nickg · Blebowski · Apr 6, 2025 · Apr 11, 2025 · Apr 11, 2025 · Apr 17, 2025
diff --git a/NEWS.md b/NEWS.md
@@ -9,6 +9,8 @@
   non-equal coverage databases.
 - Fixed a debug assertion failure when initialising an array with more
   than 2**32 elements (#1196).
+- `generate` statements now create separate hierarchy in the code
+  coverage report
 
 ## Version 1.16.0 - 2025-04-21
 - Added support for PSL `prev()`, `stable()`, `rose()` and `fell()`

diff --git a/nvc.1 b/nvc.1
@@ -1150,6 +1150,47 @@ to
 .Bd -literal -offset indent
 fold TB_TOP_LIB.TB_TOP.DUT.I_CPU_DATAPATH.I_INSTR_CACHE UNIT_TEST_LIB.CACHE_UNIT_TEST.DUT
 .Ed
+.Ss Code coverage limitations
+When part of the design hierarchy is formed by an if-generate-else or
+case-generate statement, the hierarchical path of implicit block statements
+for each of the if-else branches / case choices is the same (unless
+user uses alternative label for the branch or choice). Therefore, code
+coverage items in such distinc blocks will have equal hierarchical path.
+Consider following example:
+.Bd -literal -offset indent
+my_gen : case (op_kind) generate
+when op_add => x <= a + b;
+when op_sub => x <= a - b;
+end generate my_gen;
+.Ed
+Both assign statements above have the following hierarchical path:
+.Bd -literal -offset indent
+<PLACE_IN_HIER>.MY_GEN._P0._SO
+.Ed
+When merging code coverage and generating code coverage report, NVC recognizes
+these two coverage items are distinc despite their equal hierarchical path.
+NVC distinguishes these two coverage items based on different location in the
+source code. NVC does not merge such two items, and displays them separately
+in the code coverage report (no aliasing will occur). However, since these two
+coverage items have equal hierarchical paths, it is not possible to distinguish
+them in the exclude file. Either both or none can be excluded.
+Consider another example:
+.Bd -literal -offset indent
+my_gen : case (op_kind) generate
+when op_add => my_inst : entity work.ent
+               generic map (op => op_add);
+when op_sub => my_inst : entity work.ent
+               generic map (op => op_sub);
+end generate my_gen;
+.Ed
+The two instances will have completely equal hierarchical paths. Since
+they are both implemented by the same entity, coverage items in these two
+instances will have equal hierarchical paths as well as locations
+in the source code. Coverage data from these two instances will alias
+and NVC will merge them together. To allow fine-grained control of exlcusions
+or prevent aliasing in corner-cases, it is recommended to use alternative
+labels for branches / choices of if-generage-else and case-generate
+statements.
 .Ss Additional Information
 In coverage specification file and Exclude file
 .Ql <ENTITY_NAME>

diff --git a/src/common.c b/src/common.c
@@ -695,6 +695,7 @@ bool is_concurrent_block(tree_t t)
    case T_BLOCK:
    case T_IF_GENERATE:
    case T_FOR_GENERATE:
+   case T_CASE_GENERATE:
       return true;
    default:
       return false;

diff --git a/src/cov/cov-data.c b/src/cov/cov-data.c
@@ -993,8 +993,7 @@ cover_scope_t *cover_create_instance(cover_data_t *data, cover_scope_t *parent,
       parent->name = parent->hier = lib_name(lib_work());
    }
 
-   // TODO: do not emit scopes for components
-   assert(tree_kind(unit) == T_ARCH);
+   assert(is_concurrent_block(unit));
    assert(tree_kind(block) == T_BLOCK);
 
    cover_scope_t *s = xcalloc(sizeof(cover_scope_t));
@@ -1152,7 +1151,10 @@ static void cover_merge_scope(cover_scope_t *old_s, cover_scope_t *new_s,
          if (n_old_visits == old_s->items.count)
             break;
 
