Configuring Keyword Alignment Rules

There are several rules that enforce alignment for a group of lines based on the keywords such as ‘after’, ‘<=’ etc. Some of the configurations are available in all keyword alignment rules, while others are rule specific.

Common Keyword Alignment Configuration

Following configuration options can be independently changed for each of the keyword alignment rules.

  1. compact_alignment - if set to True it enforces single space before alignment keyword in the line with the longest part before the keyword. Otherwise the alignment occurs to the keyword maximum column. By default set to True.

    Violation

    signal sig_short   : std_logic;
signal sig_very_long      : std_logic;

    Fix (compact_alignment = True)

    signal sig_short     : std_logic;
signal sig_very_long : std_logic;

    Fix (compact_alignment = False)

    signal sig_short          : std_logic;
signal sig_very_long      : std_logic;

  2. blank_line_ends_group - if set to True any blank line encountered in the VHDL file ends the group of lines that should be aligned and starts new group. By default set to True.

    Violation

    signal wr_en : std_logic;
signal rd_en   : std_logic;

constant c_short_period : time;
constant c_long_period : time;

    Fix (blank_line_ends_group = True)

    signal wr_en   : std_logic;
signal rd_en   : std_logic;

constant c_short_period : time;
constant c_long_period  : time;

    Fix (blank_line_ends_group = False)

    signal wr_en            : std_logic;
signal rd_en            : std_logic;

constant c_short_period : time;
constant c_long_period  : time;

  3. comment_line_ends_group - if set to True any purely comment line in the VHDL file ends the group of lines that should be aligned and starts new group. By default set to True.

    Violation

    port (
    sclk_i : in std_logic;
    pclk_i : in std_logic;
    rst_i : in std_logic;
    ---- serial interface ----
    spi_ssel_o : out std_logic;
    spi_sck_o : out std_logic;
    spi_mosi_o : out std_logic;
    spi_miso_i : in std_logic
);

    Fix (comment_line_ends_group = True)

    port (
    sclk_i : in std_logic;
    pclk_i : in std_logic;
    rst_i  : in std_logic;
    ---- serial interface ----
    spi_ssel_o : out std_logic;
    spi_sck_o  : out std_logic;
    spi_mosi_o : out std_logic;
    spi_miso_i : in std_logic
);

    Fix (comment_line_ends_group = False)

    port (
    sclk_i     : in std_logic;
    pclk_i     : in std_logic;
    rst_i      : in std_logic;
    ---- serial interface ----
    spi_ssel_o : out std_logic;
    spi_sck_o  : out std_logic;
    spi_mosi_o : out std_logic;
    spi_miso_i : in std_logic
);

Note

As all keyword alignment rules have above configurations they are not mentioned in the documentation for each rule.

Rule Specific Keyword Alignment Configuration

  1. separate_generic_port_alignment - if set to True alignment within the generic declarative/mapping part is separated from alignment within the port declarative/mapping part. By default set to True.

    Violation

    generic (
    g_width : positive;
    g_output_delay : positive
);
port (
    clk_i : in std_logic;
    data_i : in std_logic;
    data_o : in std_logic
);

    Fix (separate_generic_port_alignment = True)

    generic (
    g_width        : positive;
    g_output_delay : positive
);
port (
    clk_i  : in std_logic;
    data_i : in std_logic;
    data_o : in std_logic
);

    Fix (separate_generic_port_alignment = False)

    generic (
    g_width        : positive;
    g_output_delay : positive
);
port (
    clk_i          : in std_logic;
    data_i         : in std_logic;
    data_o         : in std_logic
);

  2. if_control_statements_ends_group - if set to True any line with if control statement ends the group of lines that should be aligned and starts new group. By default set to True.

