diff options
Diffstat (limited to 'tools/profiler/lul/LulDwarfSummariser.cpp')
| -rw-r--r-- | tools/profiler/lul/LulDwarfSummariser.cpp | 359 |
1 files changed, 0 insertions, 359 deletions
diff --git a/tools/profiler/lul/LulDwarfSummariser.cpp b/tools/profiler/lul/LulDwarfSummariser.cpp deleted file mode 100644 index 74c2565df..000000000 --- a/tools/profiler/lul/LulDwarfSummariser.cpp +++ /dev/null @@ -1,359 +0,0 @@ -/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ -/* vim: set ts=8 sts=2 et sw=2 tw=80: */ -/* This Source Code Form is subject to the terms of the Mozilla Public - * License, v. 2.0. If a copy of the MPL was not distributed with this - * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ - -#include "LulDwarfSummariser.h" - -#include "mozilla/Assertions.h" - -// Set this to 1 for verbose logging -#define DEBUG_SUMMARISER 0 - -namespace lul { - -// Do |s64|'s lowest 32 bits sign extend back to |s64| itself? -static inline bool fitsIn32Bits(int64 s64) { - return s64 == ((s64 & 0xffffffff) ^ 0x80000000) - 0x80000000; -} - -// Check a LExpr prefix expression, starting at pfxInstrs[start] up to -// the next PX_End instruction, to ensure that: -// * It only mentions registers that are tracked on this target -// * The start point is sane -// If the expression is ok, return NULL. Else return a pointer -// a const char* holding a bit of text describing the problem. -static const char* -checkPfxExpr(const vector<PfxInstr>* pfxInstrs, int64_t start) -{ - size_t nInstrs = pfxInstrs->size(); - if (start < 0 || start >= (ssize_t)nInstrs) { - return "bogus start point"; - } - size_t i; - for (i = start; i < nInstrs; i++) { - PfxInstr pxi = (*pfxInstrs)[i]; - if (pxi.mOpcode == PX_End) - break; - if (pxi.mOpcode == PX_DwReg && - !registerIsTracked((DW_REG_NUMBER)pxi.mOperand)) { - return "uses untracked reg"; - } - } - return nullptr; // success -} - - -Summariser::Summariser(SecMap* aSecMap, uintptr_t aTextBias, - void(*aLog)(const char*)) - : mSecMap(aSecMap) - , mTextBias(aTextBias) - , mLog(aLog) -{ - mCurrAddr = 0; - mMax1Addr = 0; // Gives an empty range. - - // Initialise the running RuleSet to "haven't got a clue" status. - new (&mCurrRules) RuleSet(); -} - -void -Summariser::Entry(uintptr_t aAddress, uintptr_t aLength) -{ - aAddress += mTextBias; - if (DEBUG_SUMMARISER) { - char buf[100]; - SprintfLiteral(buf, - "LUL Entry(%llx, %llu)\n", - (unsigned long long int)aAddress, - (unsigned long long int)aLength); - mLog(buf); - } - // This throws away any previous summary, that is, assumes - // that the previous summary, if any, has been properly finished - // by a call to End(). - mCurrAddr = aAddress; - mMax1Addr = aAddress + aLength; - new (&mCurrRules) RuleSet(); -} - -void -Summariser::Rule(uintptr_t aAddress, int aNewReg, - LExprHow how, int16_t oldReg, int64_t offset) -{ - aAddress += mTextBias; - if (DEBUG_SUMMARISER) { - char buf[100]; - if (how == NODEREF || how == DEREF) { - bool deref = how == DEREF; - SprintfLiteral(buf, - "LUL 0x%llx old-r%d = %sr%d + %lld%s\n", - (unsigned long long int)aAddress, aNewReg, - deref ? "*(" : "", (int)oldReg, (long long int)offset, - deref ? ")" : ""); - } else if (how == PFXEXPR) { - SprintfLiteral(buf, - "LUL 0x%llx old-r%d = pfx-expr-at %lld\n", - (unsigned long long int)aAddress, aNewReg, - (long long int)offset); - } else { - SprintfLiteral(buf, - "LUL 0x%llx old-r%d = (invalid LExpr!)