Pretty-print lets with surrounding braces

The pretty-printer for `letseq` and `letrec` was not adding braces around
the variables being bound, resulting in malformed pretty-printed output such as
`letseq hw =  "Hello, World!";; ...`. After adding braces, this now becomes
`letseq { hw =  "Hello, World!"; };`, which is valid Bluespec code.

Fixes B-Lang-org#529.

src/comp/CSyntax.hs

@@ -1044,12 +1044,12 @@ instance PPrint CExpr where
     pPrint d p (Cletseq [] e) = pparen (p > 0) $
         (t"letseq in" <+> pp d e)
     pPrint d p (Cletseq ds e) = pparen (p > 0) $
-        (t"letseq" <+> foldr1 ($+$) (map (pp d) ds)) $+$
+        (t"letseq" <+> text "{" <+> foldr1 ($+$) (map (pp d) ds)) <+> text "}" $+$
         (t"in  " <> pp d e)
     pPrint d p (Cletrec [] e) = pparen (p > 0) $
         (t"let in" <+> pp d e)
     pPrint d p (Cletrec ds e) = pparen (p > 0) $
-        (t"let" <+> foldr1 ($+$) (map (pp d) ds)) $+$
+        (t"let" <+> text "{" <+> foldr1 ($+$) (map (pp d) ds)) <+> text "}" $+$
         (t"in  " <> pp d e)
     pPrint d p (CSelect e i) = pparen (p > (maxPrec+2)) $ pPrint d (maxPrec+2) e <> t"." <> ppVarId d i
     pPrint d p (CCon i []) = ppConId d i
@@ -1151,9 +1151,9 @@ instance PPrint CStmt where
             (map (ppPProp d . snd) pprops) ++
             [pp d pat <+> t "<-" <+> pp d e]
     pPrint d p (CSletseq []) = internalError "CSyntax.PPrint(CStmt): CSletseq []"
-    pPrint d p (CSletseq ds) = text "letseq" <+> foldr1 ($+$) (map (pp d) ds)
+    pPrint d p (CSletseq ds) = text "letseq" <+> text "{" <+> foldr1 ($+$) (map (pp d) ds) <+> text "}"
     pPrint d p (CSletrec []) = internalError "CSyntax.PPrint(CStmt): CSletrec []"
-    pPrint d p (CSletrec ds) = text "let" <+> foldr1 ($+$) (map (pp d) ds)
+    pPrint d p (CSletrec ds) = text "let" <+> text "{" <+> foldr1 ($+$) (map (pp d) ds) <+> text "}"
     pPrint d p (CSExpr _ e) = pPrint d p e
 
 instance PPrint CMStmt where

testsuite/README.md

@@ -115,9 +115,9 @@ on the file and checking for an error exit code.  There are
 also a small number of tests that explicitly run `vcdcheck`
 as part of their testing.
 
-One test (`bsc.bugs/b611/`) checks for a bug in `bsc2bsv`
-but otherwise this tool is not used.  There are no tests
-for the related tool, `bsv2bsc`.
+There are a number of tests that check for bugs in the `bsc2bsv` tool (e.g.,
+`bsc.bugs/bluespec_inc/b611/`) and the `bsv2bsc` tool (e.g.,
+`bsc.bugs/github/gh529/`), but otherwise these tools are not used.
 
 ### Running some or all tests
 

testsuite/bsc.bugs/github/gh529/.gitignore

@@ -0,0 +1,2 @@
+# Generated file
+Bug529.bs

testsuite/bsc.bugs/github/gh529/Bug529.bsv

@@ -0,0 +1,7 @@
+module helloWorld (Empty);
+   rule hello_world;
+      let hw = "Hello, World!";
+      $display (hw);
+      $finish;
+   endrule
+endmodule

testsuite/bsc.bugs/github/gh529/Makefile

@@ -0,0 +1,5 @@
+# for "make clean" to work everywhere
+
+CONFDIR = $(realpath ../../..)
+
+include $(CONFDIR)/clean.mk

testsuite/bsc.bugs/github/gh529/gh529.exp

@@ -0,0 +1,6 @@
+if [do_internal_checks] {
+    run_bsv2bsc Bug529.bsv
+    # We need a file extension that bsc recognizes
+    copy Bug529.bsv.bsv2bsc-out Bug529.bs
+    compile_pass Bug529.bs
+}