    Violation

    if condition = '1' then
    data_valid <= '1';
    data <= '1';
else
    data_valid <= '0';
    hold_transmission <= '1';
end if;

    Fix (if_control_statements_ends_group = True)

    if condition = '1' then
    data_valid <= '1';
    data       <= '1';
else
    data_valid        <= '0';
    hold_transmission <= '1';
end if;

    Fix (if_control_statements_ends_group = False)

    if condition = '1' then
    data_valid        <= '1';
    data              <= '1';
else
    data_valid        <= '0';
    hold_transmission <= '1';
end if;

  3. case_control_statements_ends_group - if set to True, any line with case control statements (case, when or end case) ends the group of lines that should be aligned and starts new group. If set to False, no line with case control statements ends the group of lines that should be aligned and starts a group. If set to break_on_case_or_end_case, any line with case or end case ends the group of lines that should be aligned and starts new group. By default set to True.

    Violation

    data_valid_before    <= '1';
case A is
    when A =>
        X <= F;
        XY <= G;
        XYZ <= H;
    when B =>
        a <= I;
        ab <= h;
        c <= a;
    when others =>
      null;
end case;
data_valid_after       <= '1';

    Fix (case_control_statements_ends_group = True)

    data_valid_before <= '1';
case A is
    when A =>
        X   <= F;
        XY  <= G;
        XYZ <= H;
    when B =>
        a  <= I;
        ab <= h;
        c  <= a;
    when others =>
        null;
end case;
data_valid_after <= '1';

    Fix (case_control_statements_ends_group = False)

    data_valid_before <= '1';
case A is
    when A =>
        X         <= F;
        XY        <= G;
        XYZ       <= H;
    when B =>
        a         <= I;
        ab        <= h;
        c         <= a;
    when others =>
        null;
end case;
data_valid_after  <= '1';

    Fix (case_control_statements_ends_group = break_on_case_or_end_case)

    data_valid_before <= '1';
case A is
    when A =>
        X   <= F;
        XY  <= G;
        XYZ <= H;
    when B =>
        a   <= I;
        ab  <= h;
        c   <= a;
    when others =>
        null;
end case;
data_valid_after <= '1';

  4. generate_statements_ends_group - if set to True any line with generate statement keywords ends the group of lines that should be aligned and starts new group. By default set to False.

    Violation

    data_valid_before    <= '1';
generate_label : if G_ENABLE = '1' generate
    data_valid <= '0';
    hold_transmission <= '1';
end generate;
data_valid_after       <= '1';

    Fix (generate_statements_ends_group = True)

    data_valid_before <= '1';
generate_label : if G_ENABLE = '1' generate
    data_valid        <= '0';
    hold_transmission <= '1';
end generate;
data_valid_after <= '1';

    Fix (generate_statements_ends_group = False)

    data_valid_before     <= '1';
generate_label : if G_ENABLE = '1' generate
    data_valid        <= '0';
    hold_transmission <= '1';
end generate;
data_valid_after      <= '1';

  5. loop_control_statements_ends_group - if set to True any line with loop control statement (including for and while loops) ends the group of lines that should be aligned and starts new group. By default set to False.

    Violation

    data_valid_before    <= '1';
for index in 4 to 23 loop
    data_valid <= '0';
    hold_transmission <= '1';
end loop;
data_valid_after       <= '1';

    Fix (loop_control_statements_ends_group = True)

    data_valid_before <= '1';
for index in 4 to 23 loop
    data_valid        <= '0';
    hold_transmission <= '1';
end loop;
data_valid_after <= '1';

    Fix (loop_control_statements_ends_group = False)

    data_valid_before     <= '1';
for index in 4 to 23 loop
    data_valid        <= '0';
    hold_transmission <= '1';
end loop;
data_valid_after      <= '1';

  6. no_alignment - if set to True the keyword will be forced to the left. By default set to False.

    Violation

    signal wr_en : std_logic;
signal rd_en   : std_logic;

constant c_short_period : time;
constant c_long_period : time;

    Fix

    signal wr_en : std_logic;
signal rd_en   : std_logic;

constant c_short_period : time;
constant c_long_period : time;

Note

If given keyword alignment rule has any of the above keyword alignment specific configuration, then it is explicitly noted in the documentation of this rule.

The default value for each of these case rules can be overridden using a configuration.