Bug 1883615 - Move libdl checks to moz.configure and make libdl dependencies explicit r=glandium

The -ldl flag was previously set globally, it's now set for the libs
that use it.

Also rationalize the difference between HAVE_DLOPEN and HAVE_DLFCN_H.

Differential Revision: https://phabricator.services.mozilla.com/D203594

build/moz.configure/libraries.configure

@@ -53,3 +53,21 @@ have_res_ninit = try_link(
 )
 
 set_define("HAVE_RES_NINIT", have_res_ninit)
+
+# We don't want to link with libdl even if it's present on OS X, since
+# it's not used and not part of the default installation.
+# We don't want to link against libm or libpthread on Darwin since
+# they both are just symlinks to libSystem and explicitly linking
+# against libSystem causes issues when debugging (see bug 299601).
+with only_when(building_with_gnu_cc):
+    dladdr_check = check_symbol_in_libs([None, "dl"], symbol="dladdr")
+    set_define(
+        "HAVE_DLADDR", depends(dladdr_check)(lambda check: "1" if check.found else "0")
+    )
+
+    with only_when(~target_is_darwin):
+        check_header("dlfcn.h")
+        dlopen_check = check_symbol_in_libs(["dl", None], symbol="dlopen")
+        set_config(
+            "DL_LIBS", ["-ldl"], when=depends(dlopen_check)(lambda check: check.lib)
+        )

config/external/nspr/pr/moz.build

@@ -13,6 +13,8 @@ else:
 # TODO: fix NSPR warnings and remove this
 AllowCompilerWarnings()
 
+OS_LIBS += CONFIG["DL_LIBS"]
+
 DEFINES["_NSPR_BUILD_"] = True
 if CONFIG["OS_ARCH"] == "Linux":
     OS_LIBS += CONFIG["REALTIME_LIBS"]

js/src/old-configure.in

@@ -446,27 +446,6 @@ dnl Checks for libraries.
 dnl ========================================================
 AC_CHECK_LIB(c_r, gethostbyname_r)
 
-dnl We don't want to link with libdl even if it's present on OS X, since
-dnl it's not used and not part of the default installation. OS/2 has dlfcn
-dnl in libc.
-dnl We don't want to link against libm or libpthread on Darwin since
-dnl they both are just symlinks to libSystem and explicitly linking
-dnl against libSystem causes issues when debugging (see bug 299601).
-case $target in
-*-darwin*)
-    ;;
-*)
-    AC_SEARCH_LIBS(dlopen, dl,
-        MOZ_CHECK_HEADER(dlfcn.h,
-        AC_DEFINE(HAVE_DLOPEN)))
-    ;;
-esac
-
-_SAVE_CFLAGS="$CFLAGS"
-CFLAGS="$CFLAGS -D_GNU_SOURCE"
-AC_CHECK_FUNCS(dladdr)
-CFLAGS="$_SAVE_CFLAGS"
-
 if test ! "$GNU_CXX"; then
     AC_CHECK_LIB(C, demangle)
 fi

media/mozva/moz.build

@@ -8,4 +8,6 @@ SOURCES += [
     "mozva.c",
 ]
 
+OS_LIBS += CONFIG["DL_LIBS"]
+
 Library("mozva")

memory/build/mozjemalloc.cpp

@@ -5524,7 +5524,7 @@ static void replace_malloc_init_funcs(malloc_table_t* table) {
 #include "malloc_decls.h"
 // ***************************************************************************
 
-#ifdef HAVE_DLOPEN
+#ifdef HAVE_DLFCN_H
 #  include <dlfcn.h>
 #endif
 

memory/replace/logalloc/replay/moz.build

@@ -82,6 +82,8 @@ DEFINES["IMPL_MFBT"] = True
 if CONFIG["MOZ_NEEDS_LIBATOMIC"]:
     OS_LIBS += ["atomic"]
 
