[llvm] r331537 - obj2yaml: Correctly round-trip default alignment.

[Peter Collingbourne via llvm-commits]

Author: pcc
Date: Fri May  4 09:28:41 2018
New Revision: 331537

URL: http://llvm.org/viewvc/llvm-project?rev=331537&view=rev
Log:
obj2yaml: Correctly round-trip default alignment.

Previously we were emitting the "cooked" alignment, which made it hard
to distinguish between that and the default alignment.

Differential Revision: https://reviews.llvm.org/D46418

Added:
    llvm/trunk/test/ObjectYAML/COFF/
    llvm/trunk/test/ObjectYAML/COFF/default-alignment.yaml
Modified:
    llvm/trunk/tools/obj2yaml/coff2yaml.cpp

Added: llvm/trunk/test/ObjectYAML/COFF/default-alignment.yaml
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/ObjectYAML/COFF/default-alignment.yaml?rev=331537&view=auto
==============================================================================
--- llvm/trunk/test/ObjectYAML/COFF/default-alignment.yaml (added)
+++ llvm/trunk/test/ObjectYAML/COFF/default-alignment.yaml Fri May  4 09:28:41 2018
@@ -0,0 +1,15 @@
+# RUN: yaml2obj %s | obj2yaml | FileCheck %s
+
+# CHECK:      Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ ]
+# CHECK-NEXT: SectionData:     '01'
+
+--- !COFF
+header:
+  Machine:         IMAGE_FILE_MACHINE_AMD64
+  Characteristics: []
+sections:
+  - Name:            .rdata
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ ]
+    SectionData:     01
+symbols:
+...

Modified: llvm/trunk/tools/obj2yaml/coff2yaml.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/obj2yaml/coff2yaml.cpp?rev=331537&r1=331536&r2=331537&view=diff
==============================================================================
--- llvm/trunk/tools/obj2yaml/coff2yaml.cpp (original)
+++ llvm/trunk/tools/obj2yaml/coff2yaml.cpp Fri May  4 09:28:41 2018
@@ -159,7 +159,8 @@ void COFFDumper::dumpSections(unsigned N
     NewYAMLSection.Header.PointerToRelocations =
         COFFSection->PointerToRelocations;
     NewYAMLSection.Header.SizeOfRawData = COFFSection->SizeOfRawData;
-    NewYAMLSection.Alignment = ObjSection.getAlignment();
+    uint32_t Shift = (COFFSection->Characteristics >> 20) & 0xF;
+    NewYAMLSection.Alignment = (1U << Shift) >> 1;
     assert(NewYAMLSection.Alignment <= 8192);
 
     ArrayRef<uint8_t> sectionData;