fixes #15848 [backport:1.2] (#17959)

(cherry picked from commit 51f3ef6cb8)

changelog.md

@@ -53,5 +53,23 @@
 
 - Added `unsafeIsolate` and `extract` to `std/isolation`.
 
+- `--hint:CC` now goes to stderr (like all other hints) instead of stdout.
+
+- json build instructions are now generated in `$nimcache/outFileBasename.json`
+  instead of `$nimcache/projectName.json`. This allows avoiding recompiling a given project
+  compiled with different options if the output file differs.
+
+- `--usenimcache` (implied by `nim r main`) now generates an output file that includes a hash of
+  some of the compilation options, which allows caching generated binaries:
+  nim r main # recompiles
+  nim r -d:foo main # recompiles
+  nim r main # uses cached binary
+  nim r main arg1 arg2 # ditto (runtime arguments are irrelevant)
+
+- The style checking of the compiler now supports a `--styleCheck:usages` switch. This switch
+  enforces that every symbol is written as it was declared, not enforcing
+  the official Nim style guide. To be enabled, this has to be combined either
+  with `--styleCheck:error` or `--styleCheck:hint`.
+
 ## Tool changes
 

compiler/commands.nim

@@ -145,7 +145,7 @@ proc splitSwitch(conf: ConfigRef; switch: string, cmd, arg: var string, pass: TC
 proc processOnOffSwitch(conf: ConfigRef; op: TOptions, arg: string, pass: TCmdLinePass,
                         info: TLineInfo) =
   case arg.normalize
-  of "","on": conf.options.incl op
+  of "", "on": conf.options.incl op
   of "off": conf.options.excl op
   else: localError(conf, info, errOnOrOffExpectedButXFound % arg)
 
@@ -854,6 +854,7 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     of "off": conf.globalOptions = conf.globalOptions - {optStyleHint, optStyleError}
     of "hint": conf.globalOptions = conf.globalOptions + {optStyleHint} - {optStyleError}
     of "error": conf.globalOptions = conf.globalOptions + {optStyleError}
+    of "usages": conf.globalOptions.incl optStyleUsages
     else: localError(conf, info, errOffHintsError % arg)
   of "showallmismatches":
     processOnOffSwitchG(conf, {optShowAllMismatches}, arg, pass, info)

compiler/linter.nim

@@ -93,7 +93,7 @@ proc nep1CheckDefImpl(conf: ConfigRef; info: TLineInfo; s: PSym; k: TSymKind) =
     lintReport(conf, info, beau, s.name.s)
 
 template styleCheckDef*(conf: ConfigRef; info: TLineInfo; s: PSym; k: TSymKind) =
-  if {optStyleHint, optStyleError} * conf.globalOptions != {}:
+  if {optStyleHint, optStyleError} * conf.globalOptions != {} and optStyleUsages notin conf.globalOptions:
     nep1CheckDefImpl(conf, info, s, k)
 
 template styleCheckDef*(conf: ConfigRef; info: TLineInfo; s: PSym) =

compiler/options.nim

@@ -59,6 +59,7 @@ type                          # please make sure we have under 32 options
     optUseNimcache,           # save artifacts (including binary) in $nimcache
     optStyleHint,             # check that the names adhere to NEP-1
     optStyleError,            # enforce that the names adhere to NEP-1
+    optStyleUsages,           # only enforce consistent **usages** of the symbol
     optSkipSystemConfigFile,  # skip the system's cfg/nims config file
     optSkipProjConfigFile,    # skip the project's cfg/nims config file
     optSkipUserConfigFile,    # skip the users's cfg/nims config file

doc/advopt.txt

@@ -46,6 +46,8 @@ Advanced options:
                             produce hints or errors for Nim identifiers that
                             do not adhere to Nim's official style guide
                             https://nim-lang.org/docs/nep1.html
+  --styleCheck:usages       only enforce consistent spellings of identifiers,
+                            do not enforce the style on declarations
   --showAllMismatches:on|off
                             show all mismatching candidates in overloading
                             resolution

tests/stylecheck/tusages.nim

@@ -0,0 +1,23 @@
+discard """
+  cmd: "nim c --styleCheck:error --styleCheck:usages $file"
+  errormsg: "'BAD_STYLE' should be: 'BADSTYLE'"
+  line: 20
+"""
+
+import strutils
+
+proc BADSTYLE(c: char) = discard
+
+proc toSnakeCase(s: string): string =
+  result = newStringOfCap(s.len + 3)
+  for i in 0..<s.len:
+    if s[i] in {'A'..'Z'}:
+      if i > 0 and s[i-1] in {'a'..'z'}:
+        result.add '_'
+      result.add toLowerAscii(s[i])
+    else:
+      result.add s[i]
+    BAD_STYLE(s[i])
+
+echo toSnakeCase("fooBarBaz Yes")
+