-         if ((new->hier == old->hier) && (new->flags == old->flags)) {
+         if ((new->hier == old->hier) &&
+             (new->flags == old->flags) &&
+             (loc_eq(&(new->loc), &(old->loc)))) {
+
             assert(new->kind == old->kind);
 #ifdef COVER_DEBUG_MERGE
             printf("Merging coverage item: %s\n", istr(old->hier));

diff --git a/src/cov/cov-report.c b/src/cov/cov-report.c
@@ -233,14 +233,19 @@ static void cover_print_html_header(FILE *f)
               "      height: 2px;\n"
               "      background: black;\n"
               "   }\n"
+              "   footer{\n"
+              "      display: table;\n"
+              "      text-align: center;\n"
+              "      margin-left: auto;\n"
+              "      margin-right: auto;\n"
+              "   }\n"
               "   nav {\n"
               "      float: left;\n"
               "      background-color: #ccc;\n"
               "      width: " SIDEBAR_WIDTH ";\n"
-              "      height: 100%%;\n"
+              "      overflow: auto; \n"
               "      padding: 10px;\n"
               "      margin-top: 100px;\n"
-              "      word-wrap: break-word;\n"
               "     }\n"
               "   table {\n"
               "     table-layout: fixed;"
@@ -1327,9 +1332,10 @@ static char *cover_get_report_name(const char *in)
    SHA1_CTX ctx;
    unsigned char buf[SHA1_LEN];
    char *rv = xcalloc(2 * SHA1_LEN + 1);
+   char *in_cpy LOCAL = xstrdup(in);
 
    SHA1Init(&ctx);
-   SHA1Update(&ctx, (const char unsigned*)in, strlen(in));
+   SHA1Update(&ctx, (const char unsigned*)in_cpy, strlen(in_cpy));
    SHA1Final(buf, &ctx);
 
    for (int i = 0; i < SHA1_LEN; i++)

diff --git a/src/lower.c b/src/lower.c
@@ -13045,7 +13045,7 @@ lower_unit_t *lower_instance(unit_registry_t *ur, lower_unit_t *parent,
          lu->cscope = cover_create_instance(cover, parent->parent->cscope,
                                             parent->container, unit);
       }
-      else if (tree_kind(unit) == T_ARCH)
+      else if (is_concurrent_block(unit))
          lu->cscope = cover_create_instance(cover, parent->cscope, block, unit);
       else
          lu->cscope = cover_create_scope(cover, parent->cscope, block, NULL);

diff --git a/test/regress/cover26.vhd b/test/regress/cover26.vhd
@@ -37,7 +37,7 @@ begin
 
     sub_inst_long_path : entity work.sub
     generic map (
-        nest => 16
+        nest => 60
     );
 
