[groff] 43/45: [tbl]: Fix incorrect line numbers in diagnostics.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 9a05cca66fc9bf5a61ccff9af4bf985897f421a3
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Fri Jan 21 00:02:18 2022 +1100

    [tbl]: Fix incorrect line numbers in diagnostics.
    
    Line numbers for multiple format-time diagnostics emitted by
    tbl(1)-generated groff input were off by +5 lines.
    
    * src/preproc/tbl/table.cpp: Fix it.
      (NOP_NAME): Add new preprocessor symbol to construct name of "nop"
      macro to be used as end macros for `ig` requests inside macro
      definitions.
    
      (table::init_output, table::compute_expand_list,
      table::compute_separation_factor):
        - Move `entry_list->set_location()` calls to more auspicious
          locations.
        - Replace "around line X" language in diagnostic messages with a
          more idiomatic, and less embarrassing, simple report of an
          integer.
    
      (table::init_output):
        - Add `entry_list->set_location()` call right before emitting
          diagnostic about a table row not fitting on a page.
        - Turn off eqn(1) delimiters when emitting diagnostic about a boxed
          table not fitting on a page (necessitating `.TS H` support), using
          new NOP_NAME-based end macro to achieve this inside a macro
          definition.
    
      (table::compute_expand_list): Suppress issue of too-wide table
      diagnostic when the `EXPAND` table flag is set (corresponding to the
      `expand` region option), because other code already emits diagnostics
      in this case.
    
    Fixes <https://savannah.gnu.org/bugs/?60598>.  Problem appears
    to date back to commit 3bc4a53a45, 2013-01-07.
---
 ChangeLog                 | 32 ++++++++++++++++++++++
 src/preproc/tbl/table.cpp | 69 +++++++++++++++++++++++++++++++----------------
 2 files changed, 78 insertions(+), 23 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 56c8cbe4..88b062dd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,35 @@
+2022-01-21  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       [tbl]: Fix incorrect line numbers in diagnostics.  Line numbers
+       for multiple format-time diagnostics emitted by tbl(1)-generated
+       groff input were off by +5 lines.
+
+       * src/preproc/tbl/table.cpp: Fix it.
+       (NOP_NAME): Add new preprocessor symbol to construct name of
+       "nop" macro to be used as end macros for `ig` requests inside
+       macro definitions.
+       (table::init_output, table::compute_expand_list,
+       table::compute_separation_factor):
+       - Move `entry_list->set_location()` calls to more auspicious
+         locations.
+       - Replace "around line X" language in diagnostic messages with a
+         more idiomatic, and less embarrassing, simple report of an
+         integer.
+       (table::init_output):
+       - Add `entry_list->set_location()` call right before emitting
+         diagnostic about a table row not fitting on a page.
+       - Turn off eqn(1) delimiters when emitting diagnostic about a
+         boxed table not fitting on a page (necessitating `.TS H`
+         support), using new NOP_NAME-based end macro to achieve this
+         inside a macro definition.
+       (table::compute_expand_list): Suppress issue of too-wide table
+       diagnostic when the `EXPAND` table flag is set (corresponding to
+       the `expand` region option), because other code already emits
+       diagnostics in this case.
+
+       Fixes <https://savannah.gnu.org/bugs/?60598>.  Problem appears
+       to date back to commit 3bc4a53a45, 2013-01-07.
+
 2022-01-21  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        [tbl]: Add unit test for format-time diagnostics.
diff --git a/src/preproc/tbl/table.cpp b/src/preproc/tbl/table.cpp
index f86c53ba..66a1c2b5 100644
--- a/src/preproc/tbl/table.cpp
+++ b/src/preproc/tbl/table.cpp
@@ -72,6 +72,9 @@ const int DEFAULT_COLUMN_SEPARATION = 3;
 // this must be one character
 #define COMPATIBLE_REG PREFIX "c"
 
+// for use with `ig` requests embedded inside macro definitions
+#define NOP_NAME PREFIX "nop"
+
 #define EXPAND_REG PREFIX "expand"
 
