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| author | Nicolai Haehnle <nhaehnle@gmail.com> | 2018-06-04 14:26:12 +0000 |
|---|---|---|
| committer | Nicolai Haehnle <nhaehnle@gmail.com> | 2018-06-04 14:26:12 +0000 |
| commit | 6b71fcbf269dbb5d192b7a69f5cd706aeb8c8448 (patch) | |
| tree | 671df399f0e0a2ac67033912f1cde052fa421472 | |
| parent | 26db53e38e1a8942f615fb661f283f489ca0c490 (diff) | |
TableGen: some LangRef doc fixes
Summary: Change-Id: I1442e2daa09cab727a01d8c31893b50e644a5cd3
Reviewers: tra, simon_tatham, craig.topper
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D47530
Change-Id: I397655dd18b7ff978c1affa3174740d9c1a82594
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333901 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | docs/TableGen/LangIntro.rst | 21 | ||||
| -rw-r--r-- | docs/TableGen/LangRef.rst | 15 |
2 files changed, 31 insertions, 5 deletions
diff --git a/docs/TableGen/LangIntro.rst b/docs/TableGen/LangIntro.rst index b77dad07bf0..ea46550ffc0 100644 --- a/docs/TableGen/LangIntro.rst +++ b/docs/TableGen/LangIntro.rst @@ -152,8 +152,8 @@ supported include: ``foreach <var> = [ <list> ] in <def>`` Replicate <body> or <def>, replacing instances of <var> with each value in <list>. <var> is scoped at the level of the ``foreach`` loop and must - not conflict with any other object introduced in <body> or <def>. Currently - only ``def``\s are expanded within <body>. + not conflict with any other object introduced in <body> or <def>. Only + ``def``\s and ``defm``\s are expanded within <body>. ``foreach <var> = 0-15 in ...`` @@ -348,6 +348,23 @@ In this case, the ``Z`` definition will have a zero value for its ``V`` value, despite the fact that it derives (indirectly) from the ``C`` class, because the ``D`` class overrode its value. +References between variables in a record are substituted late, which gives +``let`` expressions unusual power. Consider this admittedly silly example: + +.. code-block:: text + + class A<int x> { + int Y = x; + int Yplus1 = !add(Y, 1); + int xplus1 = !add(x, 1); + } + def Z : A<5> { + let Y = 10; + } + +The value of ``Z.xplus1`` will be 6, but the value of ``Z.Yplus1`` is 11. Use +this power wisely. + .. _template arguments: Class template arguments diff --git a/docs/TableGen/LangRef.rst b/docs/TableGen/LangRef.rst index d31f7f36c80..439d646034a 100644 --- a/docs/TableGen/LangRef.rst +++ b/docs/TableGen/LangRef.rst @@ -229,15 +229,17 @@ of: int Baz = Bar; } + Values defined in superclasses can be accessed the same way. + * a template arg of a ``class``, such as the use of ``Bar`` in:: class Foo<int Bar> { int Baz = Bar; } -* value local to a ``multiclass``, such as the use of ``Bar`` in:: +* value local to a ``class``, such as the use of ``Bar`` in:: - multiclass Foo { + class Foo { int Bar = 5; int Baz = Bar; } @@ -245,9 +247,16 @@ of: * a template arg to a ``multiclass``, such as the use of ``Bar`` in:: multiclass Foo<int Bar> { - int Baz = Bar; + def : SomeClass<Bar>; } +* the iteration variable of a ``foreach``, such as the use of ``i`` in:: + + foreach i = 0-5 in + def Foo#i; + +* a variable defined by ``defset`` + * the implicit template argument ``NAME`` in a ``class`` or ``multiclass`` .. productionlist:: |