+OS_LIBS += CONFIG["DL_LIBS"]
+
 DisableStlWrapping()
 
 include("/mozglue/build/replace_malloc.mozbuild")

mozglue/interposers/moz.build

@@ -22,4 +22,6 @@ if CONFIG["MOZ_LINKER"]:
         "/mozglue/linker",
     ]
 
+OS_LIBS += CONFIG["DL_LIBS"]
+
 FINAL_LIBRARY = "mozglue"

mozglue/misc/StackWalk.cpp

@@ -33,7 +33,7 @@ using namespace mozilla;
 #  define _GNU_SOURCE
 #endif
 
-#if defined(HAVE_DLOPEN) || defined(XP_DARWIN)
+#if defined(HAVE_DLFCN_H) || defined(XP_DARWIN)
 #  include <dlfcn.h>
 #endif
 

old-configure.in

@@ -463,27 +463,6 @@ dnl Checks for libraries.
 dnl ========================================================
 AC_CHECK_LIB(c_r, gethostbyname_r)
 
-dnl We don't want to link with libdl even if it's present on OS X, since
-dnl it's not used and not part of the default installation. OS/2 has dlfcn
-dnl in libc.
-dnl We don't want to link against libm or libpthread on Darwin since
-dnl they both are just symlinks to libSystem and explicitly linking
-dnl against libSystem causes issues when debugging (see bug 299601).
-case $target in
-*-darwin*)
-    ;;
-*)
-    AC_SEARCH_LIBS(dlopen, dl,
-        MOZ_CHECK_HEADER(dlfcn.h,
-        AC_DEFINE(HAVE_DLOPEN)))
-    ;;
-esac
-
-_SAVE_CFLAGS="$CFLAGS"
-CFLAGS="$CFLAGS -D_GNU_SOURCE"
-AC_CHECK_FUNCS(dladdr)
-CFLAGS="$_SAVE_CFLAGS"
-
 if test ! "$GNU_CXX"; then
     AC_CHECK_LIB(C, demangle)
 fi

security/manager/ssl/builtins/moz.build

@@ -6,4 +6,6 @@
 
 DIRS += ["dynamic-library"]
 
+OS_LIBS += CONFIG["DL_LIBS"]
+
 RustLibrary("builtins-static")

security/manager/ssl/ipcclientcerts/dynamic-library/moz.build

@@ -19,6 +19,8 @@ else:
         "stub.c",
     ]
 
+OS_LIBS += CONFIG["DL_LIBS"]
+
 if CONFIG["OS_TARGET"] == "Android":
     OS_LIBS += ["m"]
 

security/sandbox/linux/moz.build

@@ -18,6 +18,8 @@ USE_LIBS += [
     "nspr",
 ]
 
+OS_LIBS += CONFIG["DL_LIBS"]
+
 EXPORTS.mozilla += [
     "Sandbox.h",
     "SandboxInfo.h",

third_party/sqlite3/src/moz.build

@@ -27,6 +27,8 @@ SOURCES += [
     'sqlite3.c',
 ]
 
+OS_LIBS += CONFIG["DL_LIBS"]
+
 # -DSQLITE_SECURE_DELETE=1 will cause SQLITE to 0-fill delete data so we
 # don't have to vacuum to make sure the data is not visible in the file.
 # -DSQLITE_DEFAULT_PAGE_SIZE=32768 and SQLITE_MAX_DEFAULT_PAGE_SIZE=32768

toolkit/xre/glxtest/moz.build

@@ -22,5 +22,7 @@ CXXFLAGS += CONFIG["MOZ_PANGO_CFLAGS"]
 OS_LIBS += CONFIG["MOZ_X11_LIBS"]
 OS_LIBS += CONFIG["MOZ_GTK3_LIBS"]
 
+OS_LIBS += CONFIG["DL_LIBS"]
+
 NO_PGO = True
 DisableStlWrapping()

xpcom/base/nsTraceRefcnt.cpp

@@ -50,7 +50,7 @@
 #include <string>
 #include <vector>
 
-#ifdef HAVE_DLOPEN
+#ifdef HAVE_DLFCN_H
 #  include <dlfcn.h>
 #endif