 end architecture;
diff --git a/test/regress/cover27.sh b/test/regress/cover27.sh
@@ -0,0 +1,26 @@
+set -xe
+
+nvc -a $TESTDIR/regress/cover27.vhd -e -gG_PAR=0 --cover=statement --cover-file=cover27_a.ncdb cover27 -r
+nvc --cover-export --format=xml -o cover27_a.xml cover27_a.ncdb
+sed -i -e "s/[^ ]*regress//g" cover27_a.xml
+
+nvc -a $TESTDIR/regress/cover27.vhd -e -gG_PAR=1 --cover=statement --cover-file=cover27_b.ncdb cover27 -r
+nvc --cover-export --format=xml -o cover27_b.xml cover27_b.ncdb
+sed -i -e "s/[^ ]*regress//g" cover27_b.xml
+
+nvc -a $TESTDIR/regress/cover27.vhd -e -gG_PAR=2 --cover=statement --cover-file=cover27_c.ncdb cover27 -r
+nvc --cover-export --format=xml -o cover27_c.xml cover27_c.ncdb
+sed -i -e "s/[^ ]*regress//g" cover27_c.xml
+
+nvc -a $TESTDIR/regress/cover27.vhd -e -gG_PAR=3 --cover=statement --cover-file=cover27_d.ncdb cover27 -r
+nvc --cover-export --format=xml -o cover27_d.xml cover27_d.ncdb
+sed -i -e "s/[^ ]*regress//g" cover27_d.xml
+
+nvc --cover-merge cover27*.ncdb --output=merged.covdb
+nvc --cover-report --output=html merged.covdb 2>&1 | tee out.txt
+
+diff -u $TESTDIR/regress/gold/cover27.txt out.txt
+diff -u $TESTDIR/regress/gold/cover27_a.xml cover27_a.xml
+diff -u $TESTDIR/regress/gold/cover27_b.xml cover27_b.xml
+diff -u $TESTDIR/regress/gold/cover27_c.xml cover27_c.xml
+diff -u $TESTDIR/regress/gold/cover27_d.xml cover27_d.xml
diff --git a/test/regress/cover27.vhd b/test/regress/cover27.vhd
@@ -0,0 +1,37 @@
+library ieee;
+use ieee.std_logic_1164.all;
+
+entity cover27 is
+generic (
+    G_PAR : integer
+);
+end entity;
+
+architecture test of cover27 is
+
+    signal a,b,c,d,e,f : std_logic;
+    signal vec : std_logic_vector(3 downto 0);
+
+begin
+
+    G_IF_GEN : if (G_PAR = 0) generate
+        a <= '0';
+    elsif (G_PAR = 1) generate
+        b <= '0';
+    end generate;
+
+    T_FOR_GEN : for i in 0 to 3 generate
+        vec(i) <= a when (i = 0) else
+                  b when (i = 1) else
+                  c when (i = 2) else
+                  d;
+    end generate;
+
+    G_CASE_GEN : case (G_PAR) generate
+    when 0 => c <= '1';
+    when G_CASE_1: 1 => d <= '0';
+    when G_CASE_2: 2 => e <= '1';
+    when 3 => f <= '0';
+    end generate;
+
+end architecture;
diff --git a/test/regress/gold/cover27.txt b/test/regress/gold/cover27.txt
@@ -0,0 +1,9 @@
+** Note: Code coverage report folder: html.
+** Note: Code coverage report contains: covered, uncovered, excluded coverage details.
+** Note: code coverage results for: WORK.COVER27
+** Note:      statement:     100.0 % (10/10)
+** Note:      branch:        N.A.
+** Note:      toggle:        N.A.
+** Note:      expression:    N.A.
+** Note:      FSM state:     N.A.
+** Note:      functional:    N.A.
diff --git a/test/regress/gold/cover27_a.xml b/test/regress/gold/cover27_a.xml
@@ -0,0 +1,55 @@
+<?xml version="1.0"?>
+<scope name="WORK" /cover27.vhd">
+  <scope name="COVER27" block_name="COVER27-TEST" line="10">
+    <scope name="G_IF_GEN" block_name="G_IF_GEN" line="17">
+      <scope name="_P0" line="18">
+        <scope name="_S0">
+          <statement hier="WORK.COVER27.G_IF_GEN._P0._S0" data="1"/>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="T_FOR_GEN(0)" block_name="T_FOR_GEN" line="23">
+      <scope name="_P0" line="24">
+        <scope name="_S0">
+          <scope name="_S0">
+            <statement hier="WORK.COVER27.T_FOR_GEN(0)._P0._S0._S0" data="2"/>
+          </scope>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="T_FOR_GEN(1)" block_name="T_FOR_GEN" line="23">
+      <scope name="_P0" line="24">
+        <scope name="_S0">
+          <scope name="_S0" line="25">
+            <statement hier="WORK.COVER27.T_FOR_GEN(1)._P0._S0._S0" data="2"/>
+          </scope>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="T_FOR_GEN(2)" block_name="T_FOR_GEN" line="23">
+      <scope name="_P0" line="24">
+        <scope name="_S0">
+          <scope name="_S0" line="26">
+            <statement hier="WORK.COVER27.T_FOR_GEN(2)._P0._S0._S0" data="2"/>
+          </scope>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="T_FOR_GEN(3)" block_name="T_FOR_GEN" line="23">
