From e28c8883050d34d18ee2d66dfeece51e13adb6d5 Mon Sep 17 00:00:00 2001
From: Joshua Watt <JPEWhacker@gmail.com>
Date: Tue, 19 Nov 2019 13:12:17 -0600
Subject: [PATCH] Add --debug-prefix-map option

Adds an option to remap file prefixes in output object files. This is
analogous to the "-fdebug-prefix-map" option in GCC, and allows files to
be built in a reproducible manner regardless of the build directory.

Upstream-Status: Submitted [https://bugzilla.nasm.us/show_bug.cgi?id=3392635]
Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>

---
 asm/nasm.c              | 24 ++++++++++++++++++++++++
 include/nasmlib.h       |  9 +++++++++
 nasm.txt                |  4 ++++
 nasmlib/filename.c      | 20 ++++++++++++++++++++
 output/outas86.c        |  4 +++-
 output/outcoff.c        |  4 ++--
 output/outelf.c         | 13 ++++++++-----
 output/outieee.c        |  2 +-
 output/outobj.c         |  2 +-
 stdlib/strlcat.c        |  2 +-
 test/elfdebugprefix.asm |  6 ++++++
 test/performtest.pl     | 12 ++++++++++--
 12 files changed, 89 insertions(+), 13 deletions(-)
 create mode 100644 test/elfdebugprefix.asm

diff --git a/asm/nasm.c b/asm/nasm.c
index 76c70f6..08ff119 100644
--- a/asm/nasm.c
+++ b/asm/nasm.c
@@ -939,6 +939,7 @@ enum text_options {
     OPT_KEEP_ALL,
     OPT_NO_LINE,
     OPT_DEBUG,
+    OPT_DEBUG_PREFIX_MAP,
     OPT_REPRODUCIBLE
 };
 enum need_arg {
@@ -971,6 +972,7 @@ static const struct textargs textopts[] = {
     {"keep-all", OPT_KEEP_ALL, ARG_NO, 0},
     {"no-line",  OPT_NO_LINE, ARG_NO, 0},
     {"debug",    OPT_DEBUG, ARG_MAYBE, 0},
+    {"debug-prefix-map", OPT_DEBUG_PREFIX_MAP, true, 0},
     {"reproducible", OPT_REPRODUCIBLE, ARG_NO, 0},
     {NULL, OPT_BOGUS, ARG_NO, 0}
 };
@@ -1335,6 +1337,26 @@ static bool process_arg(char *p, char *q, int pass)
                 case OPT_REPRODUCIBLE:
                     reproducible = true;
                     break;
+                case OPT_DEBUG_PREFIX_MAP: {
+                    struct debug_prefix_list *d;
+                    char *c;
+                    c = strchr(param, '=');
+
+                    if (!c) {
+                        nasm_error(ERR_NONFATAL | ERR_NOFILE | ERR_USAGE,
+                                   "option `--%s' must be of the form `BASE=DEST'", p);
+                        break;
+                    }
+
+                    *c = '\0';
+                    d = nasm_malloc(sizeof(*d));
+                    d->next = debug_prefixes;
+                    d->base = nasm_strdup(param);
+                    d->dest = nasm_strdup(c + 1);
+                    debug_prefixes = d;
+                    *c = '=';
+                    }
+                    break;
                 case OPT_HELP:
                     help(stdout);
                     exit(0);
@@ -2298,6 +2320,8 @@ static void help(FILE *out)
         "    -w-x          disable warning x (also -Wno-x)\n"
         "    -w[+-]error   promote all warnings to errors (also -Werror)\n"
         "    -w[+-]error=x promote warning x to errors (also -Werror=x)\n"
+        "   --debug-prefix-map base=dest\n"
+        "                  remap paths starting with 'base' to 'dest' in output files\n"
         , out);
 
     fprintf(out, "       %-20s %s\n",
diff --git a/include/nasmlib.h b/include/nasmlib.h
index 87a7fc6..a3e5144 100644
--- a/include/nasmlib.h
+++ b/include/nasmlib.h
@@ -250,10 +250,19 @@ int64_t readstrnum(char *str, int length, bool *warn);
  */
 int32_t seg_alloc(void);
 
+struct debug_prefix_list {
+    struct debug_prefix_list *next;
+    char *base;
+    char *dest;
+};
+
+extern struct debug_prefix_list *debug_prefixes;
+
 /*
  * Add/replace or remove an extension to the end of a filename
  */
 const char *filename_set_extension(const char *inname, const char *extension);
+char *filename_debug_remap(char *dest, char const *inname, size_t len);
 
 /*
  * Utility macros...
diff --git a/nasm.txt b/nasm.txt
index 950c361..784618c 100644
--- a/nasm.txt
+++ b/nasm.txt
@@ -147,6 +147,10 @@ OPTIONS
 	Prepend or append (respectively) the given argument to all global or
 	extern variables.
 
