[trace] Remove default definitions of weak symbols

Instead of providing a default no-op implementation, check the symbols
for `NULL` before accessing them. Providing a default implementation
doesn't reliably work with dynamic linking. Depending on link order the
default implementations may not be overridden. By skipping the default
implementation, all link order issues are resolved. If the symbols
aren't provided the weak function will be `NULL`.

diff --git a/build/meson/lib/meson.build b/build/meson/lib/meson.build
index 053ece2ca05d659117c156d35f6598f26d48dea3..3580229800084f987485e5c1e61e76034e81ba15 100644 (file)
--- a/build/meson/lib/meson.build
+++ b/build/meson/lib/meson.build
@@ -22,7 +22,6 @@ libzstd_sources = [join_paths(zstd_rootdir, 'lib/common/entropy_common.c'),
   join_paths(zstd_rootdir, 'lib/common/threading.c'),
   join_paths(zstd_rootdir, 'lib/common/pool.c'),
   join_paths(zstd_rootdir, 'lib/common/zstd_common.c'),
-  join_paths(zstd_rootdir, 'lib/common/zstd_trace.c'),
   join_paths(zstd_rootdir, 'lib/common/error_private.c'),
   join_paths(zstd_rootdir, 'lib/common/xxhash.c'),
   join_paths(zstd_rootdir, 'lib/compress/hist.c'),

diff --git a/lib/common/zstd_trace.c b/lib/common/zstd_trace.c
deleted file mode 100644 (file)
index 3a147e9..0000000
--- a/lib/common/zstd_trace.c
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * Copyright (c) Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under both the BSD-style license (found in the
- * LICENSE file in the root directory of this source tree) and the GPLv2 (found
- * in the COPYING file in the root directory of this source tree).
- * You may select, at your option, one of the above-listed licenses.
- */
-
-#include "zstd_trace.h"
-#include "../zstd.h"
-
-#include "compiler.h"
-
-#if ZSTD_TRACE && ZSTD_HAVE_WEAK_SYMBOLS
-
-ZSTD_WEAK_ATTR ZSTD_TraceCtx ZSTD_trace_compress_begin(ZSTD_CCtx const* cctx)
-{
-    (void)cctx;
-    return 0;
-}
-
-ZSTD_WEAK_ATTR void ZSTD_trace_compress_end(ZSTD_TraceCtx ctx, ZSTD_Trace const* trace)
-{
-    (void)ctx;
-    (void)trace;
-}
-
-ZSTD_WEAK_ATTR ZSTD_TraceCtx ZSTD_trace_decompress_begin(ZSTD_DCtx const* dctx)
-{
-    (void)dctx;
-    return 0;
-}
-
-ZSTD_WEAK_ATTR void ZSTD_trace_decompress_end(ZSTD_TraceCtx ctx, ZSTD_Trace const* trace)
-{
-    (void)ctx;
-    (void)trace;
-}
-
-#endif

diff --git a/lib/common/zstd_trace.h b/lib/common/zstd_trace.h
index 8166ef8e06d521389cb3144db271d9d470e3dd55..2da5640771d1804fd7bda99cba86f235ff60aa85 100644 (file)
--- a/lib/common/zstd_trace.h
+++ b/lib/common/zstd_trace.h
@@ -114,14 +114,15 @@ typedef unsigned long long ZSTD_TraceCtx;
  * @returns Non-zero if tracing is enabled. The return value is
  *          passed to ZSTD_trace_compress_end().
  */
-ZSTD_TraceCtx ZSTD_trace_compress_begin(struct ZSTD_CCtx_s const* cctx);
+ZSTD_WEAK_ATTR ZSTD_TraceCtx ZSTD_trace_compress_begin(
+    struct ZSTD_CCtx_s const* cctx);
 
 /**
  * Trace the end of a compression call.
  * @param ctx The return value of ZSTD_trace_compress_begin().
  * @param trace The zstd tracing info.
  */
-void ZSTD_trace_compress_end(
+ZSTD_WEAK_ATTR void ZSTD_trace_compress_end(
     ZSTD_TraceCtx ctx,
     ZSTD_Trace const* trace);
 
@@ -132,14 +133,15 @@ void ZSTD_trace_compress_end(
  * @returns Non-zero if tracing is enabled. The return value is
  *          passed to ZSTD_trace_compress_end().
  */
-ZSTD_TraceCtx ZSTD_trace_decompress_begin(struct ZSTD_DCtx_s const* dctx);
+ZSTD_WEAK_ATTR ZSTD_TraceCtx ZSTD_trace_decompress_begin(
+    struct ZSTD_DCtx_s const* dctx);
 
 /**
  * Trace the end of a decompression call.
  * @param ctx The return value of ZSTD_trace_decompress_begin().
  * @param trace The zstd tracing info.
  */
-void ZSTD_trace_decompress_end(
+ZSTD_WEAK_ATTR void ZSTD_trace_decompress_end(
     ZSTD_TraceCtx ctx,
     ZSTD_Trace const* trace);
 

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index d39e74b3c20e03c7443dfc664f429a525c422208..5f4c98eaad0ec16538a68975ff1f4d5ce9fb4a1f 100644 (file)
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -4379,7 +4379,7 @@ static size_t ZSTD_compressBegin_internal(ZSTD_CCtx* cctx,
                                     ZSTD_buffered_policy_e zbuff)
 {
 #if ZSTD_TRACE
-    cctx->traceCtx = ZSTD_trace_compress_begin(cctx);
+    cctx->traceCtx = (ZSTD_trace_compress_begin != NULL) ? ZSTD_trace_compress_begin(cctx) : 0;
 #endif
     DEBUGLOG(4, "ZSTD_compressBegin_internal: wlog=%u", params->cParams.windowLog);
     /* params are supposed to be fully validated at this point */
@@ -4510,7 +4510,7 @@ static size_t ZSTD_writeEpilogue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity)
 void ZSTD_CCtx_trace(ZSTD_CCtx* cctx, size_t extraCSize)
 {
 #if ZSTD_TRACE
-    if (cctx->traceCtx) {
+    if (cctx->traceCtx && ZSTD_trace_compress_end != NULL) {
         int const streaming = cctx->inBuffSize > 0 || cctx->outBuffSize > 0 || cctx->appliedParams.nbWorkers > 0;
         ZSTD_Trace trace;
         ZSTD_memset(&trace, 0, sizeof(trace));
@@ -5456,7 +5456,7 @@ static size_t ZSTD_CCtx_init_compressStream2(ZSTD_CCtx* cctx,
     }
     if (params.nbWorkers > 0) {
 #if ZSTD_TRACE
-        cctx->traceCtx = ZSTD_trace_compress_begin(cctx);
+        cctx->traceCtx = (ZSTD_trace_compress_begin != NULL) ? ZSTD_trace_compress_begin(cctx) : 0;
 #endif
         /* mt context creation */
         if (cctx->mtctx == NULL) {

diff --git a/lib/decompress/zstd_decompress.c b/lib/decompress/zstd_decompress.c
index ca3afaf605f41c1ddd5af9f94d820cfe12d885c5..910bc034c008ebd94c57c028cbb10b698be88c6a 100644 (file)
--- a/lib/decompress/zstd_decompress.c
+++ b/lib/decompress/zstd_decompress.c
@@ -788,7 +788,7 @@ static size_t ZSTD_setRleBlock(void* dst, size_t dstCapacity,
 static void ZSTD_DCtx_trace_end(ZSTD_DCtx const* dctx, U64 uncompressedSize, U64 compressedSize, unsigned streaming)
 {
 #if ZSTD_TRACE
-    if (dctx->traceCtx) {
+    if (dctx->traceCtx && ZSTD_trace_decompress_end != NULL) {
         ZSTD_Trace trace;
         ZSTD_memset(&trace, 0, sizeof(trace));
         trace.version = ZSTD_VERSION_NUMBER;
@@ -1383,7 +1383,7 @@ size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx)
 {
     assert(dctx != NULL);
 #if ZSTD_TRACE
-    dctx->traceCtx = ZSTD_trace_decompress_begin(dctx);
+    dctx->traceCtx = (ZSTD_trace_decompress_begin != NULL) ? ZSTD_trace_decompress_begin(dctx) : 0;
 #endif
     dctx->expected = ZSTD_startingInputLength(dctx->format);  /* dctx->format must be properly set */
     dctx->stage = ZSTDds_getFrameHeaderSize;