From 48a433cfda8a3bb293b2d3a1dfea3492f2b75eb7 Mon Sep 17 00:00:00 2001 From: Thomas Wouters Date: Wed, 27 Jun 2001 14:03:30 +0000 Subject: Backport Tim's checkin 1.20: SF bug 430991: wrong co_lnotab Armin Rigo pointed out that the way the line-# table got built didn't work for lines generating more than 255 bytes of bytecode. Fixed as he suggested, plus corresponding changes to pyassem.py, plus added some long overdue docs about this subtle table to compile.c. --- Lib/compiler/pyassem.py | 31 ++++++++++++++----------------- Tools/compiler/compiler/pyassem.py | 31 ++++++++++++++----------------- 2 files changed, 28 insertions(+), 34 deletions(-) diff --git a/Lib/compiler/pyassem.py b/Lib/compiler/pyassem.py index e8810ae..0684623 100644 --- a/Lib/compiler/pyassem.py +++ b/Lib/compiler/pyassem.py @@ -613,16 +613,16 @@ def twobyte(val): class LineAddrTable: """lnotab - This class builds the lnotab, which is undocumented but described - by com_set_lineno in compile.c. Here's an attempt at explanation: + This class builds the lnotab, which is documented in compile.c. + Here's a brief recap: For each SET_LINENO instruction after the first one, two bytes are added to lnotab. (In some cases, multiple two-byte entries are added.) The first byte is the distance in bytes between the instruction for the last SET_LINENO and the current SET_LINENO. The second byte is offset in line numbers. If either offset is - greater than 255, multiple two-byte entries are added -- one entry - for each factor of 255. + greater than 255, multiple two-byte entries are added -- see + compile.c for the delicate details. """ def __init__(self): @@ -657,19 +657,16 @@ class LineAddrTable: # 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 + push = self.lnotab.append + while addr > 255: + push(255); push(0) + addr -= 255 + while line > 255: + push(addr); push(255) + line -= 255 + addr = 0 + if addr > 0 or line > 0: + push(addr); push(line) self.lastline = lineno self.lastoff = self.codeOffset diff --git a/Tools/compiler/compiler/pyassem.py b/Tools/compiler/compiler/pyassem.py index e8810ae..0684623 100644 --- a/Tools/compiler/compiler/pyassem.py +++ b/Tools/compiler/compiler/pyassem.py @@ -613,16 +613,16 @@ def twobyte(val): class LineAddrTable: """lnotab - This class builds the lnotab, which is undocumented but described - by com_set_lineno in compile.c. Here's an attempt at explanation: + This class builds the lnotab, which is documented in compile.c. + Here's a brief recap: For each SET_LINENO instruction after the first one, two bytes are added to lnotab. (In some cases, multiple two-byte entries are added.) The first byte is the distance in bytes between the instruction for the last SET_LINENO and the current SET_LINENO. The second byte is offset in line numbers. If either offset is - greater than 255, multiple two-byte entries are added -- one entry - for each factor of 255. + greater than 255, multiple two-byte entries are added -- see + compile.c for the delicate details. """ def __init__(self): @@ -657,19 +657,16 @@ class LineAddrTable: # 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 + push = self.lnotab.append + while addr > 255: + push(255); push(0) + addr -= 255 + while line > 255: + push(addr); push(255) + line -= 255 + addr = 0 + if addr > 0 or line > 0: + push(addr); push(line) self.lastline = lineno self.lastoff = self.codeOffset -- cgit v0.12