+--debug-prefix-map 'BASE=DEST'::
+    Map file names beginning with 'BASE' to 'DEST' when encoding them in
+    output object files.
+
 SYNTAX
 ------
 This man page does not fully describe the syntax of *nasm*'s assembly language,
diff --git a/nasmlib/filename.c b/nasmlib/filename.c
index 172ae0b..fda2be4 100644
--- a/nasmlib/filename.c
+++ b/nasmlib/filename.c
@@ -39,6 +39,8 @@
 #include "nasmlib.h"
 #include "error.h"
 
+struct debug_prefix_list *debug_prefixes = NULL;
+
 /*
  * Add/modify a filename extension, assumed to be a period-delimited
  * field at the very end of the filename.  Returns a newly allocated
@@ -61,3 +63,21 @@ const char *filename_set_extension(const char *inname, const char *extension)
 
     return p;
 }
+
+char *filename_debug_remap(char *dest, char const *in, size_t len)
+{
+    struct debug_prefix_list *d;
+    size_t n;
+
+    for (d = debug_prefixes; d != NULL; d = d->next) {
+        n = strlen(d->base);
+        if (strncmp(in, d->base, n) == 0) {
+            strlcpy(dest, d->dest, len);
+            strlcat(dest, &in[n], len);
+            return dest;
+        }
+    }
+
+    strlcpy(dest, in, len);
+    return dest;
+}
diff --git a/output/outas86.c b/output/outas86.c
index 54b22f8..c4a412c 100644
--- a/output/outas86.c
+++ b/output/outas86.c
@@ -110,6 +110,8 @@ static void as86_sect_write(struct Section *, const uint8_t *,
 
 static void as86_init(void)
 {
+    char filename[FILENAME_MAX];
+
     stext.data = saa_init(1L);
     stext.datalen = 0L;
     stext.head = stext.last = NULL;
@@ -131,7 +133,7 @@ static void as86_init(void)
     strslen = 0;
 
     /* as86 module name = input file minus extension */
-    as86_add_string(filename_set_extension(inname, ""));
+    as86_add_string(filename_debug_remap(filename, filename_set_extension(inname, ""), sizeof(filename)));
 }
 
 static void as86_cleanup(void)
diff --git a/output/outcoff.c b/output/outcoff.c
index c2b4eb6..e242db2 100644
--- a/output/outcoff.c
+++ b/output/outcoff.c
@@ -1259,7 +1259,7 @@ static void coff_symbol(char *name, int32_t strpos, int32_t value,
 
 static void coff_write_symbols(void)
 {
-    char filename[18];
+    char filename[19];
     uint32_t i;
 
     /*
@@ -1269,7 +1269,7 @@ static void coff_write_symbols(void)
     if (reproducible)
         memset(filename, 0, 18);
     else
-        strncpy(filename, inname, 18);
+        filename_debug_remap(filename, inname, 19);
     nasm_write(filename, 18, ofile);
 
     /*
diff --git a/output/outelf.c b/output/outelf.c
index ad8d210..29f1dc1 100644
--- a/output/outelf.c
+++ b/output/outelf.c
@@ -546,8 +546,8 @@ static void elf_init(void)
     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));
+    filename_debug_remap(elf_module, inname, sizeof(elf_module));
+    filename_debug_remap(elf_dir, nasm_dirname(cur_path), sizeof(elf_dir));
     sects = NULL;
     nsects = sectlen = 0;
     syms = saa_init((int32_t)sizeof(struct elf_symbol));
@@ -3590,13 +3590,17 @@ static void dwarf_findfile(const char * fname)
     if (dwarf_clist && !(strcmp(fname, dwarf_clist->filename)))
         return;
 
