PTHL Samples (The Tiger Compiler Project Assignment)

First, please note that all the samples, including in this section, are generated with a TC-1+ compliant compiler: its behavior differs from that of a TC-0 compiler. In particular, for the time being, forget about the options (-X and --parse).

print("Hello, World!\n")

The following example demonstrates the scanner and parser tracing. The glyphs “error→” and “⇒” are typographic conventions to specify respectively the standard error stream and the exit status. They are not part of the output per se.

$ SCAN=1 PARSE=1 tc -X --parse simple.tig
error→Parsing file: "simple.tig"
error→Starting parse
error→Entering state 0
error→Reading a token: --(end of buffer or a NUL)
error→--accepting rule at line 196("print")
error→Next token is token "identifier" (simple.tig:1.1-5: print)
error→Shifting token "identifier" (simple.tig:1.1-5: print)
error→Entering state 2
error→Reading a token: --accepting rule at line 138("(")
error→Next token is token "(" (simple.tig:1.6: )
error→Reducing stack 0 by rule 100 (line 626):
error→   $1 = token "identifier" (simple.tig:1.1-5: print)
error→-> $$ = nterm funid (simple.tig:1.1-5: print)
error→Entering state 36
error→Next token is token "(" (simple.tig:1.6: )
error→Shifting token "(" (simple.tig:1.6: )
error→Entering state 85
error→Reading a token: --accepting rule at line 197(""")
error→--accepting rule at line 266("Hello, World!")
error→--accepting rule at line 253("\n")
error→--accepting rule at line 228(""")
error→Next token is token "string" (simple.tig:1.7-23: Hello, World!
error→)
error→Shifting token "string" (simple.tig:1.7-23: Hello, World!
error→)
error→Entering state 1
error→Reducing stack 0 by rule 4 (line 296):
error→   $1 = token "string" (simple.tig:1.7-23: Hello, World!
error→)
error→-> $$ = nterm exp (simple.tig:1.7-23: "Hello, World!\n")
error→Entering state 131
error→Reading a token: --accepting rule at line 139(")")
error→Next token is token ")" (simple.tig:1.24: )
error→Reducing stack 0 by rule 45 (line 417):
error→   $1 = nterm exp (simple.tig:1.7-23: "Hello, World!\n")
error→-> $$ = nterm args.1 (simple.tig:1.7-23: "Hello, World!\n")
error→Entering state 133
error→Next token is token ")" (simple.tig:1.24: )
error→Reducing stack 0 by rule 44 (line 412):
error→   $1 = nterm args.1 (simple.tig:1.7-23: "Hello, World!\n")
error→-> $$ = nterm args (simple.tig:1.7-23: "Hello, World!\n")
error→Entering state 132
error→Next token is token ")" (simple.tig:1.24: )
error→Shifting token ")" (simple.tig:1.24: )
error→Entering state 174
error→Reducing stack 0 by rule 6 (line 304):
error→   $1 = nterm funid (simple.tig:1.1-5: print)
error→   $2 = token "(" (simple.tig:1.6: )
error→   $3 = nterm args (simple.tig:1.7-23: "Hello, World!\n")
error→   $4 = token ")" (simple.tig:1.24: )
error→-> $$ = nterm exp (simple.tig:1.1-24: print("Hello, World!\n"))
error→Entering state 25
error→Reading a token: --(end of buffer or a NUL)
error→--accepting rule at line 134("
error→")
error→--(end of buffer or a NUL)
error→--EOF (start condition 0)
error→Now at end of input.
error→Reducing stack 0 by rule 1 (line 287):
error→   $1 = nterm exp (simple.tig:1.1-24: print("Hello, World!\n"))
error→-> $$ = nterm program (simple.tig:1.1-24: )
error→Entering state 24
error→Now at end of input.
error→Shifting token "end of file" (simple.tig:2.1: )
error→Entering state 63
error→Cleanup: popping token "end of file" (simple.tig:2.1: )
