[llvm] 2892ed6 - [DebugInfo] Introduce GNU macro extension entry encodings

[David Stenberg via llvm-commits]

Author: David Stenberg
Date: 2020-08-11T13:30:52+02:00
New Revision: 2892ed6d0fa9545df8c2d846a1fdaa948c4571d9

URL: https://github.com/llvm/llvm-project/commit/2892ed6d0fa9545df8c2d846a1fdaa948c4571d9
DIFF: https://github.com/llvm/llvm-project/commit/2892ed6d0fa9545df8c2d846a1fdaa948c4571d9.diff

LOG: [DebugInfo] Introduce GNU macro extension entry encodings

This is a preparatory patch for allowing the GNU .debug_macro extension,
which is a precursor to the DWARF 5 format, to be emitted by LLVM for
earlier DWARF versions.

The entries share the same encoding and behavior as in DWARF5; there are
just more entries in the DWARF 5 format. Therefore, we could have used
those existing DWARF 5 entries, but I think that explicitly referring to
the GNU macro variants makes the code more clear.

The defines that this patch introduces can be found in GCC in the dwarf2.h header:
  https://gcc.gnu.org/git/?p=gcc.git;a=blob;
  f=include/dwarf2.h;
  h=0b6facfd4cf4c02320c7328114231b128ab42d5e;
  hb=dccbf1e2a6e544f71b4a5795f0c79015db019fc3#l425

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D82972

Added: 
    

Modified: 
    llvm/include/llvm/BinaryFormat/Dwarf.def
    llvm/include/llvm/BinaryFormat/Dwarf.h

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/BinaryFormat/Dwarf.def b/llvm/include/llvm/BinaryFormat/Dwarf.def
index f0337ef4fb54..f69877bb50df 100644
--- a/llvm/include/llvm/BinaryFormat/Dwarf.def
+++ b/llvm/include/llvm/BinaryFormat/Dwarf.def
@@ -17,7 +17,7 @@
     defined HANDLE_DW_VIRTUALITY || defined HANDLE_DW_DEFAULTED ||             \
     defined HANDLE_DW_CC || defined HANDLE_DW_LNS || defined HANDLE_DW_LNE ||  \
     defined HANDLE_DW_LNCT || defined HANDLE_DW_MACRO ||                       \
-    defined HANDLE_MACRO_FLAG ||                                               \
+    defined HANDLE_DW_MACRO_GNU || defined HANDLE_MACRO_FLAG ||                \
     defined HANDLE_DW_RLE || defined HANDLE_DW_LLE ||                          \
     (defined HANDLE_DW_CFA && defined HANDLE_DW_CFA_PRED) ||                   \
     defined HANDLE_DW_APPLE_PROPERTY || defined HANDLE_DW_UT ||                \
@@ -88,6 +88,10 @@
 #define HANDLE_DW_MACRO(ID, NAME)
 #endif
 
+#ifndef HANDLE_DW_MACRO_GNU
+#define HANDLE_DW_MACRO_GNU(ID, NAME)
+#endif
+
 #ifndef HANDLE_MACRO_FLAG
 #define HANDLE_MACRO_FLAG(ID, NAME)
 #endif
@@ -837,6 +841,18 @@ HANDLE_DW_MACRO(0x0a, import_sup)
 HANDLE_DW_MACRO(0x0b, define_strx)
 HANDLE_DW_MACRO(0x0c, undef_strx)
 
+// GNU .debug_macro extension.
+HANDLE_DW_MACRO_GNU(0x01, define)
+HANDLE_DW_MACRO_GNU(0x02, undef)
+HANDLE_DW_MACRO_GNU(0x03, start_file)
+HANDLE_DW_MACRO_GNU(0x04, end_file)
+HANDLE_DW_MACRO_GNU(0x05, define_indirect)
+HANDLE_DW_MACRO_GNU(0x06, undef_indirect)
+HANDLE_DW_MACRO_GNU(0x07, transparent_include)
+HANDLE_DW_MACRO_GNU(0x08, define_indirect_alt)
+HANDLE_DW_MACRO_GNU(0x09, undef_indirect_alt)
+HANDLE_DW_MACRO_GNU(0x0a, transparent_include_alt)
+
 // DWARF v5 Macro header flags.
 HANDLE_MACRO_FLAG(0x01, OFFSET_SIZE)
 HANDLE_MACRO_FLAG(0x02, DEBUG_LINE_OFFSET)
@@ -986,6 +1002,7 @@ HANDLE_DW_SECT(8, RNGLISTS)
 #undef HANDLE_DW_LNE
 #undef HANDLE_DW_LNCT
 #undef HANDLE_DW_MACRO
+#undef HANDLE_DW_MACRO_GNU
 #undef HANDLE_MACRO_FLAG
 #undef HANDLE_DW_RLE
 #undef HANDLE_DW_LLE

diff  --git a/llvm/include/llvm/BinaryFormat/Dwarf.h b/llvm/include/llvm/BinaryFormat/Dwarf.h
index 4e8b708f39bb..caa404e8354a 100644
--- a/llvm/include/llvm/BinaryFormat/Dwarf.h
+++ b/llvm/include/llvm/BinaryFormat/Dwarf.h
@@ -309,6 +309,14 @@ enum MacroEntryType {
   DW_MACRO_hi_user = 0xff
 };
 
+/// GNU .debug_macro macro information entry type encodings.
+enum GnuMacroEntryType {
+#define HANDLE_DW_MACRO_GNU(ID, NAME) DW_MACRO_GNU_##NAME = ID,
+#include "llvm/BinaryFormat/Dwarf.def"
+  DW_MACRO_GNU_lo_user = 0xe0,
+  DW_MACRO_GNU_hi_user = 0xff
+};
+
 /// DWARF v5 range list entry encoding values.
 enum RnglistEntries {
 #define HANDLE_DW_RLE(ID, NAME) DW_RLE_##NAME = ID,