MC/Macho-O: Align the zerofill section itself to the maximum alignment.

llvm-svn: 97991

3 files changed, 26 insertions, 1 deletions

diff --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp
index 1ec1d815de4..4b78dc034fc 100644
--- a/llvm/lib/MC/MCAssembler.cpp
+++ b/llvm/lib/MC/MCAssembler.cpp
@@ -1279,9 +1279,19 @@ void MCAssembler::Finish() {
     if (!isVirtualSection(SD.getSection()))
       continue;
 
+    // Align this section if necessary by adding padding bytes to the previous
+    // section.
+    if (uint64_t Pad = OffsetToAlignment(Address, it->getAlignment())) {
+      assert(Prev && "Missing prev section!");
+      Prev->setFileSize(Prev->getFileSize() + Pad);
+      Address += Pad;
+    }
+
     SD.setAddress(Address);
     LayoutSection(SD);
     Address += SD.getSize();
+
+    Prev = &SD;
   }
 
   DEBUG_WITH_TYPE("mc-dump", {
diff --git a/llvm/test/MC/MachO/zerofill-4.s b/llvm/test/MC/MachO/zerofill-4.s
index 3513be44378..d9c987c9b65 100644
--- a/llvm/test/MC/MachO/zerofill-4.s
+++ b/llvm/test/MC/MachO/zerofill-4.s
@@ -1,4 +1,4 @@
-// RUN: llvm-mc -triple i386-apple-darwin9 %s -filetype=obj -o - | macho-dump --dump-section-data | FileCheck %s
+// RUN: llvm-mc -triple i386-apple-darwin9 %s -filetype=obj -o - | macho-dump | FileCheck %s
 
 .zerofill __DATA,__bss,_fill0,1,0
 .zerofill __DATA,__bss,_a,4,2
diff --git a/llvm/test/MC/MachO/zerofill-sect-align.s b/llvm/test/MC/MachO/zerofill-sect-align.s
new file mode 100644
index 00000000000..5d7730f439e
--- /dev/null
+++ b/llvm/test/MC/MachO/zerofill-sect-align.s
@@ -0,0 +1,15 @@
+// RUN: llvm-mc -triple i386-apple-darwin9 %s -filetype=obj -o - | macho-dump | FileCheck %s
+//
+// Check that the section itself is aligned.
+
+        .byte 0
+        
+.zerofill __DATA,__bss,_a,1,0
+.zerofill __DATA,__bss,_b,4,4
+
+// CHECK: # Symbol 0
+// CHECK: ('n_value', 16)
+// CHECK: ('_string', '_a')
+// CHECK: # Symbol 1
+// CHECK: ('n_value', 32)
+// CHECK: ('_string', '_b')