Merge remote-tracking branch 'origin/nasm-2.14.xx'

Resolved Conflicts:
	asm/labels.c
	include/error.h
	version

4 files changed, 88 insertions, 26 deletions

diff --git a/asm/labels.c b/asm/labels.c
index 4e69d99a..cffe1027 100644
--- a/asm/labels.c
+++ b/asm/labels.c
@@ -109,9 +109,11 @@ union label {                   /* actual label structures */
         int32_t subsection;     /* Available for ofmt->herelabel() */
         int64_t offset;
         int64_t size;
+        int64_t defined;        /* 0 if undefined, passn+1 for when defn seen */
         char *label, *mangled, *special;
+        const char *def_file;   /* Where defined */
+        int32_t def_line;
         enum label_type type, mangled_type;
-        bool defined;
     } defn;
     struct {
         int32_t movingon;
@@ -369,7 +371,7 @@ handle_herelabel(union label *lptr, int32_t *segment, int64_t *offset)
             location.offset = *offset;
         } else {
             /* Keep a separate offset for the new segment */
-            *offset  = switch_segment(newseg);
+            *offset = switch_segment(newseg);
         }
     }
 }
@@ -433,6 +435,13 @@ void define_label(const char *label, int32_t segment,
     union label *lptr;
     bool created, changed;
     int64_t size;
+    int64_t lastdef;
+
+    /*
+     * The backend may invoke this before pass 1, so treat that as
+     * a special "pass".
+     */
+    const int64_t lpass = pass0 + 1;
 
     /*
      * Phase errors here can be one of two types: a new label appears,
@@ -441,17 +450,26 @@ void define_label(const char *label, int32_t segment,
      */
     lptr = find_label(label, true, &created);
 
+    lastdef = lptr->defn.defined;
+
     if (segment) {
         /* We are actually defining this label */
-        if (lptr->defn.type == LBL_EXTERN) /* auto-promote EXTERN to GLOBAL */
+        if (lptr->defn.type == LBL_EXTERN) {
+            /* auto-promote EXTERN to GLOBAL */
             lptr->defn.type = LBL_GLOBAL;
+            lastdef = 0; /* We are "re-creating" this label */
+        }
     } else {
         /* It's a pseudo-segment (extern, common) */
         segment = lptr->defn.segment ? lptr->defn.segment : seg_alloc();
     }
 
-    if (lptr->defn.defined || lptr->defn.type == LBL_BACKEND) {
-        /* We have seen this on at least one previous pass */
+    if (lastdef || lptr->defn.type == LBL_BACKEND) {
+        /*
+         * We have seen this on at least one previous pass, or
+         * potentially earlier in this same pass (in which case we
+         * will probably error out further down.)
+         */
         mangle_label_name(lptr);
         handle_herelabel(lptr, &segment, &offset);
     }
@@ -469,27 +487,51 @@ void define_label(const char *label, int32_t segment,
         size = 0;               /* This is a hack... */
     }
 
-    changed = created || !lptr->defn.defined ||
+    changed = created || !lastdef ||
         lptr->defn.segment != segment ||
-        lptr->defn.offset != offset || lptr->defn.size != size;
+        lptr->defn.offset != offset ||
+        lptr->defn.size != size;
     global_offset_changed += changed;
 
-    /*
-     * This probably should be ERR_NONFATAL, but not quite yet.  As a
-     * special case, LBL_SPECIAL symbols are allowed to be changed
-     * even during the last pass.
-     */
-    if (changed && pass0 > 1 && lptr->defn.type != LBL_SPECIAL) {
-        nasm_warn("label `%s' %s during code generation",
-                  lptr->defn.label, created ? "defined" : "changed");
+    if (changed) {
+        if (lastdef == lpass) {
+            int32_t saved_line = 0;
+            const char *saved_fname = NULL;
+
+            /*
+             * Defined elsewhere in the program, seen in this pass.
+             */
+            nasm_error(ERR_NONFATAL,
+                       "label `%s' inconsistently redefined",
+                       lptr->defn.label);
+
+            src_get(&saved_line, &saved_fname);
+            src_set(lptr->defn.def_line, lptr->defn.def_file);
+            nasm_error(ERR_NOTE, "label `%s' originally defined here",
+                       lptr->defn.label);
+            src_set(saved_line, saved_fname);
+        } else if (pass0 > 1 && lptr->defn.type != LBL_SPECIAL) {
+            /*
+             * This probably should be ERR_NONFATAL, but not quite yet.  As a
+             * special case, LBL_SPECIAL symbols are allowed to be changed
+             * even during the last pass.
+             */
+            nasm_warn("label `%s' %s during code generation",
+                      lptr->defn.label,
+                      created ? "defined" : "changed");
+        }
     }
 
     lptr->defn.segment = segment;
     lptr->defn.offset  = offset;
     lptr->defn.size    = size;
-    lptr->defn.defined = true;
+    lptr->defn.defined = lpass;
+
+    if (changed || lastdef != lpass)
+        src_get(&lptr->defn.def_line, &lptr->defn.def_file);
 