 #define LEADER_REG PREFIX LEADER
@@ -1877,14 +1880,17 @@ void table::init_output()
           ".nr " SUPPRESS_BOTTOM_REG " 0\n"
           ".mk #T\n"
           ".\\}\n");
-    if (!(flags & NOWARN))
-      prints(".if \\n[.t]<=\\n[" SAVED_DN_REG "] \\{\\\n"
-            /* Since we turn off traps, it won't get into an infinite
-               loop when we try and print it; it will just go off the
-               bottom of the page. */
-            ".  tmc \\n[.F]: around line \\n[.c]: warning:\n"
-            ".  tm1 \" table row will not fit on page \\n%\n"
-            ".\\}\n");
+    if (!(flags & NOWARN)) {
+      prints(".if \\n[.t]<=\\n[" SAVED_DN_REG "] \\{\\\n");
+      // eqn(1) delimiters have already been switched off.
+      entry_list->set_location();
+      // Since we turn off traps, troff won't go into an infinite loop
+      // when we output the table row; it will just flow off the bottom
+      // of the page.
+      prints(".  tmc \\n[.F]:\\n[.c]: warning:\n"
+            ".  tm1 \" table row will not fit on page \\n%\n");
+      prints(".\\}\n");
+    }
     prints(".nf\n"
           ".if \\n[.nm] .if \\n[ln] .nm \\n[ln]\n"
           ".nr " ROW_MAX_LINE_REG " \\n[ln]\n"
@@ -1912,11 +1918,25 @@ void table::init_output()
           ".di\n"
           ".nr " SAVED_DN_REG " \\n[dn]\n"
           ".ne \\n[dn]u+\\n[.V]u\n"
-          ".ie \\n[.t]<=\\n[" SAVED_DN_REG "] \\{\\\n"
-          ".  tmc \\n[.F]: around line \\n[.c]: error:\n"
-          ".  tmc \" table will not fit on page \\n%;\n"
-          ".  tm1 \" use .TS H/.TH with a supporting macro package\n"
-          ".\\}\n"
+          ".ie \\n[.t]<=\\n[" SAVED_DN_REG "] \\{\\\n");
+    // Protect characters in diagnostic message (especially :, [, ])
+    // from being interpreted by eqn.
+    prints(".  ds " NOP_NAME " \\\" empty\n");
+    prints(".  ig " NOP_NAME "\n"
+          ".  EQ\n"
+          "   delim off\n"
+          ".  EN\n"
+          ".  " NOP_NAME "\n");
+    entry_list->set_location();
+    prints(".  tmc \\n[.F]:\\n[.c]: error:\n"
+          ".  tmc \" boxed table will not fit on page \\n%;\n"
+          ".  tm1 \" use .TS H/.TH with a supporting macro package\n");
+    prints(".  ig " NOP_NAME "\n"
+          ".  EQ\n"
+          "   delim on\n"
+          ".  EN\n"
+          ".  " NOP_NAME "\n");
+    prints(".\\}\n"
           ".el \\{"
           ".in 0\n"
           ".ls 1\n"
@@ -2159,7 +2179,7 @@ void table::build_span_list()
 void table::compute_expand_width()
 {
   // First, compute the unexpanded table width, measuring every column
-  // (including those eligible for expansion) and warn if it's too wide.
+  // (including those eligible for expansion).
   prints(".nr " EXPAND_REG " \\n[.l]-\\n[.i]");
   for (int i = 0; i < ncolumns; i++)
     printfs("-\\n[%1]", span_width_reg(i, i));
@@ -2167,8 +2187,9 @@ void table::compute_expand_width()
     printfs("-%1n", as_string(total_separation));
   prints("\n");
   prints(".if \\n[" EXPAND_REG "]<0 \\{\\\n");
-  entry_list->set_location();
-  if (!(flags & NOWARN)) {
+  // If the "expand" region option was given, a different warning will
+  // be issued later (if "nowarn" was not also specified).
+  if ((!(flags & NOWARN)) && (!(flags & EXPAND))) {
     // Protect characters in diagnostic message (especially :, [, ])
     // from being interpreted by eqn.
     prints(".ig\n"
@@ -2176,7 +2197,8 @@ void table::compute_expand_width()
           "delim off\n"
           ".EN\n"
           "..\n");
-    prints(".tmc \\n[.F]: around line \\n[.c]: warning:\n"
+    entry_list->set_location();
+    prints(".tmc \\n[.F]:\\n[.c]: warning:\n"
           ".tm1 \" table wider than line length minus indentation\n");
     prints(".ig\n"
           ".EQ\n"
@@ -2231,7 +2253,6 @@ void table::compute_separation_factor()
     printfs("-\\n[%1]", span_width_reg(i, i));
   printfs("/%1\n", as_string(total_separation));
   prints(".ie \\n[" SEPARATION_FACTOR_REG "]<=0 \\{\\\n");
-  entry_list->set_location();
   if (!(flags & NOWARN)) {
     // Protect characters in diagnostic message (especially :, [, ])
     // from being interpreted by eqn.
@@ -2240,16 +2261,18 @@ void table::compute_separation_factor()
           "delim off\n"
           ".EN\n"
           "..\n");
-    prints(".tmc \\n[.F]: around line \\n[.c]: warning:\n"
-          ".tm1 \" table column separation set to zero\n"
+    entry_list->set_location();
+    prints(".tmc \\n[.F]:\\n[.c]: warning:\n"
+          ".tm1 \" table column separation reduced to zero\n"
           ".nr " SEPARATION_FACTOR_REG " 0\n");
   }
   prints(".\\}\n"
         ".el .if \\n[" SEPARATION_FACTOR_REG "]<1n \\{\\\n");
-  entry_list->set_location();
   if (!(flags & NOWARN)) {
-    prints(".tmc \\n[.F]: around line \\n[.c]: warning:\n"
-          ".tm1 \" table squeezed horizontally to fit line length\n");
+    entry_list->set_location();
+    prints(".tmc \\n[.F]:\\n[.c]: warning:\n"
+          ".tm1 \" table column separation reduced to fit line"
+          " length\n");
     prints(".ig\n"
           ".EQ\n"
           "delim on\n"