[ELF] - Stop mixing order of -defsym/-script commands.

Previously we always handled -defsym after other commands in command line.
That made impossible to overload values set by -defsym from linker script:

 test.script:
  foo = 0x22;
-defsym=foo=0x11 -script t.script
would always set foo to 0x11.

That is inconstent with common logic which allows to override command line
options. it is inconsistent with bfd behavior and seems breaks assumption that
-defsym is the same as linker script assignment, as -defsyms always handled out of
command line order.

Patch fixes the handling order.

Differential revision: https://reviews.llvm.org/D42054

llvm-svn: 322625

diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index d5d11e3..3664b93 100644 (file)
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -830,6 +830,13 @@ void LinkerDriver::createFiles(opt::InputArgList &Args) {
     case OPT_INPUT:
       addFile(Arg->getValue(), /*WithLOption=*/false);
       break;
+    case OPT_defsym: {
+      StringRef From;
+      StringRef To;
+      std::tie(From, To) = StringRef(Arg->getValue()).split('=');
+      readDefsym(From, MemoryBufferRef(To, "-defsym"));
+      break;
+    }
     case OPT_script:
       if (Optional<std::string> Path = searchLinkerScript(Arg->getValue())) {
         if (Optional<MemoryBufferRef> MB = readFile(*Path))
@@ -1011,14 +1018,6 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &Args) {
   for (InputFile *F : Files)
     Symtab->addFile<ELFT>(F);
 
-  // Process -defsym option.
-  for (auto *Arg : Args.filtered(OPT_defsym)) {
-    StringRef From;
-    StringRef To;
-    std::tie(From, To) = StringRef(Arg->getValue()).split('=');
-    readDefsym(From, MemoryBufferRef(To, "-defsym"));
-  }
-
   // Now that we have every file, we can decide if we will need a
   // dynamic symbol table.
   // We need one if we were asked to export dynamic symbols or if we are

diff --git a/lld/test/ELF/linkerscript/defsym.s b/lld/test/ELF/linkerscript/defsym.s
new file mode 100644 (file)
index 0000000..467adae
--- /dev/null
+++ b/lld/test/ELF/linkerscript/defsym.s
@@ -0,0 +1,19 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
+# RUN: echo "foo = 0x22;" > %t.script
+
+## This testcase checks that we apply -defsym and linker script
+## in the same order are they specified in a command line. 
+
+## Check that linker script can override -defsym assignments.
+# RUN: ld.lld %t.o -defsym=foo=0x11 -script %t.script -o %t
+# RUN: llvm-readobj -t %t | FileCheck %s
+# CHECK:      Name: foo
+# CHECK-NEXT:   Value: 0x22
+
+## Check that -defsym can override linker script. Check that multiple
+## -defsym commands for the same symbol are allowed.
+# RUN: ld.lld %t.o -script %t.script -defsym=foo=0x11 -defsym=foo=0x33 -o %t
+# RUN: llvm-readobj -t %t | FileCheck %s --check-prefix=REORDER
+# REORDER:      Name: foo
+# REORDER-NEXT:   Value: 0x33