-    out_symdef(lptr);
+    if (lastdef != lpass)
+        out_symdef(lptr);
 }
 
 /*
diff --git a/asm/nasm.c b/asm/nasm.c
index eb6f4760..4c4d6de4 100644
--- a/asm/nasm.c
+++ b/asm/nasm.c
@@ -1756,7 +1756,7 @@ static void nasm_verror_gnu(int severity, const char *fmt, va_list ap)
 
     if (!skip_this_pass(severity)) {
         if (!lineno)
-            fprintf(error_file, "%s:", currentfile ? currentfile : "nasm");
+            fprintf(error_file, "%s: ", currentfile ? currentfile : "nasm");
         else
             fprintf(error_file, "%s:%"PRId32": ", currentfile, lineno);
     }
@@ -1791,10 +1791,10 @@ static void nasm_verror_vc(int severity, const char *fmt, va_list ap)
         src_get(&lineno, &currentfile);
 
     if (!skip_this_pass(severity)) {
-        if (currentfile) {
+        if (lineno) {
 	    fprintf(error_file, "%s(%"PRId32") : ", currentfile, lineno);
 	} else {
-	    fputs("nasm: ", error_file);
+            fprintf(error_file , "%s : ", currentfile ? currentfile : "nasm");
 	}
     }
 
@@ -1871,11 +1871,19 @@ static void nasm_verror_common(int severity, const char *fmt, va_list args)
 {
     char msg[1024];
     const char *pfx;
+    bool warn_is_err = warning_is_error(severity);
+    bool warn_is_other = WARN_IDX(severity) == ERR_WARN_OTHER;
 
     switch (severity & (ERR_MASK|ERR_NO_SEVERITY)) {
-    case ERR_WARNING:
-        pfx = "warning: ";
+    case ERR_NOTE:
+        pfx = "note: ";
         break;
+    case ERR_WARNING:
+        if (!warn_is_err) {
+            pfx = "warning: ";
+            break;
+        }
+        /* fall through */
     case ERR_NONFATAL:
         pfx = "error: ";
         break;
@@ -1894,9 +1902,11 @@ static void nasm_verror_common(int severity, const char *fmt, va_list args)
     }
 
     vsnprintf(msg, sizeof msg - 64, fmt, args);
-    if (is_valid_warning(severity) && WARN_IDX(severity) != ERR_WARN_OTHER) {
+    if (is_valid_warning(severity) && (warn_is_err || !warn_is_other)) {
         char *p = strchr(msg, '\0');
-	snprintf(p, 64, " [-w+%s]", warnings[WARN_IDX(severity)].name);
+	snprintf(p, 64, " [-w+%s%s]",
+                 warn_is_err ? "error=" : "",
+                 warnings[WARN_IDX(severity)].name);
     }
 
     if (!skip_this_pass(severity))
@@ -1921,6 +1931,7 @@ static void nasm_verror_common(int severity, const char *fmt, va_list args)
     preproc->error_list_macros(severity);
 
     switch (severity & ERR_MASK) {
+    case ERR_NOTE:
     case ERR_DEBUG:
         /* no further action, by definition */
         break;
@@ -1957,6 +1968,8 @@ static void nasm_verror_common(int severity, const char *fmt, va_list args)
         }
         exit(3);
         break;
+    default:
+        break;                  /* ??? */
     }
 }
 
diff --git a/doc/changes.src b/doc/changes.src
index 1bc8f2aa..8e0bc060 100644
--- a/doc/changes.src
+++ b/doc/changes.src
@@ -31,6 +31,12 @@ filename. See \k{opt-MD}.
 
 \b Fix \c{-E} in combination with \c{-MD}. See \k{opt-E}.
 
+\b Fix missing errors on redefined labels; would cause convergence
+failure instead which is very slow and not easy to debug.
+
+\b Duplicate definitions of the same label \e{with the same value} is now
+explicitly permitted (2.14 would allow it in some circumstances.)
+
 \S{cl-2.14} Version 2.14
 
 \b Changed \c{-I} option semantics by adding a trailing path separator
diff --git a/include/error.h b/include/error.h
index c87ea68c..5d3dc22e 100644
--- a/include/error.h
+++ b/include/error.h
@@ -73,8 +73,9 @@ static inline vefunc nasm_set_verror(vefunc ve)
  */
 
 #define ERR_DEBUG		0x00000000	/* put out debugging message */
-#define ERR_WARNING		0x00000001	/* warn only: no further action */
-#define ERR_NONFATAL		0x00000002	/* terminate assembly after phase */
+#define ERR_NOTE		0x00000001	/* additional error information */
+#define ERR_WARNING		0x00000002	/* warn only: no further action */
+#define ERR_NONFATAL		0x00000003	/* terminate assembly after phase */
 #define ERR_FATAL		0x00000006	/* instantly fatal: exit with error */
 #define ERR_PANIC		0x00000007	/* internal error: panic instantly
 						 * and dump core for reference */