[binutils-gdb] readelf: Handle more RISC-V relocations

[Andreas Schwab <schwab at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=39e07931b1be69b13acb8322687f825bd00afe91

commit 39e07931b1be69b13acb8322687f825bd00afe91
Author: Andreas Schwab <schwab@suse.de>
Date:   Mon Jun 18 10:29:31 2018 +0200

    readelf: Handle more RISC-V relocations
    
    	* readelf.c (is_16bit_abs_reloc): Handle R_RISCV_SET16.
    	(is_8bit_abs_reloc): New function.
    	(is_6bit_abs_reloc): New function.
    	(is_6bit_inplace_sub_reloc): New function.
    	(apply_relocations): Use them.  Handle 6-bit relocations.

Diff:
---
 ChangeLog          |  8 ++++++
 binutils/readelf.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 80 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index cd71529..039ee53 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2018-06-19  Andreas Schwab  <schwab@suse.de>
+
+	* readelf.c (is_16bit_abs_reloc): Handle R_RISCV_SET16.
+	(is_8bit_abs_reloc): New function.
+	(is_6bit_abs_reloc): New function.
+	(is_6bit_inplace_sub_reloc): New function.
+	(apply_relocations): Use them.  Handle 6-bit relocations.
+
 2018-06-18  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* Makefile.def (fortran): Add check-target-libgomp-fortran.
diff --git a/binutils/readelf.c b/binutils/readelf.c
index c713e7f..1b50ba7 100644
--- a/binutils/readelf.c
+++ b/binutils/readelf.c
@@ -12659,6 +12659,8 @@ is_16bit_abs_reloc (Filedata * filedata, unsigned int reloc_type)
       return reloc_type == 9; /* R_NIOS_16.  */
     case EM_OR1K:
       return reloc_type == 2; /* R_OR1K_16.  */
+    case EM_RISCV:
+      return reloc_type == 55; /* R_RISCV_SET16.  */
     case EM_TI_PRU:
       return reloc_type == 8; /* R_PRU_BFD_RELOC_16.  */
     case EM_TI_C6000:
@@ -12676,6 +12678,36 @@ is_16bit_abs_reloc (Filedata * filedata, unsigned int reloc_type)
 }
 
 /* Like is_32bit_abs_reloc except that it returns TRUE iff RELOC_TYPE is
+   a 8-bit absolute RELA relocation used in DWARF debug sections.  */
+
+static bfd_boolean
+is_8bit_abs_reloc (Filedata * filedata, unsigned int reloc_type)
+{
+  switch (filedata->file_header.e_machine)
+    {
+    case EM_RISCV:
+      return reloc_type == 54; /* R_RISCV_SET8.  */
+    default:
+      return FALSE;
+    }
+}
+
+/* Like is_32bit_abs_reloc except that it returns TRUE iff RELOC_TYPE is
+   a 6-bit absolute RELA relocation used in DWARF debug sections.  */
+
+static bfd_boolean
+is_6bit_abs_reloc (Filedata * filedata, unsigned int reloc_type)
+{
+  switch (filedata->file_header.e_machine)
+    {
+    case EM_RISCV:
+      return reloc_type == 53; /* R_RISCV_SET6.  */
+    default:
+      return FALSE;
+    }
+}
+
+/* Like is_32bit_abs_reloc except that it returns TRUE iff RELOC_TYPE is
    a 32-bit inplace add RELA relocation used in DWARF debug sections.  */
 
 static bfd_boolean
@@ -12803,6 +12835,21 @@ is_8bit_inplace_sub_reloc (Filedata * filedata, unsigned int reloc_type)
     }
 }
 
+/* Like is_32bit_abs_reloc except that it returns TRUE iff RELOC_TYPE is
+   a 6-bit inplace sub RELA relocation used in DWARF debug sections.  */
+
+static bfd_boolean
+is_6bit_inplace_sub_reloc (Filedata * filedata, unsigned int reloc_type)
+{
+  switch (filedata->file_header.e_machine)
+    {
+    case EM_RISCV:
+      return reloc_type == 52; /* R_RISCV_SUB6.  */
+    default:
+      return FALSE;
+    }
+}
+
 /* Returns TRUE iff RELOC_TYPE is a NONE relocation used for discarded
    relocation entries (possibly formerly used for SHT_GROUP sections).  */
 
@@ -13006,6 +13053,9 @@ apply_relocations (Filedata *                 filedata,
 	    reloc_size = 3;
 	  else if (is_16bit_abs_reloc (filedata, reloc_type))
 	    reloc_size = 2;
+	  else if (is_8bit_abs_reloc (filedata, reloc_type)
+		   || is_6bit_abs_reloc (filedata, reloc_type))
+	    reloc_size = 1;
 	  else if ((reloc_subtract = is_32bit_inplace_sub_reloc (filedata,
 								 reloc_type))
 		   || is_32bit_inplace_add_reloc (filedata, reloc_type))
@@ -13034,6 +13084,12 @@ apply_relocations (Filedata *                 filedata,
 	      reloc_size = 1;
 	      reloc_inplace = TRUE;
 	    }
+	  else if ((reloc_subtract = is_6bit_inplace_sub_reloc (filedata,
+								reloc_type)))
+	    {
+	      reloc_size = 1;
+	      reloc_inplace = TRUE;
+	    }
 	  else
 	    {
 	      static unsigned int prev_reloc = 0;
@@ -13106,7 +13162,12 @@ apply_relocations (Filedata *                 filedata,
 		   || filedata->file_header.e_machine == EM_CYGNUS_D30V)
 		  && reloc_type == 12)
 	      || reloc_inplace)
-	    addend += byte_get (rloc, reloc_size);
+	    {
+	      if (is_6bit_inplace_sub_reloc (filedata, reloc_type))
+		addend += byte_get (rloc, reloc_size) & 0x3f;
+	      else
+		addend += byte_get (rloc, reloc_size);
+	    }
 
 	  if (is_32bit_pcrel_reloc (filedata, reloc_type)
 	      || is_64bit_pcrel_reloc (filedata, reloc_type))
@@ -13117,6 +13178,16 @@ apply_relocations (Filedata *                 filedata,
 	      byte_put (rloc, (addend + sym->st_value) - rp->r_offset,
 		        reloc_size);
 	    }
+	  else if (is_6bit_abs_reloc (filedata, reloc_type)
+		   || is_6bit_inplace_sub_reloc (filedata, reloc_type))
+	    {
+	      if (reloc_subtract)
+		addend -= sym->st_value;
+	      else
+		addend += sym->st_value;
+	      addend = (addend & 0x3f) | (byte_get (rloc, reloc_size) & 0xc0);
+	      byte_put (rloc, addend, reloc_size);
+	    }
 	  else if (reloc_subtract)
 	    byte_put (rloc, addend - sym->st_value, reloc_size);
 	  else