+    char * fname_remapped = nasm_malloc(FILENAME_MAX);
+    filename_debug_remap(fname_remapped,fname,FILENAME_MAX);
+
     /* search for match */
     match = 0;
     if (dwarf_flist) {
         match = dwarf_flist;
         for (finx = 0; finx < dwarf_numfiles; finx++) {
-            if (!(strcmp(fname, match->filename))) {
+            if (!(strcmp(fname_remapped, match->filename))) {
                 dwarf_clist = match;
+                nasm_free(fname_remapped);
                 return;
             }
             match = match->next;
@@ -3607,8 +3611,7 @@ static void dwarf_findfile(const char * fname)
     dwarf_clist = nasm_malloc(sizeof(struct linelist));
     dwarf_numfiles++;
     dwarf_clist->line = dwarf_numfiles;
-    dwarf_clist->filename = nasm_malloc(strlen(fname) + 1);
-    strcpy(dwarf_clist->filename,fname);
+    dwarf_clist->filename = fname_remapped;
     dwarf_clist->next = 0;
     if (!dwarf_flist) {     /* if first entry */
         dwarf_flist = dwarf_elist = dwarf_clist;
diff --git a/output/outieee.c b/output/outieee.c
index 7ba9036..796e5af 100644
--- a/output/outieee.c
+++ b/output/outieee.c
@@ -207,7 +207,7 @@ static void ieee_unqualified_name(char *, char *);
  */
 static void ieee_init(void)
 {
-    strlcpy(ieee_infile, inname, sizeof(ieee_infile));
+    filename_debug_remap(ieee_infile, inname, sizeof(ieee_infile));
     any_segs = false;
     fpubhead = NULL;
     fpubtail = &fpubhead;
diff --git a/output/outobj.c b/output/outobj.c
index 281839d..fc336c1 100644
--- a/output/outobj.c
+++ b/output/outobj.c
@@ -644,7 +644,7 @@ static enum directive_result obj_directive(enum directive, char *);
 
 static void obj_init(void)
 {
-    strlcpy(obj_infile, inname, sizeof(obj_infile));
+    filename_debug_remap(obj_infile, inname, sizeof(obj_infile));
     first_seg = seg_alloc();
     any_segs = false;
     fpubhead = NULL;
diff --git a/stdlib/strlcat.c b/stdlib/strlcat.c
index 7084d46..ee93dea 100644
--- a/stdlib/strlcat.c
+++ b/stdlib/strlcat.c
@@ -29,7 +29,7 @@ size_t strlcat(char *dest, const char *src, size_t size)
     size_t n;
 
     /* find the NULL terminator in dest */
-    for (n = 0; i < size && dest[n] != '\0'; n++)
+    for (n = 0; n < size && dest[n] != '\0'; n++)
         ;
 
     /* destination was not NULL terminated. Return the initial size */
diff --git a/test/elfdebugprefix.asm b/test/elfdebugprefix.asm
new file mode 100644
index 0000000..a67ba29
--- /dev/null
+++ b/test/elfdebugprefix.asm
@@ -0,0 +1,6 @@
+;Testname=unoptimized; Arguments=-O0 --debug-prefix-map elf=ELF -felf -oelfdebugprefix.o; Files=stdout stderr elfdebugprefix.o; Validate=readelf --wide --symbols elfdebugprefix.o | grep 'FILE.*ELFdebugprefix.asm'
+
+	  SECTION .text
+test:			; [1]
+	  ret
+
diff --git a/test/performtest.pl b/test/performtest.pl
index 46b1bdf..2426848 100755
--- a/test/performtest.pl
+++ b/test/performtest.pl
@@ -42,14 +42,22 @@ sub perform {
     TEST:
     while(<TESTFILE>) {
         #See if there is a test case
-        last unless /Testname=(.*);\s*Arguments=(.*);\s*Files=(.*)/;
-        my ($subname, $arguments, $files) = ($1, $2, $3);
+        last unless /Testname=(.*);\s*Arguments=(.*);\s*Files=([^;]*)(?:;\s*Validate=(.*))?/;
+        my ($subname, $arguments, $files, $validate) = ($1, $2, $3, $4);
+        chomp $files;
         debugprint("$subname | $arguments | $files");
 
         #Call nasm with this test case
         system("$nasm $arguments $testpath > $stdoutfile 2> $stderrfile");
         debugprint("$nasm $arguments $testpath > $stdoutfile 2> $stderrfile ----> $?");
 
+        if($validate) {
+            if(system("$validate >> $stdoutfile 2>> $stderrfile") != 0) {
+                print "Test $testname/$subname validation failed\n";
+                $globalresult = 1;
+            }
+        }
+
         #Move the output to the test dir
         mkpath("$outputdir/$testname/$subname");
         foreach(split / /,$files) {
