqs.rst
index e4f9b41251..2a7988cf46 100644
--- a/doc/guides/linux_gsg/sys_reqs.rst
+++ b/doc/guides/linux_gsg/sys_reqs.rst
@@ -32,7 +32,7 @@ Compilation of the DPDK
 
     * For RHEL/Fedora systems these can be installed using ``dnf groupinstall "Development Tools"``
     * For Ubuntu/Debian systems these can be installed using ``apt install build-essential``
-    * For Alpine Linux, ``apk add alpine-sdk bsd-compat-headers libexecinfo-dev``
+    * For Alpine Linux, ``apk add alpine-sdk bsd-compat-headers``
 
 .. note::
 
-- 
2.39.0