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author | Tristan Gingold <tgingold@free.fr> | 2020-06-13 12:25:01 +0200 |
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committer | Tristan Gingold <tgingold@free.fr> | 2020-06-13 16:47:59 +0200 |
commit | e0ca8bf0b0d8049c7e9f7fe53f7ed942fac61453 (patch) | |
tree | b4477194e58e9ca5b0c296caa24da39e5a2e845a /doc/using | |
parent | 8eb418a695000718920c2ef5294c185a2ef40cca (diff) | |
download | ghdl-e0ca8bf0b0d8049c7e9f7fe53f7ed942fac61453.tar.gz ghdl-e0ca8bf0b0d8049c7e9f7fe53f7ed942fac61453.tar.bz2 ghdl-e0ca8bf0b0d8049c7e9f7fe53f7ed942fac61453.zip |
vhdl: --std93c is now an alias for --std=93 -frelaxed
This simplifies the definition of --std=93c
Diffstat (limited to 'doc/using')
-rw-r--r-- | doc/using/ImplementationOfVHDL.rst | 8 | ||||
-rw-r--r-- | doc/using/InvokingGHDL.rst | 37 |
2 files changed, 26 insertions, 19 deletions
diff --git a/doc/using/ImplementationOfVHDL.rst b/doc/using/ImplementationOfVHDL.rst index 8cad2e03e..331a7e10c 100644 --- a/doc/using/ImplementationOfVHDL.rst +++ b/doc/using/ImplementationOfVHDL.rst @@ -81,13 +81,7 @@ You can select the VHDL standard expected by GHDL with the Select VHDL-93; VHDL-87 file declarations are not accepted. 93c - Select VHDL-93 standard with relaxed rules: - - - * VHDL-87 file declarations are accepted; - - * default binding indication rules of VHDL-02 are used. Default binding rules - are often used, but they are particularly obscure before VHDL-02. + Same as 93 and :option:`-frelaxed`. 00 Select VHDL-2000 standard, which adds protected types. diff --git a/doc/using/InvokingGHDL.rst b/doc/using/InvokingGHDL.rst index 63af39f08..64c1610e1 100644 --- a/doc/using/InvokingGHDL.rst +++ b/doc/using/InvokingGHDL.rst @@ -253,7 +253,9 @@ Options .. option:: --std=<STANDARD> - Specify the standard to use. By default, the standard is ``93c``, which means VHDL-93 accepting VHDL-87 syntax. For details on ``STANDARD`` values see section :ref:`VHDL_standards`. + Specify the standard to use. By default, the standard is ``93c``, + which means VHDL-93 with relaxed rules. For details on ``STANDARD`` + values see section :ref:`VHDL_standards`. .. option:: -fsynopsys @@ -318,22 +320,33 @@ Options .. option:: -frelaxed .. option:: -frelaxed-rules - Within an object declaration, allow references to the name (which references the hidden declaration). This ignores the error in the following code: + Slightly relax some rules to be compatible with various other + simulators or synthesizers: - .. code-block:: VHDL + * VHDL-87 file declarations are accepted; - package pkg1 is - type state is (state1, state2, state3); - end pkg1; + * Default binding indication rules of VHDL-02 are used. Default binding rules + are often used, but they are particularly obscure before VHDL-02. - use work.pkg1.all; - package pkg2 is - constant state1 : state := state1; - end pkg2; + * Within an object declaration, allow references to the name (which references the hidden declaration). This ignores the error in the following code: - Some code (such as Xilinx packages) have such constructs, which are valid. + .. code-block:: VHDL - (The scope of the ``state1`` constant starts at the `constant` keyword. Because the constant ``state1`` and the enumeration literal ``state1`` are homographs, the enumeration literal is hidden in the immediate scope of the constant). + package pkg1 is + type state is (state1, state2, state3); + end pkg1; + + use work.pkg1.all; + package pkg2 is + constant state1 : state := state1; + end pkg2; + + Some code (such as Xilinx packages) have such constructs, which are valid. + + (The scope of the ``state1`` constant starts at the `constant` + keyword. Because the constant ``state1`` and the enumeration + literal ``state1`` are homographs, the enumeration literal is + hidden in the immediate scope of the constant). This option also relaxes the rules about pure functions. Violations result in warnings instead of errors. |