diff options
Diffstat (limited to 'src/bldprogs/scmdiff.cpp')
| -rw-r--r-- | src/bldprogs/scmdiff.cpp | 450 |
1 files changed, 450 insertions, 0 deletions
diff --git a/src/bldprogs/scmdiff.cpp b/src/bldprogs/scmdiff.cpp new file mode 100644 index 00000000..df642c4b --- /dev/null +++ b/src/bldprogs/scmdiff.cpp @@ -0,0 +1,450 @@ +/* $Id: scmdiff.cpp $ */ +/** @file + * IPRT Testcase / Tool - Source Code Massager. + */ + +/* + * Copyright (C) 2010-2023 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, in version 3 of the + * License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <https://www.gnu.org/licenses>. + * + * SPDX-License-Identifier: GPL-3.0-only + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#include <iprt/assert.h> +#include <iprt/ctype.h> +#include <iprt/message.h> +#include <iprt/stream.h> +#include <iprt/string.h> + +#include "scmdiff.h" + + +/********************************************************************************************************************************* +* Global Variables * +*********************************************************************************************************************************/ +static const char g_szTabSpaces[16+1] = " "; + + + +/** + * Prints a range of lines with a prefix. + * + * @param pState The diff state. + * @param chPrefix The prefix. + * @param pStream The stream to get the lines from. + * @param iLine The first line. + * @param cLines The number of lines. + */ +static void scmDiffPrintLines(PSCMDIFFSTATE pState, char chPrefix, PSCMSTREAM pStream, size_t iLine, size_t cLines) +{ + while (cLines-- > 0) + { + SCMEOL enmEol; + size_t cchLine; + const char *pchLine = ScmStreamGetLineByNo(pStream, iLine, &cchLine, &enmEol); + + RTStrmPutCh(pState->pDiff, chPrefix); + if (pchLine && cchLine) + { + if (!pState->fSpecialChars) + RTStrmWrite(pState->pDiff, pchLine, cchLine); + else + { + size_t offVir = 0; + const char *pchStart = pchLine; + const char *pchTab = (const char *)memchr(pchLine, '\t', cchLine); + while (pchTab) + { + RTStrmWrite(pState->pDiff, pchStart, pchTab - pchStart); + offVir += pchTab - pchStart; + + size_t cchTab = pState->cchTab - offVir % pState->cchTab; + switch (cchTab) + { + case 1: RTStrmPutStr(pState->pDiff, "."); break; + case 2: RTStrmPutStr(pState->pDiff, ".."); break; + case 3: RTStrmPutStr(pState->pDiff, "[T]"); break; + case 4: RTStrmPutStr(pState->pDiff, "[TA]"); break; + case 5: RTStrmPutStr(pState->pDiff, "[TAB]"); break; + default: RTStrmPrintf(pState->pDiff, "[TAB%.*s]", cchTab - 5, g_szTabSpaces); break; + } + offVir += cchTab; + + /* next */ + pchStart = pchTab + 1; + pchTab = (const char *)memchr(pchStart, '\t', cchLine - (pchStart - pchLine)); + } + size_t cchLeft = cchLine - (pchStart - pchLine); + if (cchLeft) + RTStrmWrite(pState->pDiff, pchStart, cchLeft); + } + } + + if (!pState->fSpecialChars) + RTStrmPutCh(pState->pDiff, '\n'); + else if (enmEol == SCMEOL_LF) + RTStrmPutStr(pState->pDiff, "[LF]\n"); + else if (enmEol == SCMEOL_CRLF) + RTStrmPutStr(pState->pDiff, "[CRLF]\n"); + else + RTStrmPutStr(pState->pDiff, "[NONE]\n"); + + iLine++; + } +} + + +/** + * Reports a difference and propels the streams to the lines following the + * resync. + * + * + * @returns New