From bcf8f79d6d2bec986e0a530e2f9b66efccf9bf83 Mon Sep 17 00:00:00 2001
From: naruse <naruse@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Mon, 13 Aug 2018 06:20:12 +0000
Subject: [PATCH] support compressed debug_line

re-commit r64328
https://blogs.oracle.com/solaris/elf_section_compression-v2
https://gnu.wildebeest.org/blog/mjw/2016/01/13/elf-libelf-compressed-sections-and-elfutils/

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64331 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 addr2line.c  | 65 +++++++++++++++++++++++++++++++++++++++++++++-------
 configure.ac | 11 +++++++--
 2 files changed, 66 insertions(+), 10 deletions(-)

diff --git a/addr2line.c b/addr2line.c
index fbe64758bc..eb15ef0bfc 100644
--- a/addr2line.c
+++ b/addr2line.c
@@ -101,8 +101,12 @@ void *alloca();
 #define PATH_MAX 4096
 #endif
 
-#ifndef SHF_COMPRESSED /* compatibility with glibc < 2.22 */
-#define SHF_COMPRESSED 0
+#ifdef SHF_COMPRESSED
+# ifdef HAVE_LIBZ
+#  include <zlib.h>
+# endif
+#else /* compatibility with glibc < 2.22 */
+# define SHF_COMPRESSED 0
 #endif
 
 PRINTF_ARGS(static int kprintf(const char *fmt, ...), 1, 2);
@@ -478,6 +482,41 @@ follow_debuglink(const char *debuglink, int num_traces, void **traces,
     fill_lines(num_traces, traces, 0, objp, lines, offset);
 }
 
+static int
+parse_compressed_debug_line(int num_traces, void **traces,
+		 char *debug_line, unsigned long size,
+		 obj_info_t *obj, line_info_t *lines, int offset)
+{
+    void *uncompressed_debug_line;
+    ElfW(Chdr) *chdr = (ElfW(Chdr) *)debug_line;
+    unsigned long destsize = chdr->ch_size;
+    int ret = 0;
+
+    if (chdr->ch_type != ELFCOMPRESS_ZLIB) {
+	/* unsupported compression type */
+	return -1;
+    }
+
+    uncompressed_debug_line = malloc(destsize);
+    if (!uncompressed_debug_line) return -1;
+    ret = uncompress(uncompressed_debug_line, &destsize,
+	    (const Bytef *)debug_line + sizeof(ElfW(Chdr)), size-sizeof(ElfW(Chdr)));
+    if (ret != Z_OK) { /* Z_OK = 0 */
+	goto finish;
+    }
+    ret = parse_debug_line(num_traces, traces,
+	    uncompressed_debug_line,
+	    destsize,
+	    obj, lines, offset);
+    if (ret) {
+	goto finish;
+    }
+
+finish:
+    free(uncompressed_debug_line);
+    return ret ? -1 : 0;
+}
+
 /* read file and fill lines */
 static uintptr_t
 fill_lines(int num_traces, void **traces, int check_debuglink,
@@ -644,12 +683,22 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
 	goto finish;
     }
 
-    if (!compressed_p &&
-	    parse_debug_line(num_traces, traces,
-			 file + debug_line_shdr->sh_offset,
-			 debug_line_shdr->sh_size,
-			 obj, lines, offset))
-	goto fail;
+    if (compressed_p) {
+#ifdef HAVE_LIBZ
+	int r = parse_compressed_debug_line(num_traces, traces,
+		file + debug_line_shdr->sh_offset,
+		debug_line_shdr->sh_size,
+		obj, lines, offset);
+	if (r) goto fail;
+#endif
+    }
+    else {
+	int r = parse_debug_line(num_traces, traces,
+		file + debug_line_shdr->sh_offset,
+		debug_line_shdr->sh_size,
+		obj, lines, offset);
+	if (r) goto fail;
+    }
 finish:
     return dladdr_fbase;
 fail:
diff --git a/configure.ac b/configure.ac
index c5baa8c980..30d6afa9ce 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2451,6 +2451,9 @@ AS_IF([test "$rb_cv_binary_elf" = yes], [
   AC_CHECK_HEADERS([elf.h elf_abi.h])
   AS_IF([test $ac_cv_header_elf_h = yes -o $ac_cv_header_elf_abi_h = yes], [
     AC_LIBOBJ([addr2line])
+    AS_IF([test "x$compress_debug_sections" = xzlib], [
+      AC_CHECK_LIB([z], [uncompress])
+    ])
   ])
 ])
 
@@ -3067,7 +3070,11 @@ AS_CASE("$enable_shared", [yes], [
 	LIBRUBY_SO='lib$(RUBY_SO_NAME).$(SOEXT).$(MAJOR)'
 	LIBRUBY_SONAME='lib$(RUBY_SO_NAME).$(SOEXT).$(RUBY_PROGRAM_VERSION)'
 	LIBRUBY_ALIASES='$(LIBRUBY_SONAME) lib$(RUBY_SO_NAME).$(SOEXT)'
-	RUBY_APPEND_OPTIONS(LIBRUBY_DLDFLAGS, ["${linker_flag}-h${linker_flag:+,}"'$(@F)'])
+	AS_IF([test "$GCC" = yes], [
+	    LIBRUBY_DLDFLAGS="$DLDFLAGS "'-Wl,-h,$(@F)'
+	], [
+	    LIBRUBY_DLDFLAGS="$DLDFLAGS "'-h $(@F)'
+	])
 	XLDFLAGS="$XLDFLAGS "'-R${libdir}'
 	],
     [hpux*], [
@@ -3314,7 +3321,7 @@ AS_CASE(["$target_os"],
 	])
 	],
     [cygwin*|mingw*], [
-	LIBRUBY_DLDFLAGS="${LIBRUBY_DLDFLAGS}"' -Wl,--out-implib=$(LIBRUBY)'
+	LIBRUBY_DLDFLAGS="${DLDFLAGS}"' -Wl,--out-implib=$(LIBRUBY)'
 	AS_CASE(["$target_os"],
 	[cygwin*], [
 	    AS_IF([test x"$enable_shared" = xyes], [