#15550: Names of RULES aren't quoted in -ddump-splices -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Template Haskell | Version: 8.4.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * cc: alanz (added) Comment: So I've identified the problem, which lies in `Convert`: when converting a Template Haskell `RuleP` into a GHC source `RuleD`, we take the `RuleP`'s name (which is not surrounded in double quotes) and repurpose that as the `SourceText` for the `RuleD`'s name. However, the `RuleD` name's `SourceText` must be intended to be the precise name of the rewrite rule, double quotes and all, since using the unquoted name from the `RuleP` causes it to be pretty-printed without double quotes. In light of this, one way to fix this issue is with this patch: {{{#!diff diff --git a/compiler/hsSyn/Convert.hs b/compiler/hsSyn/Convert.hs index 24b0b20..87b3400 100644 --- a/compiler/hsSyn/Convert.hs +++ b/compiler/hsSyn/Convert.hs @@ -705,7 +705,7 @@ cvtPragmaD (RuleP nm bndrs lhs rhs phases) ; rhs' <- cvtl rhs ; returnJustL $ Hs.RuleD noExt $ HsRules noExt (SourceText "{-# RULES") - [noLoc $ HsRule noExt (noLoc (SourceText nm,nm')) act + [noLoc $ HsRule noExt (noLoc (quotedSourceText,nm')) act bndrs' lhs' rhs'] } }}} However, this leads me to wonder: is this `SourceText` name supposed to reflect a //user-written// rule name? That is, the exact syntax that the user types in a source Haskell file? If so, then it feels somewhat strange to put a `SourceText` here, since this `RuleD` is generated through Template Haskell behind the scenes, not through source syntax. In fact, another way to fix this issue is by not using `SourceText` at all, and instead using `NoSourceText`: {{{#!diff diff --git a/compiler/hsSyn/Convert.hs b/compiler/hsSyn/Convert.hs index 24b0b20..87b3400 100644 --- a/compiler/hsSyn/Convert.hs +++ b/compiler/hsSyn/Convert.hs @@ -705,7 +705,7 @@ cvtPragmaD (RuleP nm bndrs lhs rhs phases) ; rhs' <- cvtl rhs ; returnJustL $ Hs.RuleD noExt $ HsRules noExt (SourceText "{-# RULES") - [noLoc $ HsRule noExt (noLoc (SourceText nm,nm')) act + [noLoc $ HsRule noExt (noLoc (NoSourceText,nm')) act bndrs' lhs' rhs'] } }}} (See [http://git.haskell.org/ghc.git/blob/21f0f56164f50844c2150c62f950983b2376f8b6... pprFullRuleName] to see why that gets pretty-printed correctly.) I honestly have no idea which is the correct choice to make. Other places in `Convert` seem to vary in their uses of `SourceText` and `NoSourceText`, so it's hard to tell if there's already an established convention in `Convert`. alanz, what are your thoughts on this? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15550#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler