Today, the language front ends produces llvm.dbg.* intrinsics, used to encode arguments' debug info, in order any way, most of the times. However, if a front end mix-n-matches llvm.dbg.declare and llvm.dbg.value intrinsics to encode debug info for arguments then code generator needs a way to find argument order.

Use 8 bits from line number field to keep track of argument ordering while encoding debug info for an argument. That leaves 24 bit for line no, DebugLoc also allocates 24 bit for line numbers. If a function has more than 255 arguments then rest of the arguments will be ordered by llvm.dbg.* intrinsics' ordering in IR.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126793 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 14 insertions, 3 deletions

diff --git a/include/llvm/Analysis/DIBuilder.h b/include/llvm/Analysis/DIBuilder.h
index 417dbc4e80..32a17e4f09 100644
--- a/include/llvm/Analysis/DIBuilder.h
+++ b/include/llvm/Analysis/DIBuilder.h
@@ -326,11 +326,14 @@ namespace llvm {
     /// @param AlwaysPreserve Boolean. Set to true if debug info for this
     ///                       variable should be preserved in optimized build.
     /// @param Flags          Flags, e.g. artificial variable.
+    /// @param ArgNo       If this variable is an arugment then this argument's
+    ///                    number. 1 indicates 1st argument.
     DIVariable createLocalVariable(unsigned Tag, DIDescriptor Scope,
                                    StringRef Name,
                                    DIFile File, unsigned LineNo,
                                    DIType Ty, bool AlwaysPreserve = false,
-                                   unsigned Flags = 0);
+                                   unsigned Flags = 0,
+                                   unsigned ArgNo = 0);
 
 
     /// createComplexVariable - Create a new descriptor for the specified
@@ -344,10 +347,12 @@ namespace llvm {
     /// @param Ty          Variable Type
     /// @param Addr        A pointer to a vector of complex address operations.
     /// @param NumAddr     Num of address operations in the vector.
+    /// @param ArgNo       If this variable is an arugment then this argument's
+    ///                    number. 1 indicates 1st argument.
     DIVariable createComplexVariable(unsigned Tag, DIDescriptor Scope,
                                      StringRef Name, DIFile F, unsigned LineNo,
                                      DIType Ty, Value *const *Addr,
-                                     unsigned NumAddr);
+                                     unsigned NumAddr, unsigned ArgNo = 0);
 
     /// createFunction - Create a new descriptor for the specified subprogram.
     /// See comments in DISubprogram for descriptions of these fields.
diff --git a/include/llvm/Analysis/DebugInfo.h b/include/llvm/Analysis/DebugInfo.h
index aa69088b42..e75b74ffed 100644
--- a/include/llvm/Analysis/DebugInfo.h
+++ b/include/llvm/Analysis/DebugInfo.h
@@ -564,7 +564,13 @@ namespace llvm {
       DIFile F = getFieldAs<DIFile>(3); 
       return F.getCompileUnit();
     }
-    unsigned getLineNumber() const      { return getUnsignedField(4); }
+    unsigned getLineNumber() const      { 
+      return (getUnsignedField(4) << 8) >> 8; 
+    }
+    unsigned getArgNumber() const       {
+      unsigned L = getUnsignedField(4); 
+      return L >> 24;
+    }
     DIType getType() const              { return getFieldAs<DIType>(5); }
     
     /// isArtificial - Return true if this variable is marked as "artificial".