pState->cDiff value (just to return something). + * @param pState The diff state. The cDiffs member will be + * incremented. + * @param cMatches The resync length. + * @param iLeft Where the difference starts on the left side. + * @param cLeft How long it is on this side. ~(size_t)0 is used + * to indicate that it goes all the way to the end. + * @param iRight Where the difference starts on the right side. + * @param cRight How long it is. + */ +static size_t scmDiffReport(PSCMDIFFSTATE pState, size_t cMatches, + size_t iLeft, size_t cLeft, + size_t iRight, size_t cRight) +{ + /* + * Adjust the input. + */ + if (cLeft == ~(size_t)0) + { + size_t c = ScmStreamCountLines(pState->pLeft); + if (c >= iLeft) + cLeft = c - iLeft; + else + { + iLeft = c; + cLeft = 0; + } + } + + if (cRight == ~(size_t)0) + { + size_t c = ScmStreamCountLines(pState->pRight); + if (c >= iRight) + cRight = c - iRight; + else + { + iRight = c; + cRight = 0; + } + } + + /* + * Print header if it's the first difference + */ + if (!pState->cDiffs) + RTStrmPrintf(pState->pDiff, "diff %s %s\n", pState->pszFilename, pState->pszFilename); + + /* + * Emit the change description. + */ + char ch = cLeft == 0 + ? 'a' + : cRight == 0 + ? 'd' + : 'c'; + if (cLeft > 1 && cRight > 1) + RTStrmPrintf(pState->pDiff, "%zu,%zu%c%zu,%zu\n", iLeft + 1, iLeft + cLeft, ch, iRight + 1, iRight + cRight); + else if (cLeft > 1) + RTStrmPrintf(pState->pDiff, "%zu,%zu%c%zu\n", iLeft + 1, iLeft + cLeft, ch, iRight + 1); + else if (cRight > 1) + RTStrmPrintf(pState->pDiff, "%zu%c%zu,%zu\n", iLeft + 1, ch, iRight + 1, iRight + cRight); + else + RTStrmPrintf(pState->pDiff, "%zu%c%zu\n", iLeft + 1, ch, iRight + 1); + + /* + * And the lines. + */ + if (cLeft) + scmDiffPrintLines(pState, '<', pState->pLeft, iLeft, cLeft); + if (cLeft && cRight) + RTStrmPrintf(pState->pDiff, "---\n"); + if (cRight) + scmDiffPrintLines(pState, '>', pState->pRight, iRight, cRight); + + /* + * Reposition the streams (safely ignores return value). + */ + ScmStreamSeekByLine(pState->pLeft, iLeft + cLeft + cMatches); + ScmStreamSeekByLine(pState->pRight, iRight + cRight + cMatches); + + pState->cDiffs++; + return pState->cDiffs; +} + +/** + * Helper for scmDiffCompare that takes care of trailing spaces and stuff + * like that. + */ +static bool scmDiffCompareSlow(PSCMDIFFSTATE pState, + const char *pchLeft, size_t cchLeft, SCMEOL enmEolLeft, + const char *pchRight, size_t cchRight, SCMEOL enmEolRight) +{ + if (pState->fIgnoreTrailingWhite) + { + while (cchLeft > 0 && RT_C_IS_SPACE(pchLeft[cchLeft - 1])) + cchLeft--; + while (cchRight > 0 && RT_C_IS_SPACE(pchRight[cchRight - 1])) + cchRight--; + } + + if (pState->fIgnoreLeadingWhite) + { + while (cchLeft > 0 && RT_C_IS_SPACE(*pchLeft)) + pchLeft++, cchLeft--; + while (cchRight > 0 && RT_C_IS_SPACE(*pchRight)) + pchRight++, cchRight--; + } + + if ( cchLeft != cchRight + || (enmEolLeft != enmEolRight && !pState->fIgnoreEol) + || memcmp(pchLeft, pchRight, cchLeft)) + return false; + return true; +} + +/** + * Compare two lines. + * + * @returns true if the are equal, false if not. + */ +DECLINLINE(bool) scmDiffCompare(PSCMDIFFSTATE pState, + const char *pchLeft, size_t cchLeft, SCMEOL enmEolLeft, + const char *pchRight, size_t cchRight, SCMEOL enmEolRight) +{ + if ( cchLeft != cchRight + || (enmEolLeft != enmEolRight && !pState->fIgnoreEol) + || memcmp(pchLeft, pchRight, cchLeft)) + { + if ( pState->fIgnoreTrailingWhite + || pState->fIgnoreLeadingWhite) + return scmDiffCompareSlow(pState, + pchLeft, cchLeft, enmEolLeft, + pchRight, cchRight, enmEolRight); + return false; + } + return true; +} + +/** + * Compares two sets of lines from the two files. + * + * @returns true if they matches, false if they don't. + * @param pState The diff state. + * @param iLeft Where to start in the left stream. + * @param iRight Where to start in the right stream. + * @param cLines How many lines to compare. + */ +static bool scmDiffCompareLines(PSCMDIFFSTATE pState, size_t iLeft, size_t iRight, size_t cLines) +{ + for (size_t iLine = 0; iLine < cLines; iLine++) + { + SCMEOL enmEolLeft; + size_t cchLeft; + const char *pchLeft = ScmStreamGetLineByNo(pState->pLeft, iLeft + iLine, &cchLeft, &enmEolLeft); + + SCMEOL enmEolRight; + size_t cchRight; + const char *pchRight = ScmStreamGetLineByNo(pState->pRight, iRight + iLine, &cchRight, &enmEolRight); + + if (!scmDiffCompare(pState, pchLeft, cchLeft, enmEolLeft, pchRight, cchRight, enmEolRight)) + return false; + } + return true; +} + + +/** + * Resynchronize the two streams and reports the difference. + * + * Upon return, the streams will be positioned after the block of @a cMatches + * lines where it resynchronized them. + * + * @returns pState->cDiffs (just so we can use it in a return statement). + * @param pState The state. + * @param cMatches The number of lines that needs to match for the + * stream to be considered synchronized again. + */ +static size_t scmDiffSynchronize(PSCMDIFFSTATE pState, size_t cMatches) +{ + size_t const iStartLeft = ScmStreamTellLine(pState->pLeft) - 1; + size_t const iStartRight = ScmStreamTellLine(pState->pRight) - 1; + Assert(cMatches > 0); + + /* + * Compare each new line from each of the streams will all the preceding + * ones, including iStartLeft/Right. + */ + for (size_t iRange = 1; ; iRange++) + { + /* + * Get the next line in the left stream and compare it against all the + * preceding lines on the right side. + */ + SCMEOL enmEol; + size_t cchLine; + const char *pchLine = ScmStreamGetLineByNo(pState->pLeft, iStartLeft + iRange, &cchLine, &enmEol); + if (!pchLine) + return scmDiffReport(pState, 0, iStartLeft, ~(size_t)0, iStartRight, ~(size_t)0); + + for (size_t iRight = cMatches - 1; iRight < iRange; iRight++) + { + SCMEOL enmEolRight; + size_t cchRight; + const char *pchRight = ScmStreamGetLineByNo(pState->pRight, iStartRight + iRight, + &cchRight, &enmEolRight); + if ( scmDiffCompare(pState, pchLine, cchLine, enmEol, pchRight, cchRight, enmEolRight) + && scmDiffCompareLines(pState, + iStartLeft + iRange + 1 - cMatches, + iStartRight + iRight + 1 - cMatches, + cMatches - 1) + ) + return scmDiffReport(pState, cMatches, + iStartLeft, iRange + 1 - cMatches, + iStartRight, iRight + 1 - cMatches); + } + + /* + * Get the next line in the right stream and compare it against all the + * lines on the right side. + */ + pchLine = ScmStreamGetLineByNo(pState->pRight, iStartRight + iRange, &cchLine, &enmEol); + if (!pchLine) + return scmDiffReport(pState, 