[nasm:master] Add DW_AT_comp_dir to elf files.

[nasm-bot for Marco Vanotti]

Commit-ID:  f2a6eb4aaca361c1ebe374bf07765790eecf8869
Gitweb:     http://repo.or.cz/w/nasm.git?a=commitdiff;h=f2a6eb4aaca361c1ebe374bf07765790eecf8869
Author:     Marco Vanotti <mvanotti at dc.uba.ar>
AuthorDate: Sat, 1 May 2021 20:23:52 -0700
Committer:  Cyrill Gorcunov <gorcunov at gmail.com>
CommitDate: Sat, 8 May 2021 23:59:09 +0300

Add DW_AT_comp_dir to elf files.

This commit adds the compilation directory debug information for ELF files.
This feature helps debuggers locate the source file when debugging.
The feature is already present for Mach-O files.

Signed-off-by: Marco Vanotti <mvanotti at dc.uba.ar>
Signed-off-by: Cyrill Gorcunov <gorcunov at gmail.com>


---
 output/outelf.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/output/outelf.c b/output/outelf.c
index bb2acbb4..12e6f818 100644
--- a/output/outelf.c
+++ b/output/outelf.c
@@ -84,6 +84,7 @@ static struct hash_table section_by_name;
 static struct elf_symbol *fwds;
 
 static char elf_module[FILENAME_MAX];
+static char elf_dir[FILENAME_MAX];
 
 extern const struct ofmt of_elf32;
 extern const struct ofmt of_elf64;
@@ -552,8 +553,10 @@ static void elf_init(void)
         ".shstrtab", ".strtab", ".symtab", ".symtab_shndx", NULL
     };
     const char * const *p;
+    const char * cur_path = nasm_realpath(inname);
 
     strlcpy(elf_module, inname, sizeof(elf_module));
+    strlcpy(elf_dir, nasm_dirname(cur_path), sizeof(elf_dir));
     sects = NULL;
     nsects = sectlen = 0;
     syms = saa_init((int32_t)sizeof(struct elf_symbol));
@@ -3307,7 +3310,8 @@ static void dwarf_generate(void)
         saa_write32(pinforel, (dwarf_linesym << 8) +  R_386_32); /* reloc to line */
         saa_write32(pinforel, 0);
         saa_write32(pinfo,0);       /* DW_AT_stmt_list */
-        saa_wbytes(pinfo, elf_module, strlen(elf_module)+1);
+        saa_wbytes(pinfo, elf_module, strlen(elf_module)+1); /* DW_AT_name */
+        saa_wbytes(pinfo, elf_dir, strlen(elf_dir)+1); /* DW_AT_comp_dir */
         saa_wbytes(pinfo, nasm_signature(), nasm_signature_len()+1);
         saa_write16(pinfo,DW_LANG_Mips_Assembler);
         saa_write8(pinfo,2);        /* abbrviation number LEB128u */
@@ -3346,7 +3350,8 @@ static void dwarf_generate(void)
         saa_write32(pinforel, (dwarf_linesym << 8) + R_X86_64_32); /* reloc to line */
         saa_write32(pinforel, 0);
         saa_write32(pinfo,0);			/* DW_AT_stmt_list */
-        saa_wbytes(pinfo, elf_module, strlen(elf_module)+1);
+        saa_wbytes(pinfo, elf_module, strlen(elf_module)+1); /* DW_AT_name */
+        saa_wbytes(pinfo, elf_dir, strlen(elf_dir)+1); /* DW_AT_comp_dir */
         saa_wbytes(pinfo, nasm_signature(), nasm_signature_len()+1);
         saa_write16(pinfo,DW_LANG_Mips_Assembler);
         saa_write8(pinfo,2);			/* abbrviation number LEB128u */
@@ -3386,7 +3391,8 @@ static void dwarf_generate(void)
         saa_write64(pinforel, (dwarf_linesym << 32) +  R_X86_64_32); /* reloc to line */
         saa_write64(pinforel, 0);
         saa_write32(pinfo,0);			/* DW_AT_stmt_list */
-        saa_wbytes(pinfo, elf_module, strlen(elf_module)+1);
+        saa_wbytes(pinfo, elf_module, strlen(elf_module)+1); /* DW_AT_name */
+        saa_wbytes(pinfo, elf_dir, strlen(elf_dir)+1); /* DW_AT_comp_dir */
         saa_wbytes(pinfo, nasm_signature(), nasm_signature_len()+1);
         saa_write16(pinfo,DW_LANG_Mips_Assembler);
         saa_write8(pinfo,2);			/* abbrviation number LEB128u */
@@ -3424,6 +3430,8 @@ static void dwarf_generate(void)
     saa_write8(pabbrev,DW_FORM_data4);
     saa_write8(pabbrev,DW_AT_name);
     saa_write8(pabbrev,DW_FORM_string);
+    saa_write8(pabbrev,DW_AT_comp_dir);
+    saa_write8(pabbrev,DW_FORM_string);
     saa_write8(pabbrev,DW_AT_producer);
     saa_write8(pabbrev,DW_FORM_string);
     saa_write8(pabbrev,DW_AT_language);