diff options
Diffstat (limited to 'Lib/compiler/pyassem.py')
| -rw-r--r-- | Lib/compiler/pyassem.py | 41 |
1 files changed, 26 insertions, 15 deletions
diff --git a/Lib/compiler/pyassem.py b/Lib/compiler/pyassem.py index c8d9e90cc8..74ea562f44 100644 --- a/Lib/compiler/pyassem.py +++ b/Lib/compiler/pyassem.py @@ -419,21 +419,32 @@ class LineAddrTable: # compute deltas addr = self.codeOffset - self.lastoff line = lineno - self.lastline - while addr > 0 or line > 0: - # write the values in 1-byte chunks that sum - # to desired value - trunc_addr = addr - trunc_line = line - if trunc_addr > 255: - trunc_addr = 255 - if trunc_line > 255: - trunc_line = 255 - self.lnotab.append(trunc_addr) - self.lnotab.append(trunc_line) - addr = addr - trunc_addr - line = line - trunc_line - self.lastline = lineno - self.lastoff = self.codeOffset + # Python assumes that lineno always increases with + # increasing bytecode address (lnotab is unsigned char). + # Depending on when SET_LINENO instructions are emitted + # this is not always true. Consider the code: + # a = (1, + # b) + # In the bytecode stream, the assignment to "a" occurs + # after the loading of "b". This works with the C Python + # compiler because it only generates a SET_LINENO instruction + # for the assignment. + if line > 0: + while addr > 0 or line > 0: + # write the values in 1-byte chunks that sum + # to desired value + trunc_addr = addr + trunc_line = line + if trunc_addr > 255: + trunc_addr = 255 + if trunc_line > 255: + trunc_line = 255 + self.lnotab.append(trunc_addr) + self.lnotab.append(trunc_line) + addr = addr - trunc_addr + line = line - trunc_line + self.lastline = lineno + self.lastoff = self.codeOffset def getCode(self): return string.join(self.code, '') |