0, iStartLeft, ~(size_t)0, iStartRight, ~(size_t)0); + + for (size_t iLeft = cMatches - 1; iLeft <= iRange; iLeft++) + { + SCMEOL enmEolLeft; + size_t cchLeft; + const char *pchLeft = ScmStreamGetLineByNo(pState->pLeft, iStartLeft + iLeft, + &cchLeft, &enmEolLeft); + if ( scmDiffCompare(pState, pchLeft, cchLeft, enmEolLeft, pchLine, cchLine, enmEol) + && scmDiffCompareLines(pState, + iStartLeft + iLeft + 1 - cMatches, + iStartRight + iRange + 1 - cMatches, + cMatches - 1) + ) + return scmDiffReport(pState, cMatches, + iStartLeft, iLeft + 1 - cMatches, + iStartRight, iRange + 1 - cMatches); + } + } +} + +/** + * Creates a diff of the changes between the streams @a pLeft and @a pRight. + * + * This currently only implements the simplest diff format, so no contexts. + * + * Also, note that we won't detect differences in the final newline of the + * streams. + * + * @returns The number of differences. + * @param pszFilename The filename. + * @param pLeft The left side stream. + * @param pRight The right side stream. + * @param fIgnoreEol Whether to ignore end of line markers. + * @param fIgnoreLeadingWhite Set if leading white space should be ignored. + * @param fIgnoreTrailingWhite Set if trailing white space should be ignored. + * @param fSpecialChars Whether to print special chars in a human + * readable form or not. + * @param cchTab The tab size. + * @param pDiff Where to write the diff. + */ +size_t ScmDiffStreams(const char *pszFilename, PSCMSTREAM pLeft, PSCMSTREAM pRight, bool fIgnoreEol, + bool fIgnoreLeadingWhite, bool fIgnoreTrailingWhite, bool fSpecialChars, + size_t cchTab, PRTSTREAM pDiff) +{ +#ifdef RT_STRICT + ScmStreamCheckItegrity(pLeft); + ScmStreamCheckItegrity(pRight); +#endif + + /* + * Set up the diff state. + */ + SCMDIFFSTATE State; + State.cDiffs = 0; + State.pszFilename = pszFilename; + State.pLeft = pLeft; + State.pRight = pRight; + State.fIgnoreEol = fIgnoreEol; + State.fIgnoreLeadingWhite = fIgnoreLeadingWhite; + State.fIgnoreTrailingWhite = fIgnoreTrailingWhite; + State.fSpecialChars = fSpecialChars; + State.cchTab = cchTab; + State.pDiff = pDiff; + + /* + * Compare them line by line. + */ + ScmStreamRewindForReading(pLeft); + ScmStreamRewindForReading(pRight); + const char *pchLeft; + const char *pchRight; + + for (;;) + { + SCMEOL enmEolLeft; + size_t cchLeft; + pchLeft = ScmStreamGetLine(pLeft, &cchLeft, &enmEolLeft); + + SCMEOL enmEolRight; + size_t cchRight; + pchRight = ScmStreamGetLine(pRight, &cchRight, &enmEolRight); + if (!pchLeft || !pchRight) + break; + + if (!scmDiffCompare(&State, pchLeft, cchLeft, enmEolLeft, pchRight, cchRight, enmEolRight)) + scmDiffSynchronize(&State, 3); + } + + /* + * Deal with any remaining differences. + */ + if (pchLeft) + scmDiffReport(&State, 0, ScmStreamTellLine(pLeft) - 1, ~(size_t)0, ScmStreamTellLine(pRight), 0); + else if (pchRight) + scmDiffReport(&State, 0, ScmStreamTellLine(pLeft), 0, ScmStreamTellLine(pRight) - 1, ~(size_t)0); + + /* + * Report any errors. + */ + if (RT_FAILURE(ScmStreamGetStatus(pLeft))) + RTMsgError("Left diff stream error: %Rrc\n", ScmStreamGetStatus(pLeft)); + if (RT_FAILURE(ScmStreamGetStatus(pRight))) + RTMsgError("Right diff stream error: %Rrc\n", ScmStreamGetStatus(pRight)); + + return State.cDiffs; +} + |