With buffered warnings, change the handling of error passes

With buffered warnings, most warnings *must* be issued on every pass,
so ERR_PASS1 is simply wrong in most cases.

ERR_PASS1 now means "force this warning to be output even in
pass_first(). This is to be used for the case where the warning is
only executed in pass_first() code; this is highly discouraged as it
means the warnings will not appear in the list file and subsequent
passes may make the warning suddenly vanish.

ERR_PASS2 just as before suppresses an error or warning unless we are
in pass_final().

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>

7 files changed, 53 insertions, 39 deletions

diff --git a/output/outbin.c b/output/outbin.c
index 4bf13fa4..73a4d8a7 100644
--- a/output/outbin.c
+++ b/output/outbin.c
@@ -1328,13 +1328,13 @@ bin_directive(enum directive directive, char *args)
                 else {          /* Must be a filename. */
                     rf = nasm_open_write(p, NF_TEXT);
                     if (!rf) {
-                        nasm_warn(WARN_OTHER, "unable to open map file `%s'", p);
+                        nasm_warn(WARN_OTHER|ERR_PASS1, "unable to open map file `%s'", p);
                         map_control = 0;
                         return DIRR_OK;
                     }
                 }
             } else
-                nasm_warn(WARN_OTHER, "map file already specified");
+                nasm_warn(WARN_OTHER|ERR_PASS1, "map file already specified");
         }
         if (map_control == 0)
             map_control |= MAP_ORIGIN | MAP_SUMMARY;
diff --git a/output/outcoff.c b/output/outcoff.c
index a90e355e..2c8520f1 100644
--- a/output/outcoff.c
+++ b/output/outcoff.c
@@ -402,45 +402,51 @@ static int32_t coff_section_names(char *name, int *bits)
             coff_sects[i]->flags = flags;
         coff_sects[i]->flags &= align_and;
         coff_sects[i]->flags |= align_or;
-    } else if (pass_first()) {
-        /* Check if any flags are specified */
-        if (flags) {
-            unsigned int align_flags = flags & IMAGE_SCN_ALIGN_MASK;
-
-            /* Warn if non-alignment flags differ */
-            if ((flags ^ coff_sects[i]->flags) & ~IMAGE_SCN_ALIGN_MASK) {
-                nasm_warn(WARN_OTHER, "section attributes ignored on"
-                          " redeclaration of section `%s'", name);
+    } else if (flags) {
+        /* Check if any flags are respecified */
+        unsigned int align_flags = flags & IMAGE_SCN_ALIGN_MASK;
+
+        /* Warn if non-alignment flags differ */
+        if ((flags ^ coff_sects[i]->flags) & ~IMAGE_SCN_ALIGN_MASK &&
+            coff_sects[i]->pass_last_seen == pass_count()) {
+            nasm_warn(WARN_OTHER, "section attributes changed on"
+                      " redeclaration of section `%s'", name);
+        }
+        /* Check if alignment might be needed */
+        if (align_flags > IMAGE_SCN_ALIGN_1BYTES) {
+            unsigned int sect_align_flags = coff_sects[i]->flags & IMAGE_SCN_ALIGN_MASK;
+
+            /* Compute the actual alignment */
+            unsigned int align = 1u << ((align_flags - IMAGE_SCN_ALIGN_1BYTES) >> 20);
+
+            /* Update section header as needed */
+            if (align_flags > sect_align_flags) {
+                coff_sects[i]->flags = (coff_sects[i]->flags & ~IMAGE_SCN_ALIGN_MASK) | align_flags;
             }
-            /* Check if alignment might be needed */
-            if (align_flags > IMAGE_SCN_ALIGN_1BYTES) {
-                unsigned int sect_align_flags = coff_sects[i]->flags & IMAGE_SCN_ALIGN_MASK;
+            /* Check if not already aligned */
+            if (coff_sects[i]->len % align) {
+                unsigned int padding = (align - coff_sects[i]->len) % align;
+                /* We need to write at most 8095 bytes */
+                char         buffer[8095];
 
-                /* Compute the actual alignment */
-                unsigned int align = 1u << ((align_flags - IMAGE_SCN_ALIGN_1BYTES) >> 20);
+                nasm_assert(padding <= sizeof buffer);
 
-                /* Update section header as needed */
-                if (align_flags > sect_align_flags) {
-                    coff_sects[i]->flags = (coff_sects[i]->flags & ~IMAGE_SCN_ALIGN_MASK) | align_flags;
-                }
-                /* Check if not already aligned */
-                if (coff_sects[i]->len % align) {
-                    unsigned int padding = (align - coff_sects[i]->len) % align;
-                    /* We need to write at most 8095 bytes */
-                    char buffer[8095];
-                    if (coff_sects[i]->flags & IMAGE_SCN_CNT_CODE) {
-                        /* Fill with INT 3 instructions */
-                        memset(buffer, 0xCC, padding);
-                    } else {
-                        memset(buffer, 0x00, padding);
-                    }
-                    saa_wbytes(coff_sects[i]->data, buffer, padding);
-                    coff_sects[i]->len += padding;
+                if (pass_final())
+                    nasm_nonfatal("section alignment changed during code generation");
+
+                if (coff_sects[i]->flags & IMAGE_SCN_CNT_CODE) {
+                    /* Fill with INT 3 instructions */
+                    memset(buffer, 0xCC, padding);
+                } else {
+                    memset(buffer, 0x00, padding);
                 }
+                saa_wbytes(coff_sects[i]->data, buffer, padding);
+                coff_sects[i]->len += padding;
             }
         }
     }
 