error→Cleanup: popping nterm program (simple.tig:1.1-24: )
error→Parsing string: function _main() = (_exp(0); ())
error→Starting parse
error→Entering state 0
error→Reading a token: --(end of buffer or a NUL)
error→--accepting rule at line 164("function")
error→Next token is token "function" (:1.1-8: )
error→Shifting token "function" (:1.1-8: )
error→Entering state 8
error→Reading a token: --accepting rule at line 133(" ")
error→--accepting rule at line 195("_main")
error→Next token is token "identifier" (:1.10-14: _main)
error→Shifting token "identifier" (:1.10-14: _main)
error→Entering state 43
error→Reading a token: --accepting rule at line 138("(")
error→Next token is token "(" (:1.15: )
error→Shifting token "(" (:1.15: )
error→Entering state 93
error→Reading a token: --accepting rule at line 139(")")
error→Next token is token ")" (:1.16: )
error→Reducing stack 0 by rule 95 (line 605):
error→-> $$ = nterm funargs (:1.16: )
error→Entering state 144
error→Next token is token ")" (:1.16: )
error→Shifting token ")" (:1.16: )
error→Entering state 186
error→Reading a token: --accepting rule at line 133(" ")
error→--accepting rule at line 152("=")
error→Next token is token "=" (:1.18: )
error→Reducing stack 0 by rule 86 (line 567):
error→-> $$ = nterm typeid.opt (:1.17: )
error→Entering state 215
error→Next token is token "=" (:1.18: )
error→Shifting token "=" (:1.18: )
error→Entering state 231
error→Reading a token: --accepting rule at line 133(" ")
error→--accepting rule at line 138("(")
error→Next token is token "(" (:1.20: )
error→Shifting token "(" (:1.20: )
error→Entering state 12
error→Reading a token: --accepting rule at line 191("_exp")
error→Next token is token "_exp" (:1.21-24: )
error→Shifting token "_exp" (:1.21-24: )
error→Entering state 21
error→Reading a token: --accepting rule at line 138("(")
error→Next token is token "(" (:1.25: )
error→Shifting token "(" (:1.25: )
error→Entering state 60
error→Reading a token: --accepting rule at line 113("0")
error→Next token is token "integer" (:1.26: 0)
error→Shifting token "integer" (:1.26: 0)
error→Entering state 106
error→Reading a token: --accepting rule at line 139(")")
error→Next token is token ")" (:1.27: )
error→Shifting token ")" (:1.27: )
error→Entering state 164
error→Reducing stack 0 by rule 37 (line 397):
error→   $1 = token "_exp" (:1.21-24: )
error→   $2 = token "(" (:1.25: )
error→   $3 = token "integer" (:1.26: 0)
error→   $4 = token ")" (:1.27: )
error→-> $$ = nterm exp (:1.21-27: print("Hello, World!\n"))
error→Entering state 48
error→Reading a token: --accepting rule at line 148(";")
error→Next token is token ";" (:1.28: )
error→Reducing stack 0 by rule 48 (line 424):
error→   $1 = nterm exp (:1.21-27: print("Hello, World!\n"))
error→-> $$ = nterm exps.1 (:1.21-27: print("Hello, World!\n"))
error→Entering state 49
error→Next token is token ";" (:1.28: )
error→Shifting token ";" (:1.28: )
error→Entering state 99
error→Reading a token: --accepting rule at line 133(" ")
error→--accepting rule at line 138("(")
error→Next token is token "(" (:1.30: )
error→Shifting token "(" (:1.30: )
error→Entering state 12
error→Reading a token: --accepting rule at line 139(")")
error→Next token is token ")" (:1.31: )
error→Reducing stack 0 by rule 52 (line 436):
error→-> $$ = nterm exps.0.2 (:1.31: )
error→Entering state 51
error→Next token is token ")" (:1.31: )
error→Shifting token ")" (:1.31: )
error→Entering state 100