\n", - (unsigned long long int)aAddress, aNewReg); - } - mLog(buf); - } - - if (mCurrAddr < aAddress) { - // Flush the existing summary first. - mCurrRules.mAddr = mCurrAddr; - mCurrRules.mLen = aAddress - mCurrAddr; - mSecMap->AddRuleSet(&mCurrRules); - if (DEBUG_SUMMARISER) { - mLog("LUL "); mCurrRules.Print(mLog); - mLog("\n"); - } - mCurrAddr = aAddress; - } - - // If for some reason summarisation fails, either or both of these - // become non-null and point at constant text describing the - // problem. Using two rather than just one avoids complications of - // having to concatenate two strings to produce a complete error message. - const char* reason1 = nullptr; - const char* reason2 = nullptr; - - // |offset| needs to be a 32 bit value that sign extends to 64 bits - // on a 64 bit target. We will need to incorporate |offset| into - // any LExpr made here. So we may as well check it right now. - if (!fitsIn32Bits(offset)) { - reason1 = "offset not in signed 32-bit range"; - goto cant_summarise; - } - - // FIXME: factor out common parts of the arch-dependent summarisers. - -#if defined(LUL_ARCH_arm) - - // ----------------- arm ----------------- // - - // Now, can we add the rule to our summary? This depends on whether - // the registers and the overall expression are representable. This - // is the heart of the summarisation process. - switch (aNewReg) { - - case DW_REG_CFA: - // This is a rule that defines the CFA. The only forms we - // choose to represent are: r7/11/12/13 + offset. The offset - // must fit into 32 bits since 'uintptr_t' is 32 bit on ARM, - // hence there is no need to check it for overflow. - if (how != NODEREF) { - reason1 = "rule for DW_REG_CFA: invalid |how|"; - goto cant_summarise; - } - switch (oldReg) { - case DW_REG_ARM_R7: case DW_REG_ARM_R11: - case DW_REG_ARM_R12: case DW_REG_ARM_R13: - break; - default: - reason1 = "rule for DW_REG_CFA: invalid |oldReg|"; - goto cant_summarise; - } - mCurrRules.mCfaExpr = LExpr(how, oldReg, offset); - break; - - case DW_REG_ARM_R7: case DW_REG_ARM_R11: case DW_REG_ARM_R12: - case DW_REG_ARM_R13: case DW_REG_ARM_R14: case DW_REG_ARM_R15: { - // This is a new rule for R7, R11, R12, R13 (SP), R14 (LR) or - // R15 (the return address). - switch (how) { - case NODEREF: case DEREF: - // Check the old register is one we're tracking. - if (!registerIsTracked((DW_REG_NUMBER)oldReg) && - oldReg != DW_REG_CFA) { - reason1 = "rule for R7/11/12/13/14/15: uses untracked reg"; - goto cant_summarise; - } - break; - case PFXEXPR: { - // Check that the prefix expression only mentions tracked registers. - const vector<PfxInstr>* pfxInstrs = mSecMap->GetPfxInstrs(); - reason2 = checkPfxExpr(pfxInstrs, offset); - if (reason2) { - reason1 = "rule for R7/11/12/13/14/15: "; - goto cant_summarise; - } - break; - } - default: - goto cant_summarise; - } - LExpr expr = LExpr(how, oldReg, offset); - switch (aNewReg) { - case DW_REG_ARM_R7: mCurrRules.mR7expr = expr; break; - case DW_REG_ARM_R11: mCurrRules.mR11expr = expr; break; - case DW_REG_ARM_R12: mCurrRules.mR12expr = expr; break; - case DW_REG_ARM_R13: mCurrRules.mR13expr = expr; break; - case DW_REG_ARM_R14: mCurrRules.mR14expr = expr; break; - case DW_REG_ARM_R15: mCurrRules.mR15expr = expr; break; - default: MOZ_ASSERT(0); - } - break; - } - - default: - // Leave |reason1| and |reason2| unset here. This program point - // is reached so often that it causes a flood of "Can't - // summarise" messages. In any case, we don't really care about - // the fact that this summary would produce a new value for a - // register that we're not tracking. We do on the other hand - // care if the summary's expression *uses* a register that we're - // not tracking. But in that case one of the above failures - // should tell us which. - goto cant_summarise; - } - - // Mark callee-saved registers (r4 .. r11) as unchanged, if there is - // no other information about them. FIXME: do this just once, at - // the point where the ruleset is committed. - if (mCurrRules.mR7expr.mHow == UNKNOWN) { - mCurrRules.mR7expr = LExpr(NODEREF, DW_REG_ARM_R7, 0); - } - if (mCurrRules.mR11expr.mHow == UNKNOWN) { - mCurrRules.mR11expr = LExpr(NODEREF, DW_REG_ARM_R11, 0); - } - if (mCurrRules.mR12expr.mHow == UNKNOWN) { - mCurrRules.mR12expr = LExpr(NODEREF, DW_REG_ARM_R12, 0); - } - - // The old r13 (SP) value before the call is always the same as the - // CFA. - mCurrRules.mR13expr = LExpr(NODEREF, DW_REG_CFA, 0); - - // If there's no information about R15 (the return address), say - // it's a copy of R14 (the link register). - if (mCurrRules.mR15expr.mHow == UNKNOWN) { - mCurrRules.mR15expr = LExpr(NODEREF, DW_REG_ARM_R14, 0); - } - -#elif defined(LUL_ARCH_x64) || defined(LUL_ARCH_x86) - - // ---------------- x64/x86 ---------------- // - - // Now, can we add the rule to our summary? This depends on whether - // the registers and the overall expression are representable. This - // is the heart of the summarisation process. - switch (aNewReg) { - - case DW_REG_CFA: - // This is a rule that defines the CFA. The only forms we can - // represent are: = SP+offset or = FP+offset. - if (how != NODEREF) { - reason1 = "rule for DW_REG_CFA: invalid |how|"; - goto cant_summarise; - } - if (oldReg != DW_REG_INTEL_XSP && oldReg != DW_REG_INTEL_XBP) { - reason1 = "rule for DW_REG_CFA: invalid |oldReg|"; - goto cant_summarise; - } - mCurrRules.mCfaExpr = LExpr(how, oldReg, offset); - break; - - case DW_REG_INTEL_XSP: case DW_REG_INTEL_XBP: case DW_REG_INTEL_XIP: { - // This is a new rule for XSP, XBP or XIP (the return address). - switch (how) { - case NODEREF: case DEREF: - // Check the old register is one we're tracking. - if (!registerIsTracked((DW_REG_NUMBER)oldReg) && - oldReg != DW_REG_CFA) { - reason1 = "rule for XSP/XBP/XIP: uses untracked reg"; - goto cant_summarise; - } - break; - case PFXEXPR: { - // Check that the prefix expression only mentions tracked registers. - const vector<PfxInstr>* pfxInstrs = mSecMap->GetPfxInstrs(); - reason2 = checkPfxExpr(pfxInstrs, offset); - if (reason2) { - reason1 = "rule for XSP/XBP/XIP: "; - goto cant_summarise; - } - break; - } - default: - goto cant_summarise; - } - LExpr expr = LExpr(how, oldReg, offset); - switch (aNewReg) { - case DW_REG_INTEL_XBP: mCurrRules.mXbpExpr = expr; break; - case DW_REG_INTEL_XSP: mCurrRules.mXspExpr = expr; break; - case DW_REG_INTEL_XIP: mCurrRules.mXipExpr = expr; break; - default: MOZ_CRASH("impossible value for aNewReg"); - } - break; - } - - default: - // Leave |reason1| and |reason2| unset here, for the reasons - // explained in the analogous point in the ARM case just above. - goto cant_summarise; - - } - - // On Intel, it seems the old SP value before the call is always the - // same as the CFA. Therefore, in the absence of any other way to - // recover the SP, specify that the CFA should be copied. - if (mCurrRules.mXspExpr.mHow == UNKNOWN) { - mCurrRules.mXspExpr = LExpr(NODEREF, DW_REG_CFA, 0); - } - - // Also, gcc says "Undef" for BP when it is unchanged. - if (mCurrRules.mXbpExpr.mHow == UNKNOWN) { - mCurrRules.mXbpExpr = LExpr(NODEREF, DW_REG_INTEL_XBP, 0); - } - -#else - -# error "Unsupported arch" -#endif - - return; - - cant_summarise: - if (reason1 || reason2) { - char buf[200]; - SprintfLiteral(buf, "LUL can't summarise: " - "SVMA=0x%llx: %s%s, expr=LExpr(%s,%u,%lld)\n", - (unsigned long long int)(aAddress - mTextBias), - reason1 ? reason1 : "", reason2 ? reason2 : "", - NameOf_LExprHow(how), - (unsigned int)oldReg, (long long int)offset); - mLog(buf); - } -} - -uint32_t -Summariser::AddPfxInstr(PfxInstr pfxi) -{ - return mSecMap->AddPfxInstr(pfxi); -} - -void -Summariser::End() -{ - if (DEBUG_SUMMARISER) { - mLog("LUL End\n"); - } - if (mCurrAddr < mMax1Addr) { - mCurrRules.mAddr = mCurrAddr; - mCurrRules.mLen = mMax1Addr - mCurrAddr; - mSecMap->AddRuleSet(&mCurrRules); - if (DEBUG_SUMMARISER) { - mLog("LUL "); mCurrRules.Print(mLog); - mLog("\n"); - } - } -} - -} // namespace lul |