[PATCH v2 3/5] bpf: Always emit .BTF.ext section if generating BTF

[Cupertino Miranda]

BPF applications, when generating BTF information should always create a
.BTF.ext section.
Current implementation was only creating it when -mco-re option was used.
This patch makes .BTF.ext always be generated for BPF target objects.
The patch also adds conditions around btf_finalize function call
such that BTF deallocation happens later for BPF target.
For BPF, btf_finalize is only called after .BTF.ext is generated.

gcc/ChangeLog:

        * config/bpf/bpf.cc (bpf_option_override): Make .BTF.ext
        enabled by default for BPF.
        (bpf_file_end): Call BTF deallocation.
        * dwarf2ctf.cc (ctf_debug_finalize): Conditionally execute BTF
        deallocation.
---
 gcc/config/bpf/bpf.cc | 20 +++++++++-----------
 gcc/dwarf2ctf.cc      | 12 ++++++------
 2 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/gcc/config/bpf/bpf.cc b/gcc/config/bpf/bpf.cc
index d6ca47eeecbe..4318b26b9cda 100644
--- a/gcc/config/bpf/bpf.cc
+++ b/gcc/config/bpf/bpf.cc
@@ -195,10 +195,8 @@ bpf_option_override (void)
   if (TARGET_BPF_CORE && !btf_debuginfo_p ())
     error ("BPF CO-RE requires BTF debugging information, use %<-gbtf%>");
 
-  /* To support the portability needs of BPF CO-RE approach, BTF debug
-     information includes the BPF CO-RE relocations.  */
-  if (TARGET_BPF_CORE)
-    write_symbols |= BTF_WITH_CORE_DEBUG;
+  /* BPF applications always generate .BTF.ext.  */
+  write_symbols |= BTF_WITH_CORE_DEBUG;
 
   /* Unlike much of the other BTF debug information, the information necessary
      for CO-RE relocations is added to the CTF container by the BPF backend.
@@ -218,10 +216,7 @@ bpf_option_override (void)
   /* -gbtf implies -mcore when using the BPF backend, unless -mno-co-re
      is specified.  */
   if (btf_debuginfo_p () && !(target_flags_explicit & MASK_BPF_CORE))
-    {
-      target_flags |= MASK_BPF_CORE;
-      write_symbols |= BTF_WITH_CORE_DEBUG;
-    }
+    target_flags |= MASK_BPF_CORE;
 
   /* Determine available features from ISA setting (-mcpu=).  */
   if (bpf_has_jmpext == -1)
@@ -267,7 +262,7 @@ bpf_option_override (void)
 static void
 bpf_asm_init_sections (void)
 {
-  if (TARGET_BPF_CORE)
+  if (btf_debuginfo_p () && btf_with_core_debuginfo_p ())
     btf_ext_init ();
 }
 
@@ -279,8 +274,11 @@ bpf_asm_init_sections (void)
 static void
 bpf_file_end (void)
 {
-  if (TARGET_BPF_CORE)
-    btf_ext_output ();
+  if (btf_debuginfo_p () && btf_with_core_debuginfo_p ())
+    {
+      btf_ext_output ();
+      btf_finalize ();
+    }
 }
 
 #undef TARGET_ASM_FILE_END
diff --git a/gcc/dwarf2ctf.cc b/gcc/dwarf2ctf.cc
index 93e5619933fa..dca86edfffa9 100644
--- a/gcc/dwarf2ctf.cc
+++ b/gcc/dwarf2ctf.cc
@@ -944,7 +944,10 @@ ctf_debug_finalize (const char *filename, bool btf)
   if (btf)
     {
       btf_output (filename);
-      btf_finalize ();
+      /* btf_finalize when compiling BPF applciations gets deallocated by the
+        BPF target in bpf_file_end.  */
+      if (btf_debuginfo_p () && !btf_with_core_debuginfo_p ())
+       btf_finalize ();
     }
 
   else
@@ -1027,11 +1030,8 @@ ctf_debug_finish (const char * filename)
   /* Emit BTF debug info here when CO-RE relocations need to be generated.
      BTF with CO-RE relocations needs to be generated when CO-RE is in effect
      for the BPF target.  */
-  if (btf_with_core_debuginfo_p ())
-    {
-      gcc_assert (btf_debuginfo_p ());
-      ctf_debug_finalize (filename, btf_debuginfo_p ());
-    }
+  if (btf_debuginfo_p () && btf_with_core_debuginfo_p ())
+    ctf_debug_finalize (filename, btf_debuginfo_p ());
 }
 
 #include "gt-dwarf2ctf.h"
-- 
2.39.2