Support alignment in DILocalVariable

Fixes #217.
GaloisInc · Apr 10, 2023 · 22c4fdc · 22c4fdc
1 parent 3a68590
commit 22c4fdc
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Showing 3 changed files with 38 additions and 5 deletions.
diff --git a/disasm-test/tests/dilocalvariable.at-least-llvm14.ll b/disasm-test/tests/dilocalvariable.at-least-llvm14.ll
@@ -0,0 +1,32 @@
+;; Adapted from https://github.com/llvm/llvm-project/blob/2ede126b1b3fae52cddece5cf1f75b474a9c7932/llvm/test/Assembler/dilocalvariable.ll
+
+; CHECK: !named = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9}
+!named = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9}
+
+!llvm.module.flags = !{!10}
+!llvm.dbg.cu = !{!1}
+
+!0 = distinct !DISubprogram(unit: !1)
+!1 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang",
+                             file: !2,
+                             isOptimized: true, flags: "-O2",
+                             splitDebugFilename: "abc.debug", emissionKind: 2)
+!2 = !DIFile(filename: "path/to/file", directory: "/path/to/dir")
+!3 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!4 = !DILocation(scope: !0)
+
+; CHECK: !5 = !DILocalVariable(name: "foo", arg: 3, scope: !0, file: !2, line: 7, type: !3, flags: DIFlagArtificial, align: 32)
+; CHECK: !6 = !DILocalVariable(name: "foo", scope: !0, file: !2, line: 7, type: !3, flags: DIFlagArtificial)
+!5 = !DILocalVariable(name: "foo", arg: 3,
+                      scope: !0, file: !2, line: 7, type: !3,
+                      flags: DIFlagArtificial, align: 32)
+!6 = !DILocalVariable(name: "foo", scope: !0,
+                      file: !2, line: 7, type: !3, flags: DIFlagArtificial)
+
+; CHECK: !7 = !DILocalVariable(arg: 1, scope: !0)
+; CHECK: !8 = !DILocalVariable(scope: !0)
+!7 = !DILocalVariable(scope: !0, arg: 1)
+!8 = !DILocalVariable(scope: !0)
+!9 = distinct !{}
+
+!10 = !{i32 2, !"Debug Info Version", i32 3}
diff --git a/llvm-pretty b/llvm-pretty
diff --git a/src/Data/LLVM/BitCode/IR/Metadata.hs b/src/Data/LLVM/BitCode/IR/Metadata.hs
@@ -953,14 +953,14 @@ parseMetadataEntry vt mt pm (fromEntry -> Just r) =
 
           adj i = i + hasTag
 
-      _alignInBits <-
+      alignInBits <-
         if hasAlignment
-          then do n <- parseField r (adj 8) numeric
+          then do n <- parseField r 8 numeric
                   when ((n :: Word64) > fromIntegral (maxBound :: Word32))
                         (fail "Alignment value is too large")
-                  return (fromIntegral n :: Word32)
+                  return $ Just (fromIntegral n :: Word32)
 
-          else return 0
+          else return Nothing
 
       dilv <- DILocalVariable
         <$> (mdForwardRefOrNull ("dilvScope":ctx) mt
@@ -974,6 +974,7 @@ parseMetadataEntry vt mt pm (fromEntry -> Just r) =
               <$> parseField r (adj 5) numeric) -- dilvType
         <*> parseField r (adj 6) numeric        -- dilvArg
         <*> parseField r (adj 7) numeric        -- dilvFlags
+        <*> pure alignInBits                    -- dilvAlignment
       return $! updateMetadataTable
         (addDebugInfo isDistinct (DebugInfoLocalVariable dilv)) pm