+      <scope name="_P0" line="24">
+        <scope name="_S0">
+          <scope name="_S0" line="27">
+            <statement hier="WORK.COVER27.T_FOR_GEN(3)._P0._S0._S0" data="2"/>
+          </scope>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="G_CASE_GEN" block_name="G_CASE_GEN" line="31">
+      <scope name="_P0">
+        <scope name="_S0">
+          <statement hier="WORK.COVER27.G_CASE_GEN._P0._S0" data="1"/>
+        </scope>
+      </scope>
+    </scope>
+  </scope>
+</scope>
diff --git a/test/regress/gold/cover27_b.xml b/test/regress/gold/cover27_b.xml
@@ -0,0 +1,55 @@
+<?xml version="1.0"?>
+<scope name="WORK" /cover27.vhd">
+  <scope name="COVER27" block_name="COVER27-TEST" line="10">
+    <scope name="G_IF_GEN" block_name="G_IF_GEN" line="17">
+      <scope name="_P0" line="20">
+        <scope name="_S0">
+          <statement hier="WORK.COVER27.G_IF_GEN._P0._S0" data="1"/>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="T_FOR_GEN(0)" block_name="T_FOR_GEN" line="23">
+      <scope name="_P0" line="24">
+        <scope name="_S0">
+          <scope name="_S0">
+            <statement hier="WORK.COVER27.T_FOR_GEN(0)._P0._S0._S0" data="2"/>
+          </scope>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="T_FOR_GEN(1)" block_name="T_FOR_GEN" line="23">
+      <scope name="_P0" line="24">
+        <scope name="_S0">
+          <scope name="_S0" line="25">
+            <statement hier="WORK.COVER27.T_FOR_GEN(1)._P0._S0._S0" data="2"/>
+          </scope>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="T_FOR_GEN(2)" block_name="T_FOR_GEN" line="23">
+      <scope name="_P0" line="24">
+        <scope name="_S0">
+          <scope name="_S0" line="26">
+            <statement hier="WORK.COVER27.T_FOR_GEN(2)._P0._S0._S0" data="2"/>
+          </scope>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="T_FOR_GEN(3)" block_name="T_FOR_GEN" line="23">
+      <scope name="_P0" line="24">
+        <scope name="_S0">
+          <scope name="_S0" line="27">
+            <statement hier="WORK.COVER27.T_FOR_GEN(3)._P0._S0._S0" data="2"/>
+          </scope>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="G_CASE_1" block_name="G_CASE_1" line="32">
+      <scope name="_P0">
+        <scope name="_S0">
+          <statement hier="WORK.COVER27.G_CASE_1._P0._S0" data="1"/>
+        </scope>
+      </scope>
+    </scope>
+  </scope>
+</scope>
diff --git a/test/regress/gold/cover27_c.xml b/test/regress/gold/cover27_c.xml
@@ -0,0 +1,48 @@
+<?xml version="1.0"?>
+<scope name="WORK" /cover27.vhd">
+  <scope name="COVER27" block_name="COVER27-TEST" line="10">
+    <scope name="T_FOR_GEN(0)" block_name="T_FOR_GEN" line="23">
+      <scope name="_P0" line="24">
+        <scope name="_S0">
+          <scope name="_S0">
+            <statement hier="WORK.COVER27.T_FOR_GEN(0)._P0._S0._S0" data="1"/>
+          </scope>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="T_FOR_GEN(1)" block_name="T_FOR_GEN" line="23">
+      <scope name="_P0" line="24">
+        <scope name="_S0">
+          <scope name="_S0" line="25">
+            <statement hier="WORK.COVER27.T_FOR_GEN(1)._P0._S0._S0" data="1"/>
+          </scope>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="T_FOR_GEN(2)" block_name="T_FOR_GEN" line="23">
+      <scope name="_P0" line="24">
+        <scope name="_S0">
+          <scope name="_S0" line="26">
+            <statement hier="WORK.COVER27.T_FOR_GEN(2)._P0._S0._S0" data="1"/>
+          </scope>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="T_FOR_GEN(3)" block_name="T_FOR_GEN" line="23">
+      <scope name="_P0" line="24">
+        <scope name="_S0">
+          <scope name="_S0" line="27">
+            <statement hier="WORK.COVER27.T_FOR_GEN(3)._P0._S0._S0" data="1"/>
+          </scope>
+        </scope>
+      </scope>
+    </scope>
+    <scope name="G_CASE_2" block_name="G_CASE_2" line="33">
+      <scope name="_P0">
+        <scope name="_S0">
+          <statement hier="WORK.COVER27.G_CASE_2._P0._S0" data="1"/>
+        </scope>
+      </scope>
+    </scope>
+  </scope>
+</scope>