+    coff_sects[i]->pass_last_seen = pass_count();
     return coff_sects[i]->index;
 }
 
diff --git a/output/outelf.c b/output/outelf.c
index cd77901f..366e52de 100644
--- a/output/outelf.c
+++ b/output/outelf.c
@@ -258,8 +258,8 @@ static void elf_section_attrib(char *name, char *attr,
             *type = SHT_PROGBITS;
         } else if (!nasm_stricmp(opt, "nobits")) {
             *type = SHT_NOBITS;
-        } else if (pass_first()) {
-            nasm_warn(WARN_OTHER, "Unknown section attribute '%s' ignored on"
+        } else {
+            nasm_warn(WARN_OTHER, "unknown section attribute '%s' ignored on"
                       " declaration of section `%s'", opt, name);
         }
         opt = next;
@@ -458,14 +458,15 @@ static int32_t elf_section_names(char *name, int *bits)
         flags = (ks->flags & ~flags_and) | flags_or;
 
         i = elf_make_section(name, type, flags, align);
-    } else if (pass_first()) {
+    } else if (sects[i]->pass_last_seen == pass_count()) {
           if ((type && sects[i]->type != type)
               || (align && sects[i]->align != align)
               || (flags_and && ((sects[i]->flags & flags_and) != flags_or)))
-            nasm_warn(WARN_OTHER, "incompatible section attributes ignored on"
+            nasm_warn(WARN_OTHER|ERR_PASS1, "incompatible section attributes ignored on"
                       " redeclaration of section `%s'", name);
     }
 
+    sects[i]->pass_last_seen = pass_count();
     return sects[i]->index;
 }
 
diff --git a/output/outelf.h b/output/outelf.h
index 8eef73ae..0801eaf8 100644
--- a/output/outelf.h
+++ b/output/outelf.h
@@ -141,6 +141,7 @@ struct elf_section {
     int                 type;           /* SHT_PROGBITS or SHT_NOBITS */
     uint64_t            align;          /* alignment: power of two */
     uint64_t            flags;          /* section flags */
+    int64_t		pass_last_seen;
     char                *name;
     struct SAA          *rel;
     uint64_t             rellen;
diff --git a/output/outieee.c b/output/outieee.c
index 1247077e..f2f598ee 100644
--- a/output/outieee.c
+++ b/output/outieee.c
@@ -151,6 +151,7 @@ static struct ieeeSection {
     int32_t align;                 /* can be SEG_ABS + absolute addr */
     int32_t startpos;
     int32_t use32;                 /* is this segment 32-bit? */
+    int64_t pass_last_seen;
     struct ieeePublic *pubhead, **pubtail, *lochead, **loctail;
     enum {
         CMB_PRIVATE = 0,
@@ -705,13 +706,15 @@ static int32_t ieee_segment(char *name, int *bits)
         for (seg = seghead; seg; seg = seg->next) {
             ieee_idx++;
             if (!strcmp(seg->name, name)) {
-                if (attrs > 0 && pass_first())
+                if (attrs > 0 && seg->pass_last_seen == pass_count())
                     nasm_warn(WARN_OTHER, "segment attributes specified on"
                               " redeclaration of segment: ignoring");
                 if (seg->use32)
                     *bits = 32;
                 else
                     *bits = 16;
+
+                seg->pass_last_seen = pass_count();
                 return seg->index;
             }
         }
diff --git a/output/outobj.c b/output/outobj.c
index e861754e..c7407cf9 100644
--- a/output/outobj.c
+++ b/output/outobj.c
@@ -580,6 +580,7 @@ static struct Segment {
     struct Group *grp;          /* the group it beint32_ts to */
     uint32_t currentpos;
     int32_t align;                 /* can be SEG_ABS + absolute addr */
+    int64_t pass_last_seen;
     struct Public *pubhead, **pubtail, *lochead, **loctail;
     char *segclass, *overlay;   /* `class' is a C++ keyword :-) */
     ObjRecord *orp;
@@ -1379,7 +1380,7 @@ static int32_t obj_segment(char *name, int *bits)
                 break;
 
             if (!strcmp(seg->name, name)) {
-                if (attrs > 0 && pass_first())
+                if (attrs > 0 && seg->pass_last_seen == pass_count())
                     nasm_warn(WARN_OTHER, "segment attributes specified on"
                               " redeclaration of segment: ignoring");
                 if (seg->use32)
@@ -1387,6 +1388,7 @@ static int32_t obj_segment(char *name, int *bits)
                 else
                     *bits = 16;
                 current_seg = seg;
+                seg->pass_last_seen = pass_count();
                 return seg->index;
             }
         }
diff --git a/output/pecoff.h b/output/pecoff.h
index 8b57d6b2..7b6f46c2 100644
--- a/output/pecoff.h
+++ b/output/pecoff.h
@@ -484,6 +484,7 @@ struct coff_Section {
     char *name;
     int32_t namepos;            /* Offset of name into the strings table */
     int32_t pos, relpos;
+    int64_t pass_last_seen;
 };
 
 struct coff_Reloc {