error→Reducing stack 0 by rule 11 (line 321):
error→   $1 = token "(" (:1.30: )
error→   $2 = nterm exps.0.2 (:1.31: )
error→   $3 = token ")" (:1.31: )
error→-> $$ = nterm exp (:1.30-31: ())
error→Entering state 153
error→Reading a token: --(end of buffer or a NUL)
error→--accepting rule at line 139(")")
error→Next token is token ")" (:1.32: )
error→Reducing stack 0 by rule 51 (line 431):
error→   $1 = nterm exps.1 (:1.21-27: print("Hello, World!\n"))
error→   $2 = token ";" (:1.28: )
error→   $3 = nterm exp (:1.30-31: ())
error→-> $$ = nterm exps.2 (:1.21-31: print("Hello, World!\n"), ())
error→Entering state 50
error→Reducing stack 0 by rule 53 (line 437):
error→   $1 = nterm exps.2 (:1.21-31: print("Hello, World!\n"), ())
error→-> $$ = nterm exps.0.2 (:1.21-31: print("Hello, World!\n"), ())
error→Entering state 51
error→Next token is token ")" (:1.32: )
error→Shifting token ")" (:1.32: )
error→Entering state 100
error→Reducing stack 0 by rule 11 (line 321):
error→   $1 = token "(" (:1.20: )
error→   $2 = nterm exps.0.2 (:1.21-31: print("Hello, World!\n"), ())
error→   $3 = token ")" (:1.32: )
error→-> $$ = nterm exp (:1.20-32: (
error→  print("Hello, World!\n");
error→  ()
error→))
error→Entering state 239
error→Reading a token: --(end of buffer or a NUL)
error→--EOF (start condition 0)
error→Now at end of input.
error→Reducing stack 0 by rule 93 (line 598):
error→   $1 = token "function" (:1.1-8: )
error→   $2 = token "identifier" (:1.10-14: _main)
error→   $3 = token "(" (:1.15: )
error→   $4 = nterm funargs (:1.16: )
error→   $5 = token ")" (:1.16: )
error→   $6 = nterm typeid.opt (:1.17: )
error→   $7 = token "=" (:1.18: )
error→   $8 = nterm exp (:1.20-32: (
error→  print("Hello, World!\n");
error→  ()
error→))
error→-> $$ = nterm fundec (:1.1-32: 
error→function _main() =
error→  (
error→    print("Hello, World!\n");
error→    ()
error→  ))
error→Entering state 35
error→Now at end of input.
error→Reducing stack 0 by rule 91 (line 593):
error→   $1 = nterm fundec (:1.1-32: 
error→function _main() =
error→  (
error→    print("Hello, World!\n");
error→    ()
error→  ))
error→-> $$ = nterm fundecs (:1.1-32: 
error→function _main() =
error→  (
error→    print("Hello, World!\n");
error→    ()
error→  ))
error→Entering state 34
error→Now at end of input.
error→Reducing stack 0 by rule 54 (line 447):
error→-> $$ = nterm decs (:1.33: )
error→Entering state 83
error→Reducing stack 0 by rule 57 (line 451):
error→   $1 = nterm fundecs (:1.1-32: 
error→function _main() =
error→  (
error→    print("Hello, World!\n");
error→    ()
error→  ))
error→   $2 = nterm decs (:1.33: )
error→-> $$ = nterm decs (:1.1-32: 
error→function _main() =
error→  (
error→    print("Hello, World!\n");
error→    ()
error→  ))
error→Entering state 27
error→Reducing stack 0 by rule 2 (line 289):
error→   $1 = nterm decs (:1.1-32: 
error→function _main() =
error→  (
error→    print("Hello, World!\n");
error→    ()
error→  ))
error→-> $$ = nterm program (:1.1-32: )
error→Entering state 24
error→Now at end of input.
error→Shifting token "end of file" (:1.33: )
error→Entering state 63
error→Cleanup: popping token "end of file" (:1.33: )
error→Cleanup: popping nterm program (:1.1-32: )

A lexical error must be properly diagnosed and reported. The following (generated) examples display the location: this is not required for TC-0; nevertheless, an error message on the standard error output is required.

4.2.2 PTHL Samples